Household-level and surrounding peri-domestic environmental characteristics associated with malaria vectors Anopheles arabiensis and Anopheles funestus along an urban-rural continuum in Blantyre, Malawi.

BACKGROUND: Malaria is increasing in some recently urbanized areas that historically were considered lower risk. Understanding what drives urban transmission is hampered by inconsistencies in how "urban" contexts are defined. A dichotomized "urban-rural" approach, based on political boundaries may misclassify environments or fail to capture local drivers of risk. Small-scale agriculture in urban or peri-urban settings has been shown to be a major risk determinant. METHODS: Household-level Anopheles abundance patterns in and around Malawi's commercial capital of Blantyre (~ 1.9 M pop.) were analysed. Clusters (N = 64) of five houses each located at 2.5 km intervals along eight transects radiating out from Blantyre city centre were sampled during rainy and dry seasons of 2015 and 2016. Mosquito densities were measured inside houses using aspirators to sample resting mosquitoes, and un-baited CDC light traps to sample host seeking mosquitoes. RESULTS: Of 38,895 mosquitoes captured, 91% were female and 87% were Culex spp. Anopheles females (N = 5058) were primarily captured in light traps (97%). Anopheles abundance was greater during rainy seasons. Anopheles funestus was more abundant than Anopheles arabiensis, but both were found on all transects, and had similar associations with environmental risk factors. Anopheles funestus and An. arabiensis females significantly increased with distance from the urban centre, but this trend was not consistent across all transects. Presence of small-scale agriculture was predictive of greater Anopheles spp. abundance, even after controlling for urbanicity, number of nets per person, number of under-5-year olds, years of education, and season. CONCLUSIONS: This study revealed how small-scale agriculture along a rural-to-urban transition was associated with An. arabiensis and An. funestus indoor abundances, and that indoor Anopheles density can be high within Blantyre city limits, particularly where agriculture is present. Typical rural areas with lower house density and greater distance from urban centres reflected landscapes more suitable for Anopheles reproduction and house invasion. However, similar characteristics and elevated Anopheles abundances were also found around some houses within the city limits. Thus, dichotomous designations of "urban" or "rural" can obscure important heterogeneity in the landscape of Plasmodium transmission, suggesting the need for more nuanced assessment of urban malaria risk and prevention efforts.

Cumulative exposure to depressive symptoms and all-cause mortality among adults with HIV in Kenya, Nigeria, Tanzania, and Uganda.

OBJECTIVE: We estimated the effects of cumulative exposure to depressive symptoms on risk of all-cause mortality among people with HIV (PWH) in four African countries. DESIGN: An analysis of prospective cohort data. METHODS: The African Cohort Study (AFRICOS) is a prospective cohort of people receiving care at twelve clinics in Kenya, Nigeria, Tanzania, and Uganda. Every 6 months from January 2013 to May 2020, participants underwent laboratory monitoring, structured surveys, and assessment of depressive symptom severity using the Center for Epidemiologic Studies Depression Scale (CES-D). All-cause mortality was the outcome of interest. The predictor of interest was a time-updated measure of the percentage of days lived with depression (PDD). Marginal structural Cox proportional hazards regression models were used, adjusting for potential confounders including time-varying alcohol use, drug use, and viral load. RESULTS: Among 2520 enrolled participants, 1479 (59%) were women and the median age was 38 (interquartile range [IQR]: 32-46). At enrollment, 1438 (57%) were virally suppressed (<200 copies/ml) and 457 (18%) had CES-D at least 16, indicating possible depression. Across 9093 observed person-years, the median PDD was 0.7% (IQR: 0-5.9%) with 0.8 deaths per 100 person-years. Leading causes of death included cancer (18% of deaths) and accidents (14%). Models suggested that each 25% absolute increase in PDD was associated with a 69% increase in the risk of all-cause mortality (hazard ratio: 1.69; 95% confidence interval: 1.18-2.43). CONCLUSION: Cumulative exposure to depressive symptoms was substantially associated with the risk of mortality in this cohort of PWH in Africa.

Achieving the third 95 in sub-Saharan Africa: application of machine learning approaches to predict viral failure.

OBJECTIVE: Viral failure in people with HIV (PWH) may be influenced by multiple sociobehavioral, clinical, and context-specific factors, and supervised learning approaches may identify novel predictors. We compared the performance of two supervised learning algorithms to predict viral failure in four African countries. DESIGN: Cohort study. METHODS: The African Cohort Study is an ongoing, longitudinal cohort enrolling PWH at 12 sites in Uganda, Kenya, Tanzania, and Nigeria. Participants underwent physical examination, medical history-taking, medical record extraction, sociobehavioral interviews, and laboratory testing. In cross-sectional analyses of enrollment data, viral failure was defined as a viral load at least 1000 copies/ml among participants on antiretroviral therapy (ART) for at least 6 months. We compared the performance of lasso-type regularized regression and random forests by calculating area under the curve (AUC) and used each to identify factors associated with viral failure; 94 explanatory variables were considered. RESULTS: Between January 2013 and December 2020, 2941 PWH were enrolled, 1602 had been on antiretroviral therapy (ART) for at least 6 months, and 1571 participants with complete case data were included. At enrollment, 190 (12.0%) had viral failure. The lasso regression model was slightly superior to the random forest in its ability to identify PWH with viral failure (AUC: 0.82 vs. 0.75). Both models identified CD4 + count, ART regimen, age, self-reported ART adherence and duration on ART as important factors associated with viral failure. CONCLUSION: These findings corroborate existing literature primarily based on hypothesis-testing statistical approaches and help to generate questions for future investigations that may impact viral failure.

