Prepared by:Prepared by:

ALINGAN, MUAMIR A.ALINGAN, MUAMIR A.

BSN-4ABSN-4A

WHAT IS MALARIAWHAT IS MALARIA• A vector-borne infectious disease caused by protozoan A vector-borne infectious disease caused by protozoan

parasites. parasites. • The term MALARIA originates from MEDIEVAL ITALIAN: The term MALARIA originates from MEDIEVAL ITALIAN: MALA MALA

ARIAARIA – – “BAD AIR”“BAD AIR”;; and the disease was formerly called and the disease was formerly called agueague or or marsh fevermarsh fever due to its association with swamps.due to its association with swamps.

• It is widespread in tropical and subtropical regions, It is widespread in tropical and subtropical regions, including parts of the Americas, Asia, and Africa. including parts of the Americas, Asia, and Africa.

• Historical records suggest malaria has infected humans Historical records suggest malaria has infected humans since the beginning of mankind.since the beginning of mankind.

• It has been infected humans for over 50,000 years, and It has been infected humans for over 50,000 years, and may have been a human pathogen for the entire history may have been a human pathogen for the entire history of our species.of our species.

18801880 A French army doctor A French army doctor

working in the military working in the military hospital of Constantine hospital of Constantine Algeria named Algeria named Charles Charles Louise Alphonse LaveranLouise Alphonse Laveran observed parasites for observed parasites for the first time, inside the first time, inside the red blood cells of the red blood cells of people suffering from people suffering from malaria. He therefore malaria. He therefore proposed that malaria was proposed that malaria was caused by this protozoan, caused by this protozoan, the first time protozoa the first time protozoa were identified as were identified as causing disease.causing disease.

18841884 Ettore MarchiafavaEttore Marchiafava and and

Angelo CelliAngelo Celli, while , while studying wet blood studying wet blood smears from malarious smears from malarious patients with the new patients with the new oil-immersion lens, oil-immersion lens, looked at unstained looked at unstained blood and saw an blood and saw an active amoeboid ring active amoeboid ring in the red blood in the red blood cells. They then cells. They then published this finding published this finding and named it and named it Plasmodium.Plasmodium.

A year laterA year later Carlos FinlayCarlos Finlay, a Cuban , a Cuban

doctor treating patients doctor treating patients with yellow fever in with yellow fever in Havana, first suggested Havana, first suggested that mosquitoes were that mosquitoes were transmitting disease to transmitting disease to and from humans.and from humans.

18981898 It was Britain's It was Britain's Sir Sir

Ronald RossRonald Ross working in working in India who finally proved India who finally proved in 1898 that malaria is in 1898 that malaria is transmitted by mosquitoestransmitted by mosquitoes

NORMAL ANATOMY AND NORMAL ANATOMY AND PHYSIOLOGYPHYSIOLOGY

Blood Blood is a specialized is a specialized bodily fluidbodily fluid that delivers necessary that delivers necessary

substances to the body's substances to the body's cellscells – such as nutrients and – such as nutrients and oxygenoxygen – and – and transports transports wastewaste products away from those same cells.In products away from those same cells.In vertebratesvertebrates, it , it is composed of is composed of blood cellsblood cells suspended in a suspended in a liquidliquid called called blood plasmablood plasma. . Plasma, which constitutes 55% of blood fluid, is mostly water (90% by Plasma, which constitutes 55% of blood fluid, is mostly water (90% by volume),volume),[1][1] and contains dissolved proteins, and contains dissolved proteins, glucoseglucose, mineral ions, , mineral ions, hormoneshormones, , carbon dioxidecarbon dioxide (plasma being the main medium for excretory (plasma being the main medium for excretory product transportation), product transportation), plateletsplatelets and blood cells themselves. The and blood cells themselves. The blood cells present in blood are mainly blood cells present in blood are mainly red blood cellsred blood cells (also called (also called RBCs or erythrocytes) and RBCs or erythrocytes) and white blood cellswhite blood cells, including leukocytes and , including leukocytes and plateletsplatelets. The most abundant cells in vertebrate blood are . The most abundant cells in vertebrate blood are red blood cellsred blood cells. These contain . These contain hemoglobinhemoglobin, an , an ironiron-containing protein, -containing protein, which facilitates transportation of which facilitates transportation of oxygenoxygen by reversibly binding to by reversibly binding to this this respiratoryrespiratory gas and greatly increasing its solubility in blood. In gas and greatly increasing its solubility in blood. In contrast, carbon dioxide is almost entirely transported extracellularly contrast, carbon dioxide is almost entirely transported extracellularly dissolved in plasma as dissolved in plasma as bicarbonatebicarbonate ion ion..

Vertebrate blood is bright red when its hemoglobin is oxygenated. Some animals, such as crustaceans and mollusks, use hemocyanin to carry oxygen, instead of hemoglobin. Insects and some molluscs use a fluid called hemolymph instead of blood, the difference being that hemolymph is not contained in a closed circulatory system. In most insects, this "blood" does not contain oxygen-carrying molecules such as hemoglobin because their bodies are small enough for their tracheal system to suffice for supplying oxygen.

Jawed vertebrates have an Jawed vertebrates have an adaptive immune systemadaptive immune system, based largely on , based largely on white blood cellswhite blood cells. White blood cells help to resist infections and parasites.. White blood cells help to resist infections and parasites. PlateletsPlatelets are important in the are important in the clottingclotting of blood. of blood.[2][2] ArthropodsArthropods, using , using hemolymphhemolymph, have , have hemocyteshemocytes as part of their as part of their immune systemimmune system..

Blood is circulated around the body through Blood is circulated around the body through blood vesselsblood vessels by the pumping action of the by the pumping action of the heartheart. In animals with . In animals with lungslungs, , arterialarterial blood carries oxygen from inhaled air to the tissues of the blood carries oxygen from inhaled air to the tissues of the body, and body, and venousvenous blood carries carbon dioxide, a waste product of blood carries carbon dioxide, a waste product of metabolismmetabolism produced by produced by cellscells, from the tissues to the , from the tissues to the lungslungs to be exhaled. to be exhaled.

Medical terms related to blood often begin with Medical terms related to blood often begin with hemohemo-- or or hematohemato-- ( (also spelledalso spelled haemohaemo-- and and haematohaemato--) from the ) from the Ancient GreekAncient Greek word word αἷμααἷμα ( (haimahaima) for "blood". In terms of ) for "blood". In terms of anatomyanatomy and and histologyhistology, blood is considered a specialized form of , blood is considered a specialized form of connective tissueconnective tissue, given its origin in the bones and the presence of potentia, given its origin in the bones and the presence of potential molecular fibers in the form of l molecular fibers in the form of fibrinogenfibrinogen..

FunctionsFunctions•Blood performs many important functions within the body including:•Supply of oxygen to tissues (bound to hemoglobin, which is carried in red cells) •Supply of nutrients such as glucose, amino acids, and fatty acids (dissolved in the blood or bound to plasma proteins (e.g., blood lipids) •Removal of waste such as carbon dioxide, urea, and lactic acid •Immunological functions, including circulation of white blood cells, and detection of foreign material by antibodies •Coagulation, which is one part of the body's self-repair mechanism (the act of blood clotting when one gets cut to stop the bleeding.) •Messenger functions, including the transport of hormones and the signaling of tissue damage •Regulation of body pH •Regulation of core body temperature •Hydraulic functions

Constituents of human bloodConstituents of human blood

Blood accounts for 8% of the human body weight,Blood accounts for 8% of the human body weight,[3][3] with an with an average density of approximately 1060 kg/m3, very close to average density of approximately 1060 kg/m3, very close to pure water's density of 1000 kg/m3.pure water's density of 1000 kg/m3.[4][4] The average adult has The average adult has a a blood volumeblood volume of roughly 5 of roughly 5 litersliters (1.3 gal), composed of (1.3 gal), composed of plasma and several kinds of cells (occasionally called plasma and several kinds of cells (occasionally called corpusclescorpuscles); these formed elements of the blood are ); these formed elements of the blood are erythrocytes (erythrocytes (red blood cellsred blood cells), leukocytes (), leukocytes (white blood cellswhite blood cells), and thrombocytes (), and thrombocytes (plateletsplatelets). By volume, the red blood ). By volume, the red blood cells constitute about 45% of whole blood, the plasma about cells constitute about 45% of whole blood, the plasma about 54.3%, and white cells about 0.7%.54.3%, and white cells about 0.7%.

