Trap camera monitoring has detected New World screwworm infestations in wild animals. In April 2025, in Mirador-Río Azul National Park and the Naachtún-Dos Lagunas Biotope in Guatemala, we captured evidence of a puma (Puma concolor) likely infested with this parasite. This sighting occurred just seven months after the first reported case in domestic animals in the country.
Camera trap image of a puma (Puma concolor) with an open wound, potentially caused by a New World screwworm (Cochliomyia hominivorax) infestation, documented in the Naachtún-Dos Lagunas Biotope, Maya Biosphere Reserve, Guatemala (WCS, 2025).
Additionally, cases have been confirmed in tapirs (Tapirus bairdii) in Costa Rica, and infestations have been reported in howler monkeys, sloths, porcupines, and other mammals across several Central American countries.
Photographs. Michiel van Noppen
The New World screwworm is a parasitic fly whose larvae feed on live tissue in open wounds, causing severe infections, intense pain, and potentially the death of affected animals. After decades of eradication, the parasite returned to the region in 2023, spreading rapidly due to illegal cattle trade and insufficient sanitary surveillance.
Map. Spatial distribution of confirmed screwworm infestations in animals between January 1, 2023, and July 26, 2025 (red circles), based on data from the World Animal Health Information System. National parks with terrestrial components are shown as green polygons, according to the World Database on Protected Areas, in Central America and southern Mexico. Other types of protected areas, such as RAMSAR sites, are not shown. The blue-framed inset highlights reported cattle infestation cases in Chagres and Portobelo National Parks, Panama.
These infestations further increase the vulnerability of wildlife, already threatened by habitat loss and other environmental pressures. This is a serious threat that could destabilize ecosystems and accelerate biodiversity loss.
It is urgent to strengthen surveillance, support conservation teams, and implement coordinated regional actions to control the spread of the New World screwworm and protect our biodiversity.