Cystic echinococcosis in humans and ruminants in Portugal: a one health approach

BACKGROUND: Cystic echinococcosis or hydatid disease is an important parasitic zoonosis for public health, although neglected. Despite being a mandatory notification disease both in humans and animals, data in Portugal are almost absent. A collaborative One Health retrospective nationwide study was conducted, bringing together the expertise of public health doctors, veterinarians and epidemiologists. METHODS: Human hospitalizations caused by cystic echinococcosis and slaughterhouse records of echinococcosis from bovine, ovine and caprine species were obtained. Poisson loglinear regression model was used. Occurrence maps were generated combining animal and human cases. RESULTS: From 2008 to 2022, 298 cases of echinococcosis were identified in post-mortem inspection in Portuguese slaughterhouses (bovines n = 125, ovines=288 cases, caprines n = 14). Between 2008 and 2018, cystic echinococcosis caused 582 hospitalizations in Portuguese public hospital, with an average length of 11 (± 15.66) days, resulting in 13 deaths (2.23%). Alentejo was the region with the highest hospitalizations. For every infected animal, a 7% increase in the incidence rate of human hospitalization was found (p = 0.002, Exp(B)=1.070, 95% CI: 1.025 - 1.117). Residing in the Alentejo increased the incidence rate of human hospitalizations by 5.3 times when compared to other regions (p = 0.000, Exp(B)=5.290, 95% CI: 3.835 - 7.296). For every 100,000 person-years, there was a total of 0.528 hospitalizations and the risk of death from echinococcosis was 8 times higher for those living in the Alentejo (p < 0.001, Exp(B)=8.259, 95% CI: 2.427 - 28.106). CONCLUSIONS: Living in the Alentejo region has shown to be a high-risk factor for echinococcosis. This work gives an accurate recognition of the situation in Portugal, allowing the development of effective health control and education programs to face an important but neglected zoonotic disease under a One Health approach. KEY MESSAGES: • Considering that echinococcosis is still one of the 20 neglected tropical diseases of global health importance, is critical to map and monitor its prevalence and trends. • This study highlights the impact of this neglected zoonosis in humans and livestock, allowing the identification of the most problematic areas for echinococcosis in Portugal.