Geographic distribution of filoviruses: serological surveys

Abstract

Serological surveys of human populations have been used to define the geographic distribution of filoviruses. These surveys were deemed necessary because the natural reservoirs of filoviruses are still unknown. Most serological surveys have been conducted in Africa, given that all of the known human AFHF outbreaks have been associated with Africa in some way (for a thorough review see also [996]). The results of these studies are summarized in this section. Most of these studies have been performed using controversial assays or adequate assays using subjective and therefore controversial standards. Because of this, most of the studies have been criticized. Relatively high serum prevalence rates (10- 20%) of antibodies to ebolaviral antigens, mostly unconfirmed by neutralization assays, have been detected in many samples using IFA. Such results suggest broad filovirus circulation, which has been thought by experts to be unlikely due to the low prevalence of clinical AFHF cases. Nonetheless, the prevalence of filovirus infections may be higher than has been recognized, especially if the assays used for these surveys are determined to be more sensitive and specific than has been suspected.