Short report: identification of the likely etiologic agent of human trichinellosis in Sicily (Italy) between 1933 and 1946.

Larvae of Trichinella sp. collected in 1961 from muscle samples of the last infected domestic pig slaughtered in Sicily (Italy), and preserved in absolute ethyl alcohol until 1997, have been identified as Trichinella spiralis by the polymerase chain reaction. This finding explains the severity of the clinical picture, resulting in death, and the high number of fatal cases (20 of 184, 11%) observed in three Sicilian outbreaks between 1933 and 1945, caused by the consumption of sausages from pigs originating from the same focus of 1961. The relationship between the human outbreaks and the infected pig of 1961 is supported by epidemiologic data that show that Sicily was and is Trichinella-free, with the exception of the above reported focus.