A multi-state outbreak of cyclosporiasis, an intestinal illness caused by the parasite Cyclospora cayetanensis, has sickened more than 2,900 people across the United States, with 843 cases laboratory-confirmed and at least 1,500 more under review as of 9 July. The US Centers for Disease Control and Prevention (CDC) reports that 31 states have detected domestically acquired infections, with 86 hospitalisations and no deaths. Michigan has emerged as the epicentre, recording 1,562 cases by 10 July—a sharp rise from the state’s typical annual count of around 50. Ohio, North Carolina, Wisconsin and Texas are among other states with notable case numbers.

The parasite, which causes watery and sometimes explosive diarrhoea that can persist for more than a month if untreated, is transmitted through food or water contaminated with human faeces. Unlike many foodborne pathogens, Cyclospora requires one to two weeks in the environment to become infectious, making direct person-to-person spread unlikely. Past US outbreaks have been linked to fresh produce including bagged salad mixes, cilantro, basil, raspberries and snow peas. In the current outbreak, however, federal and state investigators have not identified a specific food vehicle or supplier. Michigan’s chief medical executive has said the working theory points to produce, while some food-safety researchers have hypothesised a common water source such as Lake Erie. The CDC notes that the outbreak season typically runs from May through August, and that case counts are likely to rise further given a six-week lag in surveillance data.

Viewed from state health departments, the response has been complicated by reporting inconsistencies. The CDC made Cyclospora notification optional in 2025, and some states combine confirmed and probable cases in their tallies while others delay reporting until investigations close. Michigan has advised residents to avoid packaged salad and to wash or cook fresh produce thoroughly, as heating above 70°C kills the parasite. Fast-food chain Taco Bell temporarily removed lettuce, cilantro, onion, pico de gallo and guacamole from menus at several locations, citing a nationwide recall, though no direct link to its supply chain has been established.

While US authorities grapple with a foodborne parasite, other regions of the Americas are confronting different vector-borne threats. In Ciudad Juárez, Mexico, local health officials report that rickettsiosis, a bacterial disease transmitted by tick bites, has caused 22 deaths this year amid a proliferation of stray dogs and inadequate sanitation. In Espírito Santo, Brazil, spotted fever—also tick-borne—has killed six people out of 14 confirmed cases in 2026, with a case fatality rate around 80%. These concurrent outbreaks underscore the varied parasitic and bacterial challenges facing public-health systems. The next milestone for US investigators will be the identification of the contamination source, which remains the critical missing piece for targeted consumer guidance.