Epidemiological and clinical patterns of trichinellosis in Bulgaria from 1995 to 2002

Sir, Trichinellosis is one of the most common helminthic zoonoses in Bulgaria.The number of infections has been incessantly on the rise during the last 17 years.From 1988 to 1998, 76 outbreaks were documented involving 6,770 people.Severe clinical courses inducing two deaths, were documented among 1,037 infected people (Kurdova et al., 1999).From 1998 to 2002, 1,804 cases of trichinellosis have been recorded in 118 outbreaks (Kurdova, 2001;Kurdova et al., 2003).From 1990 to 1992, clinical features of 117 patients with trichinellosis were studied at the Clinic of Parasitic Diseases of the Medical University of Sofia.The source of infection was uncontrolled pork from domestic pigs and wild boars in 59 % and 41 % of the infections, respectively (Boeva et al., 1995).The aim of the present study was to investigate the epidemiological and clinical patterns of people suffering from trichinellosis, who attended the Clinic of Infectious, Parasitic and Tropical Medicine of Sofia, Bulgaria, in the period 1995-2002.Place of residence, age, type of dwelling of each enrolled person in the study was recorded.Most, but not all people under study, underwent clinical and epidemiological investigations including the duration of the incubation period, the clinical signs and symptoms and laboratory features (eosinophilia, leucocytosis, muscle enzymes, and circulating antibodies).Serology was performed by three commercial kits (Bul Bio NCIP Ltd, Bulgaria): passive haemagglutination assay (PHA), immunofluorescence (IF) and ELISA, according to the producer's instructions.Serum samples were collected from the enrolled persons from three to 46 days post