Entangled epidemics: tackling vaccine-preventable diseases in the era of frequent epidemics in Africa.

Whilst the largely limited health system and funds are already overstretched while responding to multiple epidemics, ongoing vaccine-preventable diseases (VPD) including polio and measles continue to be a public health threat and expose the weaknesses of the public health system in many African countries. The surge in VPD outbreaks during epidemics appears to be a common trend in Africa, often due to reduced vaccination coverage. The World Health Organization reported that, in 2021, nearly 25 million children missed their first measles dose, 5 million more than in 2019. The drop in childhood immunizations was partly attributed to the COVID-19 pandemic which has caused significant interruption in public health services delivery and reduced vaccination coverage. Vaccines help reduce the incidence of VPD. Therefore, effective VPD outbreak response mechanisms and strategies that include ramping up catch-up campaigns for immunization during epidemic troughs including the provision of vaccines outside clinics as well as assessing newer vaccine delivery models during pandemics are essential to minimize the impact of VPD outbreaks during emerging epidemics. Ensuring access to vaccines to address outbreaks and provide supplemental vaccination is essential if we are to be a VPD-free region.

Need assessment for HIV drug resistance testing and landscape of current and future technologies in low- and middle-income countries.

Resistance to antiretroviral drugs used to treat HIV is an important and evolving concern, particularly in low- and middle-income countries (LMICs) which have been impacted to the greatest extent by the HIV pandemic. Efforts to monitor the emergence and transmission of resistance over the past decade have shown that drug resistance-especially to the nucleoside analogue and non-nucleoside reverse transcriptase inhibitors-can (and have) increased to levels that can jeopardize the efficacy of available treatment options at the population level. The global shift to integrase-based regimens as the preferred first-line therapy as well as technological advancements in the methods for detecting resistance have had an impact in broadening and diversifying the landscape of and use case for HIV drug resistance testing. This review estimates the potential demand for HIV drug resistance tests, and surveys current testing methodologies, with a focus on their application in LMICs.

First case report of a perinatally HIV-infected infant with HIV resistance to dolutegravir associated with tenofovir/lamivudine/dolutegravir use in mothers.

Perinatally HIV-infected infants can be infected with a drug-resistant virus or select for drug resistance by exposure to sub-therapeutic levels of maternal antiretroviral drugs present in breastmilk or from sub-therapeutic infant prophylaxis. We report a case of dolutegravir resistance detected in a treatment-naive perinatally HIV-infected infant whose mother was receiving tenofovir/lamivudine/dolutegravir. This case was detected during a national survey of HIV drug resistance in Haiti amongst infants testing positive for HIV through the national early infant diagnosis program between April 2020 and March 2021. This unique case underscores the need for prompt management of high viral loads in pregnant and breastfeeding women and supports HIV drug resistance surveillance efforts targeted at antiretroviral therapy-naive infants born to mothers in low-and middle-income countries.

Recommendations on data sharing in HIV drug resistance research.

• Human immunodeficiency virus (HIV) drug resistance has implications for antiretroviral treatment strategies and for containing the HIV pandemic because the development of HIV drug resistance leads to the requirement for antiretroviral drugs that may be less effective, less well-tolerated, and more expensive than those used in first-line regimens. • HIV drug resistance studies are designed to determine which HIV mutations are selected by antiretroviral drugs and, in turn, how these mutations affect antiretroviral drug susceptibility and response to future antiretroviral treatment regimens. • Such studies collectively form a vital knowledge base essential for monitoring global HIV drug resistance trends, interpreting HIV genotypic tests, and updating HIV treatment guidelines. • Although HIV drug resistance data are collected in many studies, such data are often not publicly shared, prompting the need to recommend best practices to encourage and standardize HIV drug resistance data sharing. • In contrast to other viruses, sharing HIV sequences from phylogenetic studies of transmission dynamics requires additional precautions as HIV transmission is criminalized in many countries and regions. • Our recommendations are designed to ensure that the data that contribute to HIV drug resistance knowledge will be available without undue hardship to those publishing HIV drug resistance studies and without risk to people living with HIV.

