Dengue Virus Infection in Africa

TLDR

Dengue incidence is rising globally, yet its prevalence in Africa remains poorly understood, likely due to underrecognition, limited diagnostics, and possible protective factors such as cross‑flavivirus immunity, host genetics, or low vector competence. Population‑based studies of febrile illness are needed to determine the epidemiology and true incidence of dengue in Africa. Between 1960 and 2010, 22 African countries reported sporadic dengue cases or outbreaks, while 12 reported cases only among travelers.

Abstract

Reported incidence of dengue has increased worldwide in recent decades, but little is known about its incidence in Africa. During 1960-2010, a total of 22 countries in Africa reported sporadic cases or outbreaks of dengue; 12 other countries in Africa reported dengue only in travelers. The presence of disease and high prevalence of antibody to dengue virus in limited serologic surveys suggest endemic dengue virus infection in all or many parts of Africa. Dengue is likely underrecognized and underreported in Africa because of low awareness by health care providers, other prevalent febrile illnesses, and lack of diagnostic testing and systematic surveillance. Other hypotheses to explain low reported numbers of cases include cross-protection from other endemic flavivirus infections, genetic host factors protecting against infection or disease, and low vector competence and transmission efficiency. Population-based studies of febrile illness are needed to determine the epidemiology and true incidence of dengue in Africa.