Publications

BACKGROUND: Children under the age of 15 represent 3% of the global population living with HIV, 9% of new HIV infections, and 12% of all deaths related to AIDS. This study describes the predictors of HIV among children aged 0-14 years in Nigeria.

METHODS: We analyzed data from a weighted sample of 84 130 443 children aged 0-14 years, collected as part of the 2018 Nigeria HIV/AIDS Indicator and Impact Survey (NAIIS), the largest in the world. Descriptive statistics, chi-square tests, and the Kruskal Wallis Test were employed to assess the differences between HIV-positive children in urban versus rural areas. Adjusted odds ratio (AOR) and 95% Confidence Interval (CI) from logistic regression models were used to delineate predictors of pediatric HIV.

RESULTS: Weighted data on a total of over 84 million children was analyzed, with a slightly higher median age and school enrollment observed among urban residents. HIV prevalence was low overall, at 0.1% in urban areas and 0.2% in rural areas. Among HIV-positive children, maternal awareness of HIV status was a key determinant: children whose mothers were aware of their HIV-positive status had significantly lower likelihood of HIV infection (AOR: 0.02; CI: 0.01-0.06; p <0.001). Conversely, having a living mother (AOR: 6.57; CI: 1.75-24.7; p = 0.005) and younger maternal age were associated with increased likelihood of pediatric HIV. Other sociodemographic and contextual factors, including child's age, sex, residence, school enrollment, and conflict zone status were not significantly associated with pediatric HIV acquisition.

CONCLUSIONS: The findings showed that maternal health significantly influences pediatric HIV outcomes. Children of HIV-positive mothers were less likely to acquire HIV, likely due to ART and PMTCT programs. These findings emphasize the need for strengthened targeted interventions focusing on maternal care, HIV prevention, and healthcare access among vulnerable populations.

OBJECTIVES: HIV remains highly prevalent in sub-Saharan Africa, home to approximately 66 % of all people living with HIV and 85 % of children and adolescents living with HIV globally. The region also experiences the highest levels of armed conflict, resulting in a dual burden of violence and infectious diseases like HIV. Despite these challenges, few studies have explored the impact of war and armed conflict on HIV transmission among adolescents in sub-Saharan Africa. To address this gap in the literature, our study examines HIV risk behaviors among adolescents in both conflict and non-conflict zones of Nigeria.

METHODS: This was a cross-sectional study of adolescents aged 15-19 years, identified through the Nigeria HIV/AIDS Indicator and Impact Survey (NAIIS). We assessed the prevalence of HIV risk behaviors across the entire country, stratified by conflict zone status. Bivariate associations between risk behaviors and conflict status were evaluated using the chi-square test. To identify factors associated with HIV infection among adolescents, we employed survey-weighted logistic regression models, reporting adjusted odds ratios (AOR) and 95 % confidence intervals (CI).

RESULTS: We analyzed 20,518,667 weighted records of adolescents aged 15-19 years, from both conflict (11 %) and non-conflict zones (89 %) of Nigeria. Despite the majority of adolescents residing in non-conflict zones, we found that high-risk behaviors for HIV, such as the non-use of condoms, were more prevalent in conflict zones. However, transactional sex and having two or more sexual partners were significantly higher among adolescents in non-conflict areas. Notably, the risk of HIV infection was over three times higher among adolescents who did not use condoms during sexual intercourse (AOR: 3.22, CI: 1.13, 9.19; p 0.029). Additional risk factors included younger age, educational status, engagement in transactional sex, and having multiple sexual partners.

CONCLUSIONS: This study reports the risk behaviors that contribute to HIV infection among adolescents, particularly within conflict settings. Our findings highlight the link between conflict and heightened HIV risk behaviors among Nigerian adolescents. By identifying these factors and understanding the unique challenges faced by adolescents in conflict zones, more effective, youth-friendly reproductive health programs can be developed for regions impacted by war and conflict.

BACKGROUND: Early diagnosis of TB with drug susceptibility testing (DST) is critical to achieve successful treatment outcomes. We aimed to develop and test a novel colorimetric, 12-well, thin-layer agar-based test to assess its accuracy for TB diagnosis and DST in a clinical setting in Southern Mozambique.