Predicted effects of the introduction of long-acting injectable cabotegravir pre-exposure prophylaxis in sub-Saharan Africa: a modelling study.

BACKGROUND: Long-acting injectable cabotegravir pre-exposure prophylaxis (PrEP) is recommended by WHO as an additional option for HIV prevention in sub-Saharan Africa, but there is concern that its introduction could lead to an increase in integrase-inhibitor resistance undermining treatment programmes that rely on dolutegravir. We aimed to project the health benefits and risks of cabotegravir-PrEP introduction in settings in sub-Saharan Africa. METHODS: With HIV Synthesis, an individual-based HIV model, we simulated 1000 setting-scenarios reflecting both variability and uncertainty about HIV epidemics in sub-Saharan Africa and compared outcomes for each with and without cabotegravir-PrEP introduction. PrEP use is assumed to be risk-informed and to be used only in 3-month periods (the time step for the model) when having condomless sex. We consider three groups at risk of integrase-inhibitor resistance emergence: people who start cabotegravir-PrEP after (unknowingly) being infected with HIV, those who seroconvert while on PrEP, and those with HIV who have residual cabotegravir drugs concentrations during the early tail period after recently stopping PrEP. We projected the outcomes of policies of cabotegravir-PrEP introduction and of no introduction in 2022 across 50 years. In 50% of setting-scenarios we considered that more sensitive nucleic-acid-based HIV diagnostic testing (NAT), rather than regular antibody-based HIV rapid testing, might be used to reduce resistance risk. For cost-effectiveness analysis we assumed in our base case a cost of cabotegravir-PrEP drug to be similar to oral PrEP, resulting in a total annual cost of USD$144 per year ($114 per year and $264 per year considered in sensitivity analyses), a cost-effectiveness threshold of $500 per disability-adjusted life years averted, and a discount rate of 3% per year. FINDINGS: Reflecting our assumptions on the appeal of cabotegravir-PrEP, its introduction is predicted to lead to a substantial increase in PrEP use with approximately 2·6% of the adult population (and 46% of those with a current indication for PrEP) receiving PrEP compared with 1·5% (28%) without cabotegravir-PrEP introduction across 20 years. As a result, HIV incidence is expected to be lower by 29% (90% range across setting-scenarios 6-52%) across the same period compared with no introduction of cabotegravir-PrEP. In people initiating antiretroviral therapy, the proportion with integrase-inhibitor resistance after 20 years is projected to be 1·7% (0-6·4%) without cabotegravir-PrEP introduction but 13·1% (4·1-30·9%) with. Cabotegravir-PrEP introduction is predicted to lower the proportion of all people on antiretroviral therapy with viral loads less than 1000 copies per mL by 0·9% (-2·5% to 0·3%) at 20 years. For an adult population of 10 million an overall decrease in number of AIDS deaths of about 4540 per year (-13 000 to -300) across 50 years is predicted, with little discernible benefit with NAT when compared with standard antibody-based rapid testing. AIDS deaths are predicted to be averted with cabotegravir-PrEP introduction in 99% of setting-scenarios. Across the 50-year time horizon, overall HIV programme costs are predicted to be similar regardless of whether cabotegravir-PrEP is introduced (total mean discounted annual HIV programme costs per year across 50 years is $151·3 million vs $150·7 million), assuming the use of standard antibody testing. With antibody-based rapid HIV testing, the introduction of cabotegravir-PrEP is predicted to be cost-effective under an assumed threshold of $500 per disability-adjusted life year averted in 82% of setting-scenarios at the cost of $144 per year, in 52% at $264, and in 87% at $114. INTERPRETATION: Despite leading to increases in integrase-inhibitor drug resistance, cabotegravir-PrEP introduction is likely to reduce AIDS deaths in addition to HIV incidence. Long-acting cabotegravir-PrEP is predicted to be cost-effective if delivered at similar cost to oral PrEP with antibody-based rapid HIV testing. FUNDING: Bill & Melinda Gates Foundation, National Institute of Allergy and Infectious Diseases of the National Institutes of Health.

