Health topics

Cholera surveillance and number of cases

International Health Regulations (IHR)

Cholera is one of three diseases requiring notification to WHO under the International Health Regulations. The notification of cases is published in the Weekly Epidemiological Record. The actual number of cases is considered to be much higher because of poor surveillance systems and frequent under-reporting, often motivated by fear of trade sanctions and lost tourism. WHO estimates that the officially reported cases represent around 5-10% of actual cases worldwide.

Countries/areas reporting cholera cases in 2005
Number of cholera cases reported to WHO

Countries are encouraged to use the WHO case definition for the reporting of cholera cases in order to ensure consistency. Reporting only laboratory-confirmed cases fails to reflect the true burden of the disease; it may also impede the implementation of effective cholera control measures if the real extent of the problem is under-recognized. Nevertheless, identification of high risk areas and vulnerable populations is possible through an integrated disease surveillance system which has been put in place in many developing countries.

Accurate information on the burden of disease may contribute to an open and transparent information to the public and the community and may lead to more efficient cholera control activities through destigmatizing the disease.

Cholera cases – annual summaries

Cholera cases – trends over time

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