In this study we determined the frequency of the most prevalent human papillomavirus (HPV) types in China and evaluated the association between viral loads of different oncogenic HPV types and the severity of disease.

We enrolled 15,518 women for this study and 3199 of them (20.61%) were identified as positive by a PCR assay, that can simultaneously quantify and genotype HPV.

The viral loads of HPV 16, 31, 35, 52, 58, 39, and 56 were lower for women with normal cytology compared to those with disease progression; viral loads were not appreciable for HPV 33, 18, 45, 59, 68, 53, 66, and 51. The viral load of species 9 appeared significantly higher for women with cervical intraepithelial neoplasia (CIN) 2/CIN 3 relative to women with normal/low grade squamous intraepithelial lesion (LSIL)/CIN1 (P < 0.001), and significantly lower compared to those with cervical cancer (P < 0.001). The viral load of HPV species 6 was slightly higher for women with CIN2/CIN 3 compared to women with normal/LSIL/CIN1 (P = 0.002), and not significantly different from women with cervical cancer (P = 0.548). In addition, no statistically significant difference was found in HPV species 5 or species 7 (P = 0.898; P = 0.136).

The HPV viral load-associated risk for developing into CIN and cervical cancer is likely to be species-dependent and primarily restricted to species 9 (types phylogenetically close to HPV16).