Dengue, malaria and heat deaths are being mapped at a finer grain

Dengue, facility by facility

Dengue NS1 and/or IgM positivity among febrile patients in Ghana was 6.95%, a preprint reports from a multisite surveillance study, and RT-PCR confirmed the circulation of DENV-1 and DENV-3 serotypes in Ghana. Adjusted odds of dengue positivity increased with age, with an adjusted odds ratio per five years of 1.09. The headline number is the 6.95%: roughly one in fourteen febrile patients in the study tested positive for dengue, which is a substantial share of fever to be carrying a disease that is often assumed to be something else. The more useful finding for a health official is the facility-level variation the study was designed to capture. A national average hides the fact that some facilities see far more dengue than others, and a response built on the average will over-supply the quiet clinics and under-supply the busy ones. Confirming two serotypes in circulation matters for the same reason: a population exposed to more than one serotype faces different risks than one exposed to a single strain, and the surveillance that finds the second serotype is the surveillance worth funding. m:…5348

A preprint on Nigeria makes the same point about averages, this time with wealth instead of geography. Wealth inequality is associated with higher anaemia risk in Nigerian children aged 6-59 months in 2015 and 2021, the preprint reports, and malaria parasitaemia is a mediator of the wealth-anaemia association but accounts for a small proportion of the total effect. The total risk difference for anaemia between the poorest and richest quintiles was 12.5 percentage points in 2021. Twelve and a half percentage points is the gap between the poorest fifth of children and the richest fifth, measured in the share who are anaemic. Malaria explains only a small part of the wealth gap, so a malaria programme alone will not close it. The rest comes from whatever else wealth buys, food, clean water, care, and a bednet does not substitute for those. A surveillance system that maps disease by wealth quintile is telling officials something a national average cannot: where the burden sits, and what fixing it would actually require. m:…4326

Heat kills before the heatwave is declared

A preprint on five Indian cities takes on a different kind of average: the official definition of a heatwave. The onset of excess mortality in five Indian cities occurs at temperatures substantially lower than those implied by current operational heat wave definitions, the preprint reports, and the proposed data-driven framework yields stable and interpretable threshold estimates and confidence intervals across heterogeneous climates and time-series lengths. Reliance on meteorological definitions alone for heat wave planning underestimates the population risk of heat-associated mortality in rapidly warming regions. In plain terms, people start dying from heat before the temperature reaches the level the authorities call a heatwave, so a response that waits for the declaration arrives late. The framework's contribution is a threshold estimated from the mortality data itself rather than from a meteorological convention, and the fact that the estimates stay stable across cities with different climates is what makes the method portable. A city that sets its heat threshold from its own deaths, rather than from a national definition, will act earlier, and earlier is the whole point of a heat plan. m:…3183

A preprint on Suriname shows what a decade of finer-grained records can reveal about progress and about who it leaves behind. In-hospital mortality for heart failure, ischemic heart disease and stroke declined significantly in Suriname from 2013 to 2022, the preprint reports. But ethnic disparities in stroke mortality are pronounced in Suriname, with higher mortality among Maroon, Creole, Javanese and Other groups compared to Hindustani patients, and female sex is associated with lower in-hospital mortality for heart failure, with an adjusted odds ratio of 0.835. The two findings belong together: mortality fell overall, and the fall was not shared equally. A health system that reports only the overall decline will congratulate itself; a system that reports the breakdown by ethnicity will see the work that remains. The decade of records is itself the achievement, because without them neither the progress nor the gap would be visible. m:…3182

Suriname: a 2050 fork

A companion preprint from the same country turns the records into a forecast, and the forecast is a fork. Under the status quo pathway, combined cardiovascular admissions in Suriname are projected to reach 62,643 in 2050, the preprint reports. Full HEARTS implementation is projected to reduce 2050 cardiovascular admissions by 56.1% compared to the status quo. Combining full HEARTS with improved hospital survival could reduce 2050 cardiovascular deaths to 924, compared to 2,644 under the status quo. HEARTS is the World Health Organization's package for cardiovascular care in primary health settings, and the projection treats full implementation as a scenario rather than a promise. The numbers describe the stakes of a policy choice, not a prediction: 62,643 admissions and 2,644 deaths if nothing changes, against 924 deaths if the package is fully implemented and hospital survival improves. The gap between those two futures is the argument for acting now, and it is an argument made with the country's own data. The week's papers describe a shift in public health: from national averages to facility-level, wealth-level and city-level measurement. Dengue varies by clinic, anaemia varies by wealth, heat kills before the declaration, and a country's future depends on a package it has not yet fully implemented. Granular data does not make the decisions easier. It makes them harder to avoid. m:…6093