Histoplasmosis Outbreak Linked to Venado Caves in Costa Rica ¡ª December 2024¨CJanuary 2025

What did we do?

• On January 21, 2025, CDC launched a multistate investigation with Georgia Department of Public Health, Texas Department of State Health Services, and Washington State Department of Health after a physician notified CDC of 12 family members in three states who were experiencing symptoms associated with histoplasmosis after touring Venado Caves in Costa Rica.

What did we find?

• Six adults and six children toured Venado Caves on December 24, 2024. They reported bat sightings and direct bat guano contact.
• All 12 developed symptoms consistent with histoplasmosis 8 to 19 days after exposure.
• A family member who was vacationing with the other 12 but did not attend the cave tour, did not develop symptoms. No other recreational activities raised suspicion of Histoplasma exposure.
• Five adults and 1 child sought medical care. Among these, three initially received antibiotics, which are ineffective for treating histoplasmosis, and two received corticosteroids, which can worsen fungal infections.
• One adult was hospitalized and received antifungal medication.
• Fungal testing was performed on five adults. Two were positive for Histoplasma by blood antigen test; one was also antibody-positive.
• All 12 persons had recovered or were improving by late January 2025.

Why does it matter?

• This is the second reported outbreak of histoplasmosis linked to Venado Caves, suggesting ongoing risk of Histoplasma exposure.
• Tourists who develop symptoms after visiting Venado Caves are encouraged to seek health care and disclose travel history.
• Clinicians should obtain travel history and consider histoplasmosis in patients with compatible illness that have entered caves with bats.

***This presentation has updated data that will be shared at the EIS Conference.

Abstract Category: Fungal Diseases