Strategic HIV Case Findings among Infants at Different Entry Points of Health Facilities in Cameroon: Optimizing the Elimination of Mother-To-Child Transmission in Low- and- Middle-Income Countries.

Background: HIV case finding is an essential component for ending AIDS, but there is limited evidence on the effectiveness of such a strategy in the pediatric population. We sought to determine HIV positivity rates among children according to entry points in Cameroon.

Methods: A facility-based survey was conducted from January 2015 to December 2019 among mother-child couples at various entry points of health facilities in six regions of Cameroon.

Dynamics and durability of HIV-1 neutralization are determined by viral replication.

Human immunodeficiency virus type 1 (HIV-1)-neutralizing antibodies (nAbs) that prevent infection are the main goal of HIV vaccine discovery. But as no nAb-eliciting vaccines are yet available, only data from HIV-1 neutralizers-persons with HIV-1 who naturally develop broad and potent nAbs-can inform about the dynamics and durability of nAb responses in humans, knowledge which is crucial for the design of future HIV-1 vaccine regimens. To address this, we assessed HIV-1-neutralizing immunoglobulin G (IgG) from 2,354 persons with HIV-1 on or off antiretroviral therapy (ART).

Inflammatory profile of vertically HIV-1 infected adolescents receiving ART in Cameroon: a contribution toward optimal pediatric HIV control strategies.

Antiretroviral therapy (ART) has improved the lifespan of people living with HIV. However, their immune system remains in a state of sustained activation/inflammation, which favors viral replication and depletion of helper T-cells with varying profiles according to ART-response. We herein sought to ascertain the inflammatory profile of adolescents living with perinatal HIV-1 infection (ALPHI) receiving ART in an African context.

Performance of immunochromatographic and immunoenzymatic techniques in the diagnosis of toxoplasmosis in pregnant women in Cameroon: need for harmonization.

Introduction: in order to contribute to the improvement of the management of toxoplasmosis in pregnant women in Cameroon, performance of two techniques commonly used in the diagnosis of toxoplasmosis was evaluated.

Methods: a total of 541 pregnant women were recruited from seven hospitals in two Regions of Cameroon, of which 63% (341: Batch1) were from health facilities (HF) using a immunochromatographic technique (ICT) as a screening test for toxoplasmosis, and 37% (200: Batch2) from those using an immunoenzymatic technique (IEZ). On each sample, Ig (Immunoglobulin) G (IgG) and IgM were tested by three techniques: a Rapid Diagnostic Test (RDT), an Enzyme Linked Immuno Sorbent Assay (ELISA) and a Vidas Enzyme-linked fluorescent assay taken as reference (VIDAS/ELFA).

The mother-to-child transmission of HIV-1 and profile of viral reservoirs in pediatric population: A systematic review with meta-analysis of the Cameroonian studies.

Background: The mother-to-child transmission of HIV-1 (MTCT) remains on the major route of HIV-transmission among pediatric populations in Africa. Though a prevention of MTCT (PMTCT) high-priority country, data on the MTCT burdens in Cameroon remains fragmented.

Objective: We sought to assess the pooled MTCT rate, its risk-factors, and to characterize viral reservoirs of infected-children in Cameroon.

Antiretroviral Imprints and Genomic Plasticity of HIV-1 in Non-clade B: Implications for Treatment.

Combinational antiretroviral therapy (cART) is the most effective tool to prevent and control HIV-1 infection without an effective vaccine. However, HIV-1 drug resistance mutations (DRMs) and naturally occurring polymorphisms (NOPs) can abrogate cART efficacy. Here, we aimed to characterize the HIV-1 mutation landscape in Cameroon, where highly diverse HIV clades circulate, and identify novel treatment-associated mutations that can potentially affect cART efficacy.

Alteration of the gut fecal microbiome in children living with HIV on antiretroviral therapy in Yaounde, Cameroon.

Multiple factors, such as immune disruption, prophylactic co-trimoxazole, and antiretroviral therapy, may influence the structure and function of the gut microbiome of children infected with HIV from birth. In order to understand whether HIV infection altered gut microbiome and to relate changes in microbiome structure and function to immune status, virological response and pediatric ART regimens, we characterized the gut microbiome of 87 HIV-infected and 82 non-exposed HIV-negative children from Yaounde, a cosmopolitan city in Cameroon. We found that children living with HIV had significantly lower alpha diversity in their gut microbiome and altered beta diversity that may not be related to CD4+ T cell count or viral load.

First case of Dolutegravir and Darunavir/r multi drug-resistant HIV-1 in Cameroon following exposure to Raltegravir: lessons and implications in the era of transition to Dolutegravir-based regimens.

Background: Sub-Saharan African countries are transitioning to dolutegravir-based regimens, even for patients with extensive previous drug exposure, including first-generation integrase strand-transfer inhibitors (INSTI) such as raltegravir. Such exposure might have implications on cross-resistance to dolutegravir-based antiretroviral therapies (ART).