Molecular detection of hepatitis B virus genotype E with immune escape mutations in chronic hepatitis B patients on long-term antiviral therapy in Jos, Nigeria.

Background: Previous studies in Nigeria have reported the presence of hepatitis B virus (HBV) genotype E and the availability of immune escape mutants. There is a paucity of data on chronic patients on long-term antiviral therapy for HBV infection. Objective: This study assessed HBV genotypes and drug resistance variants among patients with chronic HBV infection receiving tenofovir in Jos, Nigeria. Methods: This cross-sectional study consecutively enrolled 101 patients (51 with HIV/HBV co-infection and 50 with HBV infection only) on antiviral therapy from February 2018 to May 2019 at four hospitals in Jos, Nigeria. DNA quantification of HBV was performed on all samples; 30 samples with detectable viral load were selected for genotyping using Sanger sequencing by targeting the full-length sequences of reverse transcriptase gene of the HBV genome. Phylogenetic analysis was performed with reference sequences from GenBank. Escape mutant and drug resistance analysis were performed using HBV drug resistance interpretation and Geno2pheno. Results: Only 30 (29.7%) of the 101 study participants had detectable HBV DNA. Of these, six (20.0%) isolates were successfully amplified and sequenced. The identified genotype was E, including escape mutations L127R (16.7%) and G145A (16.7%). Conclusion: This study revealed exclusive dominance of genotype E in Nigeria. The S gene mutations G145A and L271R are known to be associated with modified antigenicity and impaired serologic assays, which may cause false negatives in the detection of anti-HBV surface antigen. The presence of mutants that are associated with vaccine immune escape may also have diagnostic and vaccine immune response implications.

Epidemiology of HIV drug resistance in low- and middle-income countries and WHO global strategy to monitor its emergence.

PURPOSE OF REVIEW: This review summarises the latest information of the epidemiology of HIV drug resistance (HIVDR) in low- and middle-income countries and the updated WHO global strategy for HIVDR surveillance and monitoring. RECENT FINDINGS: Finding from recent national-representative surveys show a rise in pretreatment drug resistance (PDR) to reverse transcriptase inhibitors and especially to the class of nonnucleoside reverse transcriptase inhibitors. Levels of PDR are especially high in infants <18 months and adults reporting prior exposure to antiretrovirals. Although viral suppression rates are generally high and increasing among adults on antiretroviral therapy, those with unsuppressed viremia have high levels of acquired drug resistance (ADR). Programmatic data on HIVDR to integrase-transfer-inhibitor resistance is scarce, highlighting the need to increase integrase-inhibitors resistance surveillance. As the landscape of HIV prevention, treatment and monitoring evolves, WHO has also adapted its strategy to effectively support countries in preventing and monitoring the emergence of HIVDR. This includes new survey methods for monitoring resistance emerging from patients diagnosed with HIV while on preexposure prophylaxis, and a laboratory-based ADR survey leveraging on remnant viral load specimens which are expected to strengthen dolutegravir-resistance surveillance. SUMMARY: Monitoring HIVDR remains pivotal to ensure countries attain and sustain the global goals for ending HIV as a public health threat by 2030.

Long-term HIV treatment outcomes and associated factors in sub-Saharan Africa: multicountry longitudinal cohort analysis.

