The evolution of Cystic Echinococcosis in humans and ruminants in Portugal: a one health approach

Cystic echinococcosis, also known as hydatid disease, is a significant parasitic zoonosis with public health implications, albeit often neglected. In Portugal, data on this zoonosis are scarce despite being a mandatory notifiable disease in both humans and animals. To assess the impact of cystic echinococcosis on both livestock and humans, we compiled data from slaughterhouse records of ruminants, human hospitalizations, and confirmed cases of human echinococcosis. Overall, a total of 298 cases of cystic echinococcosis were identified in ruminants slaughtered from national farms for human consumption in Portugal between 2008 and 2022, comprising 192 cases in ovines, 95 in bovines, and 11 in caprines. Echinococcosis led to 582 hospitalizations in Portuguese public hospitals, with an average hospital stay of 11 days (±15.66), and resulted in 13 deaths (2.23%) from 2008 to 2018. Each infected animal was associated with a 7% increase in the incidence rate of human hospitalization (p = 0.002, IRR = 1.070, 95% CI: 1.025-1.117). Additionally, for every 100,000 person-years observed between 2008 and 2018, the total number of hospitalizations was 0.528. Residence in the Alentejo region was associated with a 5.3-fold increase in the incidence rate of human hospitalizations and an 8-fold higher risk of death from echinococcosis.