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.
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.
Vergne
Laurence
L
Laboratoire Retrovirus, UR36, Institut de Recherche pour le Developpement, 911 av Agropolis, BP64501, 34394 Montpellier Cedex 5, France.
Bourgeois
Anke
A
Mpoudi-Ngole
Eitel
E
Mougnutou
Rose
R
Mbuagbaw
Josephine
J
Liegeois
Florian
F
Laurent
Christian
C
Butel
Christelle
C
Zekeng
Léopold
L
Delaporte
Eric
E
Peeters
Martine
M
D018791:CD4 Lymphocyte Count; D002163:Cameroon / Q000453:epidemiology; D002478:Cells, Cultured; D015331:Cohort Studies; D014644:Genetic Variation; D005838:Genotype; D015726:Giant Cells / Q000821:virology*; D016655:HIV Core Protein p24 / Q000235:genetics; D006679:HIV Seropositivity / Q000453:epidemiology* / Q000821:virology; D015497:HIV-1 / Q000235:genetics* / Q000276:immunology; D015498:HIV-2 / Q000235:genetics* / Q000276:immunology; D006801:Humans; D017720:Molecular Epidemiology; D010641:Phenotype; D012367:RNA, Viral / Q000235:genetics; D011995:Recombination, Genetic
D016655:HIV Core Protein p24; D012367:RNA, Viral