To be presented at the U.S. Centers for Disease Control and Prevention’s 64th Annual Epidemic Intelligence Service (EIS) conference April 20-23 in Atlanta.
Summary: Despite routine testing, raw milk from a Utah dairy sickened 99 people with Campylobacter; 1 died and 10 were hospitalized. A 2-month shutdown failed to stop the outbreak and the dairy’s raw milk permit was revoked.
Background: In Utah, raw milk sales are legal from farm to consumer. Despite routine bacterial and coliform
counts by the Utah Department of Agriculture and Food (UDAF), raw milk-related illnesses occur. In May 2014, the Utah Department of Health (UDOH) identified a cluster of 3 Campylobacter jejuni infections with indistinguishable pulsed-field gel electrophoresis (PFGE) patterns. All patients reported consuming Dairy A’s raw milk. Routine testing of UDAF-licensed Dairy A’s raw milk was acceptable. We investigated to identify a source and prevent additional infections.
Methods: UDAF used onsite milk neutralization technique to preserve C. jejuni during testing. Utah’s electronic disease surveillance system identified cases. Confirmed illness was defined as diarrhea caused by C. jejuni matching the cluster PFGE pattern. Probable illness was diarrhea and contact with a confirmed patient or raw milk purchased from Dairy A. Confirmed patients were interviewed by using a standardized questionnaire.
Results: During May 9–July 31, a total of 89 (52 confirmed and 37 probable) cases were identified. Eleven (21.2%) confirmed patients were hospitalized; 1 died. Twenty-five (48.1%) confirmed patients reported having consumed Dairy A raw milk. Fifteen (28.8%) confirmed patients reported having eaten queso fresco. Dairy A’s raw milk yielded C. jejuni with the cluster PFGE pattern. UDAF suspended Dairy A’s raw milk permit on August 4 for 2 months. Additional cases occurred in November; UDAF revoked Dairy A’s raw milk permit on December 1.
Conclusions: Routine testing of raw milk does not ensure its safety. Mandatory reporting, timely sample collection, pathogen testing, and onsite milk neutralization likely led to C. jejuni detection. Linking case and raw milk PFGE patterns might identify the source and allow implementation of control measures.