Seroprevalence of viral childhood infections in Eritrea

The seroprevalence of viral childhood infections in Africa has not been thoroughly investigated. The relatively recently discovered human parvovirus B19 (B19) and human herpesvirus 6 (HHV-6) have received particularly little attention.

To investigate the seroprevalence of viral childhood infections in different Eritrean populations and to define groups at high risk for infection.

Five population groups in Eritrea have been examined to define the prevalence of specific antibodies to several childhood viruses. The study population of more than 400 persons consisted of children, pregnant women, female sex workers and members of a secluded tribe called Rashaida.

All groups showed a high prevalence of antibodies to measles and HHV-6 (> 85%). For rubella, the seroprevalence was very high in all adult groups (93-99%) except the Rashaida group (71%). The mumps prevalence was surprisingly low in the Rashaida group (29%) compared to 46-85% in the other adults. Late encounter of mumps and rubella was also observed among the Rashaidas. The pattern of antibodies to B19 showed a higher seroprevalence in all groups (56-91%) compared to what has been reported from the western world.

The findings represent what might be expected in an unvaccinated population. The exception was the Rashaidas, which had low seroprevalences and late encounter of mumps and rubella. This is of importance because it makes this tribe vulnerable to these infections, which are associated with complications when acquired in adult age. Also noteworthy is the high frequency of antibodies to HHV-6 and particularly B19 in all groups, indicative of an early encounter of both these viruses.