Abstract:

Objective To understand the endemic status of echinococcosis in Gannan Tibetan Autonomous Prefecture. Methods The 2007-2013 survey data on hydatid disease prevention and control were collected from 8 counties/cities in Gannan Tibetan Autonomous Prefecture and analyzed. Ultrasound scanning was used to detect echinococcosis infection, ELISA was performed to detect anti-Echinococcus IgG in serum of children under 12 years, and double-antibody sandwich ELISA method was used to detect Echinococcus antigen in dog’s feces. Visceral dissection was performed to examine hydatid infection in domestic ruminants. Results The prevalence of echinococcosis in residents was 225/100 000（810/360 440）, comprising 224/10 0000（807/360 440） for cystic echinococcosis and 1/100 000（3/360 440） for alveolar echinococcosis. The prevalence was 2.3/100 000（340/151 280） in males and 2.3/100 000（470/209 160） in females, with no significant difference（χ２＝6.41，P>0.05）. Among different age populations, the 30-40 age group had the highest proportion （44.2%, 358/810） to all detected infections. Besides, the prevalence was the highest in herdsmen, followed by farmers. Echinococcosis was detected in 372 administrative villages in the Prefecture. The positive rate for serum anti-Echinococcus IgG was 4.0%（1 921/47 841） in children under 12 years. The positive rate for Echinococcus antigen in dog’s feces was 5.5%（3 523/64 521）. The rate of hydatid infection in domestic ruminants was 3.3%（1 148/35 134）. After seven years’ comprehensive control, the prevalence of echinococcosis in residents dropped from 440/100 000（97/21 938） in 2007 to 290/100 000（160/55 954） in 2013（χ２＝11.69，P<0.05）. The positive rate for serum anti-Echinococcus IgG in children also dropped from 7.9%（150/1 902） in 2007 to 2.1%（151/7 100） in 2013. Consistently, the positive rate for Echinococcus antigen in dog’s feces dropped from 11.9% （335/2 819） in 2007 to 3.3%（466/13 608） in 2013 （χ２＝338.52，P<0.05）; and the rate of hydatid infection in domestic ruminants dropped from 8.8%（235/2 658） in 2007 to 1.5%（107/7 271） in 2013（χ２＝317.86, P<0.05）. Conclusion The control activities during 2007-2013 has shown significant achievements in reducing echinococcosis in Gannan Tibetan Autonomous Prefecture.

Key words: Echinococcosis, Endemic status, Prevalence, Gannan