Peter NtiamoahWalden University, School of Public Health

PUBH-6165-2 ENVIRONMENTAL HEALTH

CHOLERA—Population, Environmental, and Behavioral

Factors

During the 19th century, cholera spread from Ganges delta in India to the rest of the world

6 pandemics were recordedMillions of people were killed across Europe,

Africa, and the AmericasThe 7th pandemic started in 1961 in South

Asia and has been registered in 163 countries Source: World Health Organization. Cholera Fact Sheet No. 107.

BACKGOUND

The spread and dynamics of cholera morbidity has their specific feature in each continentIn Asia, the epidemic process is manifested as

permanent morbidityAfrica determines the total morbidity level in

the 7th pandemicBoth Europe and America have imported

choleraReference:Mukharskaiia, L., Kariakova, L., Khaitovich, A., 2004. Cholera prevalence worldwide

and in Ukraine. ZH Mikrobiol Epidemiol Immunobiol, (1):93-6

BACKGOUND—continued

As of 2000, the spread of cholera were as follows:

Africa 27 countries Asia 13 countries Latin America 9 countries Europe 2 countries Oceania 4 countries

Approximately 79 million people are estimated to be at risk in Africa (UN)

The crude case fatality rate since the cholera outbreak in Zimbabwe is 4.3% (WHO)

Source:

World Health Organization, 2000. Water Related Diseases

United Nations. Cholera. Accessed on November 7, 2009 from http://cyberschoolbus.un.org/special/health/disease/cholera.htm

DISTRIBUTION AND INCIDENCE

Cholera is a major problem in Africa and AsiaIn the year 2000,

140,000 cases were reported to WHO 5,000 deaths resulted from cholera

Africa accounted for 87% of the above cases and deaths

In 2006, More than 6,000 deaths resulted from cholera, worldwide

About 90% of these deaths were from Africa

From August 2008 to May 2009, Cholera infected more than 97,000 people in Zimbabwe,

and killed more than 4000 people.References:

World Health Organization, 2000. Water Related Diseases

World Health Organization, 2009. WHO stresses on proper sanitation to combat cholera

DISTRIBUTION AND INCIDENCE—continued

Cholera is an acute, infectious gastroenteritis, caused by Gram-negative enterotoxin-producing strains of the bacterium Vibrio cholerae (CDC).

The enterotoxin affects the mucosal epithelium lining of the small intestine leading to an exhaustive diarrhea.

Reference:

Centers for Disease Control and prevention. Cholera.

INTRODUCTION

The enterotoxin interacts with the epithelium lining of the small intestines to pump chloride ions into the small intestine.

This creates ionic pressure which blocks sodium ions from entering the cell

The osmotic pressure can pull up to six liters of water per day through the intestinal cells creating the massive amounts of diarrhea (Mayol, 1998; Lucas, 2008).

Reference: Lucas, M., 2008. Enterocyte chloride and water secretion into the small intestine after

enterotoxin challenge: unifying hypothesis or intellectual dead end? J Physiol Biochem, 64(1):69-88

Mayol, J., Fernandez-Represa, J., 1998. Chloride secretion in the intestinal epithelium: channels, ions, and intracellular signaling. Rev. Esp. Enferm Dig, 90(10):714-21

INTRODUCTION—continued

The infection is often mild or without symptoms, but sometimes it can be severe.

Approximately one in 20 infected persons has severe disease characterized by profuse watery diarrheavomiting, and leg cramps. Low blood pressure—hypotensiveWatery stool and shock (4-12 hours of infection)Dehydration

Incubation Period: 2 hours to 5 daysWithout treatment, death can occur within

hours (CDC, WHO). Reference: Centers of Disease Control and Prevention. Cholera. World Health Organization. Cholera.

SYMPTOMS OF CHOLERA

Based on the somatic O antigen, vibrio cholerae species can be divided into two major groups:O1

Ogawa (VCO) and Inaba (VCI) O139 serotypesAll other serotypes are referred to as non-O1

Cholera is typically associated with the O1 and the O139 serotypes

Reference Stroeher, U.,Karageorgos, L., Morona, R., Manning, P., 1992. Serotype conversion in

Vibrio cholerae O1. Proc Natl Acad Sci U S A. ; 89(7): 2566–2570.

