Evolution of HIV-1 groups M and O: genetic comparative analysis of 23 HIV-1/MO inter-group recombinant forms

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HIV-1 group P infection: towards a dead-end infection?

HIV/1 group P (HIV-1/P) is the last HIV/1 group discovered and to date, comprises only two strains. To obtain new insights into this divergent group, we screened for new infections by developing specific tools, and analysed phenotypic and genotypic properties of the prototypic strain RBF168. In addition, the follow-up of the unique patient monitored so far, has raised the knowledge of the natural history of this infection and its therapeutic management. We developed an HIV-1/P specific sero-molecular strategy and screened over 29,498 specimen samples. Infectivity and evolution of the gag-30 position, considered as marker of adaptation to human, were explored by successive passages of RBF168 strain onto human PBMCs. Natural history and immuno-virological responses to combined antiretroviral therapy (cART) were analysed based on CD4 counts and plasmatic viral load evolution. No new infection was detected. Infectivity of RBF168 was found lower, relative to other main HIV groups and the conservative methionine found in the gag-30 position revealed a lack of adaptation to human. The follow-up of the patient during the five-year ART-free period, showed a relative stability of CD4 cell count with a mean of 326 mm. Initiation of cART led to rapid RNA undetectability with a significant increase of CD4, reaching 687 mm after 8 years. Our results showed that HIV-1/P strains remain extremely rare and could be less adapted and pathogenic than other HIV strains. These data lead to the hypothesis that HIV-1/P infection could evolve towards, or even already correspond to, a dead-end infection

Gradual emergence followed by exponential spread of the SARS-CoV-2 Omicron variant in Africa.

The geographic and evolutionary origins of the SARS-CoV-2 Omicron variant (BA.1), which was first detected mid-November 2021 in Southern Africa, remain unknown. We tested 13,097 COVID-19 patients sampled between mid-2021 to early 2022 from 22 African countries for BA.1 by real-time RT-PCR. By November-December 2021, BA.1 had replaced the Delta variant in all African sub-regions following a South-North gradient, with a peak Rt of 4.1. Polymerase chain reaction and near-full genome sequencing data revealed genetically diverse Omicron ancestors already existed across Africa by August 2021. Mutations, altering viral tropism, replication and immune escape, gradually accumulated in the spike gene. Omicron ancestors were therefore present in several African countries months before Omicron dominated transmission. These data also indicate that travel bans are ineffective in the face of undetected and widespread infection

Retraction.

This is a retraction of 'Gradual emergence followed by exponential spread of the SARS-CoV-2 Omicron variant in Africa' 10.1126/science.add873

Using dried blood spot for the detection of HBsAg and anti-HCV antibodies in Cameroon

Abstract Objective Dried blood spots (DBS) offer multiple benefits for collecting, storing and shipping whole blood samples. Our objective was to compare, for the first time in Africa, the performance of DBS with respect to plasma in the detection of Hepatitis B surface antigen (HBsAg) and antibodies to Hepatitis C Virus (anti-HCV) using Architect, Abbott Diagnostics. Results DBS had a sensitivity of 99%, a specificity of 100%, a positive predictive value of 99%, a negative predictive value of 100% and a kappa index of 0.99 for the detection of HBsAg. For anti-HCV detection, the sensitivity, specificity, positive predictive value, negative predictive value and kappa index were 99%, 98%, 98%, 99%, and 0.97, respectively. This study confirms that DBS may be a reliable alternative specimen type for HBV and HCV diagnosis

Evolution of HIV-1 groups M and O: genetic comparative analysis of 23 HIV-1/MO inter-group recombinant forms

International audienc

Short Communication: Characterization of a New HIV-1 Group N Isolate Originating from a Cameroonian Patient

International audienceHIV-1 group N (HIV-1/N) remains rare and mainly restricted to Cameroon. In this study, we report a new HIV-1/N infected case identified during routine HIV screening activities in Yaounde. The genetic characterization of the near full-length genome of this virus strain revealed that it is genetically distinct to all HIV-1/N described to date. However, the Vpu protein responsible for tetherin antagonism displayed the same amino acid substitutions (E15A, V19A, I25L, and V26L) as other HIV-1/N from Cameroon

First evidence of transmission of an HIV-1 M/O intergroup recombinant virus

Erratum in : First evidence of intra-familial transmission of an HIV-1 M/O intergroup recombinant virus: Erratum. [AIDS. 2017]International audienceOBJECTIVE: Despite the genetic divergence between HIV-1 groups M and O, HIV-1  M/O intergroup recombinants were reported. Actually, there is no data on the transmissibility of such recombinant forms. During a surveillance of HIV genetic diversity in Cameroon, we investigated the possible direct transmission of an HIV-1  M/O recombinant virus in an HIV-infected couple.METHODS: Consecutive samples obtained from the couple were analysed for detection of dual HIV-1 groups M and O infections, and HIV-1  M/O recombinant forms. Analyses were performed using a serological and molecular algorithm based on HIV serotyping and group-specific PCRs targeting the polymerase and envelope genes. Pattern characterization of the strains found in both patients was based on complete genome sequencing. Phylogenetic and similarity profile analyses were performed to investigate the genetic relationship between viruses from both spouses and the previously described recombinant forms.RESULTS: The sero-molecular algorithm data showed a group O serotype confirmed by molecular analysis in the envelope regions, whereas molecular tests identified HIV-1 group M in the polymerase. Phylogenetic analyses and similarity profiles of the full-length genome sequences showed that both spouses were infected with a unique recombinant virus having two recombination breakpoints in the vpr gene and LTR region. No phylogenetic link was found with the previous M/O recombinants.CONCLUSION: We provide, for the first time, molecular evidence of direct transmission of an HIV-1  M/O recombinant, highlighting the potential spread of these divergent viruses. The importance of HIV-1 recombination on genetic evolution and public health when implying divergent strains as group O has to be carefully considered

Évolution des VIH-1 groupes M et O : analyse génétique comparée de 20 formes recombinantes VIH-1 inter-groupes

International audienc

Evidence of Intra-Familial Transmission of an HIV-1 M/O Intergroup Recombinant Virus

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