Overview
- Puerto Rico introduced Indian mongooses in the 1870s to fight sugarcane rats, but the animals established wild populations instead of controlling the rodents.
- A major mongoose-linked rabies outbreak was documented in 1950 and health data since then show mongooses cause roughly 70–75% of reported animal rabies cases on the island.
- Serological surveys find uneven exposure to the virus—about 39% of animals had neutralizing antibodies in some sites and about 17% in others—indicating many mongooses have been exposed but are not all actively infected.
- Researchers estimate roughly 280 people are bitten by mongooses in Puerto Rico each year and post-mortem testing tied at least one human death to the Caribbean mongoose rabies variant.
- U.S. teams including the National Wildlife Research Center and USDA are studying mongoose density and movement and testing bait flavors—cheese was preferred—to plan a targeted oral rabies vaccination program before any large-scale rollout, which could lower spillover to people and native wildlife.