SEROGROUPS

Fecal-Oral route Drinking water or eating food contaminated

with the cholera bacteriumSources:

Feces from an infected personInadequate treatment of sewage and drinking

waterEating raw or undercooked shellfish from brackish

rivers or coastal waters eg. Gulf of Mexico Reference: World Health Organization Miller, C., Feachem, R., Drasar, B., 1985. Cholera epidemiology in developed and

developing countries: new thoughts on transmission, seasonality and control. Lancet ii, 261-3

PATHWAY

PopulationSanitationDemographics

HabitatEnvironment and geographical location

AquaticClimatic Change

CultureSocioeconomic constraintsIndividual PsychologySource of water consumption

Reference: Meade, M., 1977. Medical geography as human ecology: The dimension of population

movement. The Geographical Review, 67(4), 379-393.

OUTBREAK FACTORS

V. cholerae (O1 and O139) inhabit in seas, estuaries, brackish waters, rivers, and ponds of coastal areas of the tropical world (Africa) due to presence of:SunlightHigher temperatureHumidity due to evaporationSalinityPhytoplankton

References: Emch, M., Feldacker, C., Islam, M., Ali, M., 2008. Seasonality of cholera from 1974 to

2005: A review of global patterns Huq, A., Colwel, R., 1996. Environmental factors associated with emergence of

disease with special reference to cholera. Eastern Mediterranean Health Journal, Vol. 2, Issue 1, p. 37-45.

Environmental Factors

Climate Variability (Islam, 1994; Alam, 2006; Lipp, 2002; Sack, 2003).

Sustained temperatures, high above normal in two consecutive seasons, followed by a slight cooling in the second season, trigger an outbreak of a cholera epidemic (Olago, 2007).

References:Alam, M., Hasan, N., Sadique, A., Bhuiyan, N., Ahmed, K., et al., 2006. Seasonal cholera

caused by Vibrio cholerae serogroups O1 and O139 in the coastal aquatic environment of Bangladesh. Appl Environ Microbiol, 72(6):4096-4104

Islam, M., Drasar, B., Sack, R., 1994. Probable Role of Blue-Green-Algae in Maintaining Endemicity and Seasonality of Cholera in Bangladesh – a Hypothesis. Journal of Diarrhoeal DiseasesResearch, 12(4):245-256.

Lipp, E., Huq, A., Colwell, R., 2002. Effects of global climate on infectious disease: the cholera model. Clinical Microbiology Reviews 2002, 15(4):757

Olago, D., Marshall, M., Wandiga, S., Opondo, M., Yanda, P., et al., 2007. Climatic, Socio-economic, and Health Factors Affecting Human Vulnerability to Cholera in the Lake Victoria Basin, East Africa.

Environmental Factors—cont.

Upper troposphere humidityCloud cover

Periodic effects of ENSOWarm El Niño

Reference: Epstein, P. 1998. Health Applications of Remote Sensing and Climate Modeling. People

and pixels: Linking remote sensing and social science

Environmental Factors—cont.

Lack of clean water, inadequate sanitation management, and suboptimal food-handling practices (Kur et al, 2009)

Poor hand-washing practices and bad eating habits in Africa (Masereka, 2009)

References:

Kur, L., Mounir, C., Lagu, J., Muita, M., Rumunu, J., et al, 2009. Cholera Outbreak—Southern Sudan, 2007. MMWR, 4/10/2009.Vol. 58, issue 13, pp. 337-341

Masereka, B., 2009. Uganda, Kases: Unwashed hands cause cholera. New Vision. http://sanitationupdates.wordpress.com/2009/10/07/uganda-kasese-unwashed-hands-cause-cholera

Population Factors—Sanitation

Residential Sanitation In Africa includesFlush or pour-flush to elsewhere Pit latrine without slab or open pit Bucket Hanging toilet or hanging latrine No facilities or bush or field (open defecation)

Source: WHO/UNCEF, 2006. A Snapshot of Drinking Water and Sanitation in Africa

Population Factors—Sanitation

Waste management facilities are not available in most African countries

Effluent solid and liquid wastes are released to the environment without treatment (Onibokun, 2006; Boadi, 2003)Uncontrolled garbage problems in African

citiesOpen landfillsRefuse disposal into streams, surface

drains, and canals. References:Boadi, K., Kuitenen, 2003. Municipal Solid Waste Management in Accra Metropolitan

Area, Ghana. The Environmentalist, Vol. 23, Number 3. Onibokun, A., Kumuyi, A., 2006. Governance and Waste Management in Africa.

