An Outbreak of Human <i>Fascioliasis gigantica</i> in Southwest China

<div><p>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 <i>Fasciola gigantica</i> 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®. <i>Fasciola</i> spp. were discovered in local cattle (28.6%) and goats (26.0%). Molecular evidence showed a coexistence of <i>F. gigantica</i> and <i>F. hepatica</i>. However, all eggs seen in humans were confirmed to be <i>F. gigantica</i>. Herb (<i>Houttuynia cordata</i>) 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.</p></div

Phylogeny of <i>Fasciola</i> spp. from the present study and other sources.

<p>Red branches indicate the sequences from human stool sample. <b>C</b> represented as egg samples from cattle; <b>G</b> represented as egg samples from goat; <b>H</b> represented as eggs samples from human.</p

Typical image of involved liver in contrast-enhanced computerized tomography.

<p>The section shows the enlarged liver and spleen. The clusters of low density masses (arrows) in livers indicate the winding migration route of parasite.</p

The change of major indicators after treatment with triclabendazole.

<p>% and # denote the proportion and absolute count, respectively.</p

Manifestations of fascioliasis in 29 patients involved in an outbreak.

<p>Manifestations of fascioliasis in 29 patients involved in an outbreak.</p

Axillary temperature profile of patients during the illness course.

<p>The vertical hatched bar indicates the treatment date using triclabendazole. The fever is defined as over 37.2°C (dash line). The thick curve denotes the average temperature, which was produced by moving average with a period of 12 (equal to 3 days).</p