三种方法检测福寿螺肺囊内广州管圆线虫效果的比较研究

A Comparative Study of Three Methods in Detecting Angiostrongylus cantonensis Larvae in Lung Tissue of Pomacea canaliculata

目的比较肺检法、匀浆法和酶消化法检测福寿螺肺囊内广州管圆线虫的效果,以寻找快捷检测方法。方法将60只实验室人工感染广州管圆线虫的福寿螺均分2组,分别解剖成螺肺囊与肌肉两部分。镜检两组螺肺囊广州管圆线虫幼虫结节数,用匀浆法和酶消化法分别检测螺肺囊中广州管圆线虫幼虫,比较不同检测方法的效果。酶消化法同时检测福寿螺肌肉内幼虫数,分析螺肺囊与肌肉内幼虫数的相关关系。结果肺检法、匀浆法和酶消化法等3种方法检测螺肺囊内幼虫的灵敏度依次为96.7%、93.4%和100%,差异无统计学意义(χ2=2.069,P>0.05)。肺检法的检测速度明显快于匀浆法与酶消化法,差异具有统计学意义(Z=4.782,P<0.01);螺肺囊与肌肉组织内的幼虫数呈正相关(r=0.847,P<0.01)。结论肺检法的检测效果与匀浆法和酶消化法相似,但其检测速度更快,适合现场大规模螺体广州管圆线虫的定性筛查。

Objective To compare the efficiency of three methods, lung-microscopy, tissue homogenate and enzyme digestion in the detection of Angiostrongylus cantonensis larvae from the lungs of snails. Methods 60 Pomacea canaliculata infected by the first-stage larvae of A. cantonensis were devided into 2 groups and the lung of each snail from the two groups was separated from the soft body. All the lungs were examined under microscope and larval nodes were counted. Each lung from one group was ground and that from the other was artificially digested by enzyme, the number of larvae in each lung was recorded. The efficiency of three methods was compared. Enzyme digestion was also used to estimate number of larvae in lung and in other body parts. Results By using enzyme digestion as the standard method, the detection rate of lung-microscopy, tissue homogenate and enzyme digestion was 96.7%, 93.4% and 100% respectively （χ^2=2.069, P〉0.05）, while the lung-microscopy was significantly faster （Z=4.782, P〈0.01）. The number of larvae in snail lung was positively correlated with that in other part （r=0.847, P〈0.01）. Conclusions The lung-microscopy in larvae detection is similarly efficient to the other two methods but faster, which is therefore more suitable for snail screening in the field.