Population Factors—Waste Management

Presence of street food vendors in many citiesConsumption of raw foodstuffs Limited or lack of governmental regulations

and enforcement (WHO)Food from the street are often open and

exposed to flies

References: WHO/UNCEF, 2006. A Snapshot of Drinking Water and Sanitation in Africa

Cultural Factors—Food and Water

Drinking water sources in developing countries:Unprotected dug well Unprotected spring and streams Small cart with tank/drum Tanker truck Surface water (river, dam, lake, pond, stream,

channel, irrigation channel) Source: WHO/UNCEF, 2006. A Snapshot of Drinking Water and Sanitation

in Africa

Cultural Factors—Food and Water

Abject poverty in developing countriesLack of education concerning the diseaseObligation to shake handsCulture of eating together with fingers (from

same bowl)

Cultural Factors-Socioeconomic l

Houseflies (Musca domestica) can disseminate Vibro cholerae—spreading the bacterium from infected feces / foods to foods (Fotedar, 2001)Wings of houseflies serve as mechanical

transmission device for Vibro cholerae (Yap, 2008)

Cholera microbes survived on the external surface of flies for 5 to 7 days, and in the insect organism (Kotenok, 1977).

References:

Fotedar, R., 2001. Vector potential of houseflies (Musca domestica) in the transmission of Vibrio cholerae in India. Acta Trop., 78(1): 31-4.

Kotenok, I., Chicherin, I., 1977. Houseflies (M. domestica L.) as transmitters of the agent of cholera. Zh Mikrobiol Epidemiol Immunobiol., (12):23-7

EFFECTS OF FLIES ON CHOLERA

Flies liquefy food by regurgitating digestive juices, stomach contents and enzymes onto food before ingestion.

The pathogens are then deposited when the fly crawls on food or in the fly excrement (Kalpana, 2008).

Reference:

Yap, K., Kalpana, M., Lee, H., 2008. Wings of the common house fly (Musca domestica L.): importance in mechanical transmission of Vibrio cholerae. Trop. Biomed.,25(1):1-8.

EFFECTS OF FLIES ON CHOLERA—continued

Concerted efforts are needed fromWorld Health OrganizationUnited NationsCenters for Disease Control and PreventionLocal GovernmentsGeneral public

Work together to control sanitation and waste managementImprove hygieneProvide food safetyImprove on the quality of drinking waterProvideKeep track on any climatic changeProvide better assurance in times of an outbreak

Reference: World Health Organization. Cholera: Prevention and Control

PREVENTION

WHO Program on Cholera needs to obtain better data and ensure greater

information sharingto adopt a coordinated multisectoral approachto help improve sanitation and sewage disposal

in African countriesto ensure political commitment and community

involvement

Prevention—WHO

The Governing Council of the United Nations Environmental Programme (UNEP) mustStrengthened its cholera control measuresProvide sanitary control and personal hygiene

workshops to the local government, ministries of health, and the general public

Provide surveillance in disaster areas an refugee camps

Prevention—United Nations

Must enhance its international disease surveillance

Work with the local governments to provide better understanding of the disease

Train the locals about disease control and prevention

Prevention—CDC

Food safety standards must be enacted and regulations must be enforced

Develop better local reporting system and improve communications with UN and WHO.

Improve sanitation management in large cities and towns—no open landfill

Provide safe drinking water the populationImprove the socioeconomic status of the

people

Prevention—Local Government

Must change their behavior towards the disease

Practice personal hygiene and hand washingPractice food safety techniquesControl houseflies

Prevention—General Public

For cost-benefit comparisons Jeuland, M., Whittington, D., 2009. Cost-benefit comparisons of

investments in improved water supply and cholera vaccination programs. Vaccine, 27(23):3109-20

Lundkvist, J., Steffen, R., Jonssen, R., 2009. Cost-benefit of WC/rBS oral cholera vaccine for vaccination against ETEC-caused travelers' diarrhea. J Travel Med 16(1):28-34.

For Treatment World Health Organization

www. Who.org Centers for Disease Control and Prevention

www.cdc.gov

Further Readings

Thanks for your audience.

QUESTIONS?

Alam, M., Hasan, N., Sadique, A., Bhuiyan, N., Ahmed, K., et al., 2006. Seasonal cholera caused by Vibrio cholerae serogroups O1 and O139 in the coastal aquatic environment of Bangladesh. Appl Environ Microbiol, 72(6):4096-4104.