OBJECTIVE: In a multicountry prospective cohort of persons with HIV from six countries between 2007 and 2015, we evaluated long-term outcomes of first-line non-nucleoside reverse-transcriptase inhibitor-based antiretroviral therapy (ART), and risk factors for loss-to-follow-up, mortality, virological failure, and incomplete CD4 + T-cell recovery. METHODS: We calculated cumulative incidence of lost-to-follow-up, death, virological failure (VL ≥ 1000 cps/ml) and incomplete CD4 + T-cell recovery (<500 cells/µl) at successive years, using Kaplan-Meier and Cox regression. RESULTS: Of 2735 participants, 58.0% were female, median age was 37 (interquartile range [IQR] 32-43) years, and median pre-ART CD4 + T-cell count was 135 (IQR 63-205)/µl. Total follow-up time was 7208 person-years (median 24.3 months, IQR 18.7-58.3). Deaths by any cause and loss to follow-up occurred mostly during the first year of ART (84%, 201/240 and 56%, 199/353, respectively). During their first 6 years of ART, 71% (95% confidence interval [CI] 69.0-73.7) were retained on first-line, and among those 90-93% sustained viral suppression (<1000 cps/ml); CD4 + T-cell recovery was incomplete in 60% (220/363) of participants. The risk factors associated with poor outcomes during long-term ART were: for loss-to-follow-up, recent VL ≥1000 cps/ml, recent CD4 + T-cell count ≤50 cells/µl, age <30 years, being underweight; for mortality, recent CD4 + T-cell count ≤50 cells/µl; and, for virological failure, age <40 years, recent CD4 + T-cell count ≤200 cells/µl, poor adherence, male sex, and low-level viremia. CONCLUSION: To achieve long-term ART success towards the UNAIDS targets, early ART initiation is crucial, coupled with careful monitoring and retention support, particularly in the first year of ART. Male and youth-centred care delivery models are needed to improve outcomes for those vulnerable groups.

The prevalence of pre-treatment and acquired HIV drug resistance in Vietnam: a nationally representative survey, 2017-2018.

INTRODUCTION: Monitoring the population-level emergence and transmission of HIV drug resistance (HIVDR) is necessary for supporting public health programmes. This study provides a nationally representative prevalence estimate of HIVDR in people initiating antiretroviral therapy (ART) and estimates of acquired HIVDR and viral load (VL) suppression in people who have received it for 12 or ≥48 months in Vietnam. METHODS: The study was conducted between September 2017 and March 2018 following World Health Organization guidance. Thirty ART clinics were randomly sampled using probability proportional to size sampling from a total of 367 ART clinics in the country. RESULTS AND DISCUSSION: In total, 409 patients initiating ART were enrolled into the survey of pre-treatment HIVDR. The prevalence of any pre-treatment HIVDR was 5.8% (95% CI 3.4-9.5%), and the prevalence of non-nucleoside reverse transcriptase inhibitor resistance was 3.4% (95% CI 1.8-6.2%). Four hundred twenty-nine patients on ART for 12±3 months and 723 patients on ART for ≥48 months were enrolled into the surveys of acquired HIVDR. The prevalence of VL suppression (defined as <1000 copies/ml) in patients on ART for 12±3 and ≥48 months was 95.5% (95% CI 91.3-97.8%) and 96.1% (95% CI 93.2-97.8%), respectively. Among individuals with viral non-suppression, any HIVDR was detected in 11/14 (weighted prevalence 74.3%) of those on ART for 12±3 months and in 24/27 (weighted prevalence 88.5%) of those receiving ART for ≥48 months. CONCLUSIONS: This nationally representative study of HIVDR found high levels of VL suppression among those on ART for 12 and ≥48 months. Overall, high levels of VL suppression at both time points suggested good adherence among patients receiving ART and quality of treatment services in Vietnam. CLINICAL TRIAL NUMBER: Not applicable.

Impact of nucleos(t)ide reverse transcriptase inhibitor resistance on dolutegravir and protease-inhibitor-based regimens in children and adolescents in Kenya.

