Katherine Hsu

Monitoring HPV type-specific prevalence over time through clinic-based surveillance: A perspective on vaccine effectiveness☆

We investigated the feasibility of monitoring trends in prevalence of vaccine-preventable human papillomavirus (HPV) types in different clinic populations. We collected cervical specimens from women presenting to family planning, primary care, and sexually transmitted disease (STD) clinics for routine pap smears in five US cities during 2003-2005. We performed HPV genotyping and calculated annual type-specific prevalences; pre-vaccine era prevalence was highest for HPV 16 (6.0; 95% confidence interval [CI] 5.5-6.6%) and annual prevalences for vaccine-preventable types were stable, with few exceptions, after controlling for clinic type, age group, and city. With sufficient sample size and stable population characteristics, clinic-based surveillance systems can contribute to monitoring HPV vaccine impact in the cervical screening population.

Impact of HPV vaccination on anogenital warts and respiratory papillomatosis

ABSTRACT Human papillomavirus (HPV), the most common sexually transmitted infection in the US and worldwide, can cause cancers, anogenital warts (AGW), and recurrent respiratory papillomatosis (RRP) in men, women, and children. Global incidence of AGW ranges from 160-289 cases per 100,000 person-years and peaks in young men and women in the third decade of life. RRP has an estimated incidence of 3 per 1 million person-years in children. Pre-licensure trial efficacy, modeling and time-trend ecological studies have shown a significant short-term impact of 4vHPV vaccine. In girls aged 15-19 years, a previously published meta-analysis indicated that genital warts decreased significantly by 31%; stratified analysis revealed more substantial reductions in populations with high (≥50 %) vs. low (<50 % ) vaccination coverage (61% vs. 14%). Longer-term monitoring will reveal whether this impact continues under 9vHPV programs, and whether current declines in AGW are mirrored by declines in RRP.

Impact of Rapid Susceptibility Testing and Antibiotic Selection Strategy on the Emergence and Spread of Antibiotic Resistance in Gonorrhea

Mathematical modeling suggests that rapid diagnostics that report antibiotic susceptibility have the potential to extend the usefulness of existing antibiotics for treatment of gonorrhea compared with the current guidelines for empiric 2-drug treatment.

Expanded Sexually Transmitted Infection Surveillance Efforts in the United States Military: A Time for Action

COL Jose L. Sanchez, MC USA (Ret.)*†; Brian K. Agan, MD‡; Alice Y. Tsai, MPH*; Grace E. Macalino, PhD‡; LTC Eyako Wurapa, MC USA§; Margaret Mbuchi, PhD§; Erica Dueger, DVM, PhD∥; Katherine C. Horton, MPH∥; Silvia M. Montano-Torres, MD, MPH¶; LCDR Drake H. Tilley, MC USN¶; Karen E. Saylors, PhD**; Naiki Puplampu, MPhil, PhD††; LCDR Christopher C. Duplessis, MC USN††; LCDR Dustin J. Harrison, MSC USN‡‡; CDR Shannon D. Putnam, MSC USN (Ret.)§§; MAJ Eric C. Garges, MC USA∥∥; LCDR Benjamin J. Espinosa, MSC USN¶¶; LCDR Jamal Dejli, MSC USN***; COL Mitchell Meyers, MC USA†††; LTC Samuel L. Yingst, VC USA†††; Ann E. Jerse, PhD‡‡‡; Hala H. Maktabi, PhD, MPH*; MAJ Ronald L. Burke, VC USA*; Nikki N. Jordan, MPH§§§; Gosia Nowak, MSc, MPH∥∥∥; Katherine Hsu, MD, MPH¶¶¶; Olusegun O. Soge, PhD****††††; King K. Holmes, MD, PhD****††††; R. Scott McClelland, MD, MPH****††††; Michael R. MacDonald, MS‡‡‡‡; COL Julie A. Pavlin, MC USA (Ret.)†; COL Joel C. Gaydos, MC USA (Ret.)*†; COL Edmund C. Tramont, MC USA (Ret.)§§§§

P3.16 Impact of rapid susceptibility profiling on the emergence and spread of antibiotic resistance in gonorrhoea

