Rationale

Noncommunicable respiratory diseases and exposure to air pollution are thought to be important contributors to morbidity and mortality in sub-Saharan African adults.

Objectives

We set out to explore the prevalence and determinants of noncommunicable respiratory disease among adults living in Chikhwawa District, Malawi.

Methods

We performed a cross-sectional study among adults in communities participating in a randomized controlled trial of a cleaner-burning biomass-fueled cookstove intervention (CAPS [Cooking and Pneumonia Study]) in rural Malawi. We assessed chronic respiratory symptoms, spirometric abnormalities, and personal exposure to air pollution (particulate matter <2.5 μm in aerodynamic diameter [PM_2.5] and carbon monoxide [CO]). Weighted prevalence estimates were calculated; multivariable and intention-to-treat analyses were done.

Measurements and main results

One thousand four hundred eighty-one participants (mean [SD] age, 43.8 [17.8] yr; 57% female) were recruited. The prevalence of chronic respiratory symptoms, spirometric obstruction, and restriction were 13.6% (95% confidence interval [CI], 11.9-15.4), 8.7% (95% CI, 7.0-10.7), and 34.8% (95% CI, 31.7-38.0), respectively. Median 48-hour personal PM_2.5 and CO exposures were 71.0 μg/m³ (interquartile range [IQR], 44.6-119.2) and 1.23 ppm (IQR, 0.79-1.93), respectively. Chronic respiratory symptoms were associated with current/ex-smoking (odds ratio [OR], 1.59; 95% CI, 1.05-2.39), previous tuberculosis (OR, 2.50; 95% CI, 1.04-15.58), and CO exposure (OR, 1.46; 95% CI, 1.04-2.05). Exposure to PM_2.5 was not associated with any demographic, clinical, or spirometric characteristics. There was no effect of the CAPS intervention on any of the secondary trial outcomes.

Conclusions

The burden of chronic respiratory symptoms, abnormal spirometry, and air pollution exposures in adults in rural Malawi is of considerable potential public health importance. We found little evidence that air pollution exposures were associated with chronic respiratory symptoms or spirometric abnormalities and no evidence that the CAPS intervention had effects on the secondary trial outcomes. More effective prevention and control strategies for noncommunicable respiratory disease in sub-Saharan Africa are needed. Clinical trial registered with www.isrctn.com (ISRCTN 59448623).

Rationale

There are no population-based studies from sub-Saharan Africa describing longitudinal lung function in adults.

Objectives

To explore the lung function trajectories and their determinants, including the effects of air pollution exposures and the cleaner-burning biomass-fuelled cookstove intervention of the Cooking and Pneumonia Study (CAPS), in adults living in rural Malawi.

Methods

We assessed respiratory symptoms and exposures, spirometry and measured 48-hour personal exposure to fine particulate matter (PM_2.5) and carbon monoxide (CO), on three occasions over 3 years. Longitudinal data were analysed using mixed-effects modelling by maximum likelihood estimation.

Measurements and main results

We recruited 1481 adults, mean (SD) age 43.8 (17.8) years, including 523 participants from CAPS households (271 intervention; 252 controls), and collected multiple spirometry and air pollution measurements for 654 (44%) and 929 (63%), respectively. Compared with Global Lung Function Initiative African-American reference ranges, mean (SD) FEV₁ (forced expiratory volume in 1 s) and FVC (forced vital capacity) z-scores were -0.38 (1.14) and -0.19 (1.09). FEV₁ and FVC were determined by age, sex, height, previous TB and body mass index, with FEV₁ declining by 30.9 mL/year (95% CI: 21.6 to 40.1) and FVC by 38.3 mL/year (95% CI: 28.5 to 48.1). There was decreased exposure to PM_2.5 in those with access to a cookstove but no effect on lung function.

Conclusions

We did not observe accelerated lung function decline in this cohort of Malawian adults, compared with that reported in healthy, non-smoking populations from high-income countries; this suggests that the lung function deficits we measured in adulthood may have origins in early life.

Introduction

Pre-exposure prophylaxis (PrEP) is a safe and effective prevention strategy to reduce women's risk of HIV in pregnancy and postpartum. Effective PrEP protection requires daily PrEP adherence, but little is known about maternal PrEP continuation and factors that influence PrEP use.