Whole blood (plasma and cells) exhibits Whole blood (plasma and cells) exhibits non-Newtonian fluidnon-Newtonian fluid dynamics; its flow properties are adapted to flow effectively dynamics; its flow properties are adapted to flow effectively through tiny capillary blood vessels with less resistance through tiny capillary blood vessels with less resistance than plasma by itself. In addition, if all human hemoglobin than plasma by itself. In addition, if all human hemoglobin were free in the plasma rather than being contained in RBCs, were free in the plasma rather than being contained in RBCs, the circulatory fluid would be too viscous for the the circulatory fluid would be too viscous for the cardiovascular system to function effectively.cardiovascular system to function effectively.

Constituents of human bloodConstituents of human blood

Parameter Parameter Value Value

Hematocrit Hematocrit 45 ± 7 (38–52%) for males45 ± 7 (38–52%) for males42 ± 5 (37–47%) for 42 ± 5 (37–47%) for females females

pH pH 7.35–7.457.35–7.45

base excess base excess −−3 to +3 3 to +3

PO2 PO2 10–13 kPa (80–100 mm Hg) 10–13 kPa (80–100 mm Hg)

PCO2 PCO2 4.8–5.8 kPa (35–45 mm Hg) 4.8–5.8 kPa (35–45 mm Hg)

HCO3− HCO3− 21–27 Mm21–27 Mm

Oxygen saturation Oxygen saturation Oxygenated: 98–99%Oxygenated: 98–99%Deoxygenated: 75% Deoxygenated: 75%

CellsCells

4.7 to 6.1 million (male), 4.2 to 5.4 million (female) 4.7 to 6.1 million (male), 4.2 to 5.4 million (female) erythrocyteserythrocytes::[5][5] In most mammals, mature red blood cells In most mammals, mature red blood cells lack a lack a nucleusnucleus and and organellesorganelles. They contain the blood's . They contain the blood's hemoglobinhemoglobin and distribute oxygen. The red blood cells and distribute oxygen. The red blood cells (together with (together with endothelialendothelial vessel cells and other cells) vessel cells and other cells) are also marked by are also marked by glycoproteinsglycoproteins that define the that define the different different blood typesblood types. The proportion of blood occupied . The proportion of blood occupied by red blood cells is referred to as the by red blood cells is referred to as the hematocrithematocrit, and , and is normally about 45%. The combined surface area of all is normally about 45%. The combined surface area of all red blood cells of the human body would be roughly 2,000 red blood cells of the human body would be roughly 2,000 times as great as the body's exterior surface.times as great as the body's exterior surface.[6][6]

4,000–11,000 4,000–11,000 leukocytesleukocytes::[7][7] White blood cells are part of White blood cells are part of the the immune systemimmune system; they destroy and remove old or ; they destroy and remove old or aberrant cells and cellular debris, as well as attack aberrant cells and cellular debris, as well as attack infectious agents (infectious agents (pathogenspathogens) and foreign substances. The ) and foreign substances. The cancer of leukocytes is called cancer of leukocytes is called leukemialeukemia. .

200,000–500,000 thrombocytes:200,000–500,000 thrombocytes:[7][7] thrombocytesthrombocytes, also , also called called plateletsplatelets, are responsible for blood clotting (, are responsible for blood clotting (coagulationcoagulation). They change ). They change fibrinogenfibrinogen into into fibrinfibrin. This . This fibrin creates a mesh onto which red blood cells collect fibrin creates a mesh onto which red blood cells collect and clot, which then stops more blood from leaving the and clot, which then stops more blood from leaving the body and also helps to prevent bacteria from entering the body and also helps to prevent bacteria from entering the body. body.

PlasmaPlasma

About 55% of whole blood is About 55% of whole blood is blood plasmablood plasma, a fluid , a fluid that is the blood's liquid medium, which by itself is straw-that is the blood's liquid medium, which by itself is straw-yellow in color. The blood plasma volume totals of 2.7–3.0 yellow in color. The blood plasma volume totals of 2.7–3.0 litres (2.8–3.2 quarts) in an average human. It is litres (2.8–3.2 quarts) in an average human. It is essentially an essentially an aqueousaqueous solution containing 92% water, 8% solution containing 92% water, 8% blood plasma blood plasma proteinsproteins, and trace amounts of other materials. , and trace amounts of other materials. Plasma circulates dissolved nutrients, such as Plasma circulates dissolved nutrients, such as glucoseglucose, , amino acidsamino acids, and , and fatty acidsfatty acids (dissolved in the blood or bound (dissolved in the blood or bound to plasma proteins), and removes waste products, such as to plasma proteins), and removes waste products, such as carbon dioxidecarbon dioxide, , ureaurea, and , and lactic acidlactic acid..

Other important Other important componentscomponents include: include:

Serum albuminSerum albumin Blood-clotting factors (to facilitate Blood-clotting factors (to facilitate coagulationcoagulation) ) ImmunoglobulinsImmunoglobulins (antibodies) (antibodies) lipoproteinlipoprotein particles particles Various other Various other proteinsproteins Various Various electrolyteselectrolytes (mainly (mainly sodiumsodium and and chloridechloride) ) The term The term serumserum refers to plasma from which the clotting refers to plasma from which the clotting

proteins have been removed. Most of the proteins remaining proteins have been removed. Most of the proteins remaining are albumin and are albumin and immunoglobulinsimmunoglobulins..

Narrow range of pH valuesNarrow range of pH values

Blood Blood pHpH is regulated to stay within the narrow range is regulated to stay within the narrow range of 7.35 to 7.45, making it slightly alkaline.of 7.35 to 7.45, making it slightly alkaline.[8][8][9][9] Blood that has a pH below 7.35 is too Blood that has a pH below 7.35 is too acidicacidic, whereas , whereas blood pH above 7.45 is too blood pH above 7.45 is too alkalinealkaline. Blood pH, . Blood pH, partial pressurepartial pressure of oxygen (pO2), partial pressure of of oxygen (pO2), partial pressure of carbon dioxide (pCO2), and carbon dioxide (pCO2), and HCO3HCO3 are carefully are carefully regulated by a number of regulated by a number of homeostatic mechanismshomeostatic mechanisms, which , which exert their influence principally through the exert their influence principally through the respiratory systemrespiratory system and the and the urinary systemurinary system in order to in order to control the control the acid-base balanceacid-base balance and respiration. An and respiration. An arterial blood gasarterial blood gas will measure these. Plasma also will measure these. Plasma also circulates circulates hormoneshormones transmitting their messages to transmitting their messages to various tissues. The list of normal various tissues. The list of normal reference rangesreference ranges for various blood electrolytes is extensive.for various blood electrolytes is extensive.

