Emerging and reemerging enterovirus diseases: From poliomyelitis to hand, foot and mouth disease.

Several picornaviruses (Picornaviridae) are currently attracting interest without the need of being "emergent". The Parechovirus genus, validated 40 years after the discovery of the first two members ("echoviruses 22 and 23") includes neurotropic viruses whose molecular diagnosis demonstrated the involvement in infant meningitis and newborn sepsis, in particular type 3. Improvements in multiplex molecular diagnosis of respiratory infections - thanks to the Influenza AH1N1pdm2009 pandemy - showed that rhinoviruses may be involved in severe forms. The risk of the re-emergence of poliomyelitis in Europe, after an 11-year period of elimination, is a serious threat, owing to the circulation of the wild-type poliovirus in the Middle East and Africa because of conflicts, population displacements and poverty. The current widespread epidemics of hand-foot-mouth disease and/or meningitis infections due to enterovirus 71, with fatal encephalitis and cardio-pulmonary failure, are clear evidence of its emergence in South-East Asia. Although uncommon in Europe and less frequently incriminated than coxsackieviruses A6 and A10 in hand-foot-mouth disease, EV71 represents a real risk for the future. Extensive genotyping of the enteroviruses by the Enterovirus Surveillance Network should ward off these two potential risks of emergence/reemergence.