second level ascariasis -...

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Ascariasis

Dr. Gihan Mostafa Tawfeek

Prof. of Medical Parasitology




• Fifth level

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Considering Ascaris lumbricoides:

1- Habitat: Small intestine or large intestine2- Female is oviparous or ovo-viviparous.3- There is autoinfection : yes or no4- Life cycle shows migration to lung: yes or no




• Fifth level

• ILOs: by the end of this lecture, you will be able to:

Classify Ascaris lumbricoides according to taxonomic positions and their habitat in the humanhost. Recognize the mode of transmission of ascariasis. Recognize the geographical distribution of parasitic infection and population at risk. Correlate pathogenesis to clinical picture and complications. Request for an appropriate investigation. Give appropriate treatment to a patient with these helminthic infections. Explain what you would do to prevent the spread of these helminthic infections in yourcommunity.

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Taxonomy

Phylum • Nemathelminthes

Class • Nematoda

Small intestinal

Nematodes • Ascaris

lumbricoides

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Small intestinal Nematodes

1- Ascarislumbricoides

2- Hookworms

3-Strongyloides

stercoralis

4- Capillariaphilippinensis

Large Intestinal Nematodes

1-Trichocephalus

trichiurus

2- Enterobiusvermicularis

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Ascaris lumbricoides

•One of Nematodes•(Class: Nematoda)

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Cuticle

Subcuticle

Muscle

Body cavity

Organs

Roundworms




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Extended Modular Program 8

Lecture slides section 1

Taxonomy of Ascaris lumbricoides

Phylum Nemathelminthes

Class Nematoda

Small Intestinal Nematodes

Ascaris lumbricoides




• Fifth level

http://images.google.com.eg/imgres?imgurl=http://www.totallynatural.com.au/images/ascaris.jpg&imgrefurl=http://www.totallynatural.com.au/quick-cleanse-xpel-worms.htm&h=148&w=143&sz=3&hl=ar&start=270&um=1&tbnid=ZlIjYk1Odpl_5M:&tbnh=95&tbnw=92&prev=/images?q=ascaris&start=260&ndsp=20&svnum=10&um=1&hl=ar&sa=N




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They live in the small intestine and

cause a disease “ascariasis”




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Infected human

LIFE CYCLE

Egg containing 2nd stage

rhabditiform larva in 3 weeks

Develops in soil

Soil transmitted helminthinfection

Infection by eating

unwashed vegetables




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Larvae molt twice

Eggs hatch in the upper

small intestine liberating

larvae

Pulmonary lesion

Intestinal lesion

Embryonatedegg is

swallowed

LIFE CYCLE

Egg changes to adult in SI




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Extended Modular Program 13

Lecture slides section 1




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Ingestion of embryonated egg

containing 2nd stage

rhabditiform larva through:

1.Unwashed fruits and

vegetables, particularly those

grown in soil fertilized with

sewage

2.The common house fly

3.Hands contaminated by

polluted soil.

4. Pica (eating soil or mud).

Mode of infection and infective stage:




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Epidemiology

• Ascariasis is a world-wide (including Egypt).

• Common particularly in areas:

of bad sanitation.

Where untreated human faeces are used as fertilizers.

• Children are the most likely to become infected because of bad personal hygiene.

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Pathogenesis and clinical picture

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Early in Infection

• larvae migrating in the lung.

Late in infection

• adult worms in the small intestine




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1. Pulmonary symptoms= Loeffler’s sysyndrome

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Larval migration to lung:

1- Transient alveolar infiltration with

eosinophil.

