61 research outputs found

    Performance of rapid subtyping tools used for the classification of HIV type 1 recombinants isolated from selected countries in west and central Africa

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    HIV-1 genetic diversity in sub-Saharan Africa is broad and the AIDS epidemic is driven predominantly by recombinants in Central and West Africa. The classification of HIV-1 strains is therefore necessary to understand diagnostic efficiency, individual treatment responses as well as options for designing vaccines and antiretroviral (ARV) treatment guidelines. More so, accurate subtyping of a partial or full genome would represent the population dynamics of HIV and provide evidence for designing surveillance strategies within a geographic region. Evaluating the performance of rapid subtyping tools with options that incorporate phylogeny could be fast, more user-friendly and of high performance. A total of 570 HIV-1 partial sequences from Cameroon, Angola, Democratic Republic of Congo, Gabon and Senegal were obtained from the Los Alamos National Library (LANL) HIV Sequence Database. Phylogeny was performed using MEGA v6 and the results were used to evaluate the performance of eleven different rapid HIV-1 subtyping tools: REGA v2, REGA v3, NCBI, Stanford HIVDB, SUDI, Geno2Pheno, Euresist, STAR, jpHMM, COMET and SCUEAL. The performance of these subtyping tools differed among HIV-1 clades and across different viral genes. NCBI and SUDI showed the highest performance in subtyping. The discordance observed between the rapid subtyping tools and phylogeny implies that phylogenetic analysis is still the more suitable method for HIV-1 classification. However, the need to update the reference datasets of the subtyping tools, and validate algorithms for rapid subtyping and quality control is imperative as this information is relevant for clinical use and policymaking to the AIDS response.Keywords: HIV, phylogeny, performance, subtyping tools, algorith

    Launch of the Laboratory for Major Tropical Epidemics (LAGET) in Chad: Strengthening the capacity for epidemiological surveillance, monitoring and diagnosis of endemic or emerging infectious diseases in Central Africa

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    In an increasingly interconnected world, with the devastating effects of climate changes and humanitarian crises, pandemics and emerging infectious diseases are more likely to become our daily reality. When it comes to health care, sub-Saharan Africa faces more challenges than most other regions of the world, including lack of funds, precarity and poor infrastructures. Yet, these areas are most often on the front lines of infectious threats

    Enhancing interventions for prevention-of-mother-to-child- transmission (PMTCT) of hepatitis B virus (HBV)

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    Prevention of mother to child transmission (PMTCT) of hepatitis B virus (HBV) infection is a cornerstone of interventions to support progress towards elimination goals for viral hepatitis. Current guidelines recommend maternal screening, antiviral therapy during the third trimester of high-risk pregnancies, universal and timely HBV birth-dose vaccine, and post-exposure prophylaxis with hepatitis B immunoglobulin (HBIG) for selected neonates. However, serological and molecular diagnostic testing, treatment and HBV vaccination are not consistently deployed, particularly in many high endemicity settings, and models predict that global targets for reduction in paediatric incidence will not be met by 2030. In this article, we briefly summarise the evidence for current practice and use this as a basis to discuss areas in which PMTCT implementation can potentially be enhanced. By reducing health inequities, enhancing pragmatic use of resources, filling data gaps, developing advocacy and education, and seeking consistent investment from multilateral agencies, significant advances can be made to further reduce vertical transmission events, with wide health, societal and economic benefits

    HIV-1 recombinants with multiple parental strains in low-prevalence, remote regions of Cameroon: Evolutionary relics?

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    <p>Abstract</p> <p>Background</p> <p>The HIV pandemic disseminated globally from Central West Africa, beginning in the second half of the twentieth century. To elucidate the virologic origins of the pandemic, a cross-sectional study was conducted of the genetic diversity of HIV-1 strains in villagers in 14 remote locations in Cameroon and in hospitalized and STI patients. DNA extracted from PBMC was PCR amplified from HIV(+) subjects. Partial <it>pol </it>amplicons (N = 164) and nearly full virus genomes (N = 78) were sequenced. Among the 3956 rural villagers studied, the prevalence of HIV infection was 4.9%; among the hospitalized and clinic patients, it was 8.6%.</p> <p>Results</p> <p>Virus genotypes fell into two distinctive groups. A majority of the genotyped strains (109/164) were the circulating recombinant form (CRF) known to be endemic in West Africa and Central West Africa, CRF02_AG. The second most common genetic form (9/164) was the recently described CRF22_01A1, and the rest were a collection of 4 different subtypes (A2, D, F2, G) and 6 different CRFs (-01, -11, -13, -18, -25, -37). Remarkably, 10.4% of HIV-1 genomes detected (17/164) were heretofore undescribed unique recombinant forms (URF) present in only a single person. Nearly full genome sequencing was completed for 78 of the viruses of interest. HIV genetic diversity was commonplace in rural villages: 12 villages each had at least one newly detected URF, and 9 villages had two or more.</p> <p>Conclusions</p> <p>These results show that while CRF02_AG dominated the HIV strains in the rural villages, the remainder of the viruses had tremendous genetic diversity. Between the trans-species transmission of SIV<sub>cpz </sub>and the dispersal of pandemic HIV-1, there was a time when we hypothesize that nascent HIV-1 was spreading, but only to a limited extent, recombining with other local HIV-1, creating a large variety of recombinants. When one of those recombinants began to spread widely (i.e. became epidemic), it was recognized as a subtype. We hypothesize that the viruses in these remote Cameroon villages may represent that pre-epidemic stage of viral evolution.</p
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