US health officials investigate new parasite outbreak as measles cases reach 35-year high

US health officials are currently investigating a widespread outbreak of cyclosporiasis, an intestinal illness caused by a parasite, linked to shredded iceberg lettuce sourced from central Mexico. The Centers for Disease Control and Prevention (CDC) reported at least 1,947 confirmed cases across nine states as of July 24, 2026, resulting in 98 hospitalizations. The implicated lettuce, supplied by Taylor Farms de Mexico, was voluntarily recalled on July 17, 2026. This particular outbreak is part of a broader trend, with Cyclospora infections reported in 41 states this year, and additional investigations into other potential sources like parsley and cilantro.

Simultaneously, the United States is grappling with a significant surge in measles cases, reaching a 35-year high in 2026. As of July 24, 2026, the CDC confirmed 2,318 cases, already exceeding the 2,289 total reported for all of 2025. This marks the highest number of measles infections since 1991, with cases reported across 45 jurisdictions.

The vast majority of these measles cases, approximately 93%, are linked to outbreaks and involve individuals who are unvaccinated or whose vaccination status is unknown. Experts attribute this resurgence to declining vaccination rates, which have fallen below the 95% threshold necessary to maintain community immunity. International health officials are slated to convene in November to deliberate whether the US and Mexico should retain their measles-free status.