Baton Rouge General's Health Tip of the Week: The return of the flesh-eating screwworm

June 17, 2026 - 07:33

The new world screwworm, a flesh-eating parasite that was once wiped out in the United States, is back in the news. A recent case was found in a calf in Texas, and it has public health officials paying close attention. Despite the name, the screwworm is not actually a worm. It is the larval stage of a specific type of fly. The problem starts when a female fly lays her eggs inside an open wound or a mucous membrane. Once the eggs hatch, the maggots begin to feed on the living tissue of the host animal. This can cause severe damage and even death if left untreated. Humans are not the usual target, but people with open sores or neglected wounds can be at risk, especially in areas where the fly is active. The screwworm was successfully eliminated from the U.S. decades ago through a program that released sterilized male flies. That method is still considered the best defense. For now, the main advice is to keep any wounds clean and covered. If you notice a wound that seems to be getting worse or has an unusual smell, see a doctor right away. Early detection is key to preventing a serious infection.