title: DNA detection of Schistosoma japonicum: diagnostic validity of a LAMP assay for low-intensity infection and effects of chemotherapy in humans.
abstract: BACKGROUND
  Schistosomiasis has decreased significantly in prevalence and intensity of infection in China, thus more accurate and sensitive methods are desperately needed for the further control of schistosomiasis. The present work aimed to assess the utility of the loop-mediated isothermal amplification (LAMP) for detection of light intensity infection or false-negative patients and patients post-treatment, targeting the highly repetitive retrotransposon SjR2 of Schistosoma japonicum.
  
  
  RESULTS
  LAMP was first assessed in rabbits with low intensity infection (EPG<10). Then 110 patient sera from Hunan Province, China, and 47 sera after treatment by praziquantel were used to evaluate the diagnostic validity of LAMP. Meanwhile, 42 sera from healthy individuals in a non-endemic area, and 60 sera from "healthy" residents who were identified as being negative for feces examination and immuno-methods in an endemic area were also examined. The results showed that LAMP could detect S. japonicum DNA in sera from rabbits at 3rd day post-infection. Following administration of praziquantel, the S. japonicum DNA in rabbit sera became negative at 10 weeks post-treatment. Of 110 sera from patients, LAMP showed 95.5% sensitivity, and even for 41 patients with less than 10 EPG, the sensitivity of LAMP still reached to 95.1%. For 47 patients after treatment, the negative conversion rate of S. japonicum DNA in patient sera increased from 23.4%, 61.7% to 83.0% at 3 months, 6 months and 9 months post-treatment, respectively. No false-positive result was obtained for 42 human sera from non-endemic area, while for the 60 "healthy" individuals from endemic area, 10 (16.7%) individuals were positive by LAMP, which suggested that these individuals might be false-negative patients.
  
  
  CONCLUSIONS
  The present study demonstrated that the LAMP assay is sensitive, specific, and affordable, which would help reduce schistosomiasis transmission through targeted treatment of individuals, particularly for those with negative stool examinations who may yet remain infected. The LAMP assay may provide a potential tool to support schistosomiasis control and elimination strategies.
authors: Department of Parasitology, Medical College of Soochow University, Suzhou, Jiangsu Province, China.
authors: Jing
authors: J
authors: Xu
authors: Department of Parasitology, Medical College of Soochow University, Suzhou, Jiangsu Province, China.
authors: Zhi-Xun
authors: ZX
authors: Guan
authors: Department of Parasitology, Medical College of Soochow University, Suzhou, Jiangsu Province, China.
authors: Bo
authors: B
authors: Zhao
authors: Department of Parasitology, Medical College of Soochow University, Suzhou, Jiangsu Province, China.
authors: Yan-Yan
authors: YY
authors: Wang
authors: Department of Parasitology, Medical College of Soochow University, Suzhou, Jiangsu Province, China.
authors: Yun
authors: Y
authors: Cao
authors: Department of Parasitology, Medical College of Soochow University, Suzhou, Jiangsu Province, China.
authors: Hui-Qin
authors: HQ
authors: Zhang
authors: State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, China.
authors: Xing-Quan
authors: XQ
authors: Zhu
authors: Hunan Provincial Institute of Schistosomiasis Control, Yueyang, Hunan Province, China.
authors: Yong-Kang
authors: YK
authors: He
authors: Department of Parasitology, Medical College of Soochow University, Suzhou, Jiangsu Province, China.
authors: Chao-Ming
authors: CM
authors: Xia
mesh_terms: D000818:Animals; D000871:Anthelmintics / Q000627:therapeutic use; D002681:China / Q000453:epidemiology; D018509:DNA, Helminth / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D021141:Nucleic Acid Amplification Techniques; D011223:Praziquantel / Q000627:therapeutic use*; D011817:Rabbits; D012549:Schistosoma japonicum / Q000235:genetics*; D012554:Schistosomiasis japonica / Q000097:blood / Q000175:diagnosis* / Q000188:drug therapy*
chemical_list: D000871:Anthelmintics; D018509:DNA, Helminth; D011223:Praziquantel