A population-based study of women, aged 16 to 54 years, was conducted in 3 rural ( Xinjiang , Shanxi, and Henan) and 2 urban areas ( Beijing and Shanghai) from July 2006 to April 2007 . Over 4200 women and girls were screened. The objectives were 1) to determine the type-specific prevalence of HPV, CIN 2+, and genital warts in Chinese Women ages 16-54 years. 2) To determine specific type of HPV in the Upper and Lower vagina, endocervix and anus in women with and without CIN 2+. Data was presented at the International HPV meetings in Malmo Sweden – Spring 2009 and the primary publication was published in the Int J Gyn Cancer 2010 Sept 1; 127(5): 1151-7. Since that time a multitude of publications have examined these data from a variety of aspects (prevalence (vaginal and serum), self-collection, ethnic differences, genotype distribution). There have also been several publication combining SPOCCS III data with other POI studies as well as those from IARC (WHO), and PATH (Program for Appropriate Technology in Health).
HR HPV prevalence ranged from 7.3% Xinjiang, 12-13% in Henan, Beijing, and Shanghai to 15.8% in Shanxi. LR HPV prevalence ranged from 1.6% in Xinjiang to 5.7% in Shanxi. Pathology-confirmed ≥CIN-3 prevalence was 0.4% in Shanghai, 0.5-1.2% in Henan, Xinjiang, Beijing, and 1.6% in Shanxi. Both HR and LR HPV types had constant prevalence across age. Genital warts were uncommon, ranging from 0% in Beijing to 0.6% in Xinjiang.
Objective #2 above had as its driving question, to try to understand the difference between a self-collected HPV sample and a direct sample obtained by a physician from the endocervix. Therefore to determine why a vaginal self-collection tested for high-risk human papillomavirus (HR-HPV) by Hybrid Capture 2® (hc2) has lower sensitivity and specificity for cervical intraepithelial neoplasia grade 2 or worse (≥CIN2), we collected 5 specimens (endocervix, upper and lower vagina, perineum, vaginal self-collection) from 2,625 women. Endocervical and self-collected specimens had HR-HPV tests by hc2. All 5 anogenital specimens were tested for 37 HPV genotypes [Linear Array®, (LA)] from 397 women hc2 positive in endocervical or self-collected specimens and for a randomly selected 71 of 2,228 women hc2 negative on both specimens. Three hundred and nintey-five women who screened positive by hc2 or had abnormal cytology underwent colposcopic evaluation. Of 47 women with ≥CIN2, hc2 was positive in 97.9% (46/47) of endocervical and 80.9% (38/47), p=.008 of self-collected specimens. Seven of 9 women with ≥CIN2 and negative self-collected hc2 tests were positive for HR-HPV by LA. Of 2,578 women without ≥CIN2, hc2 was positive in 9.8% (253/2,578) of endocervical and 11.4% (294/2,578), p=.001 of self-collected specimens. Of the 41 more women without ≥CIN2 that tested hc2 positive on the self-collected but negative on endocervical specimen, LA tested positive for HR-HPV in 24, negative for HPV in 11, and negative for HR-HPV but positive for low-risk HPV in 6. Lower sensitivity of self-collected specimens is secondary to lower levels of vaginal HR-HPV. The principal cause of the lower specificity of self-collected specimens is HR-HPV present solely in the vagina which is not associated with ≥CIN2. In addition using Linear Array we observed for the 1st time that self sampling resembles direct sampling when one uses a PCR based assay.