Community survey for human cystic echinococcosis in Northwest China: A long term follow-up study

This study aimed to reveal the natural history, curative effect and possible re-infection risk factors of human cystic echinococcosis (CE) through long-term follow-up of treated and untreated CE cases in Hobukesar, Xingjiang, Northwest China. Follow-up studies about CE were carried out twice in Hobukesar from August 2005 to October 2008. Ultrasound scan was primary diagnostic method. Among 24 patients confirmed CE, 22 patients were treated (including surgery in 19 cases and chemotherapy in 3 cases). Two recurrent cases and one re-infective case were found during the studies. The type (WHO classification) of one of the recurrent cases transformed from CE4 to CE3. Ultrasound was required to differentiate primary, recurrent and re-infective cases during epidemiological investigation and follow-up of CE. Most patients did not change their habits was one of the possible causes of re-infection. One recurrent case suggested that biological status of CE4 was not inactive prompted by WHO.