Enterovirus A 71 (EV-A71) is an emerging pathogen that is circulating worldwide and mostly causes hand, foot, and mouth disease (HFMD) in children. However, in many cases, EV-A71 causes neurological complications, such as meningitis, encephalitis, or flaccid paralysis. These complications could also potentially lead to severe pulmonary edema, which is often fatal in children. No specific prophylaxis, treatment or vaccine for EV-A71 infection is currently available.
Until recently, EV-A71 strains were subdivided into three genetic groups (genogroups): genogroup A, which is infrequent and includes the prototype EV-A71 strain; two genogroups (B and C) that are circulating worldwide, particularly in Asia, where they are frequently isolated during outbreaks of HFMD. In 2003, a new genogroup (D) was identified in India, and another two genogroups (E and F) have recently been discovered in Africa and Madagascar, by the laboratories of the International Network of Pasteur Institutes. There has not yet been any major documented epidemic of disease due to these viruses in Africa. It is therefore important 1) to determine the extent to which EV-A71 strains are circulating and their diversity on this continent, 2) to evaluate their role in causing disease (HFMD and encephalitis) and the epidemic risk for populations exposed to these viruses, through comparisons of the African and Asian strains.