Outbreak of cholera in Ibadan, Nigeria.

The changing epidemiology of cholera in Ibadan, Nigeria, has become a public health challenge, and outbreaks of the disease have been occurring with increasing frequency since the first outbreak in modern times in 1970. In this outbreak, 1384 persons were seen, diagnosed and treated for the disease at the cholera unit, Ibadan from January to December 1996. The outbreak lasted for a whole year. No child under one year was seen. The age adjusted case fatality rate was 5.3%. Diarrhoea and vomiting were the most common combination of symptoms present in 97.3% of all cases, followed by diarrhoea, vomiting and dehydration (84.3%). The median number of days spent on admission was only 2 days. Cholera cases were clustered within the densely populated and poorly planned areas of the city. Though significantly more cases were seen during the rainy season than during the dry season (p<0.01), the deaths were not seasonally related (p = 0.67). Contamination of otherwise potable sources of water, late presentation to the cholera treatment unit and low levels of knowledge about diseases need to be addressed in order to effectively control this disease in the community. Progress should also be made towards developing a suitable vaccine for the control of this internationally important public health disease so that the responsibility of its control is not left entirely to individuals and communities, particularly in developing countries.