Prevalence and predictors of human papillomavirus infection in women in Ontario, Canada. Survey of HPV in Ontario Women (SHOW) Group.
BACKGROUND
Human papillomavirus (HPV) is thought to be the primary cause of cervical intraepithelial neoplasia and cervical cancer. We determined the age-specific prevalence of HPV infection and its risk factors in Ontario women.


METHODS
We obtained 2 cervical specimens from randomly selected women (in 5-year age categories, from 15 to 49 years) who were being seen in 32 family practices for cytologic screening. The specimens were tested for carcinogenic HPV by the hybrid capture II assay (Digene Corp., Silver Spring, Md.) and by polymerase chain reaction (PCR) and genotyping.


RESULTS
Of 1004 women eligible to participate, samples were obtained from 955 (95.1%). The prevalence of HPV (as determined by the hybrid capture II method) was highest, at 24.0% (95% confidence interval [CI] 16.5% to 31.5%), among women 20 to 24 years of age and was progressively lower in older age groups, reaching 3.4% (95% CI 0.1% to 6.7%) in women 45 to 49 years old. The prevalence of HPV (any type) as determined by PCR showed a similar pattern but was significantly higher (p = 0.01) among women 45 to 49 years old than among those 40 to 44 years old (13.0% [95% CI 6.4% to 19.6%] v. 3.3% [95% CI 0.1% to 6.5%]). Risk factors for positivity with the hybrid capture II method were never-married status, divorced or separated status, more than 3 lifetime partners, more than 1 partner in the preceding year, cigarette smoking and current use of oral contraceptives. The presence of squamous intraepithelial lesions on cytologic examination was strongly associated with positivity with the hybrid capture II assay (odds ratio 96.0, 95% CI 22.3 to 413.4; p < 0.01).


CONCLUSIONS
The highest prevalence of HPV was 24.0%, in women 20 to 24 years old. Risk factors supported a sexual mode of transmission, and there was a strong association between HPV and abnormal cervical cytologic results.
Sellors
J W
JW
Health Services Delivery Research Unit, Father Sean O'Sullivan Research Centre, St. Joseph's Hospital, Hamilton, Ont.
Mahony
J B
JB
Kaczorowski
J
J
Lytwyn
A
A
Bangura
H
H
Chong
S
S
Lorincz
A
A
Dalby
D M
DM
Janjusevic
V
V
Keller
J L
JL
D000293:Adolescent; D000328:Adult; D016009:Chi-Square Distribution; D004279:DNA, Viral / Q000032:analysis; D005260:Female; D005838:Genotype; D006801:Humans; D016015:Logistic Models; D008875:Middle Aged; D009864:Ontario / Q000453:epidemiology; D027383:Papillomaviridae / Q000235:genetics / Q000302:isolation & purification; D030361:Papillomavirus Infections / Q000175:diagnosis / Q000453:epidemiology*; D016133:Polymerase Chain Reaction; D015995:Prevalence; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014412:Tumor Virus Infections / Q000175:diagnosis / Q000453:epidemiology*; D002583:Uterine Cervical Neoplasms / Q000517:prevention & control / Q000821:virology; D014626:Vaginal Smears
D004279:DNA, Viral