Serologic evidence of human orthopoxvirus infections in Sierra Leone.

The article reports on a serosurvey conducted to determine whether human exposure to orthopoxviruses continues to occur in eastern Sierra Leone, a country of 6 million inhabitants on the west coast of Africa. The researchers collected and tested sera from 1596 persons by IgG ELISA and a subset of 313 by IgM capture ELISA in order to examine evidence of exposure to orthopoxviruses in the Kenema District of Sierra Leone. The survey revealed that eleven persons born after the cessation of smallpox vaccination had high orthopoxvirus-specific IgG values. It is suggested by the findings that orthopoxviruses continue to circulate in Sierra Leone.