Articles and issues

Background. Dengue transmission in Bangladesh has intensified and spread beyond Dhaka city, yet hospital-based surveillance captures only a small fraction of infections. Population-based estimates of past infection in the rapidly growing peri-urban fringe are scarce. Methods. We conducted a community-based cross-sectional serosurvey in 32 randomly selected clusters in Savar and Keraniganj upazilas between October and December 2025. One resident aged 5–60 years was randomly selected per household, interviewed and tested for anti-dengue IgG by indirect ELISA, and each household was inspected for water-holding containers and Aedes larvae. Adjusted prevalence ratios (aPR) were estimated with modified Poisson regression and cluster-robust standard errors. Results. Of 640 households approached, 612 (95.6%) participated. Overall seroprevalence was 52.6% (95% CI 47.3–57.9), rising from 29.7% among children aged 5–14 years to 69.8% among adults aged 45–60 years. Only 58 of 322 seropositive participants (18.0%) reported a previous dengue diagnosis. Seropositivity was independently associated with water stored in uncovered containers (aPR 1.34, 95% CI 1.15–1.56), larva-positive containers at inspection (aPR 1.39, 1.19–1.62) and an active construction site within 100 m (aPR 1.18, 1.01–1.38), whereas screening on all windows was protective (aPR 0.76, 0.60–0.96). Conclusions. More than half of peri-urban residents had evidence of past dengue infection, most of it undiagnosed. Household water storage, unmanaged construction sites and unscreened housing are practical targets for integrated vector management in Dhaka's expanding periphery.

Extreme heat is now a recurrent public health emergency across South Asia, where long pre-monsoon heatwaves combine with high humidity, dense informal settlements and large outdoor workforces. Heat action plans and meteorological early warnings have expanded since the Ahmedabad plan of 2013, but their links to the health workers who see heat-exposed people every day remain weak. In most districts, alerts are issued by disaster management or meteorological agencies and reach primary care facilities, if at all, as general advisories without defined actions, supplies or reporting duties. In this perspective, we argue that primary health care should become the operational core of heat-health early warning systems in the region. We describe why warnings rarely translate into clinical action, propose a tiered set of facility and community actions linked to alert levels, and identify the people most likely to be missed, including informal outdoor workers, older adults living alone, pregnant women and people with chronic disease. We also outline the data needed to make these systems accountable: syndromic surveillance of heat-related illness in primary care, linkage with mortality records and simple indicators of whether alerts led to action. Integration does not require new institutions, but it does require clear mandates, modest seasonal budgets, advance stocking of rehydration and cooling supplies, protection for staff and evaluation built in from the start. As heat extremes intensify, the community health workforce offers the most realistic route to protecting those at greatest risk.

Background. Hypertension control remains poor in low- and middle-income countries (LMICs), where physician shortages limit access to continuous care. Community health workers (CHWs) are increasingly deployed to screen, educate, monitor and support people with hypertension, but the size and determinants of their effect remain uncertain. Methods. We searched MEDLINE, Embase, CINAHL, the Cochrane Central Register of Controlled Trials and Global Index Medicus from inception to December 31, 2025, for randomized trials of CHW-led interventions among adults with hypertension in LMICs. Two reviewers independently screened records, extracted data and assessed risk of bias with RoB 2. Random-effects meta-analyses pooled mean differences in systolic blood pressure (SBP) and risk ratios (RR) for blood pressure control. Results. Eighteen trials with 33,940 participants from 17 countries were included, 12 of them cluster randomized. Compared with usual care, CHW interventions reduced SBP by a mean of 4.9 mm Hg (95% CI 3.2–6.6; 16 trials; I² = 78%) and diastolic blood pressure by 2.4 mm Hg (95% CI 1.5–3.3; 15 trials), and increased blood pressure control (RR 1.31, 95% CI 1.19–1.44; 14 trials). Reductions were larger when CHWs titrated medication under a protocol (6.8 vs 3.5 mm Hg; p for interaction = 0.012). Certainty of evidence was moderate for both primary outcomes. Conclusions. CHW-led interventions produce clinically meaningful blood pressure reductions in LMICs, particularly when CHWs can adjust treatment within structured protocols linked to primary care. Sustained financing, supervision and integration with national hypertension programs are needed to deliver these gains at scale.