Miles A. Kirby

The rapid reduction in foreign development assistance from the United States and other countries has led to disruptions in essential global health programming. Countries that previously received development assistance, such as Zambia, may experience weakening of health system capacity due to program cancellations. This study aimed to describe the impacts of USAID program defunding on healthcare delivery in Zambia. We conducted a cross-sectional survey at 34 healthcare facilities in three districts of Zambia in April and May 2025. Through facility-level assessments and individual surveys with 330 healthcare workers, we identified changes in health system building blocks that may have arisen from program defunding. The facility-level assessment found that 71% of healthcare facilities (n=24) experienced changes related to funding cuts within the previous three to four months. In open-ended surveys, healthcare workers reported impacts on the health system, including stock-outs of essential medicines, diagnostic tests, and infection control supplies; layoffs of US-supported healthcare workers; and reduced ability to work with electronic medical records. Workers described how these changes impacted workplace morale, patient satisfaction, and their ability to deliver essential services. This study reveals the immediate consequences of defunding foreign assistance, which, if left unaddressed, may weaken health systems and worsen health outcomes. To mitigate these impacts, country governments and partner organizations should prioritize interventions and investments that strengthen health systems, such as expanding healthcare revenue streams and building workforce capacity. In the wake of funding cuts, health system strengthening can reduce countries’ reliance on foreign assistance and improve population health.

Background Exposure to household air pollution from burning coal and biomass for cooking is associated with higher blood pressure and other adverse indicators of cardiovascular disease, the leading cause of death worldwide. Evidence demonstrating that switching from biomass to liquefied petroleum gas (LPG) will reduce blood pressure is limited. Methods As part of a larger trial of 3200 households, we conducted a randomized trial of 342 women aged 40 to 79 years who lived in households using biomass for cooking in rural areas of Guatemala, India, Peru, and Rwanda to assess the effects of a free LPG stove and fuel intervention. Systolic blood pressure (one of four primary outcomes) was measured once prior to randomization and up to five times after randomization over 18 months. Results A total of 418 participants were randomized (n=209 to intervention, and n=209 to control). Mean (standard deviation) systolic blood pressure at baseline was 112.7 (14.9) mmHg and 112.6 (14.7) mmHg in intervention and control participants, respectively. Adherence within the intervention arm was high. Among the 342 participants with a valid baseline and at least one valid post-randomization blood pressure measurement, mean (SD) post-randomization average systolic blood pressure was 111.5 (13.2) mmHg in the intervention arm and 111.9 (12.5) mmHg in the control arm, with an adjusted mean of difference of - 0.56 mmHg (95% confidence interval, -2.19 to 1.07, p-value = 0.50). Conclusions We did not observe evidence that an 18-month LPG stove and fuel intervention reduced blood pressure in women.

Exposure to household air pollution has been linked to adverse health outcomes among women aged 40–79. Little is known about how shifting from biomass cooking to a cleaner fuel like liquefied petroleum gas (LPG) could impact exposures for this population. We report 24-h exposures to particulate matter (PM2.5), black carbon (BC), and carbon monoxide (CO) among women aged 40 to <80 years participating in the Household Air Pollution Intervention Network trial. 209 participants were randomized to the intervention and received an LPG stove and continuous fuel supply; controls used biomass (n = 209). Exposures were measured up to six times; we used mixed-effects models to estimate differences between intervention and control groups. Preintervention exposures between groups were comparable; median postintervention exposures were 62% (76.3 vs 29.3 μg/m3), 73% (10.4 vs 2.8 μg/m3), and 57% (1.4 vs 0.6 ppm) lower for PM2.5, BC, and CO among LPG users than for controls. Reductions were similar across countries; 70% of PM2.5 exposures after intervention were below the annual WHO interim target I (IT-1) value of 35 μg/m3. We provide evidence that implementing an LPG intervention can reduce air pollution exposure over an 18-month period to at or below the annual WHO IT-1 guideline.

Household water treatment and safe storage interventions can improve microbiological water quality and reduce diarrheal disease in areas lacking access to safe water. However, with few studies evaluating effectiveness of interventions delivered programmatically for more than a year post-implementation, little is known about their sustainability. We aimed to assess the longer-term use and health effects of a household-based filter with a safe storage tank delivered through Rwanda’s Community based Environmental Health Promotion Programme (CBEHPP). We undertook a 30-month longitudinal study in Rwamagana district, following 608 households across 30 villages receiving the intervention. We conducted four unannounced follow-up visits and measured filter presence, condition and use as well as drinking water quality and child diarrhea prevalence approximately 6, 15, 24, and 30 months after the delivery of the intervention. Coverage of the water filter remained high throughout the follow-up period, with 94% of households observed to have the filter by the 30-month visit. Compared to the 6-month visit, the households with filters observed to be in good condition declined from 94.0% to 84.5% at the 30 month-visit. Reported use declined over this period from 96.9% to 84.3% of households, though presence of water in the storage tank of the filter fell from 81.4% to 59.4%. Fecal contamination of point-of-use drinking water did not get worse over the follow-ups compared to the 6-month visit. Child diarrhea prevalence in the study population varied over the follow up period, from 5.7% to 3.9%, 2.9% and 5.9% at 6, 15, 24 and 30 month visits, respectively. In summary, an intervention to promote uptake and use of water filters as part of the Rwandan national environmental health program was found to show that filters were still largely present, in good condition and in use after 30 months, meaning that the intervention effects were largely maintained.

