Human Cystic echinococcosis, Trichinellosis and Toxocariasis in Bulgaria: an update of data for 2015-2017

Background: The purpose of our study is to perform a retrospective analysis of the prevalence of some zoonotic helminth infections (trichinellosis, cystic echinococcosis, and toxocariasis) for the period 2015-2017, given their important medical and social significance for the public health system in Bulgaria and other endemic countries. Methods: We used data from the National Centre of Infectious and Parasitic Diseases and Regional Health Inspectorates for all registered cases of cystic echinococcosis and trichinellosis during the study period and data from the Department of Parasitology and Tropical Medicine on all cases seropositive for toxocariasis. Results: For the study period in the country were reported 800 confirmed cases of hydatid disease of which 715 (89.4%) primary and 85 (10.6%) cases of relapse. The group of children and adolescents accounted for 21% of the total number of infected. Ten trichinellosis outbreaks were also recorded, involving the population of 16 settlements across 10 of the 28 districts of the country. Contaminated with Trichinella larvae meat was consumed by 293 persons of whom laboratory confirmed infection was found in 113 individuals (38.6%). For the period, 408 persons with clinical symptoms suspicious for toxocariasis were tested and 78 (19.1%) of them were positive for the presence of specific anti-Toxocara antibodies. Conclusions: Parasitic zoonotic diseases have endemic spread in many countries around the world and pose a problem for public health. We present data on three helminth diseases, two of which (cystic echinococcosis and trichinellosis) are still widespread in Bulgaria and are of great medical and social importance.