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Phylogenetic analysis of human immunodeficiency virus type 1 (HIV-1) pol gene is a useful method for subtyping European strains of HIV-1. The suitability of this method for genetically diverse African strains was evaluated by comparing HIV-1 subtyping of Cameroon strains using a long fragment of the pol gene sequence to the findings obtained using env gene sequences. When the pol gene could not be amplified, the reverse transcriptase (RT) or the protease (PR) genes were used. Phylogenetic analysis of the env C2/V3 gene sequences of 60 HIV-1 isolates showed 52 to be subtype A, 2 subtype G, plus one each of subtypes C, F2 and H, with 3 subtypes not determined. A long fragment of the pol gene was amplified successfully and sequenced in 23% of cases. The RT region was amplified for 42% of the samples that could not be typed by analysing the long fragment, and the PR gene was amplified for 40% of them. Thus, 63% of samples were typable. Env and pol gene subtypings were in agreement in 86% of cases. It is concluded that the phylogenetic analysis of pol gene sequences is not a practical method for HIV-1 subtyping in areas of high subtype diversity, despite the good agreement between the env and pol gene subtypings. However, it can be a useful method for HIV-1 subtyping, provided that the gene is amplifiable. [Copyright &y& Elsevier]

To determine the prevalence of hepatitis C virus (HCV) infection and genotype distribution in a rural isolated area of Central Africa, plasma of 409 Bantous (mean age, 32 years; range, 2-78 years) living in a remote village of the rain forest of Southern Cameroon was screened for anti-HCV antibodies. HCV seropositive samples were also subjected to qualitative detection of viral RNA. HCV antibodies were detected in 70 (17.1%) individuals, 48 (68.8%) of whom had detectable viremia. The seroprevalence did not differ by gender (P = 0.37), but increased significantly with age (P < 0.05), with a strong increase in the oldest age groups. Indeed, nearly one-half (48%) of the adults >50 years old were HCV seropositive. The characterization of the viral genotypes indicated that most of the HCV strains were of genotype 4 (76%), while genotype 2 (16%), and 1 (8%) were marginally represented. The results suggest a cohort effect with an old, possibly iatrogenic, group exposure rather than a continuous exposure. A more in-depth population-based epidemiological study is needed to address this issue further., (Copyright 2003 Wiley-Liss, Inc.)

Central Africa is considered to be an area of high endemic hepatitis C infection. To determine the prevalence of anti-HCV antibodies, HCV RNA, and the genotype distribution in Cameroon, 1,494 pregnant women attending antenatal care units in Yaounde, Cameroon were screened for HCV infection. Anti-HCV antibodies were detected with a 3rd generation ELISA (Monolisa anti-HCV plus version 2, BioRad, Richmond, CA). All anti-HCV antibody-positive sera were then tested with another 3rd generation ELISA (AxSYM) HCV version 3, Abbott Laboratories, Abbott Park, IL) and subsequently for HCV RNA (Amplicor HCV, Roche Diagnostics, Basel, Switzerland). Genotype was determined by phylogenetic analysis of the NS5b gene. Seventy-three pregnant women were found to be anti-HCV antibody positive by the first ELISA, but only 28 were anti-HCV positive by both ELISA. The prevalence of anti-HCV antibodies was thus 1.9% (28/1,494) (95% CI: 1.3-2.7%). 21/28 (75%) of the positive samples by both ELISA were HCV RNA positive. The 45 samples that were HCV antibody negative by the second ELISA were also HCV RNA negative. The HCV subtypes identified were 1a (24%), 2f (38%) and 4f (38%). In contrast to previous studies, anti-HCV antibodies were rare among pregnant women in Cameroon. The percentage of HCV seropositive pregnant women who had circulating HCV RNA was similar to that observed in Europe. Several HCV genotypes were found in Cameroon., (Copyright 2003 Wiley-Liss, Inc.)