METHODS: Development of the first prototype of the second generation (2G) test in the laboratory setting followed by a cross-sectional diagnostic accuracy study with consecutive recruitment of subjects with microbiologically confirmed TB using GeneXpert MTB/RIF Ultra.

RESULTS: In the laboratory setting, the 2G test showed 100% accuracy in detecting resistance of genotypically characterised drug-resistant Mycobacterium tuberculosis strains. In the clinical setting, the sensitivity of the 2G test to detect M.tb complex versus Xpert and Mycobacteria Growth Indicator Tube (MGIT) culture using fresh sputa was 45.9% and 45.2%, respectively. The 2G test sensitivity versus MGIT decreased to 23.1% when using frozen decontaminated sputum samples.

CONCLUSION: In the clinical setting, the 2G test showed a low sensitivity versus Xpert and MGIT. The 2G test sensitivity was lower when frozen instead of fresh sputa was used. Despite these results, important information was collected to further improve this 2G test prototype and its implementation in resource-constrained settings.

Over the past two decades, betacoronaviruses (β-CoVs) have caused two epidemics and a pandemic and remain a high risk for future outbreaks through zoonotic transmissions, highlighting the need for broad biomedical countermeasures. Here, we describe a convalescent human monoclonal antibody (mAb 1871) that targets the S2 subunit of the coronavirus spike protein, with broad β-CoVs binding and sarbecovirus neutralization. Cryo-electron microscopy analysis revealed that mAb 1871 binds the upstream helix of the S2 subunit, interacting with partially conserved residues, providing a molecular basis for its cross-reactivity. Though less potent than receptor-binding domain-directed antibodies-approximately 500-fold lower neutralization potency than the emergency use authorized receptor-binding domain (RBD)-directed Pemgarda mAb against wild-type SARS-CoV-2-mAb 1871 provides protective efficacy in a mouse model. Notably, Fc effector functions are critical for its in vivo protection. This study further highlights the Fc dependence of S2-directed antibodies for in vivo protection and identifies a conserved epitope in the S2 subunit as a potential target of broad-β-CoVs countermeasures.IMPORTANCEBats and pangolins are natural reservoirs of betacoronaviruses (β-CoVs) and continue to pose a significant risk for future outbreaks through zoonotic transmissions. This highlights the need for effective countermeasures to prevent future pandemics. While neutralizing antibodies targeting the receptor-binding domain of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) received emergency use authorization, many have lost efficacy as the virus evolved, and authorizations have been revoked. In contrast to the S1 subunit, the spike protein S2 subunit is more conserved across β-CoVs, making it an attractive target for the development of broadly neutralizing antibodies. Here, we describe a human mAb that targets a conserved epitope in the S2 subunit, demonstrating broad β-CoV binding, sarbecovirus neutralization, and in vivo protection mediated by Fc effector functions in a mouse model. These findings have important implications for pan-β-CoVs therapeutics and vaccine development.

BACKGROUND: The accessible, easy to use and timely, diagnosis of tuberculosis (TB) drug-susceptibility, is often challenging, particularly in resource-constrained settings. We therefore evaluated the phenotypic thin-layer agar based MDR/XDR-TB Colour Test, also known as the "First Generation (1G) Color Plate Test (TB-CX)" performance for detecting resistance of Mycobacterium tuberculosis (Mtb) isolates to selected anti-TB drugs versus other tests routinely used in our setting.

METHODS: A cross-sectional study was conducted on Mtb clinical isolates stored at the Armauer Hansen Research Institute TB laboratory in Addis Ababa, Ethiopia. Drug-susceptibility testing was performed on 78 Mtb isolates for isoniazid, rifampicin, and moxifloxacin using the Colour Test and the Indirect Proportional Method (IPM) "in house" assay. Isoniazid and rifampicin were also evaluated by the Mycobacterial Growth Indicator Tube (MGIT) commercially available assay. Test accuracy was calculated as % agreement with 95% confidence intervals (95%CI).