Weight gain during the dolutegravir transition in the African Cohort Study.

INTRODUCTION: Dolutegravir (DTG) has become a preferred component of first-line antiretroviral therapy (ART) in many settings but may be associated with excess weight gain. We evaluated changes in weight and body mass index (BMI) after switch to single-tablet tenofovir/lamivudine/dolutegravir (TLD) by people living with HIV (PLWH) in four African countries. METHODS: The African Cohort Study (AFRICOS) prospectively follows adults with and without HIV in Kenya, Uganda, Tanzania and Nigeria. Demographics, ART regimen, weight, BMI and waist-to-hip ratio were collected every 6 months. Multivariable Cox proportional hazards modelling was used to estimate hazard ratios and 95% confidence intervals (CIs) for factors associated with developing a BMI ≥25 kg/m2 . Linear mixed effects models with random effects were used to examine the average change in BMI, weight and waist-to-hip ratio. RESULTS: From 23 January 2013 to 1 December 2020, 2950 PLWH were enrolled in AFRICOS and 1474 transitioned to TLD. In adjusted models, PLWH on TLD had 1.77 times the hazard of developing a high BMI (95% CI: 1.22-2.55) compared to PLWH on non-TLD ART. Examining change in weight among all PLWH on ART, participants on TLD gained an average of 0.68 kg (95% CI: 0.32-1.04) more than PLWH on other regimens after adjusting for duration on ART, sex, age, study site and CD4 nadir. Among participants who switched to TLD, the average change in weight prior to TLD switch was 0.35 kg/year (95% CI: 0.25-0.46) and average change in weight was 1.46 kg/year (95% CI: 1.18-1.75) in the year following transition to TLD after adjustment for confounders. CONCLUSIONS: Elevated BMI and weight gain among PLWH on TLD are concerning safety signals. Implications for the development of metabolic comorbidities should be monitored, particularly if annual weight gain persists during continued follow-up after transitioning to TLD.

Non-communicable diseases by age strata in people living with and without HIV in four African countries.

INTRODUCTION: Non-communicable diseases (NCDs) are an important driver of morbidity among ageing people living with HIV (PLWH). We examined the composite role of age and HIV status on NCDs in people living with and without HIV. METHODS: The African Cohort Study (AFRICOS) prospectively enrols participants aged ≥15 years with and without HIV at 12 sites in Kenya, Tanzania, Uganda and Nigeria. From 21 January 2013 to 1 September 2021, we assessed participants for renal insufficiency (estimated glomerular filtration rate <60 ml/minute/1.73 m2 ), elevated blood pressure (BP) (any systolic BP >139 mmHg or diastolic BP >89 mmHg), obesity (body mass index >30 kg/m2 ), diabetes mellitus (DM) (fasting glucose ≥126 mg/dl or antidiabetic medication) and dysglycemia (fasting glucose ≥99 mg/dl or non-fasting ≥199 mg/dl). Multivariable logistic regression with generalized estimating equations was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for factors associated with each NCD. The main exposure of interest was a composite of HIV status and age dichotomized around 50 years. All models were adjusted for study site and sex. The renal insufficiency model was additionally adjusted for elevated BP and dysglycemia. RESULTS AND DISCUSSION: Of 3761 participants with age data, 557 (14.8%) were age ≥50, 2188 (58.2%) were females and 3099 (82.4%) were PLWH. At enrolment, the prevalence of elevated BP, dysglycemia, renal insufficiency and obesity were n = 128 (26.9%), n = 75 (15.8%), n = 8 (1.7%) and n = 40 (8.4%), respectively, for PLWH ≥50. Compared to people without HIV age <50, PLWH age ≥50 had increased adjusted odds of having DM (OR: 2.78, 95% CI: 1.49-5.16), dysglycemia (OR: 1.98, 95% CI: 1.51-2.61) and renal insufficiency (OR: 6.20, 95% CI: 2.31-16.66). There were significant differences by study site, specifically, participants from Nigeria had the highest odds of elevated BP, dysglycemia and renal insufficiency as compared to Uganda. CONCLUSIONS: There was a high burden of NCDs in this African cohort with differences by geographic region. In order to promote healthy ageing with HIV, screening and treatment for common NCDs should be incorporated into routine HIV care with attention paid to geographic heterogeneity to better allocate resources.