Ouma J H, Sturrock R F, Klumpp R K, Kariuki H C
Division of Vector-borne Diseases, Ministry of Health, Nairobi, Kenya.
Parasitology. 1989 Dec;99 Pt 3:349-55. doi: 10.1017/s0031182000059060.
In an operational Schistosoma mansoni field-study in an area about 20 km 2 (population approximately 8000), transmission detection by simple snail sampling was compared with cercariometry. Between 1985 and 1987, 62 field sites were sampled at fortnightly intervals. Of a total of 2758 field observations, 89.8% gave full snail data; 64.4% full cercarial data; and 61.7% complete data for both methods. The complete data sets showed significant but not strong correlations between Biomphalaria pfeifferi (total and infected with S. mansoni or other trematodes) and cercarial (S. mansoni and non-human) recoveries. Non-human (but not S. mansoni) cercarial recovery decreased with deteriorating cercariometry filter quality. Both snail and cercarial recoveries diminished significantly with increasing water flows at the time of collection. Many samples yielded infected snails or cercariae, but not both, and neither method detected significantly more transmission sites. The method of choice for detecting transmission in a large-scale field-study depends on logistical and financial considerations. Relatively simple snail sampling allows quick, cheap and widespread data collection adequate for most purposes but more complicated cercariometry is still valuable for specific, small-scale studies.
在一个面积约20平方公里（人口约8000）的地区开展的曼氏血吸虫现场研究中，将通过简单的钉螺采样进行传播检测与尾蚴测量法进行了比较。1985年至1987年期间，每两周对62个现场地点进行一次采样。在总共2758次现场观察中，89.8%获得了完整的钉螺数据；64.4%获得了完整的尾蚴数据；两种方法均获得完整数据的比例为61.7%。完整数据集显示，费氏双脐螺（总数以及感染曼氏血吸虫或其他吸虫的数量）与尾蚴（曼氏血吸虫和非人类尾蚴）回收率之间存在显著但并不强烈的相关性。随着尾蚴测量法过滤质量的下降，非人类（但不是曼氏血吸虫）尾蚴回收率降低。在采集时，随着水流增加，钉螺和尾蚴回收率均显著下降。许多样本检测到感染的钉螺或尾蚴，但不是两者都检测到，而且两种方法检测到的传播地点均未显著增多。在大规模现场研究中，用于检测传播的首选方法取决于后勤和财务方面的考虑。相对简单的钉螺采样能够快速、廉价且广泛地收集数据，足以满足大多数目的，但更复杂的尾蚴测量法对于特定的小规模研究仍然很有价值。