Bones are especially affected by blood pH as they tend Bones are especially affected by blood pH as they tend to be used as a mineral source for pH buffering. to be used as a mineral source for pH buffering. Consuming a high ratio of animal protein to vegetable Consuming a high ratio of animal protein to vegetable protein is implicated in bone loss in women.protein is implicated in bone loss in women.[[

Blood in non-human vertebratesBlood in non-human vertebrates

Human blood is typical of that of mammals, Human blood is typical of that of mammals, although the precise details concerning cell although the precise details concerning cell numbers, size, numbers, size, protein structureprotein structure, and so on, vary , and so on, vary somewhat between species. In non-mammalian somewhat between species. In non-mammalian vertebrates, however, there are some key vertebrates, however, there are some key differences:differences:[11][11]

Red blood cells of non-mammalian vertebrates are Red blood cells of non-mammalian vertebrates are flattened and ovoid in form, and retain their flattened and ovoid in form, and retain their cell nuclei cell nuclei

There is considerable variation in the types and There is considerable variation in the types and proportions of white blood cells; for example, proportions of white blood cells; for example, acidophils are generally more common than in acidophils are generally more common than in humans humans

Platelets are unique to mammals; in other Platelets are unique to mammals; in other vertebrates, small, nucleated, spindle cells are vertebrates, small, nucleated, spindle cells are responsible for blood clotting instead responsible for blood clotting instead

PhysiologyPhysiology

Cardiovascular systemCardiovascular system

Blood is circulated around the body through Blood is circulated around the body through blood vesselsblood vessels by the pumping action of the by the pumping action of the heartheart. In humans, blood is . In humans, blood is pumped from the strong pumped from the strong left ventricleleft ventricle of the heart through of the heart through arteriesarteries to peripheral to peripheral tissuestissues and returns to the right and returns to the right atriumatrium of the heart through of the heart through veinsveins. It then enters the . It then enters the right right ventricleventricle and is pumped through the and is pumped through the pulmonary arterypulmonary artery to the to the lungslungs and returns to the left atrium through the and returns to the left atrium through the pulmonary veinspulmonary veins. Blood then enters the left ventricle to . Blood then enters the left ventricle to be circulated again. Arterial blood carries oxygen from be circulated again. Arterial blood carries oxygen from inhaled air to all of the cells of the body, and inhaled air to all of the cells of the body, and venous bloodvenous blood carries carbon dioxide, a waste product of carries carbon dioxide, a waste product of metabolismmetabolism by by cellscells, to the lungs to be exhaled. However, , to the lungs to be exhaled. However, one exception includes pulmonary arteries, which contain one exception includes pulmonary arteries, which contain the most deoxygenated blood in the body, while the the most deoxygenated blood in the body, while the pulmonary veins contain oxygenated blood.pulmonary veins contain oxygenated blood.

Additional return flow may be generated by the movement of Additional return flow may be generated by the movement of skeletal musclesskeletal muscles, which can compress veins and push blood , which can compress veins and push blood through the valves in veins toward the through the valves in veins toward the right atriumright atrium..

The blood circulation was famously described by The blood circulation was famously described by William HarveyWilliam Harvey in 1628 in 1628

Production and degradation of blood cellsProduction and degradation of blood cells

In vertebrates, the various cells of blood are made in In vertebrates, the various cells of blood are made in the the bone marrowbone marrow in a process called in a process called hematopoiesishematopoiesis, , which includes which includes erythropoiesiserythropoiesis, the production of red , the production of red blood cells; and myelopoiesis, the production of white blood cells; and myelopoiesis, the production of white blood cells and platelets. During childhood, almost blood cells and platelets. During childhood, almost every human bone produces red blood cells; as adults, every human bone produces red blood cells; as adults, red blood cell production is limited to the larger red blood cell production is limited to the larger bones: the bodies of the vertebrae, the breastbone bones: the bodies of the vertebrae, the breastbone (sternum), the ribcage, the pelvic bones, and the (sternum), the ribcage, the pelvic bones, and the bones of the upper arms and legs. In addition, during bones of the upper arms and legs. In addition, during childhood, the childhood, the thymusthymus gland, found in the gland, found in the mediastinummediastinum, , is an important source of is an important source of lymphocyteslymphocytes..[13][13] The The proteinaceous component of blood (including clotting proteinaceous component of blood (including clotting proteins) is produced predominantly by the proteins) is produced predominantly by the liverliver, , while hormones are produced by the while hormones are produced by the endocrine glandsendocrine glands and the watery fraction is regulated by the and the watery fraction is regulated by the hypothalamushypothalamus and maintained by the and maintained by the kidneykidney..

Healthy Healthy erythrocyteserythrocytes have a plasma life of about 120 have a plasma life of about 120 days before they are degraded by the days before they are degraded by the spleenspleen, and the , and the KupfferKupffer cells cells in the liver. The liver also clears some in the liver. The liver also clears some proteins, lipids, and proteins, lipids, and amino acidsamino acids. The kidney actively . The kidney actively secretes waste products into the secretes waste products into the urineurine..

Oxygen transportOxygen transport

About 98.5% of the About 98.5% of the oxygenoxygen in a sample of arterial blood in a sample of arterial blood in a healthy human breathing air at sea-level pressure is in a healthy human breathing air at sea-level pressure is chemically combined with the Hgb. About 1.5% is chemically combined with the Hgb. About 1.5% is physically dissolved in the other blood liquids and not physically dissolved in the other blood liquids and not connected to Hgb. The connected to Hgb. The hemoglobinhemoglobin molecule is the primary molecule is the primary transporter of oxygen in transporter of oxygen in mammalsmammals and many other species and many other species (for exceptions, see below). Hemoglobin has an oxygen (for exceptions, see below). Hemoglobin has an oxygen binding capacity of between 1.36 and 1.37 ml O2 per gram binding capacity of between 1.36 and 1.37 ml O2 per gram Hemoglobin,Hemoglobin,[14][14] which increases the total which increases the total blood oxygen capacityblood oxygen capacity seventyfold, seventyfold,[15][15] compared to if compared to if oxygen solely was carried by its solubility of 0.03 mL O2 oxygen solely was carried by its solubility of 0.03 mL O2 per litre blood per mmHg per litre blood per mmHg partial pressurepartial pressure of oxygen of oxygen (approximately 100 mmHg in arteries).(approximately 100 mmHg in arteries).[15][15]

With the exception of With the exception of pulmonarypulmonary and and umbilical arteriesumbilical arteries and their corresponding veins, and their corresponding veins, arteriesarteries carry oxygenated carry oxygenated blood away from the blood away from the heartheart and deliver it to the body via and deliver it to the body via arteriolesarterioles and and capillariescapillaries, where the oxygen is consumed; , where the oxygen is consumed; afterwards, afterwards, venulesvenules, and , and veinsveins carry deoxygenated blood carry deoxygenated blood back to the heart.back to the heart.

Under normal conditions in humans at rest, Under normal conditions in humans at rest, hemoglobin in blood leaving the lungs is about 98–hemoglobin in blood leaving the lungs is about 98–99% saturated with oxygen. In a healthy adult at 99% saturated with oxygen. In a healthy adult at rest, rest, deoxygenateddeoxygenated blood returning to the lungs is blood returning to the lungs is still approximately 75% saturated.still approximately 75% saturated.[16][16][17][17] Increased oxygen consumption during sustained Increased oxygen consumption during sustained exercise reduces the oxygen saturation of venous exercise reduces the oxygen saturation of venous blood, which can reach less than 15% in a trained blood, which can reach less than 15% in a trained athlete; although breathing rate and blood flow athlete; although breathing rate and blood flow increase to compensate, oxygen saturation in increase to compensate, oxygen saturation in arterial blood can drop to 95% or less under these arterial blood can drop to 95% or less under these conditions.conditions.[18][18] Oxygen saturation this low is Oxygen saturation this low is considered dangerous in an individual at rest (for considered dangerous in an individual at rest (for instance, during surgery under anesthesia. instance, during surgery under anesthesia. Sustained hypoxia (oxygenation of less than 90%), Sustained hypoxia (oxygenation of less than 90%), is dangerous to health, and severe hypoxia is dangerous to health, and severe hypoxia (saturations of less than 30%) may be rapidly (saturations of less than 30%) may be rapidly fatal.fatal.[19][19]

A A fetusfetus, receiving oxygen via the , receiving oxygen via the placentaplacenta, is , is exposed to much lower oxygen pressures (about 21% exposed to much lower oxygen pressures (about 21% of the level found in an adult's lungs), and, so, of the level found in an adult's lungs), and, so, fetuses produce another form of hemoglobin with a fetuses produce another form of hemoglobin with a much higher affinity for oxygen (much higher affinity for oxygen (hemoglobin Fhemoglobin F) in ) in order to function under these conditionsorder to function under these conditions

Carbon dioxide transportCarbon dioxide transport

When blood flows through capillaries, carbon dioxide diffuses When blood flows through capillaries, carbon dioxide diffuses from the tissues into the blood. Some carbon dioxide is from the tissues into the blood. Some carbon dioxide is dissolved in the blood. A part of CO2 reacts with hemoglobin dissolved in the blood. A part of CO2 reacts with hemoglobin and other proteins to form and other proteins to form carbaminocarbamino compounds. The remaining compounds. The remaining carbon dioxide is converted to carbon dioxide is converted to bicarbonatebicarbonate and and hydrogen ionshydrogen ions through the action of RBC through the action of RBC carbonic carbonic anhydraseanhydrase. Most carbon . Most carbon dioxide is transported through the blood in the form of dioxide is transported through the blood in the form of bicarbonate ions.bicarbonate ions.

