新疆塔城地区棘球蚴病流行现状调查

Prevalence of echinococcosis in Tacheng Prefecture, Xinjiang Uygur Autonomous Region, China

目的了解和掌握新疆塔城地区棘球蚴病的流行现状。方法于2015-2017年随机选择塔城地区塔城市、乌苏市、额敏县、沙湾县、托里县、裕民县和和丰县等7个县(市)的6岁及以上儿童和居民进行腹部B超检查棘球蚴病患病情况。每县随机抽取1～2所小学, B超检查6～12岁儿童棘球蚴患病情况,并采集血样, ELISA检测血清抗棘球蚴IgG抗体。各调查点采集家犬粪样, ELISA检测棘球绦虫粪抗原。采用内脏剖检法检查家畜棘球蚴感染情况。结果共B超检查277 615人,人群棘球蚴病检出率为0.25%(683/277 615),均为细粒棘球蚴病病例。2015-2017年人群棘球蚴病检出率分别为0.15%(131/84 882)、 0.23%(238/101 509)和0.34%(314/91 224),呈逐年上升趋势(P <0.005)。7个县(市)均存在棘球蚴病流行,以和丰县较高,人群棘球蚴病检出率为0.56%(65/11 606),不同县(市)检出率差异有统计学意义(P <0.01)。男性和女性棘球蚴病检出率分别为0.24%(345/141 584)和0.25%(338/136 031),两者差异无统计学意义(P> 0.05)。不同年龄组中,人群棘球蚴病检出率以35～59年龄组较高,为0.35%(113/31 843);各年龄组检出率差异有统计学意义(P <0.01)。不同职业中,人群棘球蚴病检出率以农民较高,为0.41%(365/88 411);不同职业人群检出率差异有统计学意义(P <0.01)。共检测儿童血清18 560份,血清抗棘球蚴IgG抗体阳性190份,阳性率为1.02%,呈逐年上升趋势(2015年:0.60%, 49/8 167; 2016年:0.71%, 43/6 034; 2017年:2.24%, 98/4 359)(P <0.01);不同县(市)儿童血清抗体阳性率以和丰县较高,为3.16%(60/1 900)(P <0.01)。共检测犬粪34 343份,粪抗原阳性率为1.04%(356/34 343),以2016年较高,为1.71%(206/11 824), 3年的犬粪抗原阳性率差异有统计学意义(P <0.01);各县(市)均检出犬粪抗原阳性,以和丰县较高,为3.16%(98/3 100)(P <0.01)。共检查家畜(羊) 4 008只,棘球蚴感染检出率为1.05%(42/4 008),其中, 2015年家畜感染检出率较高,为1.67%(30/1 800), 3年的感染检出率差异有统计学意义(P <0.01)。结论 2015-2017年新疆塔城地区人群棘球蚴病检出率、儿童血清抗棘球蚴抗体阳性率、犬粪棘球绦虫抗原阳性率呈不同程度的上升趋势。

Objective To determine the endemic status and prevalence of Echinococcus granulosus in Tacheng endemic area. Methods Residents with age of 6 years old and above were randomly selected from 6 cities or counties (Tacheng, Wusu, Emin, Shawan, Tuoli, Yumin and Hefeng) in Tacheng Prefecture, Xinjiang Uygur Autonomous Region, for the epidemiological investigation of echinococcosis during 2015-2017. The participants were examined with abdominal ultrasound, sera were collected for detecting anti-E. granulosus IgG by ELISA. The fecal samples of dog were collected to detect E. granulosus antigen using double antibody ELISA. The infection of E. granulosus in livestock was determined by examining cystic hydatid in the viscera of slaughtered livestock sheep. The prevalence of E. granulosus in human, dog and livestock in these areas was statistically analyzed. Results The general prevalence of hydatid disease in Tacheng residents was 0.25% (912/277 615) during 2015-2017, with an increasing trend year by year [0.15% (131/84 882) in 2015, 0.23% (238/101 509) in 2016 and 0.34% (314/91 224) in 2017] with statistical difference by year (P < 0.05). All 7 investigated cities or counties were endemic with E. granulosus, with highest prevalence in Hefeng (0.56%, 65/11 606) with statistical difference compared to other endemic areas(P < 0.01). There was no statistical difference on the prevalence of E. granulosus between males (0.24%, 345/141 584) and females (0.25%, 338/136 031)(P > 0.05). Participants of 50-59 years-old showed the highest infection rate of 0.35%(113/31 843) with statistical difference to other age groups (P < 0.01). Farmers had the highest infection rate (0.41%, 365/88 411) with statistic difference to other occupations (P < 0.01). Totally 18 560 serum samples were collected from children for antibody test and 190 were positive for anti-E. granulosus IgG with a positive rate of 1.02%, and showing an increasing trend yearly [0.60% (49/8 167) in 2015, 0.71% (43/6 034) in 2016 and 2.24% (98/4 359) in 2017] (P < 0.01). Children in Hefeng had the highest serological IgG positive rate of 3.16%(60/1 900)compared to other areas(P < 0.01). Total 34 343 dog fecal samples were examined for E. granulosus antigen with a positive rate of 1.04% (356/34 343). The highest rate of fecal antigen was identified in 2016 (1.71%, 206/11 824) compared to other years (P < 0.01). The dog fecal antigen was identified in all areas with highest rate in Hefeng (3.16%, 98/3 100)(P < 0.01). 4 008 sheep were examined for cystic hydatid with an average positive rate of 1.05% (42/4 008), with the highest rate in 2015 (1.67%, 30/1 800)(P < 0.01). Conclusion The infection of E. granulosus remains low prevalent in Tacheng Prefecture, but shows an increasing trend from 2015 to 2017 based on the infection rate in residents, antibody positive rate in children and the antigen positive rate in dog fecal sample.