Clinical and epidemiological descriptions from trichinellosis outbreaks in Bulgaria

Bulgaria is one of European countries where trichinellosis continues to be regularly diagnosed and registered. The clinical and epidemiological features of 72 cases of trichinellosis associated with five outbreaks caused by Trichinella spiralis and Trichinella britovi between 2009 and 2011, are described. At hospital admission, patients were often initially treated with antibiotics, without any improvement. A range of signs and symptoms were recorded, including: myalgia, elevated temperature, arthralgia, difficulty with movement, facial oedema, conjunctival hyperaemia, ocular haemorrhages, diarrhoea, skin rash, headache, and fatigue. Due to the variable clinical course of the disease, the diagnostic process for trichinellosis is often complex and difficult. This means the diagnosis may be established late for an appropriate treatment, potentially leading to a severe course of the disease with complications. Laboratory abnormalities were expressed by marked eosinophilia (97.2%), leucocytosis (70.8%), elevated serum creatine phosphokinase levels (82%), and antibody-positive results by ELISA and indirect hemagglutination. Patients were treated with albendazole (Zentel) 10 mg/kg for 7-10 days. In two outbreaks, the aetiological agent was T. spiralis, in one outbreak T. britovi, and an unknown Trichinella species in the fourth outbreak. The sources of infection were domestic pigs, probably fed with scraps and offal of wild game. In one outbreak, T. spiralis was also detected in brown rats trapped close to where the pig had been raised in the backyard. These epidemiological factors are relevant in considering implementation of targeted control programmes.