Carbon dioxide (CO2), the main Carbon dioxide (CO2), the main cellular waste productcellular waste product is is carried in blood mainly dissolved in carried in blood mainly dissolved in plasmaplasma, in equilibrium , in equilibrium with with bicarbonatebicarbonate (HCO3-) and (HCO3-) and carbonic acidcarbonic acid (H2CO3). 86–90% of (H2CO3). 86–90% of CO2 in the body is converted into CO2 in the body is converted into carbonic acidcarbonic acid, which can , which can quickly turn into bicarbonate, the chemical equilibrium being quickly turn into bicarbonate, the chemical equilibrium being important in the pH important in the pH bufferingbuffering of plasma. of plasma.[21][21] Blood Blood pHpH is kept is kept in a narrow range (pH between 7.35 and 7.45in a narrow range (pH between 7.35 and 7.45

Transport of hydrogen ionsTransport of hydrogen ions Some oxyhemoglobin loses oxygen and becomes deoxyhemoglobin. Some oxyhemoglobin loses oxygen and becomes deoxyhemoglobin.

Deoxyhemoglobin binds most of the hydrogen ions as it has a Deoxyhemoglobin binds most of the hydrogen ions as it has a much greater affinity for more hydrogen than does much greater affinity for more hydrogen than does oxyhemoglobin.oxyhemoglobin.Lymphatic systemLymphatic system

In mammals, blood is in equilibrium with In mammals, blood is in equilibrium with lymphlymph, which is , which is continuously formed in tissues from blood by capillary continuously formed in tissues from blood by capillary ultrafiltration. Lymph is collected by a system of small ultrafiltration. Lymph is collected by a system of small lymphatic vessels and directed to the lymphatic vessels and directed to the thoracic ductthoracic duct, which , which drains into the left drains into the left subclaviansubclavian vein vein where lymph rejoins the where lymph rejoins the systemic blood circulation.systemic blood circulation.

ThermoregulationThermoregulation

Blood circulation transports Blood circulation transports heatheat throughout the body, throughout the body, and adjustments to this flow are an important part of and adjustments to this flow are an important part of thermoregulationthermoregulation. Increasing blood flow to the surface . Increasing blood flow to the surface (e.g., during warm weather or strenuous exercise) (e.g., during warm weather or strenuous exercise) causes warmer skin, resulting in faster heat loss. In causes warmer skin, resulting in faster heat loss. In contrast, when the external temperature is low, blood contrast, when the external temperature is low, blood flow to the extremities and surface of the skin is flow to the extremities and surface of the skin is reduced and to prevent heat loss and is circulated to reduced and to prevent heat loss and is circulated to the important organs of the body, the important organs of the body, preferentially.preferentially.Hydraulic functionsHydraulic functions

The restriction of blood flow can also be used in The restriction of blood flow can also be used in specialized tissues to cause engorgement, resulting in specialized tissues to cause engorgement, resulting in an an erectionerection of that tissue; examples are the of that tissue; examples are the erectile tissueerectile tissue in the in the penispenis and and clitorisclitoris..

Another example of a hydraulic function is the Another example of a hydraulic function is the jumping spiderjumping spider, in which blood forced into the legs , in which blood forced into the legs under pressure causes them to straighten for a under pressure causes them to straighten for a powerful jump, without the need for bulky muscular powerful jump, without the need for bulky muscular legslegs

ColorColor

HemoglobinHemoglobin

Hemoglobin is the principal determinant of the color of Hemoglobin is the principal determinant of the color of blood in vertebrates. Each molecule has four heme groups, and blood in vertebrates. Each molecule has four heme groups, and their interaction with various molecules alters the exact their interaction with various molecules alters the exact color. In color. In vertebratesvertebrates and other hemoglobin-using creatures, and other hemoglobin-using creatures, arterial blood and capillary blood are bright red, as oxygen arterial blood and capillary blood are bright red, as oxygen imparts a strong red color to the heme group. Deoxygenated imparts a strong red color to the heme group. Deoxygenated blood is a darker shade of red; this is present in veins, and blood is a darker shade of red; this is present in veins, and can be seen during can be seen during blood donationblood donation and when venous blood samples and when venous blood samples are taken. Blood in are taken. Blood in carbon monoxide poisoningcarbon monoxide poisoning is bright red, is bright red, because because carbon monoxidecarbon monoxide causes the formation of causes the formation of carboxyhemoglobincarboxyhemoglobin. In . In cyanidecyanide poisoning, the body cannot poisoning, the body cannot utilize oxygen, so the venous blood remains oxygenated, utilize oxygen, so the venous blood remains oxygenated, increasing the redness. While hemoglobin-containing blood is increasing the redness. While hemoglobin-containing blood is never blue, there are several conditions and diseases wherein never blue, there are several conditions and diseases wherein the color of the heme groups make the skin appear blue. If the the color of the heme groups make the skin appear blue. If the heme is oxidized, heme is oxidized, methaemoglobinmethaemoglobin, which is more brownish and , which is more brownish and cannot transport oxygen, is formed. In the rare condition cannot transport oxygen, is formed. In the rare condition sulfhemoglobinemiasulfhemoglobinemia, arterial hemoglobin is partially , arterial hemoglobin is partially oxygenated, and appears dark red with a bluish hue (oxygenated, and appears dark red with a bluish hue (cyanosiscyanosis).).

Veins in the skin appear blue for a variety of reasons only Veins in the skin appear blue for a variety of reasons only weakly dependent on the color of the blood. Light scattering in weakly dependent on the color of the blood. Light scattering in the skin, and the visual processing of color play roles as the skin, and the visual processing of color play roles as well.well.[23][23]

Skinks in the genus Skinks in the genus PrasinohaemaPrasinohaema have green blood due to a have green blood due to a buildup of the waste product buildup of the waste product biliverdinbiliverdin..

HemocyaninHemocyanin

The blood of most The blood of most mollusksmollusks – including – including cephalopodscephalopods and and gastropodsgastropods – as well as some – as well as some arthropodsarthropods, such as , such as horseshoe crabshorseshoe crabs, is blue, as , is blue, as it contains the copper-containing protein it contains the copper-containing protein hemocyanin at concentrations of about 50 grams hemocyanin at concentrations of about 50 grams per litre.per litre.[25][25] Hemocyanin is colorless when Hemocyanin is colorless when deoxygenated and dark blue when oxygenated. The deoxygenated and dark blue when oxygenated. The blood in the circulation of these creatures, blood in the circulation of these creatures, which generally live in cold environments with which generally live in cold environments with low oxygen tensions, is grey-white to pale low oxygen tensions, is grey-white to pale yellow,yellow,[25][25] and it turns dark blue when exposed and it turns dark blue when exposed to the oxygen in the air, as seen when they to the oxygen in the air, as seen when they bleed.bleed.[25][25] This is due to change in color of This is due to change in color of hemocyanin when it is oxidized.[25] Hemocyanin hemocyanin when it is oxidized.[25] Hemocyanin carries oxygen in extracellular fluid, which is carries oxygen in extracellular fluid, which is in contrast to the intracellular oxygen transport in contrast to the intracellular oxygen transport in mammals by hemoglobin in RBCs.[25] in mammals by hemoglobin in RBCs.[25]

ETIOLOGYETIOLOGY

• Malaria is caused by protozoan parasites of the Malaria is caused by protozoan parasites of the genus genus PlasmodiumPlasmodium ( (phylum apicomplexa).phylum apicomplexa).

