Cholera in Zimbabwe
Please excuse the mess!
we are currently actively working on this page and it will be up and running by August 28, 2009. Thank you for your patience :)
Introduction
Although Cholera no longer threatens developed countries that meet the minimum hygiene standards, it is still a big factor of those countries with large numbers of people living in unsanitary conditions. Cholera thrives in such places where there is no guaranteed access to clean water or sanitation, places such as Zimbabwe. (4) Cholera is caused by the microbe Vibrio cholerae and is characterized by it's sudden onset of acute watery diarrhea. The disease itself can be traced back at least 2000 years in literature, on the Indian subcontinent long before the arrival of the Europeans. There are currently many different views on the origin of it's name. Some claim that cholera stems from the two Greek words "chole" meaning bile, and "rein" meaning flow. Put together, one would get "the flow of bile". Other people suggest that it comes from the Greek word "cholera" which means "gutter", suggesting that the symptoms of cholera resemble the heavy flow of rain on rooftop gutters. (2)
Description of Cholera
Symptoms of Cholera include an onset of acute watery diarrhea which can lead to death by dehydration within hours if left untreated. This disease is transmitted easily through ingestion of food or water contaminated with the microbe, Vibrio cholerae. (1) Vibrio cholerae's short incubation time and ability to survive long periods of time in aquatic environments makes for easy break outs in unsanitary areas, including but not limited to, third world countries. (2) This makes the disease even more deadly, if cholera has the ability to kill a healthy adult within hours then people with lower immunity; for instance malnourished children or people living with AIDs are at an even higher risk of death. In addition to poor sanitation, some suggest that the spread of cholera is intensified by the passage of the bacteria through the human gut. It is thought that there is something about the environment of the intestinal environment that will change gene expression, preparing them for further collonization of new hosts, fueling epidemics. (3) Data for individuals who develop the symptoms show that 80% will show mild to moderate acute watery diarrhea while about 20% will experience severe and rapid dehydration due to water loss through severe diarrhea. (1)
Treatment
The first and foremost treatment that one should get is timely rehydration. 80% of the patients can be treated with the sole use of oral rehydration salts while the remaining 20% will reuire rehydration by intravenous fluids. Note that antibiotics are not as useful as rehydration but they are still used to shorten the time the microbe is in the gut. (1)
Description of the microbe
Vibrio cholera is a curved rod-shaped (5) gram-negative bacterium (6) that resides naturally in aquatic ecosystems. The disease causing strains were evolved from non-pathogenic progenitor bacteria that were acquiesced from virulence genes. (5) V. Cholera is a facultative anaerobe (9) and is oxidative-positive, capable of both respiratory and fermentative metabolism. It has a single polar flagellum for motility (6) with an incubation period of 1-5 days. (9) Vibrio cholera bacteria have been found in alkaline media but survive poorly in acid. (8)
The serogroups Vibrio Cholera O1 and O139 have been found to cause severe diarrheal epidemics but strain O139 has not yet been detected outside of East and South-East Asia (7). Other strains of V. Cholerae have not yet developed into epidemics but have been found to possess more virulent genes causing mild to serious episodes of cholera. (4)
Transmission of disease
How is it transmitted? Is there a vector (animal/insect)?
Prevention
Why is this disease a problem in [Zimbabwe]
Cholera is endemic in Zimbabwe, with annual outbreaks occurring since 1998 (10). The most recent major outbreak occurred in Chitungwiza, outside of the Zimbabwean capital, on August 2008 (11 http://www.abc.net.au/news/stories/2009/07/30/2641603.htm). The epidemic follows the path of most cholera outbreaks: contamination of drinking water due to overflow from sewers. As Chitungwiza holds a booming population and suffers from perennial water shortages, the sewer system was overburdened, leading to the outbreak. Water shortages in the poorer regions of the capital resulted in the lack of hygiene worsened the situation. Coupled with the unstable political climate of the region due to post-election violence (12 http://www.abc.net.au/news/stories/2009/07/30/2641603.htm) and the collapse of health and sanitation systems, the outbreak became especially severe.
What is being done in that country to address this problem?
The cholera crisis was hit the hardest in mid-August 2008 with 87,998 cases along with 3,975 deaths recorded in March 2009. (15) Unable to control the outbreak of cholera due to factors such as economic instability, Zimbabwe’s health department, the Ministry of Health & Child Welfare (MoHCW), called for national emergency on December 3, 2008. (13) The table below lists some of the major global organizations and their area of focus in the humanitarian project (14):
| Cluser | Cluser Lead |
|---|---|
| Nutrition | UNICEF and Helen Keller International |
| Water/Sanitation & Hygiene | UNICEF and OXFAM GB |
| Emergency Telecommunications | WFP and UNICEF |
| Health | WHO |
| Agriculture | FAO |
The United Nations Children's Fund (UNICEF) responded with the 180-day emergency response plan that went on from December 2008 to May 2009. The operation have placed much emphasis in providing clean water: about 700,000L of clean water (13) is shipped daily along with materials such as purification tablets and Aluminum Sulphate. UNICEF also worked to educate the nation about preventative measures against cholera through handing out 220,000 brochures and directing campaigns in school. (13) Together with MoHCW, UNICEF utilized the media to convey their message across television and other communication broadcasts.
