Respiratory viruses are a common cause of respiratory tract infection (RTI), particularly in neonates and children. Rapid and accurate diagnosis of viral infections could improve clinical outcomes and reduce the use of antibiotics and treatment sessions. Advances in diagnostic technology contribute to the accurate detection of viruses. We performed a multiplex real-time polymerase chain reaction (PCR) to investigate the viral etiology in pediatric patients and compared the detection rates with those determined using traditional antigen tests and virus cultures. Fifteen respiratory viruses were included in our investigation: respiratory syncytial virus A/B (RSV), influenza virus A (FluA) and influenza virus B (FluB), human metapneumovirus (MPV), enterovirus (EV), human parainfluenza virus (PIV) types 1–4, human rhinovirus (RV), human coronavirus OC43, NL63, and 229E, human adenovirus (ADV), and human bocavirus (Boca). In total, 474 specimens were collected and tested. Respiratory viruses were detected more frequently by PCR (357, 75.3%) than they were by traditional tests (229, 49.3%). The leading pathogens were RSV (113, 23.8%), RV (72, 15.2%), PIV3 (53, 11.2%), FluA (51, 10.8%), and ADV (48, 10.1%). For children younger than 5 years, RSV and RV were most prevalent; for children older than 5 years, FluA and ADV were the most frequently detected. Of the specimens, 25.8% (92/357) were coinfected with two or more viruses. RV, Boca, PIV2, FluB, and PIV4 had higher rates of coinfection; MPV and PIV1 had the lowest rates of coinfection (9.1% and 5.3%). To conclude, the detection power of PCR was better than that of traditional antigen tests and virus cultures when considering the detection of respiratory viruses. RSV and RV were the leading viral pathogens identified in the respiratory specimens. One-quarter of the positive specimens were coinfected with two or more viruses. In the future, further application of PCR may contribute to the rapid and accurate diagnosis of respiratory viruses and could improve patient outcomes.

Searching for clues to the evolution of the primate T-lymphotropic viruses (PTLVs), which include the human and the simian T-lymphotropic viruses (HTLV and STLV), we have identified another PTLV, which differs sufficiently from the known PTLV-I and PTLV-II types to be designated here PTLV-L. The virus was isolated from a wild-born baboon (Papio hamadryas) from Eritrea. In a cDNA library a 1802-bp-long fragment was identified that extends from the env region, including the complete transmembrane protein gene, to part of the tax/rex gene. Homologies at the nucleotide sequence level of PTLV-L, prototype simian T-lymphotropic virus-PH969, with HTLV-I and -II, respectively, were 62% and 64% overall, 65% and 70% in the env region, and 80% and 80% in the partial tax/rex sequence. In the 59 part of the pX region a significant homology was seen only with HTLV-II (52%). Phylogenetic analysis based on the gene encoding the transmembrane protein indicates that PTLV-L represents a PTLV type with a long independent evolution, longer than any strain within the PTLV-I or PTLV-II groups. The finding of another PTLV type in African baboons is further evidence of the wide variety of PTLV found on this continent. Whether PTLV-L resembles PTLV-I and PTLV-II in the extension of its host range to other primates, including humans, remains to be seen.

Human papillomavirus (HPV) is considered to be a necessary but not sufficient cause for cervical cancer. The host immunogenetic background plays an important role in the persistence of HPV infection and subsequent development of cervical cancer. Cytotoxic T-lymphocyte antigen-4 (CTLA-4) is a molecule expressed mainly on activated T cells and is important in the down-regulation of T-cell activation. The aim of this study was to determine if polymorphisms of the CTLA-4 gene are associated with HPV-induced cervical cancer in Taiwanese women. Polymerase chain reaction–restriction fragment length polymorphism was used to genotype −318 C/T, +49 A/G and CT60 A/G polymorphisms in 144 women with cervical squamous cell carcinoma (CSCC) and 378 ethnicity-matched healthy control women. The presence and genotypes of HPV in CSCC were determined by E6-, E7-based nested polymerase chain reaction. The frequency of C/T genotype of −318 C/T polymorphism was significantly higher in patients with HPV-16-positive CSCC compared with controls (odds ratio = 1.99, 95% confidence interval = 1.16–3.42, P_c = 0.03). No significant associations were found for +49 A/G and CT60 A/G polymorphisms. Analysis of haplotypes, computationally inferred from genotype data, also revealed no significant differences in distribution among all subjects with CSCC, those with HPV-16-positive CSCC and controls. Our results suggest that the −318 C/T variant in the promoter region of the CTLA-4 gene is associated with HPV-16-associated CSCC in Taiwanese women.

To investigate the origin of human T-lymphotropic virus I (HTLV-I), strains of diverse geographical origin were analysed. We sequenced the LTR and env genes of HTLV-I strains from Brazil, Central African Republic, Taiwan and Zaire, and the simian T-lymphotropic virus type I (STLV-I) strain PHSu1 from a baboon from the Sukhumi primate centre. We performed phylogenetic analyses using neighbour-joining, parsimony and maximum likelihood methods. Three separate HTLV-I clusters were identified interspersed between STLV-I clusters. The Brazilian and the Taiwanese strains were within the first well-supported cluster containing all cosmopolitan HTLV-I strains flanked by west African STLV-I strains. The HTLV-I strains from Central African Republic and Zaire fell into a central African cluster close to the chimpanzee STLV-I isolates. The third well-supported cluster included all Melanesian HTLV-I strains and had Indonesian STLV-I strains as closest neighbours. Therefore, currently known HTLV-I strains represent three HTLV-I subtypes that most probably have originated from three geographically distinct interspecies transmission events. The highly divergent PHSu1, isolated from Papio hamadryas, was closely related to PCY-991, isolated from Papio cynocephalus, both from the Sukhumi primate centre. Both clustered together with Asian wild-caught rhesus macaque STLV-I strains suggesting recent interspecies transmission of virus from rhesus macaques to colony-bred African baboons at the Sukhumi primate centre. In the rooted env trees obtained using the STLV strain PH969 as an outgroup, the Asian strains branched off before the African strains, implying an Asian origin for HTLV/STLV type I based on presently available strains.