Rapid detection of active human cytomegalovirus infection in pregnancy using loop-mediated isothermal amplification

Understanding the association between congenital human cytomegalovirus (HCMV) infection and active maternal HCMV infection during pregnancy is important for maternal and neonatal healthcare. In the present study, a loop-mediated isothermal amplification (LAMP) method was established for the detection of CMV DNA from whole blood or amniotic fluid samples, using reverse transcription-quantitative polymerase chain reaction. The results of the present study demonstrated that the CMV LAMP assay detection was specific for CMV DNA, whereas it did not detect viral DNA from herpes simplex type 1 (HSV-1), HSV-2, varicella zoster virus, HSV-6 or HSV-7. Sensitivity determination using serially-diluted CMV glycoprotein B-containing plasmids, demonstrated that >10 copies per tube were detectable using the CMV LAMP method. Furthermore, the detection results, using the LAMP method for 336 whole blood samples, demonstrated that at a threshold of 10(1)-10(4) copies per tube, the sensitivity of this method was 86.96-100%, the specificity was 97.24-100%, the positive predictive value was 76.92-100% and the negative predictive value was 99.05-100%. The results for 11 amniotic fluid samples from pregnant women with whole blood CMV-positive and 15 control amniotic fluid samples, indicated that the CMV LAMP assay was sensitive and specific for CMV detection. In conclusion, in the present study, a CMV LAMP method was developed, which was shown to be sensitive, specific and efficient in the detection of HCMV infection. Furthermore, CMV LAMP is capable of detecting active CMV infection in pregnant women. Therefore, the current study provides novel insights into diagnostic approaches for active CMV infection in pregnant women.