The Prevalence of Transfusion-Transmitted Virus Infection in Children / 소아과

PURPOSE: Transfusion-transmitted virus(TTV) is an newly described nonenveloped human virus, with a circular, negative stranded DNA genome. Although a high prevalence of TTV infection in the normal population has been demonstrated, there is a still possibility of association with hepatitis according to the genotype of TTV. The aim of this study is to investigate the prevalence of TTV infection in Korean children. METHODS: Nested polymerase chain reaction(PCR) using priner sets generated from the noncoding region(NCR) of the viral genome was done in 105 children without liver disease, aged 0-15 years. We performed a second set of PCR using N22 primer in 88 children after the first set of PCR. RESULTS: The TTV DNA was detectable in 36(34%) of 105 children without hepatitis by 5'NCR primer. The prevalence of TTV varied with age:<1 y,16%(4/25); 1-3 y, 44%(15/31); 4-6 y, 31%(5/ 16); 7-9 y, 25%(3/12); 10-15 y, 14%(3/21). By using N22 primers, the prevalence of TTV DNA in children without hepatitis was 11.3%(11/88):<1 y 8%(2/25); 1-3 y, 13.7%(4/29); 4-6 y, 6.2%(1/16); 7-9 y, 33.3%(2/6); 10-14 y, 8.2%(1/12). CONCLUSION: Our result showed a high prevalence of TTV infection, varying with age, in Korean children. Further evaluation of genotypes of TTV in patients with hepatitis and normal children is needed.

Identification of Mycobacterium avium complex ( MAC ) clinical Strains to a Species Level by Sequencing and PCR - SSCP Analysis of rpoB DNA

A recent study showed that comparative sequence analysis of rpoB DNAs could reveal natural relationships in genus Mycobacterium [J Clin Microbiol. 37 (6). 1999]. rpoB DNAs showed interspecies variation and intraspecies conservation, Based on these data, we developed polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) protocols which enable species differentiation in genus Mycabacterium. When this assay was applied to 24 clinical isolates identified as M. avium complex (MAC) by biochemical test, these were successfully differentiated into M. avium and M. intracellulare. These results were concordant with those obtained by 16s rDNA analysis. It is the first report that PCR-SSCP analysis of rpoB DNA could be used for species differentiation of MAC strains.