Cholera vaccination should be considered for Uganda's most affected population

By Godfrey Nsereko

For a number of years, Uganda has been hit by cholera outbreaks. In 2018 alone, over 2000 cases of cholera and more than 30 deaths have been reported in the Western Uganda districts of Hoima and Kyegegwa.

Interestingly, it's particular geographical areas or spots (cholera hotspots) that are always severely affected initially before its spreads to other parts of the country yearly.

Cholera is an acute illness caused by bacteria called Vibrio cholerae, characterised by acute onset of profuse watery diarrhoea. In a very short period usually between 2 to 24 hours, so many people can become ill and die if not promptly managed by a trained health provider. The disease is transmitted through drinking water or eating food contaminated with faeces harbouring the bacteria.

Cholera is largely defined as a disease of inequity. According to the Global Task Force to End Cholera, cholera and poverty go hand in hand.  Even within affected countries, the poorest of the poor are the most affected. In Uganda, cholera outbreaks have been reported mostly in areas located near rivers or lakes in the western Rift Valley especially lakes Albert, Edward, Katwe and George.

Similarly, communities located along borders with neighbouring countries, especially the Democratic Republic of Congo and South Sudan, have been greatly affected in the past. This makes fishing communities and refugee settlements in these areas particularly vulnerable. Unfavourable conditions like overcrowding, poor sanitation, and inadequate water supply compound the risk of cholera outbreaks.

While the long term solution for the prevention of cholera remains access to safe water, hygiene promotion and sanitation, Oral Cholera Vaccines (OCV) can play an important role in outbreak prevention and control, and in possible elimination of cholera.

The cholera vaccine is not different from other vaccines that are administered on a routine basis in Uganda. The vaccine contains either weakened or killed bacteria or its components that when introduced into the human body will stimulate it to provide immunity against cholera.

The vaccine is administered through the mouth. OCVs have been reported to provide protection in about 52 percent of cases in the first year following vaccination. Protection increases to about 62 percent of cases during the second year after vaccination. This protective value of OCVs should be a basis for considering their use in cholera endemic regions of Uganda.

According to the World Health Organisation, two OCVs types are recommended and readily available. These can be procured by national governments and/or development partners for mass vaccination campaigns. Uganda is currently one of the 47 countries that are eligible for financial support for vaccines and vaccine delivery provided by GAVI and may therefore readily access the OCV in this arrangement.

The safety profile for the OCVs has been studied extensively before and after putting the vaccines on the market. The OCVs has been shown to have a good safety profile, including when used in pregnancy and in HIV-infected or other immune-compromised individuals. The commonly reported adverse effects with OCV use are mild abdominal discomfort, pain or diarrhoea.

The vaccines have been used widely in the control of cholera. Globally, more than 15 million doses of OCVs have been used in mass vaccination campaigns with WHO support since 2013. The campaigns have been implemented in areas experiencing an outbreak, in areas at heightened vulnerability during humanitarian crises, and among populations living in "cholera hotspots".

With the above in mind, Uganda's most vulnerable communities should be prime targets for cholera vaccination to prevent occurrence or during prolonged outbreaks. When we proactively take on the use of OCV as part of a multi sector cholera control plan to complement other cholera control measures such as ensuring longer term access to safe water, sanitation and hygiene (WASH), and reinforcement of surveillance, social mobilization and case management, Uganda will be on track for elimination of  cholera.

The writer is a Field Epidemiology Fellow with the Uganda Public Health Fellowship Program, Ministry of Health