西藏自治区家畜棘球蚴感染情况调查

Epidemiological survey on hydatid disease in livestock in Tibet Autonomous Region

目的了解西藏自治区家畜棘球蚴感染情况及影响因素。方法从西藏自治区日喀则、昌都、那曲、拉萨、山南、林芝和阿里等7个地区(市)的63个县,按照牧区、半农半牧区、农区和城镇等不同生产类型人口所占的比例抽取行政村。从每个行政村抽取当地繁育、宰杀的羊(猪)10头或牛5头,检查肝、肺等脏器的包囊情况,记录动物齿龄。从每个行政村抽取20户家庭,进行家庭基本情况调查,收集户主姓名、人口数、民族、养犬数量、养羊数量、养牛数量、年自宰家畜数量、自宰时间、饮水来源等信息。以家畜是否患棘球蚴病为因变量(Y),以地区(市)、家畜类型、齿龄、生产类型等为自变量(X)进行多因素非条件logistic回归分析。结果共调查家畜2 143头,其中牛995头,占46.43%;羊1 047头,占48.86%;猪101头,占4.71%。来自牧区834头,占38.92%;半农半牧区922头,占43.02%;农区362头,占16.89%;城镇25头,占1.17%。家畜棘球蚴感染检出率为13.21%(283/2 134),其中,羊、牛、猪的感染检出率分别为18.24%(191/1 047)、9.15%(91/995)、0.99%(1/101),差异有统计学意义(χ~2=50.633,P<0.01)。包囊多分布在肝脏(69.9%、178/283)。阿里地区家畜棘球蚴感染检出率最高,为28.82%(66/229);林芝市最低,为0.71%(1/140)(χ~2=123.946,P<0.01)。不同齿龄家畜中,≥10齿龄的家畜棘球蚴感染检出率最高,为18.85%(33/175)(χ~2=14.488,P<0.01)。不同生产类型家畜中,牧区家畜的棘球蚴感染检出率最高,为17.03%(142/834),城镇无家畜感染(χ~2=26.316,P<0.01)。共调查7 334户家庭,家畜养殖率为91.7%(6 722/7 334),自宰率为72.1%(5 286/7 334),屠宰时间集中在11月份。多因素非条件logistic回归分析结果显示,家畜棘球蚴感染检出率与地区(市)、家畜类型、齿龄及所在的生产类型等因素有关。结论西藏自治区羊、牛的棘球蚴感染检出率较高,应采取综合措施降低家畜感染检出率。

Objective To investigate the prevalence of hydatid disease and influencing factors in livestock in Tibet Autonomous Region. Methods A simple and stratified random sampling method was used to select villages of different types of production according to the proportions of populations in pastoral area, semi-agricultural and semi-pastoral area, agricultural area and town, from 63 counties in seven prefectures （cities） （Shigatse, Qamdo, Nagqu, Lhasa, Shannan, Nyingchi and Ali） of Tibet Autonomous Region. Ten sheep （pigs） or 5 cattle were selected in each village to examine cysts in liver and lung, accompanied by recording the animal age and number of cysts found. Twenty families were randomly selected in each village to collect basic information including householder name, family size, ethnicity, numbers of dogs, sheep and/or cattle raised, number of livestock slaughtered in each year and the slaughtering time, source of drinking water. Logistic regression analysis was performed using livestock having hydatid cyst（s） as dependent variable Y and using city, livestock type, tooth age and type of production as independent variable X. Results A total of 2 143 livestock were examined, comprising 995 cattle （46.43%）, 1 047 sheep （48.86%）, and 101 pigs （4.71%）, and comprising 834 （38.92%） from pastoral areas, 922 （43.02%） from semi-agricultural and semi-pastoral area, 362 （16.89%） from agricultural area, and 25 （1.17%） from town. The infection rate of hydatid cysts in livestock was 13.21% （283/2 134）, and that in sheep, cattle and pigs were 18.24% （191/1 047）, 9.15% （91/995）, 0.99% （1/101）, respectively （χ2 = 50.633, P 〈 0.01）. The cysts were mainly distributed in liver （69.9%, 178/283）. The infection rate was highest in Ali （28.82%, 66/229）, and lowest in Nyingchi （0.71%, 1/140） （χ2 = 123.946, P 〈 0.01）. Among different tooth age groups, the infection rate was the highest in the age group of 〉 10 tooth age （18.85%, 33/175） （χ2 = 14.488, P 〈 0.01）. Among different production types, the highest infection rate was detected in pastoral area （17.03%, 142/834） and lowest in town （no livestock infected） （χ2 = 26.316, P 〈 0.01）. Of the 7 334 families surveyed, up to 6 722 raised livestock （91.7%）, and 5 286 slaughtered livestock by themselves （72.1%）, and the slaughter mainly occurred in November. Multivariate analysis showed that the infection rate of hydatid cysts in livestock was correlated with prefecture （city）, species of livestock, tooth age, and type of production. Conclusion There is a high prevalence of hydatid disease in sheep and cattle in Tibet Autonomous Region. Comprehensive measures are needed to reduce the infection.