The Trump administration is warning about a fast-moving outbreak of the New World screwworm fly, a flesh-eating parasite that has spread through Central America and into Mexico, raising alarm among U.

Pharmaceuticals that people globally rely on for daily health — including antibiotics, antidepressants and painkillers — are entering ecosystems via wastewater, posing poorly understood risks. Once ...

Viruses are master parasites that have adapted to infect many host species. Some viruses even use multiple hosts to spread their infections—such as arboviruses that use insects to move their ...