Puerto Rico reports more leptospirosis cases annually to the Centers for Disease Control and Prevention (CDC) than any other US territory, according to the Department of Health. Between January 1 and August 31, 2026, the island recorded 158 confirmed and probable cases, 14 of them fatal. Health Department leptospirosis surveillance coordinator Yormari Rivera said delayed medical care is a major obstacle: symptoms such as fever, chills, lower back and calf pain are often mistaken for a common cold, and the incubation period can extend up to 30 days, so patients do not connect their illness to contact with wet soil, often while barefoot or in flip-flops.
The most affected population is men over 40, many with chronic conditions, who seek help late. Chief medical officer Dr. Iris Cardona attributed the island’s lead to its tropical, rainy geography. The surveillance report, released September 10, shows the highest cumulative incidence rates in the rural hill towns of Adjuntas, Maricao and Lares, plus San Juan, where close housing and flood-prone areas raise risk.
Animal raising in the island’s center attracts rodents, the bacteria’s main carriers. Cardona urged protective footwear and clothing on farms and noted the infection is treatable with antibiotics if identified early; untreated it can cause kidney or liver damage, with fatality above 50% in severe cases involving pulmonary hemorrhage.