Boadi, K., Kuitenen, 2003. Municipal Solid Waste Management in Accra Metropolitan Area, Ghana. The Environmentalist, Vol. 23, Number 3.

Centers for Disease Control and prevention. Cholera. Colwell, R., Huq, A., 2001. Marine ecosystems and cholera. Hydrobiologia 460:141-145. Emch, M., Feldacker, C., Islam, M., Ali, M., 2008. Seasonality of cholera from 1974 to 2005: A review

of global patterns Epstein, P. 1998. Health Applications of Remote Sensing and Climate

Modeling. People and pixels: Linking remote sensing and social science Islam, M., Drasar, B., Sack, R., 1994. Probable Role of Blue-Green-Algae in Maintaining Endemicity and

Seasonality of Cholera in Bangladesh – a Hypothesis. Journal of Diarrhoeal DiseasesResearch, 12(4):245-256.

Huq, A., Colwel, R., 1996. Environmental factors associated with emergence of disease with special reference to cholera. Eastern Mediterranean Health Journal, Vol. 2, Issue 1, p. 37- 45.

Kur, L., Mounir, C., Lagu, J., Muita, M., Rumunu, J., et al, 2009. Cholera Outbreak—Southern Sudan,2007. MMWR, 4/10/2009.Vol. 58, issue 13, pp. 337-341

Lipp, E., Huq, A., Colwell, R., 2002. Effects of global climate on infectious disease: the cholera model. Clinical Microbiology Reviews 2002, 15(4):757

• Lucas, M., 2008. Enterocyte chloride and water secretion into the small intestine after enterotoxin challenge: unifying hypothesis or intellectual dead end? J Physiol Biochem, 64(1):69-88

• Mayol, J., Fernandez-Represa, J., 1998. Chloride secretion in the intestinal epithelium: channels, ions, and intracellular signaling. Rev. Esp. Enferm Dig, 90(10):714-21

• Meade, M., 1977. Medical geography as human ecology: The dimension of population movement. The Geographical Review, 67(4), 379-393.

• Miller, C., Feachem, R., Drasar, B., 1985. Cholera epidemiology in developed and developing countries: new thoughts on transmission, seasonality and control. Lancet ii, 261-3

References:

• Mukharskaiia, L., Kariakova, L., Khaitovich, A., 2004. Cholera prevalence worldwide and in Ukraine. ZH Mikrobiol Epidemiol Immunobiol, (1):93-6

• Olago, D., Marshall, M., Wandiga, S., Opondo, M., Yanda, P., et al., 2007. Climatic, Socio- economic, and Health Factors Affecting Human Vulnerability to Cholera in the Lake Victoria Basin, East Africa.

Onibokun, A., Kumuyi, A., 2006. Governance and Waste Management in Africa.

Pascual, M., Dobson, A., 2005. Seasonal patterns of infectious diseases. Plos Medicine, 2(1):18- 20. 14.

Sack, B., Siddique, A., Longini, I., Nizam, A., Yunus, M.,et al., 2003. A 4-year study of the epidemiology of Vibrio cholerae in four rural areas of Bangladesh. Journal of Infectious Diseases 2003, 187(1):96-101

von Seidlein, L., Wang, X., Macuamule, A., Mondlane, C., Puri1, M., et al, 2008. Is HIV infection associated with an increased risk for cholera? Findings from a case–control study in Mozambique. Tropical Medicine and International Health, Volume 13, Number 5, pp 683–688

Stroeher, U.,Karageorgos, L., Morona, R., Manning, P., 1992. Serotype conversion in Vibrio cholerae O1. Proc Natl Acad Sci U S A. ; 89(7): 2566–2570.

United Nations. Cholera. Accessed on November 7, 2009 from http://cyberschoolbus.un.org/special/health/disease/cholera.htm

Yap, K., Kalpana, M., Lee, H., 2008. Wings of the common house fly (Musca domestica L.): importance in mechanical transmission of Vibrio cholerae. Trop. Biomed.,25(1):1-8.

World Health Organization. Cholera Fact Sheet No. 107. World Health Organization, 2000. Water Related Diseases World Health Organization, 2009. WHO stresses on proper sanitation to combat cholera WHO/UNCEF, 2006. A Snapshot of Drinking Water and Sanitation in Africa

Reference—cont.