Infectious Causes of Acute Febrile Illness in Belize, 2020-2022.

Acute febrile illness (AFI) surveillance networks can play a key role in identifying emerging pathogens and promoting global health security, especially for vulnerable populations in low- and middle-income countries. In January 2020, the Belize AFI Surveillance network was formed, and 5,643 participants were enrolled over the first 3-year period across 11 participating public hospitals. Using real-time polymerase chain reaction testing for vector-borne pathogen detection and BioFire® diagnostic testing for respiratory and gastrointestinal pathogens, the causes of illness were examined in relation to 54 pathogens in these participants. In response to the coronavirus disease 2019 pandemic, surveillance was expanded to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections. Overall, one or more pathogens were successfully identified in 51% of participants, with 43 different pathogens detected. Many important discoveries were made, including the first reported case of acute Chagas disease in Belize and eight cases of Vibrio cholerae. The most common identified vector-borne disease was dengue, with all four serotypes detected. The most common respiratory pathogens detected were SARS-CoV-2 and human rhinovirus/enterovirus. The most common gastrointestinal pathogens detected were different strains of diarrheagenic Escherichia coli and norovirus. These and other results obtained via AFI surveillance enabled in-country and academic partners to respond to disease outbreaks rapidly and to monitor disease activity across the country more effectively.