Prevalence of human enteroviruses among apparently healthy nursery school children in Accra

Abstract

Introduction: Human enteroviruses are common in children causing asymptomatic infections ranging  from mild to severe illnesses. In Ghana, information on the prevalence of non-polio enterovirus causing  acute flaccid paralysis is available but data on surveillance of these viruses in school children is scanty. Here, the prevalence of human enteroviruses among apparently healthy children in selected school in Accra was studied.

Methods: Stool samples from 273 apparently healthy children less than eight years of age in 9 selected nursery schools were collected between December 2010 and March 2011and processed for human  enteroviruses on L20B, RD and Hep-2 cell lines. Positive Isolates were characterized by microneutralisation assay with antisera pools from RIVM, the Netherlands according to standard  methods recommended by WHO.

Results: Of the 273 samples processed, 66 (24.2%) non-polio enteroviruses were isolated. More growth  was seen on Hep-2C (46%) only than RD (18%) only and on both cell lines (34%). No growth was seen on  L20B even after blind passage. Excretion of non-polio enteroviruses was found in all the schools with  majority in BD school. Serotyping of the isolates yielded predominantly Coxsackie B viruses followed by echoviruses 13 and 7. More than half of the isolates could not be typed by the antisera pools.

Conclusion: The study detected 13 different serotypes of non-polio enteroviruses in circulation but no poliovirus was found. BD school was found to have the highest prevalence of NPEV. Complete  identification through molecular methods is essential to establish the full range of NPEVs in circulation in these schools.

Key words: Non-polio enterovirus, apparently healthy, school children, Accra