Browsing by Author "Orr, Donald P."

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    Genotype-specific Concordance of Chlamydia trachomatis Genital Infection within Heterosexual Partnerships
    (Lippincott, Williams & Wilkins, 2016-12) Schillinger, Julia A.; Katz, Barry P.; Markowitz, Lauri E.; Braslins, Phillip G.; Shrier, Lydia A.; Madico, Guillermo; Van Der Pol, Barbara; Orr, Donald P.; Rice, Peter A.; Batteiger, Byron E.; Biostatistics, School of Public Health
    Background Sexual transmission rates of Chlamydia trachomatis (Ct) cannot be measured directly; however, the study of concordance of Ct infection in sexual partnerships (dyads) can help to illuminate factors influencing Ct transmission. Methods Heterosexual men and women with Ct infection and their sex partners were enrolled and partner-specific coital and behavioral data collected for the prior 30 days. Microbiological data included Ct culture, nucleic acid amplification testing (NAAT), quantitative Ct polymerase chain reaction (qPCR), and ompA genotyping. We measured Ct concordance in dyads, and factors (correlates) associated with concordance. Results 121 women and 125 men formed 128 dyads. Overall, 72.9% of male partners of NAAT-positive women and 68.6% of female partners of NAAT-positive men were Ct-infected. Concordance was more common in dyads with culture-positive members (78.6% of male partners, 77% of female partners). Partners of women and men who were NAAT-positive only had lower concordance (33.3%, 46.4%, respectively). Women in concordant dyads had significantly higher median endocervical qPCR values (3,032) compared with CT-infected women in discordant dyads (1,013 IFU DNA equivalents per ml), p<0.01. Among 54 Ct-concordant dyads with ompA genotype data for both members, 96.2% had identical genotypes. Conclusions Higher organism load appears associated with concordance among women. Same-genotype chlamydial concordance was high in sexual partnerships. No behavioral factors were sufficiently discriminating to guide partner services activities. Findings may help model coitus-specific transmission probabilities.
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    Time From First Intercourse to First Sexually Transmitted Infection Diagnosis Among Adolescent Women
    (2009-12) Tu, Wanzhu; Batteiger, Byron E.; Wiehe, Sarah E.; Ofner, Susan; Van Der Pol, Barbara; Katz, Barry P.; Orr, Donald P.; Fortenberry, J. Dennis
    Objective To determine the time between first intercourse and first sexually transmitted infection (STI) with Chlamydia trachomatis, Neisseria gonorrhoeae, or Trichomonas vaginalis and time between repeated infections. Design Observational study. Setting Three adolescent medicine clinics. Participants A cohort of 386 urban young women aged 14 to 17 years at enrollment. Main Outcome Measures Age at first intercourse; organism-specific interval between first intercourse and first STI diagnosis; interval between repeated infections; and age at first STI test prior to study participation. Results Participants had first intercourse at a young age (first, second, and third quartiles were 13, 14, and 15 years of age, respectively). By age 15 years, 25% of the women acquired their first STI, most often C trachomatis. Median interval between first intercourse and first STI diagnosis was 2 years. Within 1 year of first intercourse, 25% had their first C trachomatis infection. Repeated infections were common; within 3.6, 6, and 4.8 months, 25% of the women with prior C trachomatis, N gonorrhoeae, and T vaginalis infection were reinfected with the respective organisms. Considerable delay in STI testing was found for those who began sex at a younger age. The median interval between first sex and first test were 4.9, 3.5, 2.1, 1.8, and 1.2 years for those who had first sex at ages 10, 11, 12, 13, and 14 years, respectively. Conclusions Timely screening and treatment are important for prevention of STI sequelae. For urban adolescent women, STI screening (especially for C trachomatis) should begin within a year after first intercourse and infected individuals should be retested every 3 to 4 months.