Objective: This study was performed to further identify the previously uncharacterized human coronavirus 229E (hCoV-229E) and human coronavirus OC43 (hCoV-OC43) in Thailand by using the RT-PCR technique. In addition, we performed this study in order to delineate the prevalence, the potential clinical impacts and evaluation of the genetic characterization of this pathogen in young children who presented with acute lower respiratory tract infections (ALRI). Methods: We obtained nasopharyngeal secretions (NPs) from 226 children <5 years of age who were either attending the outpatient department or hospitalized with ALRI from March 2002 to July 2003. All clinical, laboratory, RT-PCR, direct sequencing and phylogenetic analysis data were collected and analyzed. Results: Of the 226 NPs samples from infants and young children presented with ALRI, 8 (3.54%) were positive for hCoV-229E, 2 (0.88%) were positive for hCoV-OC43, and 1 (0.44%) had co-infection. The following clinical presentations were noted: fever (100%), rhinitis (44%), acute bronchiolitis (44%), viral pneumonia (33%), viral pneumonia triggering asthma exacerbation (11%) as well as viral pneumonia causing BPD exacerbation (11%). All positive samples were subjected to direct sequencing. The amino acid sequences had 82–99% similarity to previous sequences stored in the GenBank database. Conclusion: The molecular technique we applied to detect human coronavirus appears justified as a valuable diagnostic approach to elucidate the prevalence, cause and clinical implications of ALRI among infants and young children.

Phylogenetic analysis was performed on hepatitis B virus (HBV) strains obtained from 86 hepatitis B surface antigen (HBsAg) positive donors from Thailand originating throughout the country. Based on the S gene, 87.5% of strains were of genotype C while 10.5% were of genotype B, with all genotype B strains obtained from patients originating from the central or the south Thailand. No genotype B strains were found in the north of Thailand. Surprisingly, one patient was infected with a genotype H strain while another patient was infected with a genotype G strain. Complete genome sequencing and recombination analysis identified the latter as being a genotype G and C2 recombinant with the breakpoint around nucleotide position 700. The origin of the genotype G fragment was not identifiable while the genotype C2 fragment most likely came from strains circulating in Laos or Malaysia. The performance of different HBsAg diagnostic kits and HBV nucleic acid amplification technology (NAT) was evaluated. The genotype H and G/C2 recombination did not interfere with HBV detection.