Rapid Detection and Identification of Human Respiratory Syncytial Virus, Human Parainfluenza Virus Type 1, 2 and 3 by Single-tube Multiplex Reverse Transcription Polymerase Chain Reaction

Laboratory diagnosis of respiratory viral infection has traditionally been based upon virus isolation and/or viral antigen identification. Recently, more sensitive and specific nucleic acid detection methods by reverse transcription- polymerase chain reaction (RT-PCR) have been developed, however, conventional RT-PCR can identify only a single suspected virus. To identify the causative agents which belong to Paramyxoviridae of respiratory virus infections, we have developed a single-tube multiplex RT-PCR using four primer sets which can amplify respiratory syncytial virus and parainfluenza virus type 1, 2 and 3 simultaneously. Assay sensitivity of single-tube multiplex RT-PCR allowed a detection in the range of 3~500 TCID50 and there were no cross amplification among other respiratory viral agents based on the test using reference virus stocks. The single-tube multiplex RT-PCR was able to directly detect viruses in respiratory specimens, with virus being detected 11 of 80 samples as compared to 9 of 80 samples detected by indirect immunofluorescence or antigen detection following shell vial culture. This result suggests that the single-tube multiplex RT-PCR can be established as a more sensitive and rapid diagnostic application than shell vial assay for the detection of respiratory infection of Paramyxoviridae.

Human Cytomegalovirus (HCMV) Infection in Organ Transplant Recipients / 감염

BACKGROUND: Human cytomegalovirus (HCMV) is not eradicated from a host after a primary infection and persists in a latent form. When the immunological condition of the host is compromised, the virus can be reactivated and cause serious disease. Given that the prevalence of anti-HCMV IgG antibody positivity is over 95% in Korean adult population, the transplant recipients in Korea are likely to be a high risk of developing HCMV infection and diseases. METHODS: Fourteen bone marrow recipients, 44 kidney transplant recipients and 4 liver transplant recipients were evaluated for excretion of HCMV. Urine and blood were cultured by conventional method at the time of transplantation and at regular intervals thereafter. To evaluate sensitivity and specificity of shell vial assay for detecting HCMV, the specimens from 41 transplant recipients were cultured by using both shell vial assay and conventional virus culture. RESULTS: The frequency of HCMV infection was 50%(7/14) in allogeneic bone marrow (BM) recipients, 36%(16/44) in kidney recipients and 25%(1/4) in liver transplant recipients. HCMV diseases were observed in only 3 cases; 3 BM recipients developed interstitial pneumonitis. Sensitivity and specificity of shell vial assay for the detection of HCMV was 50%(3/6) and 91%(32/35), respectively. CONCLUSION: HCMV infections in organ transplant recipients were relatively common in Korea. HCMV started to be excreted in urine about 1 month after transplantation and were found in 33-50% of all recipients later on. Sensitivity of shell vial assay was so low that it needs to be complemented with other diagnostic methods.