Case Presentation: We report a 65 years old Cameroonian, previously exposed to raltegravir, and failing on third-line treatment with multi-drug resistance to darunavir/r and dolutegravir.

Performance of the BD FACSPresto near to patient analyzer in comparison with representative conventional CD4 instruments in Cameroon.

Background: In the context of scaling the viral load in resource limited settings, following HIV infected patient's adults and children with CD4+ T-lymphocyte count still very important in settings where the decentralization of treatment still has some challenges. Effective HIV monitoring in these resource-constrained settings needs affordable and reliable CD4+ T lymphocytes enumeration methods. We investigated the validity of a BD FACSPresto POC which is a dedicated system for enumeration that uses immunofluorescent technologies.

Thrombocytopenia according to antiretroviral drug combinations, viremia and CD4 lymphocytes among HIV-infected patients in Cameroon: a snapshot from the City of Yaoundé.

Objective: Thrombocytopenia is an abnormal decrease in blood platelets, which can affect the prognosis of people living with HIV (PLHIV). In order to assess the burden of this haematological disorder, we evaluated the frequency of thrombocytopenia according to antiretroviral drug combinations, viremia and the immune status of PLHIV.

Results: A cross-sectional and analytical study was conducted from June to November 2016 among 310 PLHIV at the "Chantal BIYA" International Reference Centre, Yaoundé, Cameroon.

Near full genome characterization of HIV-1 unique recombinant forms in Cameroon reveals dominant CRF02_AG and F2 recombination patterns.

Introduction: In Cameroon, a manifold diversity of HIV strains exists with CRF02_AG and unique recombinant forms (URFs) being the predominant strains. In recent years, a steady increase in URFs and clade F2 viruses has been monitored through partial genome sequencing. There is an information gap in the characterization of emerging URFs along the full genome, which is needed to address the challenges URFs pose towards diagnosis, treatment and HIV-1 vaccine design.

Immune Correlates of Disease Progression in Linked HIV-1 Infection.

Genetic and immunologic analyses of epidemiologically-linked HIV transmission enable insights into the impact of immune responses on clinical outcomes. Human vaccine trials and animal studies of HIV-1 infection have suggested immune correlates of protection; however, their role in natural infection in terms of protection from disease progression is mostly unknown. Four HIV-1 Cameroonian individuals, three of them epidemiologically-linked in a polygamous heterosexual relationship and one incidence-matched case, were studied over 15 years for heterologous and cross-neutralizing antibody responses, antibody binding, IgA/IgG levels, antibody-dependent cellular cytotoxicity (ADCC) against cells expressing wild-type or CD4-bound Env, viral evolution, Env epitopes, and host factors including HLA-I alleles.

Development of a Versatile, Near Full Genome Amplification and Sequencing Approach for a Broad Variety of HIV-1 Group M Variants.

Near full genome sequencing (NFGS) of HIV-1 is required to assess the genetic composition of HIV-1 strains comprehensively. Population-wide, it enables a determination of the heterogeneity of HIV-1 and the emergence of novel/recombinant strains, while for each individual it constitutes a diagnostic instrument to assist targeted therapeutic measures against viral components. There is still a lack of robust and adaptable techniques for efficient NFGS from miscellaneous HIV-1 subtypes.

HIV-1 drug resistance testing is essential for heavily-treated patients switching from first- to second-line regimens in resource-limited settings: evidence from routine clinical practice in Cameroon.

Background: With the phase-out of stavudine (d4T), change to first-line regimens with zidovudine (AZT) or tenofovir (TDF) in resource-limited settings (RLS) might increase risks of cross-resistance to nucleos(t) ide reverse transcriptase inhibitors (NRTI). This would restrict the scope of switching to the World Health Organisation (WHO)-recommended standard second-line combinations (SLC) without HIV drug resistance (HIVDR)-testing in routine clinical practice.

Methods: An observational study was conducted among 101 Cameroonian patients (55.

Next-generation sequencing provides an added value in determining drug resistance and viral tropism in Cameroonian HIV-1 vertically infected children.

With limited and low-genetic barrier drugs used for the prevention of mother-to-child transmission (PMTCT) of HIV in sub-Saharan Africa, vertically transmitted HIV-1 drug-resistance (HIVDR) is concerning and might prompt optimal pediatric strategies.The aim of this study was to ascertain HIVDR and viral-tropism in majority and minority populations among Cameroonian vertically infected children.A comparative analysis among 18 HIV-infected children (7 from PMTCT-exposed mothers and 11 from mothers without PMTCT-exposure) was performed.

Short Communication: False Recent Ratio of the Limiting-Antigen Avidity Assay and Viral Load Testing Algorithm Among Cameroonians with Long-Term HIV Infection.