The support team at the World Health Organization (WHO) monitors the cholera crisis carefully, sending updates and alerts regularly to inform the nation of any immediate action. WHO recommends not using mass chemoprophylaxis together with antibiotics as it does not get rid of cholera but instead may increase one’s resistance against antibiotics. (16) As people with cholera can be severely dehydrated, WHO advise people to take oral rehydration salts as soon as possible. (16)
Nongovernmental organizations (NGOs) such as the Red Cross and Médecins Sans Frontières also made contributions to the Zimbabwe cholera outbreak. In addition to providing food and equipment, the Red Cross also installed an emergency response unit (ERU) that is responsible for delivering clean water and promoting sanitation practices. People are advised to wash their hands and keep food free from bacterial contamination by cooking them well-done and boil water. (17) Médecins Sans Frontières have established numerous cholera treatment centers in rural cities where major governmental assistance may not be available. (18)
What else could be done to address this problem
The WHO maintains that providing prompt rehydration and oral rehyradtion salts (ORS; a sodium and glucose solution in safe water) is sufficient to successfully treat most patients (1) which could improve the current situation in the short run and drastically reduce the mortality rate of the disease in Zimbabwe. However, ultimately the restoration of Zimbabwe’s health and sanitation systems, which collapsed under the weight of the growing economic and political presures hitting the country (10) is the only viable long term solution to ending the Cholera epidemic rampant in many parts of the country. Future Cholera outbreaks will continue and prevention efforts, which include continued clean water and proper sanitation access (7), will be stiffled unless the government, and the public utilitizes it controls, can stabilized and the turmoil and unrest, found in many parts of the country, subsides.
The identification that Cholera “has a historical context linking it to specific seasons and biogeographical zones” (19) has lead to the establishment of Cholera as a paradigm (2) on how the understanding of a disease, which usually consisted of its known virulence, can be further suplemented with information concerning the enviornmental factors, such as transmission and epideomiology, in order to formulate models to understand the dynamics of the disease (20). The discovery that the infectivity of Virio cholerae can be enhanced through the passage of a host (3) has come to elucidate the explosive number of outbreaks which was mostly though to be the result of an extremely short incubatoin period (7). Futhermore, the established association between V. Cholerae with copepods, whereby the bacteria becomes concentrated in zooplankters, and the subsequent ingestion of the copepods in communities consuming untreated water(2), has lead to the proposal of by Colwell et al. that “a simple and effective measure to filter plankton from water using sari material has been developed, and preliminary evidence shows a significant reduction in cholera cases in those households using this filtration procedure.” (20)
Finally, the future of Cholerae prevention, as well as and any other infectious disease, lies in the ability to develop effective and accurate climate models which could serve as early-warning systems for infectious disease outbreaks, such as the mathematical model developed for V. Cholerae in Bangladesh (20). This shift in focus from containment to prevention in public health measures represents a positive step in the direction toward minimizizing the death rate during outbreaks such as the ones in Zimbabe.
References
(1) WHO, "WHO position paper on Oral Rehydration Salts to reduce mortality from cholera"
(3) [http://www.sciencemag.org/cgi/content/full/296/5574/1783a Pennisi, Elizabeth, "Cholera Strengthened by Trip Through Gut" Science 7 June 2002: Vol. 296. no. 5574, pp. 1783 - 1784, DOI: 10.1126/science.296.5574.1783a]
(5) Faruque, S, Nair, G. "Vibrio cholerae: Genomics and Molecular Biology" Caister Academic Press. 2008
(6) "Vibrio cholerae and Asiatic Cholera".
(7) WHO, "Cholera". November 2008
(9) "Vibrio Cholerae". 2 June 2003
(10) BBC NEWS, "Zimbabwe Cholera Deaths near 500"
(13) UNICEF, "UNICEF Humanitarian Action Update Zimbabwe." 4 February 2009
(14) "The Cluster Approach in Zimbabwe."
(15) WHO, "Cholera Country Profile: Zimbabwe." 6 March 2009
(16) WHO, "Cholera in Zimbabwe." 2 December 2008
(17) British Red Cross, "What We are Doing."
(18) MSF Article, "Day after day brings more work on cholera outbreak in Zimbabwe." 17 February 2009
Edited by [Jasmine Kim,Francisco Madamba, Jennie Ma, Diem, Chris, and Hae Young Suh, insert last names!], students of Rachel Larsen