RESULTS: The median (range) times in days determining Mtb resistance or susceptibility for the Colour Test, IPM and MGIT assays were of 9 (5-18), 15 (13-18) and 19 (14-21) days, respectively. The Colour Test provided results significantly (p < 0.001) more rapidly than the IPM or MGIT assays. The colour test showed a sensitivity and specificity of 91%(95% CI: 87-96) and 87%(95% CI:75-95) for detecting isoniazid resistance,and 93%(95% CI:81-99) and 92%(95% CI:82-97) for detecting rifampicin resistance, respectively, when compared to MGIT DST. For detecting MDR-TB the sensitivity and specificity were 90%(95% CI:76-97) and 96%(95% CI:88-99),respectively. The colour test showed a sensitivity of 97%(95%CI = 87-100) and specificity of 89% (95%CI = 79-96) for detecting isoniazid resistance while for rifampicin resistance,it showed a sensitivity of 82%(95%CI = 64-93)and a specificity of 80%(95% CI = 68-90) rifampicin resistance. Colour Test accuracy compared to IPM to detect isoniazid, rifampicin resistance and MDR-TB was 92% (95%CI = 86-98), 81% (95%CI = 72-90), and 90% (95%CI = 83-96). IPM test accuracy compared to MGIT DST for detecting isoniazid and rifampicin resistance and MDR-TB was 91% (95%CI = 85-97), 83% (95%CI = 75-92), and 85% (95%CI = 77-93), respectively. Moxifloxacin drug-susceptibility testing could not be assessed because only two isolates showed evidence of resistance.

CONCLUSION: The accuracy of Mtb drug-susceptibility testing was similar comparing: Colour Test versus IPM, Colour Test versus MGIT; and comparing IPM versus MGIT. The Colour Test was easy to use and determined drug-susceptibility significantly more rapidly than the IPM and MGIT assays. Thus, implementing the Colour Test in clinical settings could make drug-susceptibility testing more accessible and rapid in high TB burden, and resource-constrained settings, including in Ethiopia.

BACKGROUND AND OBJECTIVE: Human immunodeficiency virus (HIV) is a major public health concern among pregnant women in Nigeria, with seven in every hundred women likely to have an HIV infection. Understanding factors associated with HIV infection among pregnant women is critical to improving prevention strategies, especially in conflict regions. This study investigates demographic, socio-economic, and behavioral determinants of HIV among pregnant women in Nigeria, with conflict exposure included as a key predictor in the analysis.

METHODS: This study is a cross-sectional design using data from the 2018 Nigeria HIV/Acquired Immunodeficiency Syndrome (AIDS) Indicator and Impact Survey, the largest population-based HIV survey globally, implemented between July and December 2018 across all 36 states and the Federal Capital Territory of Nigeria. We analyzed weighted data from 3,879,192 pregnant women (both HIV-positive and negative), conducting bivariate and multivariate analyses to identify predictors of HIV infection among women aged 15-49 years while adjusting for potential confounders. Adjusted Odds Ratios (AORs) with 95% confidence intervals (CIs) were generated using unconditional logistic regression models to determine significant predictors.

RESULTS: Our analysis revealed that women in conflict zones were younger, less educated, and more likely to be in polygynous marriages and the lowest wealth quintile compared to those in non-conflict zones. In a multivariable analysis, residence in a conflict zone was associated with nearly twofold adjusted odds of HIV positivity (AOR = 1.93; CI: 0.98-3.82; p = 0.057). Increasing maternal age (AOR = 1.06; CI: 1.02-1.10; p = 0.002) and middle to fourth wealth quintile status (AOR = 4.10 and 3.80, respectively; p < 0.05) were significantly associated with a higher likelihood of HIV infection. Recent non-marital sexual activity was also significantly associated with HIV positivity (AOR = 2.96; p = 0.037).

CONCLUSION AND GLOBAL HEALTH IMPLICATIONS: The study identifies conflict exposure and socio-economic status as significant predictors of HIV infection among pregnant women in Nigeria. Our analysis reveals important demographic, socio-economic, and behavioral factors associated with HIV prevalence in this population. These findings underscore the need for comprehensive HIV prevention strategies that address the complex interplay of social determinants, particularly in vulnerable populations.