Current serological assays that are used for cross-sectional HIV incidence estimation have been shown to misclassify individuals with chronic infection. Limited information exists on the performance of cross-sectional incidence assays in Central Africa. HIV-positive individuals from Cameroon who were infected for at least 1 or 2 years were evaluated to determine the false recent ratio (FRR) of a two-assay algorithm, which includes the Limiting Antigen Avidity (LAg-Avidity) assay (normalized optical density units, ODn <1.

Multimethod Longitudinal HIV Drug Resistance Analysis in Antiretroviral-Therapy-Naive Patients.

The global intensification of antiretroviral therapy (ART) can lead to increased rates of HIV drug resistance (HIVDR) mutations in treated and also in ART-naive patients. ART-naive HIV-1-infected patients from Cameroon were subjected to a multimethod HIVDR analysis using amplification-refractory mutation system (ARMS)-PCR, Sanger sequencing, and longitudinal next-generation sequencing (NGS) to determine their profiles for the mutations K103N, Y181C, K65R, M184V, and T215F/Y. We processed 66 ART-naive HIV-1-positive patients with highly diverse subtypes that underlined the predominance of CRF02_AG and the increasing rate of F2 and other recombinant forms in Cameroon.

Contrasting antibody responses to intrasubtype superinfection with CRF02_AG.

HIV superinfection describes the sequential infection of an individual with two or more unrelated HIV strains. Intersubtype superinfection has been shown to cause a broader and more potent heterologous neutralizing antibody response when compared to singly infected controls, yet the effects of intrasubtype superinfection remain controversial. Longitudinal samples were analyzed phylogenetically for pol and env regions using Next-Generation Sequencing and envelope cloning.

HIV-1 Drug Susceptibility to Potential Second- and Third-Line Antiretroviral Regimens among Cameroonian Patients: Evidence from a Cross-sectional Design.

Background: Scale-up of antiretroviral therapy (ART) and the growing number of long-term treated patients may favor multi-HIV drug resistance (HIVDR) in resource-limited settings. Understanding the burden of HIVDR with ART-exposure may provide new insights for an effective long-term management of infected patients.

Methods: Sixty-six HIV-infected individuals (18 ART-naïve, 24 failing first-line, 24 failing second-line ART) living in Yaoundé-Cameroon were evaluated by sequencing protease-reverse transcriptase (PR-RT, n=62), envelope-V3 loop (V3, n=58) and integrase (IN, n=30) regions.

Hepatitis B and C Co-Infections in Some HIV-Positive Populations in Cameroon, West Central Africa: Analysis of Samples Collected Over More Than a Decade.

As people infected with the human immunodeficiency virus (HIV) in Sub-Saharan Africa live longer due to availability of antiretroviral treatment (ART), so is the rise of associated infections with their burdens on patients. But reliable data on the prevalence of co-infection with hepatitis B (HBV) or C (HCV) still remains sparse and many individuals with HIV do not know their co-infection status. This study attempted to estimate the seroprevalence and identify risk factors associated with hepatitis B and/or C co-infections in HIV-infected individuals from five Regions of Cameroon by screening 531 HIV infected subjects for the presence of HBV surface antigen (HBsAg) and antibodies to HCV (HCV-Ab).

Phylogenetics of HIV-1 subtype G env: Greater complexity and older origins than previously reported.

HIV-1 subtype G has played an early and central role in the emergent complexity of the HIV-1 group M (HIV-1M) epidemic in central/west Africa. Here, we analysed new subtype G env sequences sampled from 8 individuals in Yaoundé, Cameroon during 2007-2010, together with all publically available subtype G-attributed full-length env sequences with known sampling dates and locations. We inferred that the most recent common ancestor (MRCA) of the analysed subtype G env sequences most likely occurred in ∼1953 (95% Highest Posterior Density interval [HPD] 1939-1963): about 15 years earlier than previous estimates.

Use of amplification refractory mutation system PCR assay as a simple and effective tool to detect HIV-1 drug resistance mutations.

Access to genotyping assays to determine successful antiretroviral treatment (ART) is limited in resource-constrained settings by high cost, suggesting the need for a cost-effective and simplified method to identify HIV-1 drug resistance (HIVDR) mutations. In this study, an amplification refractory mutation system (ARMS)-PCR assay was developed and used to investigate the most frequent HIVDR mutations affecting first-line ART in settings where WHO ART guidelines are applied. Seventy-five HIV-positive (HIV(+)) samples from Cameroon were used to assess the performance of this assay.

Drug resistance among drug-naive and first-line antiretroviral treatment-failing children in Cameroon.

Background: Scale-up to antiretroviral therapy (ART) requires surveillance for HIV drug resistance. With the goal of attaining 100% pediatric ART coverage in Cameroon, strategies to limit the spread of HIV resistance among children are very important.

Methods: From June 2009 through February 2011, 92 HIV-1-infected children (41 ART-naive, 51 failing first-line ART) living in Yaoundé, Cameroon, were enrolled; HIV-1 Prot-RT genotypic resistance testing (GRT) was performed using an inhouse assay.