Responding to Sierra Leone's first Haemophilus ducreyi outbreak: Lessons for emergency preparedness and response.

Sierra Leone reported its first outbreak of cutaneous Hemophilic ducreyi in November 2025 amid ongoing public health emergencies. The outbreak, initially detected in a primary school in Bombali district, Northern Sierra Leone, resulted in 449 suspected and 96 confirmed cases, primarily among children aged 5-15 years, with no associated deaths. Rapid activation of the district emergency operations center enabled coordinated epidemiologic investigations, active case finding, laboratory confirmation, case management, infection prevention and control, and community engagement. Most ulcers presented on the lower limbs and healed within eight weeks with appropriate wound care as the mainstay and available antibiotics, implemented under an antimicrobial stewardship framework. The outbreak highlights delayed community-level detection, underscoring surveillance gaps relative to the 7-1-7 response framework. Strengthened risk communication, infection prevention, and enhanced laboratory support were critical to the response. This event emphasizes the need for heightened surveillance, standardized chronic ulcer management, and further research into transmission dynamics and comprehensive outbreak response of cutaneous Hemophilic ducreyi infection.