Echinococcosi cistica nell'area di Rieti: conoscenza del fenomeno e proposta di un modello di valutazione dei rischi per i lavoratori del settore zootecnico

Human cystic echinococcosis (CE), also known as hydatid disease, is an helminthic zoonosis caused by infection with the larval stages of the cestode parasites Echinococcus granulosus. CE continues to represent a global health hazard affecting approximately over 1 million individuals worldwide. Indeed, Echinococcus granulosus infection is globally distributed and found in every continent, except Antarctica. In endemic regions, human incidence rates for CE can reach greater than 50 per 100,000 person-years, and prevalence levels as high as 5–10% may occur in parts of Argentina, Peru, east Africa, central Asia and China. Echinococcus granulosus may cause illness in intermediate hosts, generally herbivorous animals and people who are infected accidentally. Workers such as slaughters, tanners, stockbreeders, shepherds, butchers, veterinarians are supposed to be at higher risk of the infection. The present study aims to evaluate the seroprevalence of CE in workers exposed and in blood donors, and to determine the prevalence of occupational and non-occupational risk factors associated with CE infection in both groups. A cross-sectional study was conducted in a central region of Italy (Latium) in the period from September 2015 to September 2016. It included 177 workers exposed to biological risk of the Echinococcus granulosus infection (shepherds) and 192 apparently healthy blood donors selected from the same geographical area. General and medical information, including job history, occupational and non-occupational risk factors were collected using specific questionnaire. Human sera from shepherds and donors were sampled and analyzed using a commercially available enzyme linked immunosorbent assay (ELISA). Seropositive samples were further analysed by Western blotting. Logistic regression was performed to evaluate the potential risk factors associated with the presence of antibodies. The results showed that 18 subjects (4.88%) were ELISA seropositive. High seropositivity was recorded in workers (5,65%), followed by the donors (4.17%). Only one seropositive sample was confirmed by Western blotting. The Individual Risk Score (IRS), based on sum of occupational and non occupational risk factors, was associated to seropositivity (P=0.000 8; OR=1.889; 95% CI=1.689-2.113). The results of this study reinforce the necessity to implement the prevention of risks at workplace, with special reference to the biological risk, using appropriate tools for the identification and the assessment of hazards combined with public health education and information.