An Outbreak of Human Fascioliasis gigantica in Southwest China.

Fascioliasis is a common parasitic disease in livestock in China. However, human fascioliasis is rarely reported in the country. Here we describe an outbreak of human fascioliasis in Yunnan province. We reviewed the complete clinical records of 29 patients and performed an epidemiological investigation on the general human population and animals in the outbreak locality. Our findings support an outbreak due to Fasciola gigantica with a peak in late November, 2011. The most common symptoms were remittent fever, epigastric tenderness, and hepatalgia. Eosinophilia and tunnel-like lesions in ultrasound imaging in the liver were also commonly seen. Significant improvement of patients' condition was achieved by administration of triclabendazole®. Fasciola spp. were discovered in local cattle (28.6%) and goats (26.0%). Molecular evidence showed a coexistence of F. gigantica and F. hepatica. However, all eggs seen in humans were confirmed to be F. gigantica. Herb (Houttuynia cordata) was most likely the source of infections. Our findings indicate that human fascioliasis is a neglected disease in China. The distribution of triclabendazole®, the only efficacious drug against human fascioliasis, should be promoted.

[Clinical diagnosis and treatment in an outbreak of Fasciola gigantica infection in Yunnan Province].

OBJECTIVE: To carry out clinical diagnosis and treatment of Fasciola gigantica infection during an outbreak in Yunnan Province. METHODS: Data on epidemiology, diagnosis and treatment were collected from 27 patients. A questionnaire survey to the patients and partial villagers was carried out including history of raw food-eating and pet-raising. Animal feces were collected and examined by precipitation method and eggs incubation method. Cattle from two patients families were dissected to find Fasciola infection. Serum samples from patients, family members, and villagers were detected. Possible intermediate snails were collected from the vicinity of streams and ponds in 15 villages where patients lived. RESULTS: The earliest onset of symptoms among the patients was on March 10, 2011 and the last case was on January 10, 2012. The clinical manifestations were mainly fever with unknown reason, decreasing hemoglobin, increasing eosinophils, and hepatosplenomegaly. No parasite eggs were found in feces. Antibodies against F. gigantica were positive by ELISA in 23 patients. Fasciola eggs were then found in 4 patients' feces on February 16, 2012. F. gigantica eggs and adults were found in the hepatobiliary system of dissected cattle. Triclabendazole [10 mg/(kg x d) x2 d] was administered orally for the patients and the clinical symptoms eased. Snails including Physa acuta, Radix swinhoei and Galba pervia were collected and cercariae were found in only one snail. CONCLUSION: An outbreak of F. gigantica infection has been confirmed and the diagnosed cases effectively treated with triclabendazole.