Mortality surveillance as an early warning system for respiratory infection outbreaks: lessons from the COVID-19 pandemic in Alexandria, Egypt.

BACKGROUND: The COVID-19 pandemic highlighted critical gaps in mortality surveillance, particularly in low- and middle-income countries (LMICs). This study evaluated the feasibility of using routine mortality data as an early warning system for respiratory outbreaks in Alexandria, Egypt. METHODS: A retrospective time-series analysis of 61,378 deaths (2017-2022) was conducted. Respiratory failure (ICD-10: J96.90) was used as a proxy for COVID-19-related mortality. As population denominators were unavailable at subdistrict level, analyses relied on proportionate mortality, reflecting the pragmatic data scope of the current registry system. Expected deaths were estimated using an exponential smoothing model, and excess mortality was identified when observed deaths exceeded expectations for three or more consecutive months. RESULTS: Deaths attributed to respiratory failure increased notably during 2020-2021, with sustained excess mortality signals corresponding to pandemic peaks. Mortality among adults aged 70-75 years rose markedly, and total years of life lost during the pandemic reached 41,819 across high-risk age groups (40-70 years). CONCLUSIONS: Routine mortality data can serve as a practical foundation for early detection of respiratory disease outbreaks in resource-limited settings. Future investments should focus on strengthening human resources, expanding digital infrastructure, and improving data standardization to ensure the long-term sustainability and scalability of mortality surveillance systems in LMICs.