Typhoid Fever Cases in Ghana’s Eastern Region Rose 2.5-Fold Over Nine Years, Forecast Warns of Continued High Burden

Reported typhoid fever incidence in Ghana’s Eastern Region climbed from 108 to 273 cases per 10,000 population between 2016 and 2024, a 2.5-fold increase, according to a retrospective analysis of national surveillance data published in BMC Public Health. Over the nine-year period, the region recorded a total of 446,553 reported cases, and statistical forecasts suggest that reported incidence will remain high, with recurring seasonal fluctuations, through 2029. The research team, led by John Sonnyinado Duako Baffoe and colleagues, drew on case reports submitted through Ghana’s District Health Information Management System 2 (DHIMS2), the country’s routine health surveillance database.

They converted raw case counts into incidence rates using population data, then applied time-series methods to characterize temporal and seasonal patterns. Spatial variation was mapped at the district level using quintile mapping, and alert and epidemic thresholds were evaluated with the C2 method, which compares current case counts against a rolling 12-month reference window. Demographic patterns in the data were striking.

Adults aged 20 to 49 years accounted for the largest share of reported cases, and females represented 62.4 percent of the total. When the researchers calculated age-specific incidence rates, however, the highest rates fell among adults aged 50 years and older, a reminder that the composition of case counts and the underlying risk per person can point in different directions. The analysis also revealed pronounced spatial heterogeneity across the region’s districts.

Birim Central recorded the highest reported incidence, marking it as a potential hotspot for targeted intervention. Seasonal peaks recurred throughout the study period, with alert threshold exceedances occurring more frequently than epidemic threshold exceedances, indicating sustained pressure on the surveillance system even when formal epidemic levels were not crossed. To explore a possible environmental driver, the team obtained rainfall estimates from the Climate Hazards Group InfraRed Precipitation with Station Data (CHIRPS) Version 2.0 dataset.

They observed an exploratory one-month lagged correlation between rainfall and reported typhoid incidence, with a correlation coefficient of 0.230 and a nominal p-value of 0.018. The authors are careful to note the limits of this finding: the analysis did not account for temporal autocorrelation or confounding, so it cannot establish that rainfall drives case reports. For forecasting, the researchers fitted a Seasonal Autoregressive Integrated Moving Average (SARIMA) model to the monthly case series.

The model’s projections point to continued high reported incidence with seasonal fluctuations through 2029, giving health planners a quantitative baseline for resource allocation. To probe how diagnostic confirmation might affect the picture, the team also generated a sensitivity and exploratory series. They applied a pooled laboratory-confirmed prevalence estimate of 4.14 percent, drawn from a Ghanaian meta-analysis, to the surveillance case counts.

This exploratory exercise underscores a central caveat of the study: the reported figures reflect what the surveillance system captures, which may differ substantially from the true burden of laboratory-confirmed typhoid fever. The study’s design carries further limitations worth keeping in view. The rainfall correlation, as the authors state, is exploratory and unadjusted, and the analysis is a retrospective secondary analysis of routinely reported data rather than a study of confirmed infections.

The authors conclude that strengthened surveillance, better diagnostic confirmation, targeted interventions in spatial hotspots such as Birim Central, and improved water, sanitation, and hygiene (WASH) measures are needed to reduce the reported burden. Until those measures take hold, the forecasts suggest the Eastern Region should prepare for a continued high volume of reported typhoid cases, punctuated by the seasonal peaks that have characterized the past nine years.

Subject of Research: Spatiotemporal patterns and forecasting of reported typhoid fever incidence in Ghana's Eastern Region, 2016–2024

Article Title: Spatiotemporal patterns and forecasted reported incidence of typhoid fever in Ghana’s Eastern Region, 2016–2024, with forecasts to 2029

Article References: Baffoe, J. S. D., Noora, C. L., Adu, G. A., Ameme, D. K., Frimpong, J. A., Osafo, M. B., Bandoh, D. B., Addo-Lartey, A., Nambagyira, A., Avunyitor, J. E., Mohammed, A. G., Coffie, M. C., Sackey, S. O. O., Djimatey, M. B., Afari, E., & Kenu, E. (2026). Spatiotemporal patterns and forecasted reported incidence of typhoid fever in Ghana’s Eastern Region, 2016–2024, with forecasts to 2029. BMC Public Health. https://doi.org/10.1186/s12889-026-30027-2

Image Credits: AI Generated

DOI: 10.1186/s12889-026-30027-2

Keywords: typhoid fever, Ghana, Eastern Region, surveillance, SARIMA forecasting, spatial epidemiology, seasonality, rainfall correlation, WASH, DHIMS2, public health, spatiotemporal