Global distribution and health impact of infectious disease outbreaks, 1996-2023: a worldwide retrospective analysis of World Health Organization emergency event reports.

Abstract

Background: Over 30 priority pathogens with pandemic potential were identified, underscoring the need for targeted surveillance and prevention. As infectious disease outbreaks increase globally, particularly from zoonotic and vector-borne pathogens, understanding their distribution is crucial for effective public health responses. We aimed to provide a comprehensive analysis of global infectious disease outbreaks from 1996-2023, addressing gaps in previous research.

Methods: We sourced data from the World Health Organization emergency events webpage, focusing on key details like disease name, location, date, and fatalities. We calculated case fatality rates (CFR) to assess outbreak severity. We categorised outbreaks into six types - respiratory, vector-borne, foodborne/waterborne, direct contact infections, non-infectious conditions, and others. Data extraction was independently performed and cross-verified for accuracy.

Results: Between 1996-2023, a total of 3013 global outbreak events were reported. The Democratic Republic of the Congo had the highest frequency of outbreaks, with 272 events, followed by China with 254, and Saudi Arabia with 202. Influenza was the most frequently reported disease, with 771 outbreaks, followed by Ebola (n = 342) and Middle East respiratory syndrome-related coronavirus (MERS-CoV) (n = 305). Significant outbreaks included the 2023 global dengue outbreak, which accounted for five million cases and 5000 deaths. The CFR was highest for the Marburg virus at 76.86%, followed by haemorrhagic fever at 63.63%, and Ebola at 63.00%. The data underscore the varying severity and distribution of outbreaks, highlighting the critical need for robust global health surveillance and targeted interventions.

Conclusions: In this study, we highlighted the significant impact of influenza, Ebola, and MERS-CoV. The high case fatality rates of viruses like Marburg and Ebola emphasised the need for early detection and rapid response systems. Strengthening global cooperation, investing in health care infrastructure, and integrating digital surveillance technologies are crucial to enhancing preparedness and reducing future outbreak impacts.