Bovine fasciolosis in two Algerian slaughterhouses: Prevalence and assessment of liver suitability for human consumption

Fasciolosis, a hepatobiliary distomatosis affecting domestic ruminants and incidentally humans, poses a threat to both animal and public health, leading to substantial economic losses. This study aimed to determine the prevalence of fasciolosis in cattle slaughtered in Tizi Ouzou, Algeria, and to describe the morphological and histological changes in the liver. A total of 376 bovine carcasses slaughtered between July 2018 and April 2019 underwent post mortem inspection, and corresponding livers were investigated for fasciolosis according to conventional meat inspection procedures. Twenty-six livers, found to be affected with fasciolosis, were sampled at five different sites for histopathological analysis using both hematoxylin-eosin (H&E) and Masson's trichrome stain methods. The overall prevalence was 6.9% (CI 4.4-9.5%). Gross changes related to bovine fasciolosis, including size, color, and consistency abnormalities as well as the worms’ migratory path and distomian cholangitis, were not observed in the majority of the affected livers. Additionally, the infestation degree was low in 56.5% of the fasciolosis-affected livers. In contrast, numerous histopathological damages, including infiltrations, degeneration, necrosis, and fibrosis, were revealed in hepatic parenchyma, connective septa, portal region, and bile ducts throughout all the sampled liver tissues (P> 0.05). Hepatic involvement observed in both the acinus and portal lobule throughout their respective zones was quantified with a degree ranging from 25% to 100% (P> 0.05). Fasciolosis, a common disease in cattle slaughtered in Tizi Ouzou, induces irreversible hepatic tissue damage, thereby compromising the organoleptic and nutritional value of the liver, making it unfit for human consumption.