Background: In a substantial proportion of respiratory tract diseases of suspected infectious origin, the etiology is unknown. Some of these cases may be caused by the recently described human bocavirus (hBoV). The aim of this study was to investigate the frequency and the potential clinical relevance of hBoV in pediatric patients.

The human bocavirus (hBoV) was first described in 2005 in respiratory tract samples. The clinical relevance of hBoV is still unclear. The aim of our study was to establish a real-time PCR assay for the detection and quantification of hBoV DNA, to apply the real-time assay for the analysis of stool and serum samples for the presence of hBoV DNA, and to perform a phylogenetic analysis of the hBoV positive samples. A total of 834 nasopharyngeal aspirates (NPA), 10 serum samples, and 31 stool samples of children with acute respiratory diseases were retrospectively tested. For phylogenetic analysis, 968 bp of the VP2 gene were sequenced from 69 hBoV-positive NPA samples. The qualitative results of the real-time hBoV PCR were in good agreement with a conventional hBoV PCR. We found that 12% of the NPA were positive for hBoV DNA. The median viral load in the NPA was 4.9 ؋ 10 3 copies/ml (range, 2.7 ؋ 10 0 to 1.5 ؋ 10 11 copies/ml). There was no difference of the hBoV load in NPA between children with or without known coinfection, but the load was significantly higher in children with bronchitis than in children with the diagnosis of febrile seizures. hBoV DNA was found in 1 of 10 serum samples and in 14 of 31 stool samples. hBoV sequence identity was >99% in the VP2 region. In conclusion, hBoV DNA can be found in NPA samples at very high titers. In addition to being found in the respiratory tract, hBoV was found in stool samples. The clinical relevance of these findings remains to be determined.

Multilayer argon plasma coagulation (APC) is a new effective method for the treatment of genital warts. We assessed the generation of aerosols containing human papilloma virus (HPV) DNA during treatment of genital warts with multilayer APC and with CO₂ laser ablation. Surveillance petri dishes, swabs from the glasses and nasolabial folds of the operating physician, and swabs taken from the suction units used during CO₂ laser ablation were tested by HPV PCR. HPV DNA corresponding to patient derived HPV types of genital warts was not found in any of the petri dishes and swabs obtained during APC treatment. HPV DNA was detected in none of the petri dishes obtained during CO₂ laser treatment, but in suction filters. In conclusion, both CO₂ laser ablation with plume suction and APC treatment seem to have a low risk of HPV contamination of the operation room.

Background: Avidity determination of antigen-specific immunoglobulin G (IgG) antibodies is an established serological method to differentiate acute from past infections. In order to compare the avidity of varicella-zoster virus (VZV) IgG in pairs of serum and cerebrospinal fluid (CSF) samples, we developed a new technique of avidity testing, the results of which are not influenced by the concentration of specific IgG.