Cholera is an intestinal infection characterised by watery stool and diarrhoea. It is caused by the Vibrio cholerae, a bacterium, which releases toxins in the human intestine. This toxin activates excess secretion of water from the intestinal lumen that often leads to severe dehydration and sometimes death. Conditions that can lead to outbreaks include a disruption in water supply, poor basic sanitation and poor hygiene. Infected people show symptoms within two to five days. They can spread the disease even when they are not ill themselves by shedding the bacteria in their faeces.
As in other developing countries, cholera outbreaks occur mainly during the rainy season although they also sometimes occur in dry season. Flooding can cause septic tanks to contaminate surface water, especially open wells used for drinking and food preparation. Contaminated flood water from the rains can also flow to vegetables and fruits which, if not properly washed, can cause an outbreak.
Cholera outbreaks happen when groups of people share infected water or food. When this happens, many people will require help at the same time. Health facilities and resources are often inadequate and ill-prepared to deal with such pressure.
The outbreaks which have occurred in Zimbabwe are often driven by different factors. What they all point to, however, is that the country has not yet taken sufficient steps to address the “epidemiological triangle” that drives cholera outbreaks – host, agent and environmental factors. This includes early detection, better and stronger sanitation infrastructure that can withstand heavy rains as well as basic health infrastructure.
It has been difficult to eradicate cholera because of the “epidemiological triangle” of host, agent and environmental factors.
Humans are the hosts. They carry and spread the disease. A person who has received treatment and is healthy again is still capable of spreading the infection to others. Vaccines are not very effective or long-lasting.
Vibrio cholerae is the agent. It is ingested from contaminated food or water. The organisms that survive the stomach’s acidity travel to the small intestine of the human host, where they multiply. The bacteria attach to the mucous membrane of the intestines and can stay there for years.
The environmental factors include poor access to clean, safe water and the lack of basic sanitation facilities.
To prevent and wipe out cholera, it’s necessary to interrupt the host-agent-environment relationship. This can be achieved through more effective vaccines, improved host immunity, water chlorination and better ways of disposing of sanitary waste.
In poor countries, the lack of standard infection prevention and control in health facilities adds to the risk of diseases spreading. Health workers need to be continuously trained to detect, correctly diagnose and manage cases of cholera in a safe and effective manner.
Eradicating cholera will require a multi-sectoral approach but overall government must show the political will to invest in infrastructure as well as health sector development. – Wires
