Transmission Dynamics of Typhoid Fever in the Ejura/Sekyedumase Municipality of The Ashanti Region, Ghana: A Ten-Year Retrospective Trend Analysis.

Abstract

This study examined the transmission dynamics and temporal trends of typhoid fever in Ejura/Sekyedumase over ten years (2013–2023), with specific objectives to (1) determine the prevalence and trends of typhoid fever; (2) analyze socio-demographic patterns across age and gender; and (3) evaluate the influence of seasonality and climate on disease incidence using predictive time-series models. A retrospective design was employed, utilizing secondary health data from the Ejura/Sekyedumase Municipal Health Directorate. Monthly reported typhoid cases were aggregated, cleaned, and analyzed using R (version 4.3.2). Time-series modelling involved Seasonal-Trend decomposition (STL) and Auto-Regressive Integrated Moving Average (ARIMA) modelling, with further validation using Error-Trend-Seasonal (ETS) and Prophet forecasting techniques. The findings revealed a persistent endemic trend with recurrent seasonal peaks, particularly during the rainy months (May–August). Young adults aged 20 years and above (≥ 20) exhibited the highest burden, accounting for over two-thirds of reported cases, followed by adolescents (15-19 years old). A gender analysis revealed a slightly higher incidence among females, reflecting gendered exposure patterns associated with water collection, domestic food preparation, and childcare. The Augmented Dickey–Fuller (ADF) and KPSS tests confirmed non-stationarity in the original series (ADF p = 0.207; KPSS p = 0.039), leading to first differencing before modelling. The ARIMA (1,1,1)(1,1,1)[12] model provided the best fit (AIC = 1451.72, RMSE = 95.51), capturing both short-term fluctuations and strong annual seasonality. The study concludes that typhoid fever in Ejura/Sekyedumase is driven by a combination of seasonal climatic variability, poor sanitation, and socio-cultural practices that facilitate faecal–oral transmission.