Methods

The PrEP in pregnancy and postpartum (PrEP-PP) study enrolled consenting pregnant, HIV-negative women at first antenatal care (ANC) visit with follow-up through 12 months postpartum. Eligible and consenting women and girls ≥16 years received HIV prevention counselling and were offered PrEP. Interviewers collected socio-demographic and behavioural data from participants at each visit. We analysed the proportion of women who initiated PrEP and the proportion who continued PrEP after 3 months with associated correlates by estimating the prevalence ratio adjusting for a priori confounders.

Results

Between August 2019 and October 2021, we enrolled 1201 pregnant women (median gestation 21 weeks; age 26 years); 84% of women initiated PrEP at their first ANC visit (n = 1014); 55% were married or cohabiting. Overall, 66% of women on PrEP returned for a repeat prescription at 1 month; 58% returned at 3 months (n = 493 of 844). Almost one-half of women on PrEP reported a side effect at 1 month, mostly nausea/vomiting. Women on PrEP in the first and second trimesters had higher odds of reporting side effects (aOR 2.61; 95% CI 1.17-5.84) versus postpartum women. Women who reported side effects continued with PrEP less than those who did not report side effects (aPR = 0.87; 95% CI 0.77-0.97). Women with ≥1 previous pregnancy (aPR = 0.76; 95% CI 0.57-1.01) or were postpartum (aPR 0.85; 95% CI 0.75-0.97) were less likely to continue PrEP compared to women who were primigravid or pregnant. Women who reported having an HIV+ partner (aPR = 1.45; 95% CI 1.13-1.85) or high HIV risk perception (aPR = 1.20, 95% CI = 1.01-1.41) were more likely to continue on PrEP than those who had HIV-negative partners or low risk perception.

Conclusions

PrEP initiation and early continuation were high in this setting, compared to other studies in women. Being postpartum and experiencing side effects were associated with lower PrEP continuation, presenting opportunities for counselling on early transient side effects. Interventions for postpartum women on PrEP are needed.

We have previously shown accelerated ageing in adolescents perinatally infected with HIV (PHIV +), based on discrepancies between epigenetic and chronological age. The current study examines follow-up longitudinal patterns of epigenetic ageing and the association of epigenetic ageing with cognition as well as whole brain structure changes in PHIV + and healthy controls enrolled in the Cape Town Adolescent Antiretroviral Cohort Study (CTAAC). The Illumina EPIC array was used to generate blood DNA methylation data from 60 PHIV + adolescents and 36 age-matched controls aged 9-12 years old at baseline and again at a 36-month follow-up. Epigenetic clock software estimated two measures of epigenetic age acceleration: extrinsic epigenetic accelerated ageing (EEAA) and age acceleration difference (AAD) at both time points. At follow-up, each participant completed neuropsychological testing, structural magnetic resonance imaging, and diffusion tensor imaging. At follow-up, PHIV infection remains associated with increased EEAA and AAD. Accelerated epigenetic ageing remained positively associated with viral load and negatively associated with CD4 ratio. EEAA was positively associated with whole brain grey matter volume and alterations in whole brain white matter integrity. AAD and EEAA were not associated with cognitive function within the PHIV + group. Measures of epigenetic ageing, as detected in DNA methylation patterns, remain increased in PHIV + adolescents across a 36-month period. Associations between epigenetic ageing measures, viral biomarkers, and alterations in brain micro- and macrostructure also persist at 36-month follow-up. Further study should determine if epigenetic age acceleration is associated with cognitive functional changes due to brain alterations in later life.

Background

Exposure to household air pollution is associated with an increased risk of pneumonia in children in low- and middle-income countries; however, exposure-response data are limited, and there are uncertainties around the extent to which biomass-fueled cookstoves can reduce these exposures.

Research question

What is the association between exposure to household air pollution and pneumonia in children under the age of 5 years in rural Malawi and what are the effects of a biomass-fueled cookstove intervention on personal exposure to household air pollution?

