Under-5 mortality surveillance in low-income and middle-income countries: insights from two Health and Demographic Surveillance Systems in rural Gambia.

Without complete data on under-5 mortality, tracking progress towards achieving Sustainable Development Goal 3.2 will be challenging. Such data are also needed to ensure proper planning and prioritisation of scarce resources in low-income and middle-income countries. However, most low-income and middle-income countries have weak Civil Registration and Vital Statistics (CRVS) systems, leaving a critical gap in understanding under-5 mortality dynamics. This paper outlines a community-based approach to enhance under-5 mortality surveillance in low-income countries, using The Gambia as a case study. The methodology involves Health and Demographic Surveillance Systems (HDSSs) in Basse and Fuladu West, employing unique identification numbers, periodical household visits and collaboration with communities, village reporters and project field workers to ensure comprehensive data collection. Verbal autopsies (VAs) are conducted by trained field workers, and causes of death are determined using the physician-certified VA method. Between 1 September 2019 and 1 September 2023, 1333 deaths were detected, for which causes of death were determined for 97.1% (1294 of 1333). The most common causes of death detected were acute respiratory infections including pneumonia, sepsis, diarrhoeal diseases and birth asphyxia. Challenges include the cost of maintaining the HDSSs, poor road infrastructure, Electronic Data Capture transition challenges, and the need for national integration of HDSS data into the CRVS system. The success of this model highlights its potential for scalable and adaptable under-5 mortality surveillance in resource-limited settings.