The dengue situation in Africa

Abstract

Dengue outbreaks and epidemics have been reported in all regions of Africa, and it is believed that all four dengue virus serotypes are in circulation. Available data suggest that dengue is endemic to 34 African countries and that Aedes aegypti mosquitoes – the primary vector for dengue transmission – are known to be present in all but five countries. Whether populations in Africa are susceptible to dengue at the same rates as in Asia and Latin America is difficult to determine from the available data. Several factors may affect the transmission of dengue in Africa, including vector efficiency, viral infectivity, host vulnerability and environmental factors, such as increasing urbanisation. Current dengue prevention strategies in Africa focus on vector control, although the primary aim of such efforts is typically the prevention of malaria. Further research is needed to characterise the epidemiology of dengue in Africa and to better understand the factors involved in differences in vulnerability to dengue across Africa.

Imported Dengue Infection in a Spanish Hospital with a High Proportion of Travelers from Africa: A 9-Year Retrospective Study

“…Epidemiological studies in these countries are scarce. Dengue infection had been reported in Equatorial Guinea previously, 13 but to our knowledge no studies have been conducted in this country. In Nigeria, a recent report carried out on 310 febrile patients showed a 67.7% seroprevalence of dengue using plaque reduction neutralization testing to rule out cross-reactivity.…”

“…Although several outbreaks have been reported in this continent and the number of epidemiological studies has increased in recent years, studies are still scarce. 13,14 Therefore, there is a need to collect epidemiological data on dengue infection in Africa to uncover the probably large hidden African dengue burden and its extension within this continent. 15 In our study, we found the highest rate of diagnosed cases in patients who had visited Asia (9%), followed by those traveling from Latin America and the Caribbean (6.1%) and, very close behind, from Africa (4.5%).…”

Probable Importation of Dengue Virus Type 4 to Angola from Brazil

“…Even though published reports are scarce, dengue has been documented in at least 34 countries in Africa ( 2 ). The role of travelers as sentinels of infectious disease has proven to be invaluable in this regard; dengue in returning travelers was the only evidence for local DENV transmission for 12 of these countries.…”

Circulation of Dengue Virus Type 3 Genotype III in Africa Since 2008

“…Effectively, epidemics may remain undetected until diagnosis is assessed in another country from a returning infected visitor. Moreover, travelers may be more susceptible to dengue infection than locals, particularly travelers from non-endemic to endemic areas [8]. Dengue is also under recognized in Africa because of low awareness by health care providers, other prevalent febrile illnesses, and lack of diagnostic testing and systematic surveillance [9].…”

“…Dengue virus is still expanding worldwide to new territories with the first epidemic in Cape Verde in 2009 with more than 17,000 cases [7]. It is likely that all four subtypes of the dengue virus are present but the lack of formal laboratory testing or surveillance initiatives means that it is difficult to verify this [8].…”