O-83 Evidence of human, rodent, and bat hantavirus infections in Grenada

Methods: We collected serum from people reporting fever from throughout Grenada between 2023–2025. Participants were recruited from health centers, private clinics and laboratories, and from community outreach and house visits. Additionally, rodents and bats were collected across Grenada. Serum was tested for anti-hantavirus IgG using commercial ELISAs, and pan-hantavirus RT-PCR

Results: We tested 400 randomly selected human febrile cases for anti-hantavirus antibodies, as well as 10 mice, 42 rats, and 65 bats. Minimal human sample size was determined to be 355 to detect a seroprevalence of 10%. An IACUC-approved sample size of 120 animals (excluding pregnant and lactating females) was calculated but implementation of a stepwise testing approach reduced the total number of samples needed. We determined a hantavirus seroprevalence of 3.5% (1.7–5.3%) among humans in Grenada. Interpretation of animal ELISAs was more difficult given lack of positive controls, but we did not detect any positive mice, and estimate the rat seroprevalence to be 19% and the bat seroprevalence to be 17%. RT-PCR testing is ongoing with potential positive detections in mice, rats, bats, and humans, pending sequencing for confirmation.

Conclusion: These results provide the first evidence of human hantavirus infection in Grenada. Additionally, we provide the first reported evidence of hantavirus infection in bats in the Caribbean region. Our results suggest ongoing low-level transmission of hantaviruses from small mammal reservoirs to humans as a previously unrecognized etiology of febrile illness in Grenada. Ongoing attempts to identify circulating hantavirus species will provide insights to Grenadian hantavirus ecology, inform public health measures, and guide future diagnostic testing.