BackgroundHuman Papillomavirus (HPV) genotype distribution and co-infection occurrence was studied in cervical cytologic specimens from Murcia Region, (southeast Spain), to obtain information regarding the possible effect of the ongoing vaccination campaign against HPV16 and HPV18.MethodsA total of 458 cytologic specimens were obtained from two outpatient gynecological clinics. These included 288 normal benign (N/B) specimens, 56 atypical squamous cell of undetermined significance (ASC-US), 75 low-grade squamous intraepithelial lesions (LSIL) and 39 high-grade squamous intraepithelial lesions (HSIL). HPV genotyping was performed using PCR and tube array hybridization.ResultsThe most frequent genotype found was HPV16 (14.9% in N/B; 17.9% in ASC-US; 29.3% in LSIL and 33.3% HSIL). Distribution of other genotypes was heavily dependent on the cytologic diagnoses. Co-infections were found in 15.3% of N/B, 10.7% of ASC-US, 48% of LSIL and 25.6% of HSIL cases (significantly different at p < 0.001). Strikingly, in N/B diagnoses, genotypes from A5 species were found as coinfecting in all cases. Genotypes from A7 or A9 species appeared in co-infections in 56.5% and 54% respectively whereas genotypes from A6 species appeared in 25.1% of cases.ConclusionHPV vaccination might prevent 34.6% and 35.8% of LSIL and HSIL, respectively. Co-infection rate is dependent on both cytologic diagnosis and HPV genotype. Moreover, genotypes belonging to A5, A7 and A9 species are more often found as co-infections than genotype pertaining to A6 species. This suggests that phylogenetically related genotypes might have in common similar grades of dependency for cervical epithelium colonization.

Background: Human papillomavirus (HPV) genotyping is usually performed on cytological specimens with the aim of discerning between high- and low-risk genotypes. Methods: Paraffin-embedded sections (n = 241) comprising 16 normal/benign (N/B) cervical sections, 72 low-grade squamous intraepithelial lesions (LSIL), 133 high-grade SIL (HSIL), 6 invasive carcinomas (cervical cancer), and 14 atypical immature metaplasias (AIMs) were DNA extracted and HPV genotyped. Results: The most frequent HPV genotypes found were 16 and 58. HPV16 was detected in 0% N/B, 18.1% LSIL, 42.9% HSIL (p < 0.001), 50% carcinoma, and 35.7% AIM, whilst HPV58 was detected in 25.0, 20.8, 16.5, 0 and 35.7% of these lesions, respectively. Discussion: The high prevalence of HPV58 and the low prevalence of HPV18 suggest the limited effectiveness of HPV vaccination in southeast Spain (prevention of 45.1% HSILs). The HPV genotype distribution profile in AIM suggests that these lesions are more similar to LSIL than HSIL pointing to a low risk of progression to cervical cancer. These results reinforce the necessity of assessing the specific genotype rather than distinguishing between high- or low-risk HPV. The use of histological section instead of cytological specimens for specific HPV genotyping would be very useful in order to ascertain the oncogenic potential of each of the genotypes found in a given area.