Acute histoplasmosis in four immunocompetent Canadian travellers to a cenote in Yucatán, Mexico.

A group of four healthy Canadian travellers visited a cenote in the Yucatán peninsula in April 2024 and subsequently developed symptomatic histoplasmosis. Diagnosis was made in the acute period with a positive urine Histoplasma antigen test in three of the cases. Two developed severe presentations and were treated with itraconazole, including a three-year-old child with disseminated disease. The sensitivity of different modalities for diagnostics depends on the timing and severity of illness, with Histoplasma urine antigen being most sensitive in early infection, serology converting 4-8 weeks following exposure and cultures generally of low sensitivity. Treatment depends on the disease manifestations and host immunologic status. Many patients have relatively mild, self-limited, influenza-like illness and the diagnosis may be overlooked. Given the number of Canadian tourists travelling to the Yucatán peninsula and the popularity of visiting cenotes, awareness of the risk of histoplasmosis associated with this exposure should be promoted.