Residential biomass burning is an important source of black carbon (BC) exposure among rural communities in low- and middle-income countries. We collected 7165 personal BC samples and individual/household level information from 3103 pregnant women enrolled in the Household Air Pollution Intervention Network trial. Women in the intervention arm received free liquefied petroleum gas stoves and fuel throughout pregnancy; women in the control arm continued the use of biomass stoves. Median (IQR) postintervention BC exposures were 9.6 mu g/m(3) (5.2-14.0) for controls and 2.8 mu g/m(3) (1.6-4.8) for the intervention group. Using mixed models, we characterized predictors of BC exposure and assessed how exposure contrasts differed between arms by select predictors. Primary stove type was the strongest predictor (R-2 = 0.42); the models including kerosene use, kitchen location, education, occupation, or stove use hours also provided additional explanatory power from the base model adjusted only for the study site. Our full, trial-wide, model explained 48% of the variation in BC exposures. We found evidence that the BC exposure contrast between arms differed by study site, adherence to the assigned study stove, and whether the participant cooked. Our findings highlight factors that may be addressed before and during studies to implement more impactful cookstove intervention trials.

Environmental Health Perspectives is an Open Access journal published by the National Institute of Environmental Health Sciences. Environmental Health Perspectives is an Open Access journal published by the National Institute of Environmental Health Sciences.

Objective: Household Air Pollution Intervention Network (HAPIN) investigators tested a complex, non-pharmacological intervention in four low- and middle-income countries as a strategy to mitigate household air pollution and improve health outcomes across the lifespan. Intervention households received a liquefied petroleum gas (LPG) stove, continuous fuel delivery and regular behavioral reinforcements for 18 months, whereas controls were asked to continue with usual cooking practices. While HAPIN was designed as an explanatory trial to test the efficacy of the intervention on four primary outcomes, it introduced several pragmatic aspects in its design and conduct that resemble real-life conditions. We surveyed HAPIN investigators and asked them to rank what aspects of the design and conduct they considered were more pragmatic than explanatory. Methods: We used the revised Pragmatic Explanatory Continuum Indicator Summary (PRECIS-2) to survey investigators on the degree of pragmatism in nine domains of trial design and conduct using a five-point Likert rank scale from very explanatory (1) to very pragmatic (5). We invited 103 investigators. Participants were given educational material on PRECIS-2, including presentations, papers and examples that described the use and implementation of PRECIS-2. Results: Thirty-five investigators (mean age 42 years, 51% female) participated in the survey. Overall, only 17% ranked all domains as very explanatory, with an average (±SD) rank of 3.2 ± 1.4 across domains. Fewer than 20% of investigators ranked eligibility, recruitment or setting as very explanatory. In contrast, ≥50% of investigators ranked the trial organization, delivery and adherence of the intervention and follow-up as very/rather explanatory whereas ≤17% ranked them as rather/very pragmatic. Finally, p < 0.001). Conclusion: HAPIN investigators did not consider their efficacy trial to be rather/very explanatory and reported that some aspects of the design and conduct were executed under real-world conditions; however, they also did not consider the trial to be overly pragmatic. Our analysis underscores the importance of using standardized tools such as PRECIS-2 to guide early discussions among investigators in the design of environmental health trials attempting to measure efficacy.

Globally, cleaner cooking fuels are increasingly promoted to reduce household air pollution. However, there is concern that reductions in smoke from biomass fuels could lead to more favorable conditions for mosquitoes and potentially increase vectorborne disease risk. We investigated household entry, host-seeking, household exit, and mortality among Anopheles mosquitoes across three cooking fuel types: wood, charcoal, and liquid petroleum gas (LPG) in six experimental huts in Rwanda. Fifty laboratory-reared Anopheles gambiae mosquitoes were released each night in entry compartments outside each hut, and fuels were burned for 1 hour in the hut verandas. Collectors conducted human landing catch during cooking and for 2 hours afterward, and CDC light traps were used for the rest of the night to measure host-seeking. Differences in each outcome were assessed using generalized linear mixed models with random effects for hut, collector, and day. Cooking with LPG compared with wood and charcoal was associated with substantial increases in household entry and host-seeking. Household exit was not significantly different across fuels, and mortality was lower in LPG-burning huts compared with wood. Although these results are not directly generalizable to field conditions, they indicate a potential for clean fuel adoption to increase exposure to Anopheles mosquitoes compared with traditional biomass fuels. Additional entomological and epidemiological studies are needed to investigate changes in disease vector exposure associated with clean fuel adoption, and evaluate whether enhanced vector control interventions should be promoted in tandem with cleaner cooking fuels.