Boffa pilgrimage in Guinea: Syndromic surveillance during the 2025 pilgrimage

The Boffa Catholic pilgrimage brings together approximately 25,000 participants each year in Guinea. During the pilgrimage, the Archdiocese of Conakry provides free on-site medical support to pilgrims. In this report, we describe syndromic surveillance data from pilgrims who consulted the archdiocesan mission in 2025. From April 27 to May 4, 2025, 8640 patients were recorded. The mean age was 34.3 (±14.8) years. The male-to-female sex ratio was 1.08. Fatigue without a specific diagnosis was the most common complaint (42.4%). Dermatologic conditions (21.8%), febrile illnesses (20.7%) and gastrointestinal disorders (6.4%) were also frequent. Infectious diseases, notably malaria (19.8%) as well as typhoid fever, parasitic diarrhea, respiratory tract infections and superinfected insect bites, accounted for a significant proportion of consultations. Blisters affected 19.3% of patients. 8.2% patients were hospitalized. No death was recorded. These preliminary results suggest that infectious diseases significantly impact the Boffa pilgrimage. Further studies involving microbiological investigations would provide a more detailed picture of infections in the context of this mass gathering. • The Boffa Catholic pilgrimage brings together approximately 25,000 participants each year in Guinea. • Of 8640 patients consulting during the 2025 edition, fatigue without a specific diagnosis was the most common complaint (42.4%). • Dermatologic conditions (21.8%), febrile illnesses (20.7%) and gastrointestinal disorders (6.4%) were also frequent. • Infectious diseases, notably malaria (19.8%) as well as typhoid fever, parasitic diarrhea, respiratory tract infections and superinfected insect bites, accounted for a significant proportion of consultations. • Blisters affected 19.3% of patients.