Federal health officials are responding to two separate parasite-related threats that have prompted increased monitoring and emergency response efforts across the United States
One involves a rise in cyclosporiasis, a gastrointestinal illness caused by the microscopic parasite Cyclospora cayetanensis. The infection spreads through contaminated food or water, most often fresh produce, and can cause severe watery diarrhea, stomach cramps, nausea, vomiting, loss of appetite, and low-grade fever.
According to the Centers for Disease Control and Prevention (CDC), Michigan has reported more than 708 confirmed cases as of July 7, far above its typical annual total of around 50 cases. Ohio has recorded at least 170 cases since late June, while Indiana, New York, and North Carolina have each reported more than 100 infections. At least 20 people have been hospitalized nationwide, though no deaths have been reported. Investigators from the CDC, the Food and Drug Administration (FDA), and state health departments are working to identify the contaminated food source, but officials say there is no evidence that all cases stem from a single nationwide outbreak.
At the same time, federal agencies are responding to the return of the New World screwworm, a flesh-eating fly that threatens livestock and wildlife. The USDA confirmed the first U.S. animal case of 2026 in a calf in Texas, with additional cases since identified in cattle, goats, sheep, and a dog in Texas and New Mexico.
The insect lays eggs in open wounds, and the resulting larvae feed on living tissue, causing a condition known as myiasis. While untreated infestations can be fatal for animals, officials stress that the risk to humans remains very low, and no locally acquired human infections have been reported.
To contain the outbreak, authorities have established quarantine zones, expanded trapping operations along the southern border, and increased the release of sterile male flies. Officials emphasize that the cyclosporiasis surge and the screwworm response are unrelated but remain active public health investigations.
