Epidemiology of human alveolar echinococcosis in China.

Globally human alveolar echinococcosis (AE) is a rare zoonotic helminthic disease confined to the Northern Hemisphere as sporadic infections in rural populations, principally in some areas of North America, west-central Europe, the Near East, Siberia, Central Asia, Japan and China. In China the first human cases were reported from western regions in the 1960s, but most hospital records remain fragmented and inadequate. From the mid-1990s mass screening surveys using portable ultrasound scanners recorded higher prevalences (up to 6% by county) than in any other areas of the world with some village rates as high as 15%. Risk factors identified for AE cases included ethnicity, sex, age and occupation. The role of the dog in transmission of Echinococcus multilocularis to humans now appears to be significant and may be one of the most important risk factor, in combination with landscape/land-use features conducive to maintaining wildlife host populations.