Human case of Fasciola gigantica-like infection, review of human fascioliasis reports in Nepal, and epidemiological analysis within the South Central Asia

Abstract

Abstract The diagnosis of a 22 year-old male patient from Kerabari, Morang District, Nepal led to the review of human fascioliasis cases and analysis of the epidemiological situation in that country not included in the WHO fascioliasis map. Symptom onset one month before egg detection and normal levels of ALT and AST did not agree with the 3–4-month migratory period of fascioliasis. A shorter acute phase may happen when the main biliary duct is reached by the migratory juveniles directly from the intestinal lumen. The causal agent was ascribed to F. gigantica-like worms after considering adult fluke morphology, altitude of the patient’s infection area, fasciolid characteristics in the neighbouring Bangladesh, and lymnaeid snail vector species known in Nepal and in the patient’s infection area. Previous reports of human infection by Fasciola in Nepal are reviewed. The patient in question proved to be the twelfth case and the first in whom a F. gigantica-like infection is reported. In Nepal, the wide geographical distribution of livestock fascioliasis, with high prevalences in buffaloes, cattle and goats, and the reports of Fasciola-infected schoolchildren close to the capital Kathmandu, give rise to concern on the situation in remote rural areas in a country where most of the population lives in rural areas. Moreover, the climate change impact in Nepal remembers Pakistan, where human fascioliasis emergence has been related to climate change and man-made irrigation. All in all, the present analysis suggests that human infection by Fasciola may be underestimated in Nepal.