Re-evaluation of patients involved in a trichinellosis outbreak caused by Trichinella britovi 15 years after infection

This study re-evaluates 13 out of 48 subjects involved in a trichinellosis outbreak that occurred in Central Italy (Umbria Region) in 1988 resulting from the consumption of raw boar meat harboring Trichinella britovi. During the outbreak, 28 of 48 serologically positive subjects were asymptomatic, whereas 20 subjects presented one or more clinical signs including but not limited to fever, myalgia, periorbital oedema and conjunctivitis. Several patients were hospitalized with severe clinical signs requiring treatment with mebendazole and corticosteroids. Upon re-evaluation of 13 patients, none presented clinical signs; however, three still had increased CPK or LDH serum levels with some signs of electromyographic changes. In this study, enzyme immunoassays (EIA) were used to test the 13 positive sera for reactivity with T britovi antigens using both excretory/ secretory (E/S) antigens and a synthetic antigen composed of P-tyvelose conjugated to bovine serum albumin. Western blots (WB) were also carried out using a commercial kit. Studies using EIA with E/S antigen identified five positive sera; however, using beta-tyvelose as antigen, only one positive sample was identified. Nearly all sera reacted positively with one or more Trichinella antigens when analyzed by WB, in particular to the 45 kDa beta-tyvelose containing glycoprotein. Results indicate that T britovi, though less pathogenic than other Trichinella species, is clearly capable of inducing sustainable sequelae.