We assessed the impact of using dolutegravir or a protease inhibitor with an inactive nucleoside-reverse transcriptase inhibitor (NRTI) in children and adolescents. We observed high-levels of viral suppression among those on tenofovir-lamivudine-dolutegravir even in presence of an inactive NRTI backbone but lower levels among those on protease inhibitors, especially those retained on an inactive abacavir. Although tenofovir may be recycled with dolutegravir, more studies are needed to determine if abacavir can be reused with dolutegravir or protease inhibitors.

Hypertension and Associated Inflammatory Markers Among HIV-Infected Patients in Tanzania.

There remains a dearth of data regarding the association between chronic inflammation and hypertension (HTN) in sub-Saharan Africa, a region that accounts for >70% of the global burden of HIV infection. Therefore, we assessed the levels of biomarkers among HIV+ individuals and its associations with HTN in Tanzania. A cross-sectional study was conducted at one of the largest clinics in Tanzania and data from 261 HIV+ patients were analyzed. Standardized tools were used to collect data. Blood pressure was measured using Omron® M2 blood pressure monitor. Enzyme-linked immunosorbent assay was used to test for inflammatory markers [C-reactive protein (CRP), interleukin (IL)-6, IL-18, soluble tumor necrosis factor receptor type I (sTNFRI), sTNFRII]. Bivariate and multivariable analysis was conducted to examine association between the biomarkers and HTN. We further conducted age-sex-alcohol-adjusted models to control for any confounders. The prevalence of HTN was 43% with a high prevalence reported in female (70%) participants and those older than 55 years of age (77%). Being women, older than 55 years of age, married, and being overweight was associated with HTN. The highest correlations were observed between TNR2 and CRP (ɤ = 0.13, P = 0.044), and TNR2 and IL-18 (ɤ = 0.13, P = 0.034). Participants who had elevated CRP levels were 2 times more likely to experience HTN in the age-adjusted model [odds ratio (OR) = 3.5, 95% confidence interval (CI) = 1.1-11.3], age-sex-adjusted model (OR = 3.3, 95% CI = 1.0-10.9), and the full model (OR = 2.9, 95% CI = 0.8-10.0). Our study shows that high CRP levels are significantly associated with the higher prevalence of HTN notwithstanding all other markers, which showed a positive association with HTN despite not being significant. These findings point to the importance of creating awareness, education, and screening for HTN among HIV patients in high epidemic countries. More rigorous studies are needed to know the exact pathway mechanisms of inflammation in HIV patients.

COVID-19 and indirect health implications in Africa: Impact, mitigation measures, and lessons learned for improved disease control.

Seth Inzaule and co-authors discuss implications of the COVID-19 pandemic for health in African countries.

Genomic-informed pathogen surveillance in Africa: opportunities and challenges.

The ongoing COVID-19 pandemic has highlighted the need to incorporate pathogen genomics for enhanced disease surveillance and outbreak management in Africa. The genomics of SARS-CoV-2 has been instrumental to the timely development of diagnostics and vaccines and in elucidating transmission dynamics. Global disease control programmes, including those for tuberculosis, malaria, HIV, foodborne pathogens, and antimicrobial resistance, also recommend genomics-based surveillance as an integral strategy towards control and elimination of these diseases. Despite the potential benefits, capacity remains low for many public health programmes in Africa. The COVID-19 pandemic presents an opportunity to reassess and strengthen surveillance systems and potentially integrate emerging technologies for preparedness of future epidemics and control of endemic diseases. We discuss opportunities and challenges for integrating pathogen genomics into public health surveillance systems in Africa. Improving accessibility through the creation of functional continent-wide networks, building multipathogen sequencing cores, training a critical mass of local experts, development of standards and policies to facilitate best practices for data sharing, and establishing a community of practice of genomics experts are all needed to use genomics for improved disease surveillance in Africa. Coordination and leadership are also crucial, which the Africa Centres for Disease Control and Prevention seeks to provide through its institute for pathogen genomics.

