Qin Zhi-Qiang, Xu Jing, Feng Ting, Lv Shan, Qian Ying-Jun, Zhang Li-Juan, Li Yin-Long, Lv Chao, Bergquist Robert, Li Shi-Zhu, Zhou Xiao-Nong
Key Laboratory of Parasite and Vector Biology, Ministry of Health; National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai 200025, China.
Ingerod, SE-454 94 Brastad, Sweden.
Trop Med Infect Dis. 2018 Dec 15;3(4):124. doi: 10.3390/tropicalmed3040124.
infection in snails can be monitored by microscopy or indirectly by sentinel mice. As both these approaches can miss infections, more sensitive tests are needed, particularly in low-level transmission settings. In this study, loop-mediated isothermal amplification (LAMP) technique, designed to detect a specific 28S ribosomal (Sj28S) gene with high sensitivity, was compared to microscopy using snail samples from 51 areas endemic for schistosomiasis in five Chinese provinces. In addition, the results were compared with those from polymerase chain reaction (PCR) by adding DNA sequencing as a reference. The testing of pooled snail samples with the LAMP assay showed that a dilution factor of 1/50, i.e., one infected snail plus 49 non-infected ones, would still result in a positive reaction after the recommended number of amplification cycles. Testing a total of 232 pooled samples, emanating from 4006 snail specimens, showed a rate of infection of 6.5%, while traditional microscopy found only 0.4% positive samples in the same materials. Parallel PCR analysis confirmed the diagnostic accuracy of the LAMP assay, with DNA sequencing even giving LAMP a slight lead. Microscopy and the LAMP test were carried out at local schistosomiasis-control stations, demonstrating that the potential of the latter assay to serve as a point-of-care (POC) test with results available within 60⁻90 min, while the more complicated PCR test had to be carried out at the National Institute of Parasitic Diseases (NIPD) in Shanghai, China. In conclusion, LAMP was found to be clearly superior to microscopy and as good as, or better than, PCR. As it can be used under field conditions and requires less time than other techniques, LAMP testing would improve and accelerate schistosomiasis control.
蜗牛感染情况可通过显微镜检查或借助哨兵小鼠进行间接监测。由于这两种方法都可能漏检感染情况，因此需要更灵敏的检测方法，尤其是在低水平传播环境中。在本研究中，将旨在高灵敏度检测特定28S核糖体（Sj28S）基因的环介导等温扩增（LAMP）技术与使用来自中国五个省份51个血吸虫病流行区蜗牛样本的显微镜检查进行了比较。此外，通过添加DNA测序作为参考，将结果与聚合酶链反应（PCR）的结果进行了比较。用LAMP检测法对混合蜗牛样本进行检测表明，稀释因子为1/50，即一只感染蜗牛加49只未感染蜗牛，在推荐的扩增循环次数后仍会产生阳性反应。对总共232个混合样本（来自4006个蜗牛标本）进行检测，感染率为6.5%，而传统显微镜检查在相同材料中仅发现0.4%的阳性样本。平行PCR分析证实了LAMP检测法的诊断准确性，DNA测序甚至使LAMP略占优势。显微镜检查和LAMP检测在当地血吸虫病防治站进行，这表明LAMP检测法有潜力作为即时检测（POC）方法，在60 - 90分钟内得出结果，而更复杂的PCR检测必须在中国上海的国家寄生虫病研究所（NIPD）进行。总之，发现LAMP明显优于显微镜检查，与PCR相当或更好。由于它可在现场条件下使用且比其他技术所需时间更少，LAMP检测将改善并加速血吸虫病防治工作。
