Welcome to the twenty-fourth edition of FOI Clinical. Each week, we'll send you a briefing on outbreak news. When something urgent breaks, you'll get an alert the same day.
In this edition
Cyclosporiasis – Measles – West Nile virus – Covid-19 – Legionnaires': New York City – Grand Canyon mystery illness – New World screwworm – Ebola – Marburg: Uganda
National interest
Cyclosporiasis
The Taylor Farms de México recall is the most significant food safety development of the 2026 outbreak season. On July 17, CDC and FDA traced the multistate Midwest cluster, spanning Michigan, Ohio, West Virginia, Kentucky, and Indiana, to shredded iceberg lettuce supplied by Taylor Farms de México, a grower in central Mexico. FDA reports that 90% of interviewed cases in the five-state cluster reported eating iceberg lettuce.
Taylor Farms issued a voluntary recall on July 17 covering products distributed June 29–July 16 across 27 states, including Marketside Iceberg Salad and Shredded Lettuce sold at Walmart, as well as products distributed through Taco Bell, Jack in the Box, and Sysco. On July 18, a Taylor Farms lettuce sample not included in the recalled products tested positive. On July 19, FDA reversed course and announced the result was a false positive; FDA laboratory experts concluded the finding "does not represent true amplification." No microbiologically confirmed positive product sample exists. The recall remains in effect; FDA and CDC state that epidemiological and traceback evidence "overwhelmingly" supports iceberg lettuce as the vehicle.
The five-state cluster now has 1,644 cases and 94 hospitalizations per CDC. Reporting from individual states is substantially higher. The five-state cluster is distinct from a New York City cluster (403+ cases), which has no confirmed link to Taylor Farms and likely involves a separate produce source, consistent with NYC's historical pattern of Cyclospora outbreaks linked to raspberries and cilantro from separate importers.
State burdens as of July 20–21 (state health department sources):
| Jurisdiction | Cases | Hospitalized | As of |
|---|---|---|---|
| Michigan | 7,171 | 102 | July 22 (MDHHS) |
| Ohio (NW Ohio) | 2,029–2,149 | — | July 21 |
| Ohio (statewide) | 1,316 | 96 | July 17 (ODH) |
| MI + OH combined | >8,000 | — | July 21 |
| New York City | 403+ | — | July 10 (DOHMH; separate cluster) |
| National confirmed (CDC) | 1,645 | 141 | July 13–14 |
| National total (incl. under review) | ~11,500 | — | ~July 21 |
The most recent reporting week in NNDSS shows 874 cases, with year to date totals at 3,713 (2.5x prior year). The last five weeks have seen increases from 64→73→180→358→874. Thus, there is no current evidence of slowing per NNDSS data. Colorado (153 YTD) cases are predominantly travel-associated and not linked to the Taylor Farms cluster. CDC expects cases to continue rising through the end of August.
Clinical reminders: Standard stool O&P does not detect Cyclospora; request modified acid-fast staining or Cyclospora-specific PCR explicitly. TMP-SMX DS BID × 7–10 days remains the only reliably effective treatment. Full clinical guidance is available in the FOI HAN alert.
Measles
CDC updated this year's running total to 2,260 confirmed cases on July 16 across 44 jurisdictions. Independent trackers put the total slightly higher at 2,295, which surpasses the 2025 total and makes this the largest year in 35 years.