Development of conventional and realtime quantitative polymerase chain reaction assay in the diagnosis and monitoring of XXXX .

@entity1 @entity9250 @entity1908 @entity9859 @entity50417
UNASSIGNED: Scabies remains the most prevalent, endemic, and neglected @entity50417 globally and can cause institutional outbreaks. Sensitivity of routine microscopy demonstration of Sarcoptes scabiei mites or eggs in skin scraping is only about 50%. Except for three studies using conventional or two-tube nested polymerase chain reaction (PCR) on a small number of cases, no systematic study has been performed to improve the laboratory diagnosis of this important infection. We developed a conventional and a realtime quantitative PCR reaction assay based on the mitochondrial chromosomal c oxidase subunit 1 gene ( @entity9859 ) of @entity9250 . The @entity9859 gene is relatively well conserved with no high sequence similarities with other @entity1 skin mites, pathogenic zoonotic mites or common house dust mite species. This mitochondrial gene is also present in large quantity in arthropod cells potentially improving sensitivity of PCR based assay. In our study, both assays are specific and are more sensitive than microscopy in diagnosing @entity1908 , with a positive and negative predictive value of 100%. The @entity9250 DNA copy number in the microscopy-positive specimens were significantly higher than those in the microscopy-negative specimens (median @entity9250 DNA copy number, 3.604 log10 vs 2.457 log10 copies per reaction; P = 0.0213). In the @entity1 with crusted @entity1908 , qPCR assay performed on lesional skin swabs, instead of scrapings, revealed that parasitic DNA load took about 2 weeks to become negative after treatment. The utility of using lesional skin swabs for PCR should be further evaluated as an alternative sample for diagnosis of @entity1908 .
