Massive infection with fasciola hepatica in man

The six year clinical course of a patient who acquired a massive infection with the liver fluke, Fasciola hepatica, is described. A peripheral blood eosinophilia was an almost constant finding throughout the illness. The patient may well have been infected with a multiple of 40 adult flukes as his fecal ova count (1,000/g) was 40 times greater than that of a subject with an asymptomatic infection. During the illness, cholecystectomy was carried out. The surface of the liver was studded with greyish white hard nodules. Microscopy of the gallbladder revealed a nonspecific chronic cholecystitis; a liver biopsy disclosed florid changes of large duct biliary obstruction, granulomas, patchy periductular fibrosis and an ovum morphologically similar to an ovum of Fasciola hepatica surrounded by a granuloma. Three exacerbations of symptoms were associated with severe microcytic hypochromic anemia, possibly due to blood loss into the biliary tract. A course of bithionol was associated with rapid amelioration of symptoms and disappearance of ova from feces. No evidence of recurrence of infection occurred during the following two and a half years. The infection was probably acquired by eating wild watercress (Nasturtium officinale) containing encysted metacercariae at a campsite frequented by the patient in the Lake District of England. At this site, a habitat suitable for the life cycle of F. hepatica was found, including snails of the genus Limnaea truncatula, which were shown to contain cercariae. The site is in a region with a high rainfall, a factor known to favor the life cycle of F. hepatica. Infection with this parasite should be considered whenever a clinical picture suggestive of biliary tract disease is associated with an eosinophilia.