• There are several species of Plasmodium Parasites There are several species of Plasmodium Parasites but only four of them are significant to the but only four of them are significant to the cause of malaria diseases to humans. Some of cause of malaria diseases to humans. Some of these are in to animals. Like birds,reptiles, these are in to animals. Like birds,reptiles, monkeys, chimpanzees, and rodents.monkeys, chimpanzees, and rodents.

PATHOPHYSIOLOGYPATHOPHYSIOLOGY

A female Anopheles mosquito bites, injecting saliva containing sporozoites, the infective form of malaria parasite.

The sporozoites enter the liver and multiply

In the liver, the sporozoites change into merozoites, another form of the parasite.

Merozoites are released from the liver and enter the bloodstream.

Merozoites attack Red Blood Cells.

Red Blood cells burst and release the merozoites which invade other red blood cells

and cause recurring chills and fever.(At this point the infected person becomes a reservoir of malaria that infects

any mosquito that feeds on him.)

PLASMODIUM VIVAX

PLASMODIUM MALARIAE

PLASMODIUM OVALE

PLASMODIUM FALCIPARUM

• P. Vivax is the most common cause of infection, responsible for about 80% of all malaria cases.

• However, P. Falciparum is the most important cause of disease, and responsible for about 15% of infections and 90% of deaths.

The Parasite’s primary hosts and The Parasite’s primary hosts and transmission vectors are female transmission vectors are female mosquitoes of the Anopheles genus.mosquitoes of the Anopheles genus.

The disease is transmitted to The disease is transmitted to humans when an infected humans when an infected AnophelesAnopheles mosquito bites a person and injects mosquito bites a person and injects the malaria parasites (sporozoites) the malaria parasites (sporozoites) into the blood.into the blood.

Mosquito injects the Mosquito injects the infective plasmodial infective plasmodial sporozoites.sporozoites.

Sporozoites enter the liver Sporozoites enter the liver cells, and transform into cells, and transform into merozoites which penetrate RBC.merozoites which penetrate RBC.

Once in RBC, Once in RBC, merozoites merozoites reproduce rapidly, reproduce rapidly, producing many more producing many more merozoites, which merozoites, which burst out of the burst out of the RBC & penetrate new RBC & penetrate new cells. cells.

Some of these Some of these merozoites form merozoites form male & female male & female gametocytes, which gametocytes, which can be picked up by can be picked up by another mosquito.another mosquito.

Inside the gut of Inside the gut of the mosquito, the mosquito, gametocytes will gametocytes will fertilize creating fertilize creating zygote.zygote.

The zygote then develops into an The zygote then develops into an oocyst and ruptures to release oocyst and ruptures to release thousands of sporozoites.thousands of sporozoites.

Ready for Ready for another cycle.another cycle.

Only female mosquitoes feed on Only female mosquitoes feed on blood, thus males do not blood, thus males do not transmit the disease. The transmit the disease. The females of the Anopheles genus females of the Anopheles genus of mosquito prefer to feed at of mosquito prefer to feed at night. They usually start night. They usually start searching for a meal at dusk, searching for a meal at dusk, and will continue throughout and will continue throughout the night until taking a meal.the night until taking a meal.

Malaria parasites can also be Malaria parasites can also be transmitted by transmitted by blood blood transfusiontransfusion, although this is , although this is rare.rare.

SIGNS & SYMPTOMSSIGNS & SYMPTOMS

The symptoms characteristic of malaria include The symptoms characteristic of malaria include flu-like illness with fever, chills, muscle flu-like illness with fever, chills, muscle aches, joint pain (athralgia), vomiting, anemia aches, joint pain (athralgia), vomiting, anemia caused by hemolysis, hemoglobinuria, caused by hemolysis, hemoglobinuria, convulsions, and headache.convulsions, and headache.

The classical symptom of malaria is cyclical The classical symptom of malaria is cyclical occurrence of sudden coldness followed by rigor occurrence of sudden coldness followed by rigor and then fever and sweating lasting four to six and then fever and sweating lasting four to six hours, occurring every two days in hours, occurring every two days in P. vivaxP. vivax and and P. ovaleP. ovale infections, while every three for infections, while every three for P. P. malariaemalariae. . P. falciparumP. falciparum can have recurrent fever can have recurrent fever every 36-48 hours or a less pronounced and every 36-48 hours or a less pronounced and almost continuous fever.almost continuous fever.

People with severe People with severe P. P. falciparumfalciparum malaria can develop malaria can develop bleeding problemsbleeding problems, , shockshock, , liver or kidney failureliver or kidney failure, , central nervous system central nervous system problemsproblems, , comacoma, and can die , and can die from the infection or its from the infection or its complications. complications.

Cerebral malaria (coma, or Cerebral malaria (coma, or altered mental status or altered mental status or seizures) can occur with seizures) can occur with severe severe P. falciparumP. falciparum infection. It is lethal if not infection. It is lethal if not treated quickly; even with treated quickly; even with treatment, about 15%-20% die.treatment, about 15%-20% die.

INCUBATION PERIODINCUBATION PERIOD

The period between the mosquito bite and the onset of the The period between the mosquito bite and the onset of the malarial illness is usually one to three weeks (seven to malarial illness is usually one to three weeks (seven to 21 days). This initial time period is highly variable as 21 days). This initial time period is highly variable as reports suggest that the range of incubation periods may reports suggest that the range of incubation periods may range from four days to one year. range from four days to one year.

The usual incubation period may be increased when a The usual incubation period may be increased when a person has taken an inadequate course of malaria person has taken an inadequate course of malaria prevention medications. prevention medications.

Certain types of malaria (Certain types of malaria (P. vivaxP. vivax and and P. ovaleP. ovale) ) parasites can also take much longer, as long as eight to parasites can also take much longer, as long as eight to 10 months, to cause symptoms. These parasites remain 10 months, to cause symptoms. These parasites remain dormant (inactive or hibernating) in the liver cells dormant (inactive or hibernating) in the liver cells during this time. Unfortunately, some of these dormant during this time. Unfortunately, some of these dormant parasites can remain even after a patient recovers from parasites can remain even after a patient recovers from malaria, so the patient can get sick again. This malaria, so the patient can get sick again. This situation is termed situation is termed relapsing malariarelapsing malaria. .

TREATMENTTREATMENT

Malaria can be a severe, potentially fatal disease Malaria can be a severe, potentially fatal disease (especially when caused by P. Falciparum) and (especially when caused by P. Falciparum) and treatment should be initiated as soon as possible.treatment should be initiated as soon as possible.

The Word Health Organization recommends that those The Word Health Organization recommends that those in endemic areas, treatment should be started in endemic areas, treatment should be started within 24 hours after the first symptoms appear. within 24 hours after the first symptoms appear. Treatment of patients with uncomplicated malaria Treatment of patients with uncomplicated malaria can be conducted on an ambulatory basis (without can be conducted on an ambulatory basis (without hospitalization) but patients with severe malaria hospitalization) but patients with severe malaria should be hospitalized if possible.should be hospitalized if possible.

In areas where malaria is not endemic, all patients In areas where malaria is not endemic, all patients with malaria (uncomplicated or severe) should be with malaria (uncomplicated or severe) should be kept under clinical observation if possible.kept under clinical observation if possible.

Drug TreatmentDrug Treatment The first effective treatment for malaria The first effective treatment for malaria

was the bark of was the bark of cinchona treecinchona tree, which , which contains QUININE. It was first used by contains QUININE. It was first used by the inhabitants of Peru, where these the inhabitants of Peru, where these trees mainly grow.trees mainly grow.

Today, there are several antimalarial Today, there are several antimalarial drugs available for treatment:drugs available for treatment:

ChloroquineChloroquine sulfadoxine-pyrimethamine (Fansidar®) sulfadoxine-pyrimethamine (Fansidar®) mefloquine (Lariam®) mefloquine (Lariam®) atovaquone-proguanil (Malarone®) atovaquone-proguanil (Malarone®) quinine quinine doxycycline doxycycline artemisin derivativesartemisin derivatives primaquineprimaquine

But, drug treatment of malaria is not But, drug treatment of malaria is not always easy. You have to consider some always easy. You have to consider some factors in treating different conditions factors in treating different conditions of patients having malaria.of patients having malaria.

