Novel Multiplexed HIV/Simian Immunodeficiency Virus Antibody Detection Assay

Steve Ahuka-Mundeke, Ahidjo Ayouba, Placide Mbala-Kingebeni, Florian Liegeois, Amandine Esteban, Octavie Lunguya-Metila, Didace Demba, Guy Bilulu, Valentin Mbenzo-Abokome, Bila-Isia Inogwabini, Jean-Jacques Muyembe-Tamfum, Eric Delaporte, and Martine Peeters

Author affiliations: University of Montpellier, Montpellier, France (S. Ahuka-Mundeke, A. Ayouba, F. Liegeois, A. Esteban, E. Delaporte, M. Peeters); Institut National de Recherche Biomédicales, Kinshasa, Democratic Republic of Congo (S. Ahuka-Mundeke, P. Mbala-Kingebeni, O. Lunguya-Metila, J.-J. Muyembe-Tamfum); Cliniques Universitaires de Kinshasa, Kinshasa (S. Ahuka-Mundeke, P. Mbala-Kingebeni, O. Lunguya-Metila, J.-J. Muyembe-Tamfum); Zone de Santé de Kole, Sankuru, Kasai Oriental, Democratic Republic of Congo (D. Demba, G. Bilulu); World Wildlife Fund For Nature, Kinshasa (V. Mbenzo-Abokome, B-I. Inogwabini)

Abstract

Like most emerging infectious disease viruses, HIV is also of zoonotic origin. To assess the risk for cross-species transmission of simian immunodeficiency viruses (SIVs) from nonhuman primates to humans in the Democratic Republic of Congo, we collected 330 samples derived from nonhuman primate bushmeat at 3 remote forest sites. SIV prevalences were estimated by using a novel high-throughput assay that included 34 HIV and SIV antigens in a single well. Overall, 19% of nonhuman primate bushmeat was infected with SIVs, and new SIV lineages were identified. Highest SIV prevalences were seen in red-tailed guenons (25%) and Tshuapa red colobus monkeys (24%), representing the most common hunted primate species, thus increasing the likelihood for cross-species transmission. Additional studies are needed to determine whether other SIVs crossed the species barrier. With the newly developed assay, large-scale screening against many antigens is now easier and faster.

Like many emerging infectious disease viruses, HIV is also of zoonotic origin (1). The closest relatives of HIV-1 are simian immunodeficiency viruses (SIVs), specifically SIVcpz and SIVgor in chimpanzees (Pan troglodytes troglodytes) and gorillas (Gorilla gorilla), respectively, from west-central Africa (2,3). SIVsmm in sooty mangabeys (Cercocebus atys) from west Africa are the closest relatives of HIV-2 (4,5). SIVs from mangabeys, gorillas, and chimpanzees crossed the species barrier >12 times (1,6). Exposure to blood, secretions, or tissues from infected primates through hunting and butchering of bushmeat represents the most plausible source for human infection.

Humans are still hunting and butchering a wide diversity of primate species and the possibility of additional cross-species transfers of viruses has to be considered (7,8). Recent reports showed ongoing transmission of simian retroviruses to humans in central Africa, i.e., a wide variety of simian foamy viruses and new human T-lymphotropic virus variants, closely related to viruses in co-habiting nonhuman primates, have been observed in humans who report primate hunting and butchering (9–12). The description in 2009 of HIV-1 group P, closely related to SIVgor, in a patient from Cameroon living in France, shows also that our knowledge on HIV diversity and possible cross-species transmissions is still incomplete and illustrates how rapidly new viruses can spread today to other continents (6).

Given the potential pathogenicity of these lentiviruses, as illustrated by the actual HIV-1 group M pandemic that resulted from a single cross-species transmission, it is necessary to estimate to what extent humans are exposed to SIVs and whether other viruses crossed the species-barrier. SIV infection has already been identified in >40 nonhuman primate (NHP) species from Africa but our knowledge on prevalence and geographic distribution remains limited; few large-scale studies on retroviral infections in wild primate populations have been conducted (13). SIV prevalences can vary among species and within species according to geographic areas (2,14,15), and exposure to infected primates and subsequent risk for cross-species transmission can thus differ across Africa.

SIV infections were initially identified on the basis of cross-reactivity with HIV antigens (8), but to increase sensitivity, SIV lineage-specific ELISAs have been developed. These assays must be regularly updated when new SIV lineages are discovered (14–17). Therefore, they become time-consuming and bench work–consuming, use relatively large volumes of scarce biological material, and are not adapted for large-scale surveillance studies. We adapted the Multiple Analyte Profiling technology (xMAP; Luminex Inc., Austin, TX, USA), which is a flow cytometry–based system (18), for simultaneous antibody detection against 34 peptides representing the actual known HIV/SIV diversity. This new assay was used to study SIV infection in primate bushmeat in the Democratic Republic of Congo (DRC), home to a wide diversity of primate species.

Suggested citation for this article: Ahuka-Mundeke S, ayouba A, Mbala-Kingebeni, Liegeois F, Esteban A, Lunguya-Metila O, et al. Novel multiplexed HIV/simian immunodeficiency virus antibody detection assay. Emerg Infect Dis [serial on the Internet]. 2011 Dec [date cited]. http://dx.doi.org/10.3201/eid1712.110783