Description of an outbreak of human Trichinellosis in a historically free area from Argentina. Importance of surveillance studies

CALCAGNO M., BOURLOT I., VILLARRUEL E., FLORENTIN A, TAUS R., VENTURIELLO SM.

Conferencia; XIII International Conference on Trichinellosis; 2011

Recent studies have demonstrated the presence of Trichinella spiralis infection in a free of parasitosis area. However, an outbreak of human trichinellosis occurred in that area from Argentina (Gualeguaychú, Entre Ríos) in July 2010. A total of 62 individuals were infected by pork meat subproducts digestion from a commercial source. The number of individuals positive for trichinellosis was 56 (90%); 44/56 confirmed by laboratory testing (71%) and 12/56 (19%) by epidemiologic nexus. Clinical characteristics, laboratory parameters and inmunoserological (IS) specific testing (ELISA, IIF and/or immunoelectrotransference) of the individuals involved were evaluated. Food samples were analyzed by artificial digestion. The results showed: a- Parasitic burden in food: 1.1 ML/g, being T. spiralis the species found. b- Affected individuals’ mean age: 39 years old. Age-adjusted rate (years) of confirmed cases: 0-14: 9% (n=5); 15-29: 18% (n=10); 30-49: 52% (n=29); 50-64: 19% (n=11) and >65: 2% (n=1); by genre: 66% (n=37) men and 34% (n=19) women. c- Most frequent symptoms: myalgia (93%, n=50), bipalpebral oedema (78%, n=42) and fever (70%, n=38). The 26 patients confirmed (46%) received anti-parasitic and anti-inflammatory treatment, and 7 (12%) individuals anti-inflammatory treatment. Patients evolved satisfactorily without side effects. Hospitalization was not necessary. d- Patients asked for eosinophils count (n=34) presented increased values (mean value, mv: 25.3%). Mean leukocyte count: 11047/mm3. e- Infection was confirmed one month post-ingestion in 73% (n=33) of the 44 individuals diagnosed. f- CPK and LDH values higher than normal values were detected in 15/24 (62%) and in 9/20 (45%) serum with mvCPK: 687 UI/l and mvLDH: 583 UI/l. g- There are no control centers for pork-meat infection detection in the area. Lack of sanitary controls of pork meat and the lack of knowledge regarding this infection led to this outbreak in an area historically free of this parasitosis. This lack of local control socially and economically affected all the pork production chain (farmers, traders, prime age individuals). Previous studies in the area helped human and animal health professionals to conduct immediate prevention and control measures.