Histopathological evaluation of Capillaria hepatica (Bancroft, 1893) in Cricetomys gambianus (Waterhouse, 1840)

Hepatic capillariasis is a global neglected zoonotic disease with small rodents and lagomorphs as host animals although cases have occurred in over 140 mammals, including in humans to underscore its health implications to both animals and humans. A total of 20 free-living Cricetomys gambianus were sampled from the wild within the Federal Capital Territory, Nigeria, for the presence of and effects of Capillaria hepatica between August 2023 – May 2024. The lungs, liver, spleen, and kidneys of the sampled rats were promptly harvested, observed and recorded, and fixed in 10% formalin for histopathological evaluations after humane animal sacrifice according to standard procedures. There were no obvious gross lesions while cellular changes occurred only in the liver that were characterized by the presence of clusters of parasitic eggs with hepatic necrosis and inflammatory responses. The presence of the ellipsoidal-shaped and double layered straited shelled-eggs with operculum and the hepatic cellular changes led to a definitive diagnosis of Capillaria hepatica with a 10% prevalence rate. The findings highlighted the health risk to the animal and the human consumers of infected. Cricetomys gambianus whose meat is considered a delicacy within the study area and other parts of the world. Outside the probable role of host animal’s adaptation strategy being responsible for the non-typical granulomatous inflammation and hepatic septal fibrotic cellular changes, there is a need for more studies to further elucidate the pathogenesis of the disease condition in this particular animal species in the patho-epidemiology of hepatic capillariasis within the study area.