Post-survey follow-up for human cystic echinococcosis in northwest China

In Hobukesar, Xinjiang Uygur Autonomous Region, (China), a mass-screening programme for human cystic echinococcosis (CE)was performed during 1995 and 1996. After the survey 51 cases were followed-up using ultrasound scan and serology for 1-8 years(1996-2003). These included 20 CE cases treated by surgery (endocystectomy), four CE cases treated by percutaneous drainage(PAIR), six untreated CE cases, five ultrasound 'query' cases, eight cases of isolated hepatic calcifications, four previous CE surgery cases whose ultrasound was now normal, and four seropositive cases who exhibited a normal hepatic ultrasound. Follow-up results indicated that in the untreated CE patients, one case exhibited a spontaneous cure within 4 years, another case changed from a hepatic hydatid cyst that contained a floating laminated membrane (type CE3) to a cyst that contained daughter cysts (type CE2)within 1 year of follow-up. In the 20 surgically treated cases, two recurrent CE cases occurred within 4 years, and five cases had had residual cavities for more than 4 or 8 years. Of the 4 PAIR treated cases, two recurrent cases of CE occurred within 4 or 8 years of follow-up. Serological follow-up data showed that specific IgG antibody levels were persistently positive in most CE cases, but exhibited a decreasing tendency in cases that were effectively treated by surgery; In contrast, serum IgG levels in the PAIR group or in the recurrent CE cases after surgery exhibited an increasing tendency. At least one persistent seropositive case with an isolated hepatic calcification was considered to be abortive CE.