Evaluation of genital human papillomavirus infections by polymerase chain reaction among Croatian women.

Infection with specific human papillomavirus (HPV) types is the strongest risk factor in cervical carcinogenesis. In this study we analysed, by means of polymerase chain reaction (PCR), cervical specimens obtained from consenting women with abnormal Pap smears collected from 1996 to 1998. Consensus- and type-specific-primers directed PCR were used in order to detect the presence and to determine the most common HPV types: 6, 11, 16, 18, 31 and 33. Out of 1874 specimens, 1207 (64%) contained one or more HPV types. Approximately half HPVs were typed (621 out of 1207) and the others remained untyped (586 out of 1207), 51% and 49%, respectively. Beside low-risk HPV 6/11 (5%), the most frequently observed HPVs were high-risk HPV types, especially type 16 (12%), while HPV types 18 (2%), 31 (5%) and 33 (3%) were less frequent. The HPV positivity rate declined with age, although all HPV types were equally distributed in different age groups. The presence of HPV DNA significantly increased from 55% to 78% along with the severity of the cervical lesions, i.e. low- and high-grade squamous intraepithelial lesions (LSIL, HSIL). Undetermined HPV types, other than 6/11, 16, 18, 31 and 33 were equally distributed in LSIL and HSIL which indicates that they represent low- as well as high-risk HPV types. Our results indicated that HPV infections, especially those with HPV 16, represent a significant public health concern in Croatia.