1.1. The infecting species of Plasmodium parasites.The infecting species of Plasmodium parasites. Different species of Plasmodium parasites may vary in Different species of Plasmodium parasites may vary in treating patients.treating patients.

2.2. The clinical situation of the patient.The clinical situation of the patient. Mild malaria can be treated with oral medication.Mild malaria can be treated with oral medication. Severe malaria (having one or more symptoms of either Severe malaria (having one or more symptoms of either coma, severe anemia, renal failure, shock, etc.) coma, severe anemia, renal failure, shock, etc.) requires intravenous (IV) drug treatment and fluids.requires intravenous (IV) drug treatment and fluids.

Malaria may pose a serious threat to a pregnant women Malaria may pose a serious threat to a pregnant women and her pregnancy. Infection may be more severe than and her pregnancy. Infection may be more severe than those women who are not pregnant.those women who are not pregnant.

3.3. The drug susceptibility of the infecting parasites.The drug susceptibility of the infecting parasites. Determined by the geographic area where the infection Determined by the geographic area where the infection was acquired.was acquired.

Different areas of the world have malaria types that Different areas of the world have malaria types that are resistant to certain medications.are resistant to certain medications.

Correct drug must be prescribed by the doctor who is Correct drug must be prescribed by the doctor who is familiar with malaria treatment protocol.familiar with malaria treatment protocol.

There are three main factors in determining There are three main factors in determining treatmenttreatment

PUBLIC HEALTH PREVENTION PUBLIC HEALTH PREVENTION & NURSING MANAGEMENTS& NURSING MANAGEMENTS

MALARIA CONTROLMALARIA CONTROL The goal of malaria control in The goal of malaria control in

malaria-endemic countries is to reduce malaria-endemic countries is to reduce as much as possible the health impact as much as possible the health impact of malaria on a population, using the of malaria on a population, using the resources available, and taking into resources available, and taking into account other health priorities.account other health priorities.

Malaria control does not aim to Malaria control does not aim to eliminate malaria totally. Complete eliminate malaria totally. Complete elimination of the malaria parasite elimination of the malaria parasite (and thus the disease) would (and thus the disease) would constitute eradication. While constitute eradication. While eradication is more desirable, it is eradication is more desirable, it is not currently a realistic goal for not currently a realistic goal for most of the countries where malaria most of the countries where malaria is endemic. is endemic.

Malaria control is carried out through the following Malaria control is carried out through the following interventions, which are often combined:interventions, which are often combined:

Case ManagementCase Management (diagnosis and treatment) of patients (diagnosis and treatment) of patients suffering from malaria.suffering from malaria.

Persons who are sick should be treated promptly Persons who are sick should be treated promptly and correctly. It eliminates an essential and correctly. It eliminates an essential component of the cycle (the parasite) and thus component of the cycle (the parasite) and thus interrupts the transmission cycle.interrupts the transmission cycle.

WHO recommends that anyone suspected of having WHO recommends that anyone suspected of having malaria should receive diagnosis and treatment malaria should receive diagnosis and treatment with an effective drug within 24 hours of the with an effective drug within 24 hours of the onset of symptoms. onset of symptoms.

Prevention of InfectionPrevention of Infection through vector control. through vector control. Infection is prevented when malaria-carrying Infection is prevented when malaria-carrying Anopheles mosquitoes are prevented from Anopheles mosquitoes are prevented from biting humans.biting humans.

Vector control aims to reduce contacts Vector control aims to reduce contacts between mosquitoes and humans.between mosquitoes and humans.

Some vector control measures like Some vector control measures like ((destruction of larval breeding sites, destruction of larval breeding sites, insecticide spraying inside housesinsecticide spraying inside houses) may ) may require organized teams and resources that require organized teams and resources that are not always available.are not always available.

Insecticide-treated bed netsInsecticide-treated bed nets could also be an could also be an alternative in vector control and personal alternative in vector control and personal protection. It could be conducted by the protection. It could be conducted by the community themselves and become a major community themselves and become a major intervention in malaria control.intervention in malaria control.

Prevention of DiseasePrevention of Disease by administration of by administration of antimalarial drugs to particularly vulnerable antimalarial drugs to particularly vulnerable population groups such as pregnant women and population groups such as pregnant women and infants.infants.

Administration of antimalarial drugs to Administration of antimalarial drugs to vulnerable population groups does not prevent vulnerable population groups does not prevent infection, which happens through mosquito infection, which happens through mosquito bites. But drugs can prevent disease by bites. But drugs can prevent disease by eliminating the parasites that are in the eliminating the parasites that are in the blood, which are the forms that cause disease. blood, which are the forms that cause disease.

Pregnant women are the vulnerable group most Pregnant women are the vulnerable group most frequently targeted. They may receive, for frequently targeted. They may receive, for example, "intermittent preventive treatment" example, "intermittent preventive treatment" (IPT) with antimalarial drugs given most often (IPT) with antimalarial drugs given most often at antenatal consultations during the second at antenatal consultations during the second and third trimesters of pregnancy.and third trimesters of pregnancy.

MALARIA IN THE MALARIA IN THE PHILIPPINESPHILIPPINES

The The Philippines is one of the Southeast Asian Philippines is one of the Southeast Asian countriescountries plagued plagued with malaria. Although the country with malaria. Although the country doedoes s notnot co contntribute ribute significantly to the global significantly to the global mortalitymortality attributed to m attributed to malaria, the disease remains alaria, the disease remains to be a majorto be a major cause cause ofof “healthy “healthy days of life lost” days of life lost” (HDLL) in the(HDLL) in the endem endemicic arareas of the eas of the country. Malaria country. Malaria affects theaffects the soci socioeconooeconomic wemic wellll-bein-being of the affected g of the affected population, andpopulation, and the d the diffeifferent socioecrent socioeconomiconomic activities affectactivities affect transm transmisission, prevsion, prevention,ention, and and control of the disease.control of the disease. Thus, this situ Thus, this situationation not only not only generates an enormousgenerates an enormous ec econonomic, soomic, socialcial and health and health burden to these people perburden to these people per se, but se, but also poses a huge also poses a huge and persistent challenge toand persistent challenge to the the health deliverers of health deliverers of the Malaria Control Programthe Malaria Control Program..

PHILIPPINE SCENARIOPHILIPPINE SCENARIO

MALARIA AS A HEALTH PROBLEMMALARIA AS A HEALTH PROBLEM It is the eighth leading cause of morbidity in the It is the eighth leading cause of morbidity in the

Philippines. (HIS 2000) Philippines. (HIS 2000) According to DOH Secretary Reynaldo Duque, “an According to DOH Secretary Reynaldo Duque, “an

average of three Filipinos die daily due to malaria average of three Filipinos die daily due to malaria despite the government’s intensified efforts to despite the government’s intensified efforts to control the occurrence of the ailment”.control the occurrence of the ailment”.

Malaria has become a health threat.Malaria has become a health threat. Although malaria endemicity is now generally moderate Although malaria endemicity is now generally moderate

to low, the disease continues to be a major to low, the disease continues to be a major impediment to human and economic development in areas impediment to human and economic development in areas where it persistswhere it persists

This disease is still endemic in 65 of the 79 This disease is still endemic in 65 of the 79 provinces in the country, and around 10 million provinces in the country, and around 10 million people who live in these areas are at risk of getting people who live in these areas are at risk of getting the disease.the disease.

Morbidity trend suggest that there might be a cause Morbidity trend suggest that there might be a cause and effect relationship between the activities which and effect relationship between the activities which aim to eradicate malaria and its incidence aim to eradicate malaria and its incidence

There is a decreasing number of deaths caused by There is a decreasing number of deaths caused by malariamalaria

Chloroquine, the cheapest medicine against malaria is Chloroquine, the cheapest medicine against malaria is losing its effectivenesslosing its effectiveness

Malaria as a Health Services ProblemMalaria as a Health Services Problem It poses challenges of access to health care for prompt It poses challenges of access to health care for prompt

and effective treatmentand effective treatment There are shortages of antimalarial drug supplies, There are shortages of antimalarial drug supplies,

especially in peripheral health centersespecially in peripheral health centers The disease still costs the Philippine economy to spend The disease still costs the Philippine economy to spend

over Php 100 million in order to sustain control over Php 100 million in order to sustain control effortsefforts

Failures in treatment still occur despite the Failures in treatment still occur despite the preventability of malaria.preventability of malaria.

