Health 19 July 2026 Nile Post
US Diarrhoea Outbreak: Source Identified as False Positive
Health officials have announced that a positive test for the parasite cyclospora, initially linked to a food supplier for Taco Bell, was a false positive. This means the true source of the widespread explosive diarrhoea outbreak remains unknown. Source: https://nilepost.co.ug/news/357624/test-that-found-source-of-us-explosive-diarrhoea-outbreak-was-false-positive-health-officials-say
An extensive outbreak of explosive diarrhoea across the United States, which saw thousands fall ill and hundreds hospitalised, has had a key piece of evidence revealed as a false positive, health officials announced. Initially, tests on iceberg lettuce from supplier Taylor Farms, which also supplies the Taco Bell fast-food chain, indicated the presence of the parasite cyclospora.
The U.S. Food and Drug Administration (FDA) had reported this positive result on Saturday. However, a re-examination of the sample by FDA laboratory experts concluded that the finding did not represent true amplification and should be considered a false positive, owing to the complexities in detecting cyclospora.
This development means the exact source of the cyclospora parasite, which causes the foodborne illness cyclosporiasis, is still undetermined. Symptoms of the illness, which were first detected on May 13, include prolonged watery diarrhoea, sudden weight loss, and loss of appetite, with symptoms typically appearing up to two weeks after consumption.
While no deaths have been reported, at least 94 individuals have been hospitalised due to the outbreak. The Centers for Disease Control and Prevention (CDC) had advised against consuming shredded iceberg lettuce served at Taco Bell locations in several states, including Indiana, Kentucky, Michigan, Ohio, and West Virginia. Taco Bell has since stated it has completed the removal of affected lettuce from its restaurants.
Taylor Farms had voluntarily initiated a removal of all iceberg lettuce sourced from central Mexico from the U.S. market and notified its customers. They confirmed they have stopped receiving product from the implicated lot and suspended distribution. The FDA stated it collected the sample during targeted surveillance of imports as part of its ongoing investigation.