28 Nov 2015
Cholera: TanzaniaOngoing surveillance of cholera in Tanzania (including the islands of Pemba and Zanzibar)
An outbreak of cholera was first reported in Dar es Salaam in late August 2015 and has since spread to 19 regions of Tanzania, including the islands of Pemba and Zanzibar. As of 18 November, the cumulative number of suspected/confirmed cases is 9,240 including 132 deaths . Cases were first reported in Zanzibar on 19 September 2015 and in Pemba on 1 November 2015. As of 20 November 2015, 206 cases have been reported in Zanzibar (sometimes referred to as Unguja) and 174 cases in Pemba. Four cholera-related deaths have been reported from the two islands. The start of the rainy season makes further cases likely .
Cholera is an acute diarrhoeal disease caused by the Gram negative bacillus Vibrio cholerae serogroup O1 or O139. Vibrio cholerae is transmitted through contaminated water or food in areas of poor sanitation. Direct person to person transmission is rare.
The overall risk of cholera for travellers is extremely low and is in the order of 0.2 cases per 100,000 travellers ..Those at higher risk include those who are living or working in unsanitary conditions and drink untreated water or eat poorly cooked seafood in endemic areas.
Advice for travellersYou are advised to practise food and water hygiene precautions. Cholera vaccine is not routinely recommended, but can be considered if you are travelling to affected areas particularly if you are undertaking activities that may result in a greater risk to exposure to cholera, e.g. working in a humanitarian aid or relief work setting, or if you are travelling to remote areas with limited access to safe water and medical care [2, 3].
Advice for health professionals
Health professionals should be alert to the possibility of cholera in those who have recently returned from areas currently experiencing cholera outbreaks presenting with a severe watery diarrhoeal illness, and send the appropriate samples (with a full clinical and travel history) to the Public Health England Gastrointestinal Bacterial Reference Unit.
- United Republic of Tanzania. Cholera outbreak 2015. Office of the Resident Coordinator Situation Report No.2. 20 November 2015. [Accessed 24 November 2015].
- Hill, DR, Ford L, Lalloo DG. Oral cholera vaccines: use in clinical practice. Lancet Infect Dis 6:361-73, 2006.
- Public Health England. Immunisation against infectious disease. Cholera; Chapter 14. [Accessed 24 November 2015].