2- Alveolar hemorrhage

Clinical picture: 1- Fever, cough with blood tinged sputum, dyspnea, asthma.2- Symptoms begin 9-12 days after infection.3- Symptoms subside spontaneously within a couple of weeks

Alveolus




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2. Intestinal symptoms

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Pathogenesis

Mechanical irritation to mucosa

Clinical picture:

Abdominal pain,

vomiting and

diarrhea




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Complications

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1- Even if a single worm is

irritated

Migration of worms

Expulsion from mouth

or nose

Obstruction of ducts or

appendix

Obstructive jaundice Acute

pancreatitis

Acute appendiciitis

Penetration of liver

Liver abscess

Perforation of intestine

Peritonitis

Congregation of worms

Intestinal obstruction




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Expulsion from mouth or anus




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D

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Abdominal pain, vomiting and

diarrhea. Complications:

Intestinal obstruction,

appendicitis, liver abscess, peritonitis

and expulsion of worms from mouth,

nose, anus and with stool and

growth retardation.Fever, cough with blood

tinged sputum, dyspnea, asthma

Diagnostic stages in stool




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Management DiagnosisTreatmentPrevention




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DiagnosisLaboratory diagnosis

Stool examination

Egg

1-With stool

2- With vomitus

3-From mouth

4-From nose

Adult

Sputum examination

Larva

Blood picture

Temporary Eosinophilia

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Sputum examination

•May reveal larvae (early in infection)and Charcot-Leyden crystals •(collections of crystalloid are formed from the breakdown of eosinophils).

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Stool examination

•Fertilized egg: 60x 40 microns, oval and contains unsegmented embryo. It may be brownish with outer coarse mamillation.

•Fertilized decorticated egg: may be pale yellow without outer mamillations.

•Unfertilized egg: 90x 60 microns,

•elongated barrel shaped and

•surrounded by incomplete

•mamillated coat. It is dark and

•contains refractile granules




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Early infection (larval migration):Chest radiography shows scattered mottling of the lungs (ground glass appearance) which tend to be migratory and usually clear after several weeks.

Late infection: Radiography of the gastrointestinal tract after barium meal reveals adult worms as cylindrical filling defects.

Imaging techniques




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Treatment

• 1- Owing to the potential migration, infected individuals should be treated:

• Albendazole 400 mg one dose orally is the drug of choice

• 2- Cases with complication should be sent to hospital.




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30Extended Modular Program

How to prevent

ascariasis????




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1. Treatment of patients.

2. Sanitary sewage disposal.

3. Health education regarding washing of

raw vegetables and fruits and washing of

hands before meals.

4. Treatment of human excreta before

usage as a fertilizer by exposure to sun light

or raising the temperature to 51ºC.

5. Fly control.

How to prevent

ascariasis????




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A 3-year-old girl, a daughter of parents with low educational and socio-economic; her father is a farm vet. She came down with her condition in the previous 72 hours with a diffuse abdominal pain, progressive food intolerance, vomiting, and diarrhea associated with the presence of worms in mouth and anus for the last 24 hours as referred by parents. The previous day she was feverish and received unspecified antihelminthic with increased symptoms. Abdominal radiograph showed bowel obstruction data. Due to intestinal obstruction (IO) and the failure of anthelmintic treatment, urgent surgical management was scheduled. An ileum enterotomy was performed and the worms were removed. Hydration and antibiotics were administered for 72 hours, and after restart of peristalsis, albendazole 100 mg twice a day for 3 days. The patient was discharged uneventfully, with a plan to deworm in 6 weeks.

a) What organism is most likely responsible for the patient’s illness?b) How did the patient become infected?c) What could be the precipitating factors of the condition?e) What is the basic data in your diagnosis?




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Extended Modular Program33

1. Ascariasis is a world-wide (including Egypt), particularly in areas of bad sanitation and where untreated human faeces are used as fertilizers.

2. Ascariasis is characterized by pulmonary symptoms (Loeffler’s syndrome) caused by larval migration and intestinal symptoms caused by adult worms.

3. Even a single worm of Ascaris lumbricoides can cause serious trouble if become irritated




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The cause of pulmonary manifestation in ascariasis is:

a.Ascaris Adults.b.Larvae.c. Eggs.d.Egg containing larvae.e.All of the above

second level ascariasis -...

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