Baseline integrase drug resistance mutations and conserved regions across HIV-1 clades in Cameroon: implications for transition to dolutegravir in resource-limited settings.

BACKGROUND: Transition to dolutegravir-based regimens in resource-limited settings (RLS) requires prior understanding of HIV-1 integrase variants and conserved regions. Therefore, we evaluated integrase drug resistance mutations (DRMs) and conserved regions amongst integrase strand transfer inhibitor (INSTI)-naive patients harbouring diverse HIV-1 clades in Cameroon. METHODS: A cross-sectional study was conducted amongst 918 INSTI-naive patients from Cameroon (89 ART-naive and 829 ART-experienced patients). HIV-1 sequences were interpreted regarding INSTI-DRMs using the Stanford HIVdb v8.9-1 and the 2019 IAS-USA list. Amino acid positions with <1% variability were considered as highly conserved. Subtyping was performed by phylogeny. RESULTS: Overall prevalence (95% CI) of INSTI-DRMs was 0.8% (0.4-1.7), with 0.0% (0.0-4.0) amongst ART-naive versus 0.9% (0.5-1.9) amongst ART-experienced patients; P = 0.44. Accessory mutations (95% CI) were found in 33.8% (30.9-37.0), with 38.2% (28.1-49.1) amongst ART-naive versus 33.4% (30.4-36.7) amongst ART-experienced patients; P = 0.21. Of 288 HIV-1 integrase amino acid positions, 58.3% were highly conserved across subtypes in the following major regions: V75-G82, E85-P90, H114-G118, K127-W132, E138-G149, Q168-L172, T174-V180, W235-A239 and L241-D253. Wide genetic diversity was found (37 clades), including groups M (92.3%), N (1.4%), O (6.2%) and P (0.1%). Amongst group M, CRF02_AG was predominant (47.4%), with a significantly higher frequency (95% CI) of accessory mutations compared with non-AG [41.4% (36.8-46.0) versus 27.1% (23.3-31.2) respectively; P < 0.001]. CONCLUSIONS: The low baseline of INSTI-DRMs (<1%) in Cameroon suggests effectiveness of dolutegravir-based regimens. In spite of high conservation across clades, the variability of accessory mutations between major circulating strains underscores the need for monitoring the selection of INSTI-DRMs while scaling up dolutegravir-based regimens in RLS.

Clinical Impact of Pretreatment Human Immunodeficiency Virus Drug Resistance in People Initiating Nonnucleoside Reverse Transcriptase Inhibitor-Containing Antiretroviral Therapy: A Systematic Review and Meta-analysis.

BACKGROUND: Increased access to antiretroviral therapy (ART) has resulted in rising levels of pretreatment human immunodeficiency virus drug resistance (PDR). This is the first systematic review and meta-analysis to assess the impact of PDR on treatment outcomes among people initiating nonnucleoside reverse transcriptase inhibitor (NNRTI)-based ART, including the combination of efavirenz (EFV), tenofovir (TDF), and lamivudine or emtricitabine (XTC). METHODS: We systematically reviewed studies and conference proceedings comparing treatment outcomes in populations initiating NNRTI-based ART with and without PDR. We conducted subgroup analyses by regimen: (1) NNRTIs + 2 nucleoside reverse transcriptase inhibitors (NRTIs), (2) EFV + 2 NRTIs, or (3) EFV/TDF/XTC; by population (children vs adults); and by definition of resistance (PDR vs NNRTI PDR). RESULTS: Among 6197 studies screened, 32 were analyzed (31 441 patients). We found that individuals with PDR initiating NNRTIs across all the subgroups had increased risk of virological failure compared to those without PDR. Risk of acquisition of new resistance mutations and ART switch was also higher in people with PDR. CONCLUSIONS: This review shows poorer treatment outcomes in the presence of PDR, supporting the World Health Organization's recommendation to avoid using NNRTIs in countries where levels of PDR are high.