Although dengue exists in the WHO African Region, surveillance data are poor. Outbreak reports exist, although they are not complete, and there is evidence that dengue outbreaks are increasing in size and frequency. Dengue is not officially reported to WHO by countries in the region. Dengue-like illness has been recorded in Africa though usually without laboratory confirmation and could be due to infection with dengue virus or with viruses such as chikungunya that produce similar clinical symptoms. Dengue has mostly been documented in Africa from published reports of serosurveys or from diagnosis in travellers returning from Africa, and dengue cases from countries in Sub-Saharan Africa. A serosurvey suggests that dengue existed in Africa as far back as 1926--1927, when the disease caused an epidemic in Durban, South Africa. Cases of dengue imported from India were detected in the 1980s. For eastern Africa, the available evidence so far indicates that DEN-1, -2 and -3 appear to be common causes of acute fever. Examples of this are outbreaks in the Comoros in various years (1948, 1984 and 1993, DEN-1 and -2) and Mozambique (1984--1985, DEN-3) (16).

In western Africa in the 1960s, DEN-1, -2 and -3 were isolated for the first time from   samples taken from humans in Nigeria. Subsequent dengue outbreaks have been reported from different countries, as for example from Burkina Faso (1982, DEN-2) (18) and Senegal (1999, DEN-2) Also DEN-2 and DEN-3 cases were confirmed in Côte d’Ivoire in 2006 and 2008.

Despite poor surveillance for dengue in Africa, it is clear that epidemic dengue fever caused by all four dengue serotypes has increased dramatically since 1980, with most epidemics occurring in eastern Africa, and to a smaller extent in western Africa, though this situation may be changing in 2008. While dengue may not appear to be a major public health problem in Africa compared to the widespread incidence of malaria and HIV/AIDS, the increasing frequency and severity of dengue epidemics worldwide calls for a better understanding of the epidemiology of dengue infections with regard to the susceptibility of African populations to dengue and the interference between dengue and the other major communicable diseases of the continent.