Molecular epidemiology of enteroviruses causing uveitis and multisystem hemorrhagic disease of infants.

We studied molecular epidemiology of highly virulent echovirus 11 and 19 strains that were isolated during five outbreaks of enterovirus uveitis (EU) in Siberia in 1980-1989, and three outbreaks of multisystem hemorrhagic disease of infants (MHD) in 1988-1991. Three genome regions, 5'NTR, VP1-2A junction, and a fragment of 3D polymerase, were analyzed. Phylogenetic grouping in the VP1-2A region correlated with serotyping results. All studied EV11 and EV19 strains, including the prototype EV11 and EV19, formed a major phylogenetic group in VP1-2A region. Within that group, several EV11 isolates from EU and MHD outbreaks formed a distinct cluster in VP1-2A and 5' NTR genome regions, designated EV11/B. All strains of this cluster possessed high virulence for monkeys compared with the prototype echoviruses. Subgrouping within this cluster correlated with year of virus isolation, not with the disease the viruses caused in infants (EU or MHD).