Gross and histopathological lesions associated with zoonoses in rodents captured in households from selected districts of Uganda
MetadataShow full item record
Rodents live in close proximity to humans in many habitats around the world. They are a threat to public health because of the physical destruction to property and pathogens they carry. Several epidemiological studies investigating rat-borne illnesses have been done around Uganda, however, lesions associated with zoonoses in rodents have not been described. This study was conducted on rodents captured during a major surveillance studies on acute febrile illnesses in Uganda. Rodents were captured from households using Sherman’s rat traps, euthanized searched for arthropod vectors. The vectors were collected for another study and the euthanised rodents were identified morphologically. The dead rats were necropsied and gross lesions were recorded. Organs collected from the rodents were preserved in 10% buffered formalin and processed for histopathology using routine procedures for Haematoxylin and eosin. A total of 159 rodents were captured of which 74.2% (n=118) were black rats (Rattus rattus), 20.1% (n=32) were house mice (Mus musculus) and 5.7% (n=09) were shrews. Grossly, most of the lesions were observed in the liver of 12 black rats. These consisted of mild to moderate and in some instance severe multifocal pale areas of necrosis. Histopathological examination of these liver lesions revealed numerous multifocal well demarcated and walled-off granulomas compressing and destroying the hepatic cord and parenchyma while others had cysts with different developmental stages of tapeworm (Taenia taeniaformis). The granulomas contained Capillaria hepatica nematodes in different developmental stages with numerous typical ova. There was degeneration and necrosis of hepatocytes, bridging fibrosis and biliary hyperplasia, surrounded by inflammatory foci composed of lymphocytes, plasma cells and macrophages. The brains of rodents with these liver lesions also had vacuolation of the neuropil of the brain stem and parts of white matter of the cerebrum. This study highlights the presence of C. hepatica as zoonotic agent circulating in rodents in Uganda with R. rattus as the major reservoir. Further study of this disease in rodents and children is required since the children are the most affected. Clinicians need to be aware of hepatic capillariasis in differential diagnosis of liver diseases amongst children in Uganda.