Transcript Incidence, clearance, and persistence of HPV in a cohort

Persistence of HPV in a cohort of
female adolescents
Erika Samoff, Emilia H. Koumans, Lauri E.
Markowitz, Maya Sternberg, Mary K. Sawyer,
David Swan, John R. Papp, William Secor,
Elizabeth R. Unger
Centers for Disease Control (CDC), Emory
University Dept. of Pediatrics
Background
HPV and Cervical Cancer
• HPV is necessary but not sufficient to cause
cervical cancer
• Other sexually transmitted infections may affect
HPV persistence and development of cancer
• C. trachomatis has been associated with cervical
cancer
Background
HPV Persistence
• Persistence of HPV infection is associated with
development of cervical cancer
• Concurrent infection (HPV and another genital
tract infection) may alter host ability to clear virus
• Infection with >1 HPV type may affect the
probability of persistence
Study objective
To assess whether concurrent infection with
C. trachomatis, other organisms, or
additional HPV types
are associated with HPV persistence.
Methods
Study Population
• Adolescent primary care clinic in public
hospital, Atlanta GA
• Inclusion:
– Adolescent (age 12-19)
– Sexually active
• Exclusion
– HIV-infected
– Pregnant
• Female
Methods
Data collection and laboratory methods
• Study visits
– Behavioral and exposure data
– Urine, vaginal, and cervical samples
– 6 month intervals
• Laboratory analyses
– HPV: Roche line-blot assay (37 HPV types)
– C. trachomatis and N. gonorrheae: Nucleic acid amplification
tests
– T. vaginalis: wet mount
– Bacterial vaginosis: Gram stain scored with Nugent’s criteria
Methods
HPV Persistence
• Analysis population
– Study participants with detection of HPV and a following visit
separated by at least 6 months
• Persistent outcome
– detection of the same HPV type at a pair of sequential visits
separated by at least 6 months
• Unit of analysis was pairs of visits (high risk and low risk)
• Coinfection was assessed at the initial of the pair of visits
Methods
HPV persistence
Visit 1
Visit 2
HPV 6
Visit 3
HPV 6
Woman 1
Woman 2
HPV 18
HPV 16
HPV 16
Methods
Regression Analysis
• Associations with persistence measured
using logistic regression
• Generalized estimating equations
– allows for analysis of correlated data
– exchangeable correlation structure
– robust standard errors
Results
Study Population
N=282 (at least 2 study visits)
Median
Range
16.5
4
9
6
13.3-19.9
1-150
6-42
5-8*
Age
Lifetime sex partners
Duration of follow-up (months)
Months between visits
*90% of visits; range for all visits: 5-41 months
Results
Cumulative HPV detection
N
%
Low-risk HPV type
144/282
51
High-risk HPV type
203/282
72
>1 HPV type
135/282
48
Results
Cumulative detection of other genital
tract infections
N
%
C. trachomatis
121/282
43
N. gonorrheae
56/282
20
T. vaginalis
65/282
23
Bacterial vaginosis
138/282
49
Results
HPV persistence
N
%
Low-risk persistence
13/71
18
High-risk persistence
77/181
43
Results: Univariate Logistic Regression
Associations with high-risk HPV persistence
Coinfection at index visit
OR (95% C.I.)
C. trachomatis
2.1 (1.1-3.9)
N. gonorrheae
1.3 (0.6-3.9)
T. vaginalis
1.5 (0.5-5.0)
Bacterial vaginosis
1.3 (0.6-2.7)
>1 HPV type
2.6 (1.5-4.9)
Results: Multivariate Logistic Regression
Associations with high-risk HPV persistence
Coinfection at index visit
Adjusted OR
(95% C. I.)
C. trachomatis
5.1 (1.8-14.5)
>1 HPV type
3.6 (1.2-10.3)
Results
Factors not associated with persistence of
high-risk HPV types
• Frequency of sex act (vaginal, anal, or oral) in the
previous 90 days
• Number of sex partners in the previous 90 days
• Number of lifetime sex partners before HPV detection
• Douching in previous 90 days
• Oral contraceptive use in previous 90 days
• Smoking was associated in univariate but not
multivariate analysis
Conclusions
• Co-infection with C. trachomatis is
associated with persistence of high-risk
HPV types
• Infection with >1 HPV type is associated
with persistence of high-risk HPV types.
Acknowledgements
Study participants
Study interviewers
Study Coordinators
Sakinah Carter
Antonya Pierce
Jamia Holland
April Cameron
CDC/DSTDP
Emily Koumans
Lauri Markowitz
Eileen Dunne
Deblina Datta
Maya Sternberg
Elizabeth R. Unger