Current Status of Fasciola and Fascioliasis in Ecuador: A Systematic Scoping Review, 2026

Background: Fascioliasis caused by Fasciola hepatica and F. gigantica is an important foodborne zoonotic trematodiasis affecting ruminants and humans worldwide. Ecuador has long been recognized as an endemic country, particularly in the Andean region; however, available knowledge remains fragmented across medical, veterinary, and malacological fields. Here, we update and synthesize the available evidence on the epidemiology of fascioliasis with the aim of identifying critical knowledge gaps and guiding future research and national policy. Methods: This study was conducted according to the PRISMA-ScR guidelines. Four electronic databases (Web of Science, PubMed, Google Scholar, and SciELO) were systematically searched through July 2026. Additional publications were identified through manual searches of reference lists, university repositories, and grey literature. Eligible publications reporting original data on infection in humans and other herbivorous mammals, environmental contamination, Fasciola species, lymnaeid intermediate host snails, including their presence, geographical distribution, abundance, or infection status in Ecuador, were analysed. Two reviewers independently screened eligible studies and extracted relevant data, which were subsequently synthesized using descriptive analyses and narrative synthesis. Results: Thirty-six studies published between 1995 and 2026 met the inclusion criteria. Most (63.9%) investigations were conducted in the Andean region, where high infection rates in livestock and competent lymnaeid snails sustain endemicity. Livestock fascioliasis was extensively documented in 15 (42%) studies, with prevalence ranging from 0% to 84.8% in cattle, 61.7–100% in sheep, 21.9% in pigs, and 10.7% in guinea pigs. Liver condemnation due to fascioliasis generated substantial economic losses, although the overall national burden remains unknown. Human evidence was limited to one seroepidemiological survey, demonstrating a 6% seroprevalence in one rural Andean community, and three case reports. In 17 studies, five lymnaeid snail species (Galba cousini, G. schirazensis, G. neotropica, G. cubensis, and Pseudosuccinea columella) were reported, with G. cousini showing evidence as the intermediate host. Molecular studies identified F. hepatica as the only species circulating in Ecuador. No study was found on plant carriers, and none was conducted in the Galapagos Islands. Triclabendazole (TCBZ) was effective in sheep and cattle, with high reinfection rates in 5 months; no study reported on TCBZ resistance. TCBZ is unavailable for human use. There is an absence of a national control programme, standardized diagnostic algorithms or contemporary human epidemiological studies. Conclusions: Fascioliasis remains an important yet neglected zoonosis in Ecuador, with active transmission in the Andean region where infected livestock, competent lymnaeid snails, and suitable environmental conditions coexist. F. hepatica is the sole circulating species and G. cousini the intermediate host; the epidemiological role of other lymnaeid and animal species requires further investigation. Coordinated One Health studies, equitable access to diagnostics and triclabendazole, standardised molecular monitoring, and integrated human–animal-environmental control strategies should be prioritised to reduce Fasciola transmission in Ecuador.