Hand, foot and mouth disease: seroprevalence of Coxsackie A16 and Enterovirus 71 in Germany.

Coxsackie A16 (CA16) and Enterovirus 71 (EV71) are members of the picornaviridae family and are associated with hand, foot and mouth disease (HFMD), in rare cases also to acute neurological diseases. HFMD outbreaks have been reported from many parts of the world, especially Southeast Asia. The objective of the study was to analyze CA16 and EV71 seroepidemiologically in the population of Frankfurt/M., Germany. A total of 696 individuals (349 males and 347 females, divided into seven different age groups, 1-4, 5-9, 10-14, 15-19, 20-39, 40-59 and >60 years) were tested for serum antibodies against CA16 and EV71 by the use of a microneutralization test. Sera were collected at the Frankfurt university hospital from patients suffering from other diseases between March and September 2006. CA16 and EV71 infections were observed to be widely present in the population. The age-adjusted seroprevalence for individuals >or=1 year was found to be 62.9% for CA16 and 42.8% for EV71 without a gender-specific significant difference. Only 12.0 and 27.0% of the children aged 1-4 had antibodies to EV71 and CA16, respectively - indicating that 88 and 73% of the children in this age group were susceptible to the infection. A total of 213 individuals (30.6%) was seropositive for both viruses, 303 (43.5%) showed neutralizing antibodies (NtAb) to at least one of the two viruses. A total of 180 individuals (25.9%) revealed no antibodies. High CA16 and EV71 antibody titers were found especially in the age group of the 10- to 14-year-olds, without gender-specific difference. The seroprevalence study demonstrates a common spread of CA16 and EV71 in Germany, but a relatively high susceptibility of the younger population to CA16 and EV71. Obviously, the manifestation rate, i.e., distinct disease of these infections is low.