Causes of Malaria Treatment Failure in the PhilippinesCauses of Malaria Treatment Failure in the Philippines Drug resistanceDrug resistance Non-compliance of patients in the treatment regimenNon-compliance of patients in the treatment regimen Deficient drug absorptionDeficient drug absorption Self-medicationSelf-medication Resorting to herbal remediesResorting to herbal remedies Seeking help when the disease is severe (Malaria is Seeking help when the disease is severe (Malaria is

fatal only when it is seen in its later stages.)fatal only when it is seen in its later stages.)

Epidemiology of malaria is complex, due toEpidemiology of malaria is complex, due to Variety of ecological conditions observed in different Variety of ecological conditions observed in different

island groupsisland groups Occurrence of more than one vector species Occurrence of more than one vector species

Malaria Control Program of the Department of Malaria Control Program of the Department of HealthHealth

For 2007, The Department of Health has developed a For 2007, The Department of Health has developed a malaria control program as a measure to help eradicate malaria control program as a measure to help eradicate the spread of the disease. Some of the program the spread of the disease. Some of the program strategies are:strategies are:

1. Early diagnosis of the disease and prompt treatment.1. Early diagnosis of the disease and prompt treatment.This was achieved through:This was achieved through:

diagnostic centers which serve as cites of microscopydiagnostic centers which serve as cites of microscopy manning by a RDT (Rapid Diagnostic Test) trained manning by a RDT (Rapid Diagnostic Test) trained personnelpersonnel

promotion of the existence of diagnostic promotion of the existence of diagnostic centers                            centers                           

2. Controlling the spread of mosquitoes 2. Controlling the spread of mosquitoes This was achieved through:This was achieved through:

giving out insecticide-treated mosquito netsgiving out insecticide-treated mosquito nets indoor spraying which targets houses and not only indoor spraying which targets houses and not only

communities communities 

3. Implementation of community-based malaria control 3. Implementation of community-based malaria control This was achieved through:This was achieved through:

social mobilizationsocial mobilization education sessionseducation sessions

JOURNALSJOURNALSMosquito Nose Transplants Help Fight MalariMosquito Nose Transplants Help Fight Malari

Main Category: Main Category: Tropical DiseasesTropical DiseasesAlso Included In: Also Included In: Biology / BiochemistryBiology / Biochemistry;  ;  Aid / DisastersAid / DisastersArticle Date: 16 Feb 2010 - 9:00 PDTIn .Article Date: 16 Feb 2010 - 9:00 PDTIn .

a new approach to combating a new approach to combating malariamalaria, a disease that affects half a billion people worlwide, US , a disease that affects half a billion people worlwide, US scientists successfully transplanted most of the "nose" of the disease-spreading Anopheles scientists successfully transplanted most of the "nose" of the disease-spreading Anopheles mosquito into frogs' eggs and fruit flies so they could analyse the insect's odorant receptors and mosquito into frogs' eggs and fruit flies so they could analyse the insect's odorant receptors and find out how to lure it into traps and even prevent it being able to detect and thereby target find out how to lure it into traps and even prevent it being able to detect and thereby target humans.humans.

You can read about the two studies by researchers from Yale University in New Haven, You can read about the two studies by researchers from Yale University in New Haven, Connecticut, and Vanderbilt University in Nashville, Tennessee, in a report in the 3rd February Connecticut, and Vanderbilt University in Nashville, Tennessee, in a report in the 3rd February online issue of the journal online issue of the journal NatureNature and there is also a complementary article in the and there is also a complementary article in the Proceedings of Proceedings of the National Academy of Sciences, PNASthe National Academy of Sciences, PNAS..

The mosquito Anopheles gambiae is the major route through which humans in sub-Saharan Africa The mosquito Anopheles gambiae is the major route through which humans in sub-Saharan Africa become infected with malaria. While we know that the insect uses its sense of smell to find human become infected with malaria. While we know that the insect uses its sense of smell to find human hosts, we know little about the underlying molecular process.hosts, we know little about the underlying molecular process.

A mosquito's "nose" is in its antennae which carry nerve cells covered with odorant receptors that A mosquito's "nose" is in its antennae which carry nerve cells covered with odorant receptors that react to different chemical compounds in the insect's environment. These receptors are similar to react to different chemical compounds in the insect's environment. These receptors are similar to those that give us our senses of smell and taste in our nose and on our taste buds.those that give us our senses of smell and taste in our nose and on our taste buds.

Co-author Dr Laurence Zwiebel, professor of biological sciences at Vanderbilt, told the press Co-author Dr Laurence Zwiebel, professor of biological sciences at Vanderbilt, told the press that:"We've successfully expressed about 80 percent of the Anopheles mosquito's odorant that:"We've successfully expressed about 80 percent of the Anopheles mosquito's odorant receptors in frog's eggs and in the fruit fly antennae."receptors in frog's eggs and in the fruit fly antennae."

Zwiebel's lab at Vanderbilt is where they successfully transplanted the Zwiebel's lab at Vanderbilt is where they successfully transplanted the receptors into frogs' eggs. The transplant into fruit-fly (Drosophila melanogaster) receptors into frogs' eggs. The transplant into fruit-fly (Drosophila melanogaster) eggs was done at the laboratory of John Carlson, Eugene Higgins Professor of eggs was done at the laboratory of John Carlson, Eugene Higgins Professor of Molecular, Cellular and Developmental Biology at Yale and is written up as a Molecular, Cellular and Developmental Biology at Yale and is written up as a complementary study in complementary study in PNASPNAS..

Scientists have previously used frogs' eggs to study olfactory receptors in moths, Scientists have previously used frogs' eggs to study olfactory receptors in moths, bees and fruit flies. For this study, the researchers injected DNA that codes for the bees and fruit flies. For this study, the researchers injected DNA that codes for the mosquito's olfactory receptors into a frog egg and waited for it to produce proteins. mosquito's olfactory receptors into a frog egg and waited for it to produce proteins. Eventually the surface of the egg became covered with mosquito odorant Eventually the surface of the egg became covered with mosquito odorant receptors.receptors.

They then tested the engineered egg's reaction to being exposed to various They then tested the engineered egg's reaction to being exposed to various odorant chemicals. They floated the egg in a buffer solution in a voltage clamp (so odorant chemicals. They floated the egg in a buffer solution in a voltage clamp (so they could measure changes in the egg's electrical properties) and dissolved the they could measure changes in the egg's electrical properties) and dissolved the chemicals one by one in the solution. They detected a measurable electrical chemicals one by one in the solution. They detected a measurable electrical response in the egg.response in the egg.

Guirong Wang, lead author of the Guirong Wang, lead author of the PNASPNAS study, and a senior researcher in study, and a senior researcher in Zwiebel's lab, said:"The frog egg system is relatively rapid, highly sensitive and Zwiebel's lab, said:"The frog egg system is relatively rapid, highly sensitive and allows us to do very precise measurements of odorant response."allows us to do very precise measurements of odorant response."

Wang, who personally conducted several thousand measurements of egg Wang, who personally conducted several thousand measurements of egg responses to changes in odorant, described this method as a "medium throughput responses to changes in odorant, described this method as a "medium throughput system", because although they could set it up quite quickly, they had to make the system", because although they could set it up quite quickly, they had to make the odorant solutions by hand, which took much longer.odorant solutions by hand, which took much longer.

