Genotype Frequency of Human Papillomavirus Determined by PCR and DNA Sequencing in Korean Women

Abstract

Human Papilloma viruses (HPVs) are etiological agents for cervical cancer and are classified into low- and high-risk categories. The aim of this study was to determine the frequency of the HPV genotype in the HPV screening test of Korean women using PCR-direct sequencing. Consensus primers of L1 legion were used for the amplification of HPV DNA and the PCR products (450 bps) obtained were analyzed by automatic sequencing. Sequences were compared with those in GenBank by using the BLAST program. Cervical swab samples of 3,978 women (20-73 years) were tested and the average age was 37.6 years. In this study, 1,174 samples were HPV positive out of 3,978 cervical swab samples screened (29.5%) and 136 samples (11.6%) showed a double infection. A total of 1,310 HPV genotypes were analyzed. The HPV positive rate was the lowest in the 20 years group (69.5%) and most of the samples of the > 60 years group were found HPV positive. Among thirty seven different HPV types identified by sequencing, 21 were HPV high risk types and 16 HPV low risk types were 69.8% (914/1,310) and 26.0% (340/1,310), respectively. In HPV high-risk types, 16 (13.21%), was the most frequently found. HPV 53 (9.62%) and 58 (9.24%) were also frequently found. This group was followed by HPV types 70 (5.50%), 33 (4.73%), 66 (4.20%), 18 (4.05%), 52 (4.05%), 31 (3.97%) and 56 (3.51%) in descending order of frequency. Among HPV low-risk types, 62 (4.20%), 6 (3.59%), 81 (3.59%), 84 (3.51%), and 11 (2.6%) were frequently found. In conclusion, PCR-direct sequencing could be used for quick and reliable typing of known and novel HPVs from clinical specimens. This data could be useful for epidemiological study of HPV and it also allows type-specific follow-up of women who have been treated for cervical intraepithelial neoplasia.