Gorillas and HIV

Richard T. Ellison III, MD reviewing D'arc M et al. Proc Natl Acad Sci U S A 2015 Mar 2.

Simian immunodeficiency viruses related to HIV-1 groups O and P have been identified in western lowland gorillas in southern Cameroon.

Most recent human epidemic viral diseases, including severe acute respiratory syndrome, Middle East respiratory syndrome, Ebola, and AIDS, have had a zoonotic origin. Defining the animal reservoir of these viruses can be helpful in preventing future epidemics. Earlier work showed that HIV-1 viruses in groups M and N probably arose from chimpanzee-to-human transmission of simian immunodeficiency viruses (SIVs) in southern Cameroon (NEJM JW Infect Dis Sep 2006 and Science 2006; 313:523). A multinational team of investigators has now shown that viruses in groups O and P were likely transmitted to humans from gorillas in the same area.

Researchers tested nearly 3000 fecal samples from gorilla populations in Cameroon, Gabon, the Democratic Republic of the Congo, and Uganda for the presence of HIV cross-reactive antibodies. They identified 70 positive samples, all from western lowland gorillas at four sites in southern Cameroon; these samples came from at least 16 different individuals. Subsequent studies confirmed the presence of gorilla simian immunodeficiency virus (SIVgor) in at least 16 additional gorillas at these sites, with the prevalence of infection ranging from <1% to >20%. Full-length genome sequencing of three SIVgor isolates showed three distinct SIVgor clades, with one of these clades closely related to HIV-1 group O and another to HIV-1 group P.

Citation(s):

D'arc M et al. Origin of the HIV-1 group O epidemic in western lowland gorillas. Proc Natl Acad Sci U S A 2015 Mar 2; [e-pub].