%0 Journal Article
%T Serologic evidence of human orthopoxvirus infections in Sierra Leone
%A Adam MacNeil
%A Jason Abel
%A Mary G Reynolds
%A RR Lash
%A Richard Fonnie
%A Lansana D Kanneh
%A Willie Robert
%A Victor K Lungay
%A Augustine Goba
%A Lina M Moses
%A Inger K Damon
%A Kevin Karem
%A Daniel G Bausch
%J BMC Research Notes
%D 2011
%I BioMed Central
%R 10.1186/1756-0500-4-465
%X To examine evidence of exposure to orthopoxviruses in the Kenema District of Sierra Leone, we collected and tested sera from 1596 persons by IgG ELISA and a subset of 313 by IgM capture ELISA. Eleven persons born after the cessation of smallpox vaccination had high orthopoxvirus-specific IgG values, and an additional 6 persons had positive IgM responses. No geographic clustering was noted.These data suggest that orthopoxviruses continue to circulate in Sierra Leone. Studies aimed at obtaining orthopoxvirus isolates and/or genetic sequences from rodents and symptomatic humans in the area are indicated.Orthopoxviruses are large DNA viruses in the family Poxviridae [1]. Included in the Orthopoxvirus genus are variola virus, the causative agent of smallpox; vaccinia virus, the live virus component of the smallpox vaccine; monkeypox virus, the causative agent of monkeypox; and as well as other zoonotic viruses, including many not known to cause human disease. Smallpox vaccination results in broadly reactive anti-orthopoxvirus serologic responses that persist for decades [2].Sierra Leone is a country of 6 million inhabitants on the west coast of Africa (Figure 1). In response to an outbreak of smallpox in Sierra Leone in 1967-1968, a large vaccination campaign was launched, resulting in vaccination coverage close to 80% [3]. Although we were unable to verify the precise date that routine smallpox vaccination ceased in Sierra Leone, veteran colleagues in the region put it at 1972-73. Smallpox was declared eradicated in 1980. Numerous cases of human monkeypox were detected in West Africa between 1970 and 1986, including a single case in Sierra Leone in 1970, but no cases have been reported since [4-7]. However, a monkeypox outbreak resulting in 47 confirmed and probable cases occurred in the United States in 2003, and was linked to a West African strain of the virus imported through a shipment of African mammals from Ghana [8-10].Despite the absence of reported human orthop
%U http://www.biomedcentral.com/1756-0500/4/465