Incidence, duration, and reappearance of type-specific cervical human papillomavirus infections in young women.
BACKGROUND
We describe the incidence and duration of cervical human papillomavirus (HPV) infection episodes along with the risk of infection reappearance following a period of nondetection.


METHODS
Women (1,788) ages 16 to 23 years underwent cytologic testing and PCR-based testing of cervical swab samples for HPV DNA (HPV-16/18/31/33/35/45/52/58/59) at approximately 6-month intervals for up to 4 years in the context of a phase 3 clinical trial (placebo arm). HPV type-specific incidence rates were estimated per 100 person-years. Duration of type-specific cervical infection episodes and risk of reappearance following a period of nondetection were estimated using Kaplan-Meier methods.


RESULTS
HPV-16 exhibited the highest (5.9), and HPV-35 and HPV-33 exhibited the lowest (1.0) incidence rates per 100 person-years. Mean cervical infection durations ranged from 13 months for HPV-59 to 20 months for HPV-16 and 58 (with ongoing infections censored at the time of treatment, if done). The risk of cervical infection reappearance within approximately 3 years following a period of nondetection ranged from 0% to 16% across HPV types, with a mean of 8%. Limited evidence was found for a role of false-positive HPV tests, missed infections that were above the threshold for detection, or new acquisition of infection in accounting for patterns of infection reappearance.


CONCLUSIONS
Incidence of high-risk cervical infection was observed to vary considerably more across HPV types than infection duration. A nontrivial proportion of women exhibited infection reappearance following a period of nondetection, with a potential explanation for many such events observed within this analysis being a return to detectable levels of a previously acquired infection.


CONCLUSIONS
The risk of HPV infection reappearance following a period of nondetection has not been previously reported for individual HPV types, and this study finds that a nontrivial proportion of infected women exhibit reappearances. Future studies could ascertain subject-level factors that potentially modify the risk of infection reappearance.
Insinga
Ralph P
RP
Merck Research Laboratories, North Wales, PA 19454-10099, USA. Ralph_insinga@merck.com
Perez
Gonzalo
G
Wheeler
Cosette M
CM
Koutsky
Laura A
LA
Garland
Suzanne M
SM
Leodolter
Sepp
S
Joura
Elmar A
EA
Ferris
Daron G
DG
Steben
Marc
M
Brown
Darron R
DR
Elbasha
Elamin H
EH
Paavonen
Jorma
J
Haupt
Richard M
RM
D000293:Adolescent; D017326:Clinical Trials, Phase III as Topic; D004279:DNA, Viral / Q000032:analysis; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D015994:Incidence; D027383:Papillomaviridae / Q000235:genetics / Q000302:isolation & purification; D030361:Papillomavirus Infections / Q000453:epidemiology* / Q000517:prevention & control / Q000821:virology; D016133:Polymerase Chain Reaction; D015995:Prevalence; D016032:Randomized Controlled Trials as Topic; D002577:Uterine Cervical Diseases / Q000453:epidemiology* / Q000821:virology*; D055815:Young Adult
D004279:DNA, Viral