Antioxidants May Help Prevent Malaria Complications That Damage BrainAntioxidants May Help Prevent Malaria Complications That Damage Brain

Using an experimental mouse model for Using an experimental mouse model for malariamalaria, an international group of scientists has discovered , an international group of scientists has discovered that adding antioxidant therapy to traditional antimalarial treatment may prevent long-lasting cognitive that adding antioxidant therapy to traditional antimalarial treatment may prevent long-lasting cognitive impairment in cerebral malaria. Their findings were published online June 24, 2010, in the journal impairment in cerebral malaria. Their findings were published online June 24, 2010, in the journal PLoS PLoS PathogensPathogens..

Malaria, an infection caused by parasites that invade liver and red blood cells, is transmitted to humans by the Malaria, an infection caused by parasites that invade liver and red blood cells, is transmitted to humans by the female Anopheles mosquito. Malaria is one of the leading infectious diseases worldwide, affecting more than female Anopheles mosquito. Malaria is one of the leading infectious diseases worldwide, affecting more than 400 million people and causing more than 2 million deaths each year, mainly among African children. Recently, 400 million people and causing more than 2 million deaths each year, mainly among African children. Recently, the U.S. Centers for Disease Control and Prevention (CDC) issued a report on 11 laboratory-confirmed cases the U.S. Centers for Disease Control and Prevention (CDC) issued a report on 11 laboratory-confirmed cases of malaria among U.S. emergency responders and those traveling in the United States from Haiti.of malaria among U.S. emergency responders and those traveling in the United States from Haiti.

Cerebral malaria is a severe, potentially fatal neurologic complication of infection by the most-feared malarial Cerebral malaria is a severe, potentially fatal neurologic complication of infection by the most-feared malarial parasite, Plasmodium falciparum. Recent studies of children with cerebral malaria indicate that cognitive parasite, Plasmodium falciparum. Recent studies of children with cerebral malaria indicate that cognitive deficits, which may impair memory, learning, language, and mathematical abilities, persist in many survivors deficits, which may impair memory, learning, language, and mathematical abilities, persist in many survivors even after the infection itself is cured.even after the infection itself is cured.

"Cerebral malaria and its molecular mechanisms are under intense study, but the cognitive dysfunction that can "Cerebral malaria and its molecular mechanisms are under intense study, but the cognitive dysfunction that can persist in survivors in the aftermath of successful treatment has gone unrecognized until recently," says Guy A. persist in survivors in the aftermath of successful treatment has gone unrecognized until recently," says Guy A. Zimmerman M.D., professor and associate chair for research in the University of Utah School of Medicine's Zimmerman M.D., professor and associate chair for research in the University of Utah School of Medicine's Department of Internal Medicine and a contributor to the study. "This complication may impose an enormous Department of Internal Medicine and a contributor to the study. "This complication may impose an enormous social and economic burden because of the number of people at risk for severe malaria worldwide. Our findings social and economic burden because of the number of people at risk for severe malaria worldwide. Our findings demonstrate that, by using experimental models of cerebral malaria in mice, we can explore mechanisms of demonstrate that, by using experimental models of cerebral malaria in mice, we can explore mechanisms of cognitive damage and also examine potential treatments for reducing or preventing neurologic and cognitive cognitive damage and also examine potential treatments for reducing or preventing neurologic and cognitive impairment."impairment."

Zimmerman and colleagues in Brazil studied the persistence of cognitive damage in mice with documented Zimmerman and colleagues in Brazil studied the persistence of cognitive damage in mice with documented cerebral malaria after cure of the acute parasitic disease with chloroquine, an antimalarial therapy. By cerebral malaria after cure of the acute parasitic disease with chloroquine, an antimalarial therapy. By administering a battery of behavioral tests to these mice, post-doctoral fellow Patricia Reis, Ph.D., determined administering a battery of behavioral tests to these mice, post-doctoral fellow Patricia Reis, Ph.D., determined that impairment in memory skills was still present 30 days after the initial malaria infection. Cognitive deficits that impairment in memory skills was still present 30 days after the initial malaria infection. Cognitive deficits that persist for years after the episode of cerebral malaria have also been reported in 11 percent to 28 percent that persist for years after the episode of cerebral malaria have also been reported in 11 percent to 28 percent of children who survive the infection.of children who survive the infection.

"Although we believe that long-term cognitive dysfunction after cerebral malaria is initiated by injury to the brain "Although we believe that long-term cognitive dysfunction after cerebral malaria is initiated by injury to the brain during the initial period of untreated infection, it is possible that the mechanisms for persistent cognitive deficits during the initial period of untreated infection, it is possible that the mechanisms for persistent cognitive deficits are independent of those that cause neurological injury and death during acute cerebral malaria," says are independent of those that cause neurological injury and death during acute cerebral malaria," says Zimmerman. "Future research is aimed at clarifying this point. However, we have been able to demonstrate that Zimmerman. "Future research is aimed at clarifying this point. However, we have been able to demonstrate that oxidative oxidative stressstress is present in the brains of mice infected with cerebral malaria." is present in the brains of mice infected with cerebral malaria."

Malaria And Algae Linked To Common Ancestor By 'Little Brown Balls'Malaria And Algae Linked To Common Ancestor By 'Little Brown Balls'

Unconspicuous "little brown balls" in the ocean have helped settle a long-standing Unconspicuous "little brown balls" in the ocean have helped settle a long-standing debate about the origin of debate about the origin of malariamalaria and the algae responsible for toxic red tides, according to and the algae responsible for toxic red tides, according to a new study by University of British Columbia researchers. a new study by University of British Columbia researchers.

In an article published this week in theIn an article published this week in the Proceedings of the National Academy of Sciences Proceedings of the National Academy of Sciences Early Edition, UBC Botany Prof. Patrick Keeling describes the genome of Chromera and its Early Edition, UBC Botany Prof. Patrick Keeling describes the genome of Chromera and its role in definitively linking the evolutionary histories of malaria and role in definitively linking the evolutionary histories of malaria and dinoflalgellate algaedinoflalgellate algae. .

"Under the microscope, Chromera looks like boring little brown balls," says Keeling. "In fact, "Under the microscope, Chromera looks like boring little brown balls," says Keeling. "In fact, the ocean is full of little brown and green balls and they're often overlooked in favour of more the ocean is full of little brown and green balls and they're often overlooked in favour of more glamorous organisms, but this one has proved to be more interesting than its flashier glamorous organisms, but this one has proved to be more interesting than its flashier cousins." cousins."

First described in the journal Nature in 2008, Chromera is found as a symbiont inside corals. First described in the journal Nature in 2008, Chromera is found as a symbiont inside corals. Although it has a compartment - called a plastid - that carries out photosynthesis like other Although it has a compartment - called a plastid - that carries out photosynthesis like other algae and plants, Chromera is closely related to apicomplexan parasites - including malaria. algae and plants, Chromera is closely related to apicomplexan parasites - including malaria. This discovery raised the possibility that Chromera may be a "missing link" between the two. This discovery raised the possibility that Chromera may be a "missing link" between the two.

Now Keeling, along with PhD candidate Jan Janouskovec, postdoctoral fellow Ales Horak Now Keeling, along with PhD candidate Jan Janouskovec, postdoctoral fellow Ales Horak and collaborators from the Czech Republic, has sequenced the plastid genome of Chromera and collaborators from the Czech Republic, has sequenced the plastid genome of Chromera and found features that were passed down to both apicomplexan and dinoflagellate plastids, and found features that were passed down to both apicomplexan and dinoflagellate plastids, linking the two lineages. linking the two lineages.

"These tiny organisms have a huge impact on humanity in very different ways," says Keeling. "These tiny organisms have a huge impact on humanity in very different ways," says Keeling. "The tool used by dinoflagellates and Chromera to do good - symbiosis with corals - at some "The tool used by dinoflagellates and Chromera to do good - symbiosis with corals - at some point became an infection mechanism for apicomplexans like malaria to infect healthy cells. point became an infection mechanism for apicomplexans like malaria to infect healthy cells.

"Resolving their evolutionary origins not only settles a long-standing scientific debate but "Resolving their evolutionary origins not only settles a long-standing scientific debate but could ultimately provide crucial information for tackling diseases and environmental could ultimately provide crucial information for tackling diseases and environmental concerns." concerns."

~ end of presentation ~