The detection of Schistosoma mansoni infection in both its intermediate (snail) and definitive (human) hosts is useful in providing information on the transmission of schistosomiasis. Three pairs of previously designed PCR primers (SM^1-7, SM^F/R & ND5) used for the detection of S. mansoni infection were tested. We assess the utility of each of these primer sets for detecting S. mansoni infection both in artificially exposed laboratory bred Biomphalaria glabrata, and field infected African Biomphalaria sudanica and Biomphalaria pfeifferi. Two of the three primer sets (SM^F/R & ND5) detected S. mansoni infection in snails, but amplification of S. mansoni DNA with SM^1-7 was unreliable. For the artificially exposed laboratory bred B. glabrata snails, SM^F/R and ND5 both detected infection in more snails than the cercarial shedding method. Infection detection rates were 62.4% for ND5, 57.1% for SM^F/R and 50.4% using traditional cercarial shedding methods. Both SM^F/R and ND5 detected S. mansoni infection in 91% of snails observed shedding cercariae, increasing to 98.5% when low stringency PCR methods were used. When comparing each of the detection methods using a Bayesian latent class analysis model, ND5 had the highest detection sensitivity and negative predictive value (NPV), while SM^F/R had the highest detection specificity and positive predictive value (PPV). In field collected Biomphalaria snails, ND5 detected S. mansoni infection in 21 of 24 snails categorised as shedding S. mansoni cercariae and 4 of 24 snails categorised as shedding non-S. mansoni cercariae, while SM^F/R detected infection in 18 of 24 snails categorised as shedding S. mansoni cercariae and in 3 of 24 snails categorised as shedding non-S. mansoni cercariae. All SM^F/R and ND5 PCR products were shown to be S. mansoni indicating that these field snails must have been infected with both S. mansoni and cercariae from other Schistosoma species. This indicates that the two primer sets are specific for S. mansoni and will not amplify non-S. mansoni species when used at their recommended annealing temperatures. Both the SM^F/R and ND5 primers effectively detected S. mansoni infection in three Biomphalaria species and have improved detection sensitivity over cercarial shedding.

在其中间（蜗牛）和确定性（人类）宿主中检测曼氏血吸虫感染有助于提供有关血吸虫病传播的信息。测试了三对用于检测曼氏沙门氏菌感染的先前设计的PCR引物（SM ^1-7，SM ^{F / R}和ND5）。我们评估了这些引物对在人工暴露的实验室繁殖的光滑的Biomphalaria glabrata和野外感染的非洲Biomphalaria sudanica和Biomphalaria pfeifferi中检测曼氏链球菌感染的实用性。检测到三个引物组中的两个（SM ^{F / R}和ND5）蜗牛感染曼氏沙门氏菌，但用SM ^1-7扩增曼氏沙门氏菌DNA不可靠。对于人工暴露的实验室繁殖的B. glabrata蜗牛，SM ^{F / R}和ND5都比detected虫脱落方法检测到更多的蜗牛感染。ND5的感染检出率为62.4％，SM ^{F / R的}感染检出率为57.1％，使用传统的宫颈脱落方法的感染检出率为50.4％。SM ^{F / R}和ND5均检测到曼氏链球菌观察到91％的蜗牛感染了尾c，当使用低严格度PCR方法时感染增加到98.5％。使用贝叶斯潜在类别分析模型比较每种检测方法时，ND5具有最高的检测灵敏度和阴性预测值（NPV），而SM ^{F / R}具有最高的检测特异性和阳性预测值（PPV）。在野外收集的生物淋菌蜗牛中，ND5在分类为脱落曼氏尾尾c的24只蜗牛中有21只和分类为非-S脱落的24只蜗牛中有4只检测到曼氏沙门氏菌感染。mansoni尾c，而SM ^{F / R}在分类为脱落的Mansoni的24只蜗牛中有18只检测到感染。尾c中的24只蜗牛中有3只被归类为非S型。曼氏尾cer。所有SM ^{F / R}和ND5 PCR产物均显示为曼氏链球菌，表明这些田间蜗牛必须同时感染了其他血吸虫物种的曼氏链球菌和尾c 。这表明这两个引物对曼氏曼氏沙门氏菌具有特异性，并且在推荐的退火温度下使用时不会扩增非曼氏曼氏沙门氏菌。SM ^{F / R}和ND5引物均能有效检测出3种Biomphalaria中的曼氏沙门氏菌感染 种类，并具有优于子宫颈脱落的检测灵敏度。