Study design and methods

We measured personal exposure to carbon monoxide (CO; 48 hours of continuous measurement and transcutaneous carboxyhemoglobin) every 6 months in children who participated in a cluster-randomized controlled trial of a cleaner burning biomass-fueled cookstove intervention to prevent pneumonia in children under the age of 5 years in rural Malawi (the Cooking And Pneumonia Study). Exposure-response and multivariable analyses were done.

Results

We recruited 1805 (928 intervention; 877 control) children (mean age, 25.6 months; 50.6% female). We found no evidence of an association between exposure to CO (incident rate ratio, 1.0; 95% CI, 0.967 to 1.014; P = .53) or carboxyhemoglobin (incident rate ratio, 1.00; 95% CI, 0.993 to 1.003; P = .41) in children who experienced pneumonia vs those who did not. Median exposure to CO in the intervention and control groups was was 0.34 (interquartile range, 0.15 to 0.81) and 0.37 parts per million (interquartile range, 0.15 toa 0.97), respectively. The group difference in means was 0.46 (95% CI, -0.95 to 0.012; P = .06).

Interpretation

Exposure to CO in our population was low with no association seen between exposure to CO and pneumonia incidence and no effect of the Cooking And Pneumonia Study intervention on these exposures. These findings suggest that CO may not be an appropriate measure of household air pollution exposure in settings such as rural Malawi and that there is a need to develop ways to measure particulate matter exposures directly in young children instead.

Clinical trial registration

ISRCTN59448623.

Background

Intensified viral load monitoring for pregnant and breastfeeding women has been proposed to help address concerns around antiretroviral therapy (ART) adherence, viraemia and transmission risk, but there have been no systematic evaluations of existing policies.

Methods

We used an individual Monte Carlo simulation to describe longitudinal ART adherence and viral load from conception until 2 years' postpartum. We applied national and international guidelines for viral load monitoring to the simulated data. We compared guidelines on the percentage of women receiving viral load monitoring and the percentage of women monitored at the time of elevated viral load.

Results

Coverage of viral load monitoring in pregnancy and breastfeeding varied markedly, with between 14% and 100% of women monitored antenatally and 38-98% monitored during breastfeeding. Specific recommendations for testing at either a fixed gestation or a short, fixed period after ART initiation achieved more than 95% testing in pregnancy but this was much lower (14-83%) among guidelines with no special stipulations. By the end of breastfeeding, only a small proportion of simulated episodes of elevated viral load more than 1000 copies/ml were successfully detected by monitoring (range, 20-50%).

Discussion

Although further research is needed to understand optimal viral load frequency and timing in this population, these results suggest that current policies yield suboptimal detection of elevated viral load in pregnant and breastfeeding women.

BACKGROUND: In low- and middle-income countries countries, millions of deaths occur annually from household air pollution (HAP), pulmonary tuberculosis (PTB), and HIV-infection. However, it is unknown whether HAP influences PTB risk among people living with HIV-infection. METHODS: We conducted a case-control study among 1,277 HIV-infected adults in Bukavu, eastern Democratic Republic of Congo (February 2018 - March 2019). Cases had current or recent (<5y) PTB (positive sputum smear or Xpert MTB/RIF), controls had no PTB. Daily and lifetime HAP exposure were assessed by questionnaire and, in a random sub-sample (n=270), by 24-hour measurements of personal carbon monoxide (CO) at home. We used multivariable logistic regression to examine the associations between HAP and PTB. RESULTS: We recruited 435 cases and 842 controls (median age 41 years, [IQR] 33-50; 76% female). Cases were more likely to be female than male (63% vs 37%). Participants reporting cooking for >3h/day and ≥2 times/day and ≥5 days/week were more likely to have PTB (aOR 1·36; 95%CI 1·06-1·75) than those spending less time in the kitchen. Time-weighted average 24h personal CO exposure was related dose-dependently with the likelihood of having PTB, with aOR 4·64 (95%CI 1·1-20·7) for the highest quintile [12·3-76·2 ppm] compared to the lowest quintile [0·1-1·9 ppm]. CONCLUSION: Time spent cooking and personal CO exposure were independently associated with increased risk of PTB among people living with HIV. Considering the high burden of TB-HIV coinfection in the region, effective interventions are required to decrease HAP exposure caused by cooking with biomass among people living with HIV, especially women.

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