AEGiS-12IAC: Study of HIV-1 ENV variability in Cameroon.

12th International AIDS Conference

Geneva, Switzerland - June 28-July 3, 1998

Study of HIV-1 ENV variability in Cameroon.

Int Conf AIDS 1998 Jun 28-Jul 3; 12:20 (abstract no. 11191)

Heyndrickx L, Jassens W, Vereecken K, Coppens S, Fransen K, Ndumbe P, Van der Groen G
Department of Microbiology, Institute of Tropical Medicine, Antwerp, Belgium.

OBJECTIVE: Study of the prevalence and variability of HIV-1 strains circulating in the general population or belonging to different risk groups, in different regions of Cameroon in 1996 and 1997.

MATERIALS AND METHODS: In the period November 1996-April 1997 Cameroonian serum samples were collected in 8 different geographic areas (n = 1825) as well as from different target populations: blood donors (107); sexually transmitted diseases (STD) infected individuals (995); tuberculosis (10); commercial sex workers (5); general population (450); AIDS suspects (17); pregnant women (241). The samples were screened in CSCCD, Yaounde with the Behring Enzygnost HIV-1/2 Plus. So far, fifty seven of these repeated reactives were tested on their reactivity in V3 group O peptide enzyme immunoassay (PEIA). RNA was extracted followed by a one tube RT-PCR. Heteroduplex mobility assay (HMA) was performed using ES7-ES8 primers. Samples that could not be amplified or subtyped by HMA were cloned, sequenced and phylogenetically analysed. HMA PCR negative samples were amplified for the C2V3 env region, sequenced and phylogenetically analysed. From C2V3 env PCR negative samples we tried to amplify a diagnostic pol fragment (Fransen et al. Mol Cell Probes 1994; 8: 317-322).

RESULTS: A total of 177/1825 samples were repeatedly reactive. No HIV-1 group O samples were identified. A nested PCR with ES7-ES8 primers was positive for 42/57 samples. HMA was positive for 38/57 samples, of which 37 belonged to subtype A and 1 to subtype E. Cloning, sequencing and phylogenetic analysis of the C2V3 env encoding region of four samples which could not be subtyped by HMA, resulted in subtype A classification. For the remaining 15 HMA PCR negative samples, only four samples could be amplified for the C2V3 env region sequence analysis resulted in subtype A classification. From 1 our of 11 remaining samples a diagnostic pol fragment could be amplified.

CONCLUSION: Of 57 samples collected in different regions of Cameroon in the period 1996 up to 1997, so far 46 (80%) were classified as env subtype A and one as env subtype E. These results differ from those obtained in 1993, whereby 61% (11/17) of the samples were subtype A, and a larger variety of other subtypes B, E, F, H, and group O were documented (Nkengasong et al., AIDS 1994; 8: 1405-1412). Ongoing analysis on a larger set of samples will help to better estimate the prevalence of different HIV-1 subtypes circulating in Cameroon.

Keywords: AEGIS, HIV-1, HIV-2, Acquired Immunodeficiency Syndrome, Prostitution, Polymerase Chain Reaction, Tuberculosis, Cameroon, Pregnancy, Female, Human, ICA12
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