Cholera has been confirmed in over 40 persons among those admitted to the Sukraraj Tropical and Infectious Diseases Hospital in Teku with complaints of severe gastro-enteritis this month. The disease is believed to have been caused by drinking contaminated water in the heavily populated areas of Kuleshwor and Kalimati. And as two of the patients were from the Central Jail, there are worries about the spread of the disease to other inmates who live in close quarters and possibly drink from the same water source. There are also understandable concerns about this disease spreading to displaced persons living in camps in less hygienic conditions in Kathmandu and in other earthquake-affected districts. So far, the disease seems to have been contained, and no deaths have been reported. 

Global phenomenon 

Cholera has been infecting humans since the early 1800s, and it has been 55 years since the seventh global cholera pandemic that started in Indonesia in 1960. Each year, cholera affects an estimated two to four million persons and causes over 100,000 deaths around the world. It is a disease of poverty affecting impoverished populations in countries with poor water and sewage treatment systems. And until cholera reached Haiti in October 2010, most cholera outbreaks have occurred in Africa and South Asia. In Haiti, there have been more than 500,000 cases and over 8,000 deaths making it the largest cholera epidemic in the world. From Haiti, cholera has spread to the Dominican Republic, Cuba and Mexico.

Cholera has been known to exist in Kathmandu and the disease usually surfaces in the monsoon. Epidemics have been reported from time to time in Western Nepal. In a large study of 600 Nepali adults done at the Sukraraj Hospital several years ago, the Vibrio cholerae bacteria was found to be the most common cause of acute diarrhoea, indicating that this is a common problem among Nepali adults. In contrast, not a single case of cholera was detected in the foreigner population with acute diarrhoea studied at CIWEC Clinic Travel Medicine Center for two years from 2012-14, indicating that if you are careful about what you drink, as most foreigners are, you can avoid cholera. 

Dissecting the disease 

Cholera is an acute infectious disease of the small intestine caused by the toxin that produces strains of V. cholerae. These bacteria can live in water sources and infect a large number of persons causing an epidemic. The incubation period (the time from when you catch the infection to the disease) is usually one to two days, but it can vary from several hours to three to five days. It is usually transmitted by eating or drinking contaminated food or water. A large number of bacteria are required to cause the disease. Hence, contaminated water is the most likely source. The disease is unlikely to spread directly from one person to another due casual contact. 

Cholera is characterised by profuse watery diarrhoea, vomiting, muscle cramps and severe dehydration. An infected person can go into shock due to circulatory collapse within a few hours of falling ill. In places like Kathmandu where cholera cases have been observed every year, mild and unnoticed infections can also occur. If treated promptly, only less than one percent of the patients infected with the disease die.         

Prevention is cure 

Cholera can be prevented by drinking boiled, bottled or treated water. As there is a severe shortage of municipal water supply in Kathmandu, most people buy water from tankers from different vendors and different sources. Whatever be the source, water can be treated with chlorine (available as Piyush in pharmacies) or iodine. Bottled water from established brands available in sealed  one-litre bottles or 20-litre jars are also safe. However, low-priced water sold in big jars might not be safe for direct consumption.  Therefore, it is crucial that people treat water before consuming it. Likewise, people should wash their hands before eating, eat freshly cooked hot foods and dispose waste properly. 

If someone shows symptoms suggestive of cholera, for example, severe watery diarrhoea and signs of shock or circulatory collapse, the person should immediately be given oral rehydration treatment and taken to the nearest medical facility for fluid resuscitation which is key to treatment. Antibiotics like tetracycline or doxycycline can also help shorten the duration of the illness. The epidemic in Haiti, in cholera-naïve populations, has shown that death rates are higher in remote populations, older patients, severe cases and those who do not seek care. Nonetheless, we ought to continue to monitor the situation in heavily populated camps in Kathmandu where earthquake-affected persons are residing and in places where people fromquake-affected districts have been resettled. 

Threat of an epidemic 

Lastly, it has been claimed that cholera entered Haiti through UN peace keeping troops from Nepal due to leakage of raw sewage from their camp that contaminated a river below it. As a result, the UN was sued over the devastation of Haiti from the cholera outbreak, but this case has been dismissed by the New York courts. Clearly, for bugs, there are no borders and the world is truly a global village. So, we as a nation need to invest in a clean and hygienic water supply system for all our people and improve our sewage disposal system to stay safe from the ever persistent threat of fecal-orally transmitted infections. 

In the meantime, the municipal water supply should be adequately chlorinated, the water supplied by tankers from different sources should get chlorinated at delivery points, particularly in camps and in different communities. Individuals will have to continue to disinfect water before consumption in their own homes. If we are not careful about following these simple rules, we may be faced with epidemic of enterically transmitted infections like cholera, typhoid and hepatitis.

Pandey is the medical director of CIWEC Hospital and the public health lead person for the America Nepal Medical Foundation