BACKGROUND: The COVID 19 pandemic led to significant disruptions in health services, including immunisation programs, which contributed to a major post-pandemic diphtheria outbreak in Kano State, Nigeria. This region accounted for 85% of the nation's documented diphtheria cases.

METHODS: This study examined the epidemiology, clinical characteristics, and mortality outcomes of cases diagnosed between February 2022 and April 2024. Data were collected through the Surveillance Outbreak Response Management and Analysis System (SORMAS), and case definitions followed WHO guidelines. Case fatality rate (CFR) was calculated, and a logistic regression model was used to assess mortality-related risk factors, reporting adjusted odds ratios (AOR).

FINDINGS: A total of 18,320 cases were analysed, with the outbreak showing a bimodal distribution. The primary peak occurred in August 2023, followed by a smaller secondary peak in early 2024. The case fatality rate (CFR) was 4.5%. Patients who were not vaccinated had more than double the likelihood of death compared to fully vaccinated individuals (AOR 2.45; 95% CI: 2.05, 2.94, p < 0.0001; logistic regression). Similarly, patients without vaccination documentation also had greater odds, with more than 87% increase likelihood of mortality compared to fully vaccinated individuals (AOR 1.87, 95% CI: 1.27, 2.68, p < 0.0001; logistic regression).

INTERPRETATION: Our study reinforces previous reports of the weakening preventive health delivery systems in resource constrained settings, particularly after the disruptions caused by the COVID 19 pandemic leading to the resurgence of vaccine preventable diseases, such as diphtheria. These highlight the need for improved vaccination coverage and surveillance systems.

FUNDINGS: This research did not receive any external funding.

UNLABELLED: We previously reported that live, but not dead, virulent Mycobacterium tuberculosis (Mtb) H37Rv bacilli induce cell death in human lung fibroblast cell lines, MRC-5, MRC-9, and TIG-1. Here, using two distinct Mtb strains from two different lineages (HN878 lineage 2 and H37Rv lineage 4), we confirmed cell death at day 2 after infection with a device that measures cell growth/cytotoxicity in real time (Maestro-Z [AXION]). Mtb bacilli uptake by the fibroblast was confirmed with a transmission electron microscope on day 2. Expressions of inflammatory cytokines and interleukin (IL)-1β, IL-6, and IL-8 were observed when exposed to live, but not dead bacteria. The cell death of fibroblasts induced by both Mtb strains tested was prevented by caspase-1/4 and NLRP3 inflammasome inhibitors, but not by caspase-3 and caspase-9 inhibitors. Therefore, we classified the fibroblast cell death by Mtb infection as pyroptosis. To investigate the biological and pathological relevance of fibroblast cell death by Mtb infection, we performed dual RNA-Seq analysis on Mtb within fibroblasts and Mtb-infected fibroblasts at day 2. In Mtb bacilli tcrR, secE2, ahpD, and mazF8 genes were highly induced during infection. These genes play roles in survival in a hypoxic environment, production of a calcium-binding protein-inducing cytokine, and regulation of transcription in a toxin-antitoxin system. The gene expressions of IL-1β, IL-6, and IL-8, caspase-4, and NLRP3, but not of caspase-3 and caspase-9, were augmented in Mtb bacilli-infected fibroblasts. Taken together, our study suggests that Mtb bacilli attempt to survive in lung fibroblasts and that pyroptosis of the host fibroblasts activates the immune system against the infection.

IMPORTANCE: The role of "non-classical immune cells," that is, fibroblasts, epithelial cells, adipocytes, etc., except for the "classical immune cells," that is, macrophages and lymphoid cells, is not well known in the infection of Mtb bacilli. We have previously found that live, but not dead, Mtb bacilli induce cell death in human lung fibroblasts, except in human macrophages and monocytes. The present study reveals that fibroblasts ingest Mtb bacilli the same as macrophages and that in vivo Mtb bacilli within fibroblasts attempt to survive in the host cells, and pyroptosis, including the production of inflammatory cytokines, is induced in the Mtb-infected fibroblasts. Our results suggest that pyroptosis of the host fibroblasts activates the immune system against the infection.