Trichinellosis has been a nationally notifiable disease in the United States since 1966 and is reportable in 48 states, New York City, and the District of Columbia. The purpose of national surveillance is to estimate incidence of infection, detect outbreaks, and guide prevention efforts.
During 2008–2012, a total of 90 cases of trichinellosis were reported to CDC from 24 states and the District of Columbia. Six (7%) cases were excluded from analysis because a supplementary case report form was not submitted or the case did not meet the case definition. A total of 84 confirmed trichinellosis cases, including five outbreaks that comprised 40 cases, were analyzed and included in this report. During 2008–2012, the mean annual incidence of trichinellosis in the United States was 0.1 cases per 1 million population, with a median of 15 cases per year. Pork products were associated with 22 (26%) cases, including 10 (45%) that were linked with commercial pork products, six (27%) that were linked with wild boar, and one (5%) that was linked with home-raised swine; five (23%) were unspecified. Meats other than pork were associated with 45 (54%) cases, including 41 (91%) that were linked with bear meat, two (4%) that were linked with deer meat, and two (4%) that were linked with ground beef. The source for 17 (20%) cases was unknown. Of the 51 patients for whom information was reported on the manner in which the meat product was cooked, 24 (47%) reported eating raw or undercooked meat.
The risk for Trichinella infection associated with commercial pork has decreased substantially in the United States since the 1940s, when data collection on trichinellosis cases first began. However, the continued identification of cases related to both pork and nonpork sources indicates that public education about trichinellosis and the dangers of consuming raw or undercooked meat still is needed.
Wilson NO, Hall RL, Montgomery SP, Jones JL; Trichinellosis Surveillance - United States, 2008-2012; MMWR Surveill Summ. 2015 Jan 16;64 Suppl 1:1-8.