Factors Influencing HIV Drug Resistance among Pregnant Women in Luanda, Angola: Findings from a Cross-Sectional Study

Trends in active hepatitis B virus infection and associated risk factors among blood donor candidates from Luanda, Angola

Hepatitis B virus (HBV) infection is a global public health concern with a high burden in the African region. Assessing trends in HBV infection over time can provide insights into the effectiveness of prevention/treatment strategies in different settings. Herein, we investigate trends in active HBV infection and associated risk factors among blood donor candidates from Luanda, Angola. This was a retrospective study conducted with 96,654 medical records of blood donors consulted between 2018 and 2022 at the Angolan National Blood Institute. Participants were screened for hepatitis B surface antigen (HBsAg). Chi-square, Prevalence Ratio, and logistic regression were used to analyse interactions between demographic variables and were deemed significant when p < 0.05. Active HBV infection was 10% (95% CI: 9.4-10.6). Men (AOR: 1.38, p < 0.001), employed (AOR: 3.25, p < 0.001) and non-urbanised regions (AOR: 1.16, p = 0.019), were more likely to contract the HBV, while aged 30 years or older (AOR: 0.78, p < 0.001) and married (AOR: 0.66, p < 0.001), were less likely to contract the infection. From 2018 to 2022, HBV infections increased from 18.2 to 21.9%. Infections increased in under 30 years (31.3-52.5%, p < 0.001), males (91.1 to 91.8%, p = 0.149), urbanised regions (2.7 to 3.3%, p = 0.538), and unmarried (93.9 to 95.8%, p = 0.019). We revealed a highly active HBV infection over the past 5 years in the adult population of Luanda, Angola. Age, gender, occupation, place of residence and marital status have influenced the dissemination of HBV in Angola. Our findings may facilitate the planning and evaluation of the HBV control program in Angola.

Seroprevalence and Risk Factors of STIs among Rejected Blood Donors at the National Blood Transfusion Service in Angola

Sexually transmitted infections (STIs) are a global health concern. Blood donation centres employ comprehensive screening measures to identify donors with STIs, such as HIV, HBV, HCV, and syphilis, which can also transmitted through blood transfusions. Herein, we investigated the seroprevalence of STIs and demographic determinants related to multiple infections among rejected blood donors at the National Blood Transfusion Service (NBTS) in Angola. This was a cross-sectional study conducted with 1885 rejected blood donors serologically screened for anti-HBsAg, anti-HCV, anti-HIV, and anti-TP during pre-donation screening at the NBTS, located in Luanda, the capital city of Angola, between March 2022 to July 2023. Overall, HIV (11.2%), HBsAg (71.7%), HCV (9.30%), and Syphilis (8.80%) were detected. The multiple infection rate was 2.30%. HIV and syphilis were associated with age (p < 0.05). HBV was related to age, areas of residence, and occupation (p < 0.05). HCV was related to areas of residence and educational level (p < 0.05). No relationship was observed between demographic characteristics with multiple infections (p > 0.05). Individuals aged over 40 years (OR: 2.48, p = 0.393), males (OR: 1.33, p = 0.639), non-urbanized regions (OR: 1.18, p = 0.594), low educational level (OR: 3.46, p = 0.222), and employed (OR: 1.34, p = 0.423), were more likely to have multiple infections. Our results demonstrate a high rate of circulation of STIs among blood donation candidates in Luanda. HBV was the main reason for the rejection of candidates. However, nucleic acid-based screening techniques should be considered to ensure better quality screening for occult infections in blood donor candidates.

MARVEL-minimising the emergence and dissemination of HIV-1 drug resistance in Portuguese-speaking African Countries (PALOP): low-cost portable NGS platform for HIV-1 surveillance in Africa

BACKGROUND

HIV-1 infections remain a global public health concern. Scaled-up antiretroviral treatment (ART) is crucial for reducing morbidity and mortality related to HIV/AIDS. The emergence of drug-resistance mutations (DRMs) compromises viral suppression and contributes to the continued HIV-1 transmission. Several reports indicate a recent increase in acquired (ADR) and transmitted (TDR) drug resistance in Africa, probably linked to the lack of implementation of HIV drug resistance (HIVDR) testing and suboptimal treatment adherence. Herein, we will develop a low-cost protocol using third-generation sequencing (Oxford Nanopore Technology) for HIV-1 surveillance in Portuguese-speaking African Countries - PALOP [Angola (AO), Cape Verde (CV), Mozambique (MZ), and Sao Tome & Principe (STP)].

METHODS

This is a multicentric cross-sectional study that includes around 600 adult patients newly diagnosed with HIV-1 in the PALOP. An epidemiological questionnaire previously validated by our research team will be used to collect sociodemographic and clinical data. Also, whole blood samples will be collected and the plasma samples will be subjected to drug resistance testing using an in-house low-cost NGS protocol. Data analysis will involve bioinformatics, biostatistics and machine learning techniques to generate accurate and up-to-date information about HIV-1 genetic diversity, ADR and TDR.

