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 published in the International J of Cancer winter 2010.
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. Several manuscripts have been published with an epidemiological focus using the SPOCCS III data combined with other POI studies as well as those from IARC (WHO), and PATH.
Object #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.