Biological and genetic characteristics of HIV infections in Cameroon reveals dual group M and O infections and a correlation between SI-inducing phenotype of the predominant CRF02_AG variant and disease stage

Abstract

In Yaounde, Cameroon, HIV-1 group-specific V3 serology on 1469 HIV-positive samples collected between 1996 and 2001 revealed that group O infections remained constant around 1% for 6 years. Only one group N sample was identified and 4.3% reacted with group M and O peptides. Although the sensitivity of the group-specific polymerase chain reaction (PCR) in two genomic regions was not optimal, we confirmed, in at least 6 of 49 (12.2%) dual O/M seropositive samples and in 1 of 9 group O samples, dual infection with group O and M viruses (n = 4) or with group O or M virus and an intergroup recombinant virus (n = 3). Partial env (V3-V5) sequences on a subset of 295 samples showed that at least eight subtypes and five circulating recombinant forms (CRFs) of HIV-1 group M co-circulate; more than 60% were CRF02_AG and 11% had discordant subtype/CRF designations between env and gag. Similarly as for subtype B, the proportion of syncytium-inducing strains increased when CD4 counts were low in CRF02_AG-infected patients. The V3-loop charge was significantly lower for non-syncytium-inducing strains than for syncytium-inducing strains but cannot be used as an individual marker to predict phenotype. The two predominant HIV-1 variants in Africa, CRF02_AG and subtype C, thus have different biological characteristics.

Origin and Biology of Simian Immunodeficiency Virus in Wild-Living Western Gorillas

“…The viruses invoked in either of these scenarios may exist in as-yet-unsampled apes in Equatorial Guinea, Gabon, or the Republic of the Congo. Indeed, the relative prevalence of group O infections has been reported to be much higher in Equatorial Guinea (9% of HIV-1 infections) than in Cameroon (2% of HIV-1 infections), pointing to this area as a possible starting point of the HIV-1 group O epidemic (3,15,43,74,80). Formally, there is a third possibility, namely, that chimpanzees harboring SIVgor-like viruses first infected humans, who then passed the virus to gorillas.…”

Transfer and Evaluation of an Automated, Low-Cost Real-Time Reverse Transcription-PCR Test for Diagnosis and Monitoring of Human Immunodeficiency Virus Type 1 Infection in a West African Resource-Limited Setting

“…The future challenges for these promising real-time PCR techniques include, first, validating their performance characteristics in large cohorts of ARV-treated patients from other resource-limited countries where other clades of HIV-1 are circulating. For countries with multiple coexisting HIV-1 subtypes, such as Cameroon (39), the flexibility of real-time PCR with respect to primers and probe provides an advantage in dealing the HIV-1 diversity challenge. For this purpose, a newly designed minor groove binder HIV-1 probe has been developed, and its evaluation is in progress in the laboratory of virology in Necker Hospital (Paris).…”

HIV Type 1polGene Diversity and Genotypic Antiretroviral Drug Resistance Mutations in Malabo, Equatorial Guinea

“…To discriminate among HIV types and HIV-1 groups, the plasma samples were first subjected to an indirect ELISA assay using V3 loop peptide antigens specific to HIV-1 groups O, M, N, and HIV-2, as previously described. 11 The serological assays identified 48 samples as HIV-1 group M and one sample as HIV-2. RNA was extracted from plasma using the QIAamp Viral RNA extraction kit (Qiagen SA, Courtabeauf, France) followed by RT-PCR to amplify a 1865-base pairs (bp) fragment of the pol gene using a previously described protocol for HIV-1 genotypic drug resistance testing.…”