Ivermectin and One Health: repositioning and the concern with the environmental

The discovery, the commercial success, and the social use of ivermectin (IVM) were always recognized worldwide and gave the authors the Nobel price of Medicine/Physiology in 2015. It exclusive endectocide activity and safety, allowed its immediate integration in various health protocols to virtually all animal species, including humans. Even tough, the large-scale use of IVM in high frequency has caused the selection of resistant parasites. As IVM is a multitarget product, it is being repositioning to act against the SARS-CoV-2 virus. Environmental protection must also be considered, as the environment elimination of IVM may affect marine ecosystems and unassisted communities with low social development, with low access to safe water and to proper sewage systems.

Fasciola hepatica infection in cattle and the use of simulation models for endemic areas.

Fasciolosis is a food-borne disease that causes great distress to a range of hosts, including humans. The objectives of this study were to (1) evaluate the liver damage and carcass weight of cattle naturally infected with Fasciola hepatica from the state of Rio Grande do Sul (RS), Brazil, and to (2) determine the distribution of adult flukes in 12,236 cattle liver from RS. The data from these experiments were used to calculate the overall economic loss due to F. hepatica infection. Eighteen adult Polled Hereford cows were divided into a triclabendazole (TbG) and a F. hepatica-positive group (FhG). For Experiment 1, a generalized linear mixed model revealed a statistical difference in carcass weight (49.8 kg) between TbG and FhG. The Monte Carlo analysis also revealed that the animals' weight differences were due to the disease. For Experiment 2, the prevalence of infected livers was above 16% (1904/12,236), mostly (20.1%) from the south-west region of RS. The Susceptible-infected-recovered (SIR) epidemic model revealed the evolution of the infection using a high infectivity and low recovery rate. Other distinctive scenarios that occur in RS were also established with different rates of infectivity. The economic assessment showed a potential loss of US$45 million to the beef cattle industry of RS, with an overall State cost of US$90.3 million. These novel findings reveal the importance of fasciolosis infection, which can cause a significant health condition and poor animal welfare.