Early Dignosis of Human Facioliasis by Metacercaria Precipitation Method

Fascioliasis is a cosmopolitan parasitic disease common between human and herbivorous animals. Since the disease leads to significant liver damage, it should be diagnosed and treated more quickly and more accurately. The etiologic agent is Fasciola hepatica (and rarely Fasciola gigantica).
In Iran Fascioliasis is more prominent in the humid north provinces as compared to other areas. The disease initiates with ingestion of drinking water and raw vegetables (lettuce, watercress and ... ) that harbor metacercariae. Then, the larvae reside and mature in biliary ducts. The most common symptoms are fever, right upper quadrant abdominal pain, eosinophilia, gastrointestinal disorders and allergic reactions.
Diagnosis is usually based on clinical symptoms and epidemiologic informations. It is confirmed by parasitologic and serologic methods. As parasitologic tests are only definitive in 30% of cases, and serologic methods are highly diagnostic and accurate, we used metacercaria precipitation test for early diagnosis of human fascioliasis for the first time in Iran. We used in vitro-bred metacercariae as major antigens. They were incubated with serum samples offasciola-infected patients and healthy individuals (control group). Different dilutions of 1/5 and 1/10 were used. Precipitation reactions were assessed after 6,24 and 48 hours. In this study, the sensitivity and specificity of the test at 1/5 dilution were higher than other dilutions and were 95% and 100% respectively. Due to the simplicity and the lack of heavy expenditure, and since the test helps early diagnosis of disease, we suggest that this be used at any part of the country. Due to unavailabillity of nitazoxanide, our patients, with positive metacercaria precipitation test, were treated with triclabendazole which was fUlly effective.