OBJECTIVE:To define a routine algorithm for the specific diagnosis and complete follow-up of HIV-1 group O (HIV-O) infections in Cameroun.
METHODS:During 18 months, samples referred to Centre Pasteur ...du Cameroun for HIV testing or viral monitoring were screened for HIV-O infection with an in-house serotyping assay. HIV-O viral load was quantified by real-time polymerase chain reaction in the LTR gene and resistance genotyping was performed on pol and env sequences.
RESULTS:Of the 7030 samples tested, 78 HIV-O infections (1.1%) were identified, including 7 M and O dually seroreactive samples (9%). All treatment-naive patients and 59% of the patients receiving HAART had detectable viral loads. Analysis of pol sequences from 15 treatment-naive patients revealed a high number of polymorphisms in the protease region, with natural residues implicated in genotypic resistance to tipranavir and saquinavir for HIV-1 group M according to the Agence Nationale de Recherches sur le Sida et les Hépatites virales algorithm. Six patients (40%) harbored the 181C mutation conferring natural resistance to nonnucleoside reverse transcriptase inhibitors. Among antiretroviral-treated patients, major resistance mutations described for HIV-1 group M were found.
CONCLUSIONS:HIV-O prevalence remains relatively low in Cameroun. The cocirculation of groups M and O in this country leads to replicative dual infections. HIV-O-infected patients in this region can now benefit from effective and specific tools for a complete monitoring of infection. However, further studies are needed to understand long-term response to antiretrovirals of these complex variants.
Chikungunya virus, Cameroon, 2006 Peyrefitte, Christophe N; Rousset, Dominique; Pastorino, Boris A M ...
Emerging infectious diseases,
05/2007, Letnik:
13, Številka:
5
Journal Article
Recenzirano
Odprti dostop
We report the isolation of chikungunya virus from a patient during an outbreak of a denguelike syndrome in Cameroon in 2006. The virus was phylogenetically grouped in the Democratic Republic of the ...Congo cluster, indicating a continuous circulation of a genetically similar chikungunya virus population during 6 years in Central Africa.
HIV-1 are now classified into four groups: M (major), O (outlier), N (non-M - non-O), and a new group P, the prototype of which is the divergent strain recently characterized in a Cameroonian patient ...1. Recombination between HIV strains is a very frequent phenomenon, greatly increasing genetic diversity, particularly for group M. HIV-M and HIV-O strains co-circulate in west-central Africa and dual infections have been reported in some individuals 2-4, leading to the emergence of M/O recombinants despite the great genetic divergence between these groups. Only three recombinant strains have been characterized to date in unrelated patients with dual infections, all in Cameroon 3,5,6. The transmissibility of these rare recombinants and their ability to circulate remain unknown. We report in the present article the first M/O mosaic strain circulating outside Cameroon and potentially corresponding to direct transmission of a well established recombinant form.
HIV-1 is subdivided into three groups: M (major, HIV-M), O (outlier, HIV-O) and N (non-M/non-O). HIV-O is mainly found in Cameroon where it represents 1% of the HIV infections. The high genetic ...divergence between groups M and O viruses and the large intragroup O diversity lead to major consequences in diagnosis and follow-up of the HIV-O infected patients.
The lack of HIV type-1 (HIV-1) viral load (VL) monitoring in resource-limited settings might favour the accumulation of resistance mutations and thus hamper second-line treatment efficacy. We ...investigated the factors associated with resistance after the initiation of antiretroviral therapy (ART) in the absence of virological monitoring.
Cross-sectional VL sampling of HIV-1-infected patients receiving first-line ART (nevirapine or efavirenz plus stavudine or zidovudine plus lamivudine) was carried out; those with a detectable VL were genotyped.
Of the 573 patients undergoing VL sampling, 84 were genotyped. The mean number of nucleoside/nucleotide reverse transcriptase inhibitor (NRTI) mutations increased with the duration of ART exposure (P=0.02). Multivariable analysis showed that patients with a CD4+ T-cell count < or =50 cells/mm(3) at ART initiation (baseline) had a higher mean number of both NRTI and non-NRTI (NNRTI) mutations than those with a baseline CD4+ T-cell count >50 cells/mm(3) (2.10 versus 0.56; P<0.0001; and 1.65 versus 0.76; P=0.005, respectively). A baseline CD4+ T-cell count < or =50 cells/mm(3) predicted > or =1 NRTI mutation (adjusted odds ratio AOR 7.49, 95% confidence interval CI 2.20-32.14), > or =1 NNRTI mutation (AOR 4.25, 95% CI 1.36-15.48), > or =1 thymidine analogue mutation (AOR 8.45, 95% CI 2.16-40.16) and resistance to didanosine (AOR 6.36, 95% CI 1.49-32.29) and etravirine (AOR 4.72, 95% CI 1.53-15.70).
Without VL monitoring, the risk of drug resistance increases with the duration of ART and is associated with lower CD4+ T-cell counts at ART initiation. These data might help define strategies to preserve second-line treatment options in resource-limited settings.
To assess mother-to-child transmission (MTCT) of hepatitis C virus (HCV) in Cameroon, 5,008 pregnant women were screened for HCV antibodies. Eighty-nine (1.8%) were HCV-antibody (HCV-Ab) positive. ...Among these, 7 (7.9%) were HBsAg positive, 6 (6.7%) HIV-positive, and one (1.1%) was co-infected by both hepatitis B virus (HBV) and HIV. Sixty-eight (76%) out of 89 HCV-Ab positive pregnant women were HCV-RNA positive. The HCV genotype determination indicated the predominance of genotype 4 (45.3%), followed by the genotypes 1 (28.1%) and 2 (26.6%). The mean HCV-RNA levels of 41 women at the time of delivery was 4.8 (range 0.06-34.7) x 10(6) RNA copies/mL. Finally, 35 women delivered 36 live children. None of those screened at 6 weeks and 6 months of age were HCV-RNA positive. The failure to detect HCV vertical transmission suggests that the mother-to-child transmission (MTCT) is not a major route of HCV transmission in Cameroon.
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