An insight into the epidemiology of foodborne zoonotic fascioliasis in small ruminants in northwestern region of Bangladesh.

Fascioliasis is one of the most common foodborne zoonotic infection of ruminants in Bangladesh. To estimate the prevalence and associated risk factors of fascioliasis and extent of liver damage, 825 livers of sheep and goats were randomly inspected during onsite slaughterhouse visiting in Naogaon, Natore, Rajshahi and Joypurhat districts. The overall prevalence of fascioliasis was 25.09% and significantly (P = 0.008) higher in goats (26.11%) than sheep (24.00%). During gross inspection, Fasciola infected livers were increased in size, fibrosed, fatty, multiple white or reddish necrotic foci on the parietal surface, hard to cut, calcified, and numerous mature and immature flukes were also observed. In histoarchitecture, inflammatory cell infiltration in the hepatic parenchyma and periportal area, fibrous connective tissue proliferation around necrotic area, hyperplastic bile duct, congestion, and primary biliary cirrhosis were seen in acute and chronic fascioliasis. Epidemiological investigations revealed that fascioliasis was higher in goats than sheep. Age, sex, BCS and season were found to have statistically significant associations with fascioliasis in goats. In case of sheep, age (OR = 5.8671; 95% CI: 2.9482-11.6757, P < 0.0001), sex (OR = 3.7317; 95% CI: 1.9052-7.3094, p < 0.0001), BCS (OR = 6.0346; 95% CI: 1.7986-20.2472, p < .0001), and season (OR = 8.2308; 95% CI: 3.9922-16.9693, p =  < .0001) were also found to have statistically significant associations with fascioliasis. Results of the study can help for molecular epidemiology of fascioliasis in small ruminants to plan fluke control programs for safe food production.