DISCUSSION

The implementation of this low-cost NGS platform for HIV-1 surveillance in the PALOP will allow: (i) to increase DRM surveillance capacity in resource-limited settings; (ii) to understand the pattern and determinants of dissemination of resistant HIV-1 strains; and (iii) to promote the development of technical and scientific skills of African researchers for genomic surveillance of viral pathogens and bioinformatics analysis. These objectives will contribute to reinforcing the capacity to combat HIV infection in Africa by optimizing the selection of ART regimens, improving viral suppression, and reducing ADR or TDR prevalence in PALOPs, with relevant implications for public health.

HIV-1 diversity and pre-treatment drug resistance in the era of integrase inhibitor among newly diagnosed ART-naïve adult patients in Luanda, Angola

The surveillance of drug resistance in the HIV-1 naïve population remains critical to optimizing the effectiveness of antiretroviral therapy (ART), mainly in the era of integrase strand transfer inhibitor (INSTI) regimens. Currently, there is no data regarding resistance to INSTI in Angola since Dolutegravir-DTG was included in the first-line ART regimen. Herein, we investigated the HIV-1 genetic diversity and pretreatment drug resistance (PDR) profile against nucleoside/tide reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs), protease inhibitors (PIs), and INSTIs, using a next-generation sequencing (NGS) approach with MinION, established to track and survey DRMs in Angola. This was a cross-sectional study comprising 48 newly HIV-diagnosed patients from Luanda, Angola, screened between March 2022 and May 2023. PR, RT, and IN fragments were sequenced for drug resistance and molecular transmission cluster analysis. A total of 45 out of the 48 plasma samples were successfully sequenced. Of these, 10/45 (22.2%) presented PDR to PIs/NRTIs/NNRTIs. Major mutations for NRTIs (2.2%), NNRTIs (20%), PIs (2.2%), and accessory mutations against INSTIs (13.3%) were detected. No major mutations against INSTIs were detected. M41L (2%) and I85V (2%) mutations were detected for NRTI and PI, respectively. K103N (7%), Y181C (7%), and K101E (7%) mutations were frequently observed in NNRTI. The L74M (9%) accessory mutation was frequently observed in the INSTI class. HIV-1 pure subtypes C (33%), F1 (17%), G (15%), A1 (10%), H (6%), and D (4%), CRF01_AG (4%) were observed, while about 10% were recombinant strains. About 31% of detected HIV-1C sequences were in clusters, suggesting small-scale local transmission chains. No major mutations against integrase inhibitors were detected, supporting the continued use of INSTI in the country. Further studies assessing the HIV-1 epidemiology in the era of INSTI-based ART regimens are needed in Angola.

Long-Term and Low-Level Envelope C2V3 Stimulation by Highly Diverse Virus Isolates Leads to Frequent Development of Broad and Elite Antibody Neutralization in HIV-1-Infected Individuals

A minority of HIV-1-infected patients produce broadly neutralizing antibodies (bNAbs). Identification of viral and host correlates of bNAb production may help develop vaccines. We aimed to characterize the neutralizing response and viral and host-associated factors in Angola, which has one of the oldest, most dynamic, and most diverse HIV-1 epidemics in the world. Three hundred twenty-two HIV-1-infected adults from Angola were included in this retrospective study. Phylogenetic analysis of C2V3C3 env gene sequences was used for virus subtyping. Env-binding antibody reactivity was tested against polypeptides comprising the C2, V3, and C3 regions. Neutralizing-antibody responses were determined against a reference panel of tier 2 Env pseudoviruses in TZM-bl cells; neutralizing epitope specificities were predicted using ClustVis. All subtypes were found, along with untypeable strains and recombinant forms. Notably, 56% of the patients developed cross neutralizing, broadly neutralizing, or elite neutralizing responses. Broad and elite neutralization was associated with longer infection time, subtype C, lower CD4+ T cell counts, higher age, and higher titer of C2V3C3-specific antibodies relative to failure to develop bNAbs. Neutralizing antibodies targeted the V3-glycan supersite in most patients. V3 and C3 regions were significantly less variable in elite neutralizers than in weak neutralizers and nonneutralizers, suggesting an active role of V3C3-directed bNAbs in controlling HIV-1 replication and diversification. In conclusion, prolonged and low-level envelope V3C3 stimulation by highly diverse and ancestral HIV-1 isolates promotes the frequent elicitation of bNAbs. These results provide important clues for the development of an effective HIV-1 vaccine. IMPORTANCE Studies on neutralization by antibodies and their determinants in HIV-1-infected individuals have mostly been conducted in relatively recent epidemics caused by subtype B and C viruses. Results have suggested that elicitation of broadly neutralizing antibodies (bNAbs) is uncommon. The mechanisms underlying the elicitation of bNAbs are still largely unknown. We performed the first characterization of the plasma neutralizing response in a cohort of HIV-1-infected patients from Angola. Angola is characterized by an old and dynamic epidemic caused by highly diverse HIV-1 variants. Remarkably, more than half of the patients produced bNAbs, mostly targeting the V3-glycan supersite in HIV-1. This was associated with higher age, longer infection time, lower CD4+ T cell counts, subtype C infection, or higher titer of C2V3C3-specific antibodies relative to patients that did not develop bNAbs. These results may help develop the next generation of vaccine candidates for HIV-1.