Vaccination May Control Cholera Outbreaks in African Refugee Camps

Vaccinating against cholera in African refugee camps can save lives, prevent disease, and possibly save costs, according to an economic analysis conducted by a team of researchers at the National Institute of Child Health and Human Development (NICHD) and other institutions. The study appeared in the February 18 Journal of the American Medical Association.

Cholera is an intestinal infection caused by the bacterium Vibrio cholerae, explained the study's first author, Abdollah Naficy MD, MPH, a researcher at NICHD's Division of Epidemiology, Statistics, and Prevention Research. Cholera spreads easily under the poor sanitation conditions found in many refugee camps, when human sewage comes in contact with drinking water. The increasing number of refugees fleeing wars, civil unrest, famine and natural disasters is likely to add to the number of cholera deaths that have occurred in many parts of Africa.

Conventional medical wisdom holds that the best course of action in refugee settings is to prevent cholera outbreaks before they occur, through such basic means of sanitation as providing clean drinking water and installing latrines, and to arrange for prompt rehydration treatment in the event of an outbreak. However, despite these recommendations, cholera outbreaks continue to occur with alarming frequency in refugee settings and extract a considerable toll of deaths. Modern oral cholera vaccines offer the possibility of preventing these deaths, but the use of vaccines has been surrounded by controversy because of assertions that vaccination may be too costly or may divert resources away from treatment of patients during an outbreak.

According to the article, the key factor in determining whether vaccination can be added at no additional cost to current cholera control measures in African refugee camps is the cost of each vaccine dose. If, through improvements in manufacturing or technology, the cost of the currently available rBS-WC oral cholera vaccine could be reduced from the currently estimated 50 cents per dose to 22 cents per dose, then supplementing current cholera control measures in African refugee camps with mass vaccination would become a cost-effective option. In Vietnam, an oral cholera vaccine, which has been found to be protective in preliminary studies, is being produced at a cost below the 22 cents per dose, and large-scale evaluations of the vaccine's effectiveness are in progress.

In addition, the analysis shows that the current practice of providing supplies to treat victims of cholera outbreaks at the establishment of refugee camps, which the researchers refer to as "preemptive therapy," prevents more deaths and is more cost-effective ($320 per death averted) than making these provisions after the outbreak occurs ($586 per death averted).