The infection with Human papillomavirus (HPV) is the necessary cause for cervical cancer. There are at least 15
High-Risk (HR) HPV types that are significantly associated with progression of cervical intraepithelial neoplasia to cervical
cancer. Since previous studies showed that the prevalence of HPV in cervical cancers varies among different geographic
regions, we wanted to investigate the prevalence of HPV types in Croatia, especially low abundant HR HPV
types. By means of consensus primers directed polymerase chain reaction (PCR), we analysed cervical DNA samples of
2,136 Croatian women, mostly with abnormal cervical smears, in order to detect the presence of HPV. Type-specific primers
were then used to determine Low-Risk (LR) HPV types 6/11 and HR HPV types 16, 18, 31, 33, 45, 52 and 58. Out of
2,136 specimens, 1,255 (58.8%) were positive for HPV. More than half of positive samples were typed (64.5%) and 35.5%
still remained untyped. Multiple HPV infections were found in 10.3% of the cases. The most prevalent type, including
both single and multiple infections, was HPV 16 with the prevalence of 15.9%, followed by HPV types 31, 6/11, 33, 18, 52,
45 and 58 with 8.7%, 7.1%, 4.5%, 3.8%, 2.3%, 1.2% and 1.1%, respectively. The significant increase of frequency from
Low-grade Squamous Intraepithelial Lesions (LSIL) to High-grade Squamous Intraepithelial Lesions (HSIL) was observed
for HR HPV types 16, 18, 31 and 33 but not 45, 52 and 58. The frequency of unknown HPV types was almost the
same in cervical specimens of women with LSIL and those with HSIL, 19.8% and 21.1%, respectively. The prevalence of
HPV infection rate decreased significantly with patient age from 68.5% (age group 12 to 24 years) to 38.8% (age group 45
to 54 years). But, in women aged 55 or older the overall prevalence increased to 56.6%. Our results indicate that prevalence
of HR HPV types in Croatia is similar to other countries. We suggest that HPV positive women in Croatia should be
closely monitored by typing for HR HPV types: 16, 18, 31, 33, 45, 52 and 58
