Diagnosis of human fascioliasis in Arusha region, northern Tanzania by microscopy and clinical manifestations

Abstract

Human fascioliasis (HF) is a zoonotic disease that has been reported in many countries. Fascioliasis is included in the list of WHO’s Neglected Tropical Diseases as a Food -Borne Zoonosis which is acquired from infected livestock as the primary host. Human fascioliasis has not been described before in the East Africa region, including Tanzania. We enrolled 1460 patients presenting at a primary healthcare centre in Arusha Region, northern Tanzania. The patients provided fresh stool samples for routine ova and parasite screening using saline and iodine preparations. Subsequent stool samples were preserved in 5% formalin in saline and subjected to ether sedimentation for microscopic examination and identification. Of 1460 patients, 305 (20.9 %) were diagnosed positive for fascioliasis based on the demonstration of brownish, oval eggs with inconspicuous opercula. Two distinct egg sizes were identified: large 170–212.5 by 115–150 μm (mean 194.5 by 130.5 μm) and smaller eggs 120–150 by 87.5 – 112.5 μm (mean 138.8 by 101 μm). Clinically, patients presented with fever and abdominal pain. They were treated with Nitazoxanide (302) or Triclabendazole (3) and 122 (40.0 %) of them were cleared of infection with a single course. Snails of the genus Lymnaea were found in the surroundings. This report serves to remind medical professionals in East Africa that HF is a probable differential diagnosis in patients presenting with similar symptoms. It is possible to diagnose fascioliasis by light microscopy although specific antigen tests are required for confirmation. Human fascioliasis however, has not been described or reported in Tanzania before and begs further investigation.

Keywords: “Human fascioliasis”, diagnosis, treatment, Tanzania