Introduction Increasing antibiotic resistance limits treatment for gonorrhoea. We examined the extent to which a hypothetical point-of-care (POC) test reporting antibiotic susceptibility profiles could delay emergence of resistance and prolong effectiveness of existing antibiotics. Methods We developed a deterministic compartmental model describing gonorrhoea transmission in a risk-stratified single-sex population with three different antibiotics available to treat infections. Probabilities of resistance emergence on treatment and fitness costs associated with resistance were based on characteristics of fluoroquinolones, azithromycin, and ceftriaxone, as inferred from a previous phylogenomic analysis. We compared strategies in which a POC test was used to guide therapy in varying proportions of cases against the current empiric approach (dual treatment with azithromycin plus ceftriaxone). Results Based on current estimates of gonoccoal susceptibility patterns in the United States, the model indicated that continued empiric dual antibiotic treatment without POC testing resulted in >5% of isolates being resistant to both azithromycin and ceftriaxone within 15 years. When POC testing was used in 10% of identified cases, this time was delayed by 4 years, while time to reach a 1% prevalence of triply-resistant strains was delayed by 5 years. With POC testing in >55% of identified cases, it took over 100 years for dual and triple resistance to exceed 1%, and with POC testing in ≥75% of cases, strains resistant to azithromycin and/or ceftriaxone did not persist in the population. Results were sensitive to assumptions about fitness costs and test sensitivity only when POC test deployment was relatively low (<25%). Conclusion Rapid diagnostics that indicate antibiotic susceptibility have the potential to extend the usefulness of existing antibiotics for treatment of gonorrhoea. More broadly, integration of evidence on fitness costs associated with resistance can enhance strategies for rational antibiotic selection and further delay emergence of resistance.

O01.6 Evaluating chlamydia trends in the united states 2000–2015 using a pair formation transmission model

Introduction In the United States reported cases of chlamydia have increased since reporting began, due in part to increased screening. However, the implication of these trends for the population prevalence remains unclear. We aimed to understand and reconcile the epidemiological trends, and examine counterfactuals. Methods We developed a deterministic heterosexual pair formation model to simulate chlamydia epidemiology in the US heterosexual population aged 15-54y. The pair formation model accounts explicitly for sexual partnership dynamics, such as re-infection within the partnership, and the model is stratified by age, risk and relationship type (long-term v. casual). We used a Bayesian approach to calibrate model parameters (including time-varying screening, reporting and test sensitivity) to age- and sex-specific national case report rates from 2000–2015 (ages 15-54y), lab-measured population prevalence estimates from NHANES 1999–2014 (15-39y), and sexual behaviour data from the Youth Risk Behaviour Survey (15-18y). Results Model estimates were able to reproduce both chlamydia prevalence and reported case rates. Results indicate an increase in chlamydia screening in women. Conclusion This analysis is the first to fit a chlamydia transmission model to national sex- and age- specific prevalence and case report time trends. The results suggest screening would have to achieve a higher coverage, or we should investigate novel strategies to reduce chlamydia prevalence further. This model could be used to investigate the impact of novel prevention interventions, such as improved partner notification strategies and targeted screening programs.

P5-S6.34 Provider characteristics associated with gonorrhoea treatment errors, Massachusetts, 2010

Background Massachusetts experienced a 29% increase in gonorrhoea cases during 2010. In 4% of cases where treatment was known, treatment was inconsistent with public health guidelines. We examined healthcare provider characteristics associated with gonorrhoea treatment errors to help target future educational outreach strategies. Methods Case-control study where treatment error cases were defined as any patient 15–65u2005years of age, diagnosed with gonorrhoea in 2010, who did not receive ceftriaxone 125u2005mg or 250u2005mg IM or other approved cephalosporin regimen, or azithromycin 2u2005g PO. Two controls were randomly selected from patients who received correct treatment, matched to cases in regard to age, sex, and month of diagnosis. Data regarding exposures to various provider characteristics were collected from case report cards, provider licensing databases, and direct provider phone calls. Proportions of cases and controls were compared on the basis of provider training, years in practice, specialty, and practice type by χ2 analysis or Fishers exact test. Results 76 cases were matched to 152 controls. In preliminary analysis, no differences were identified with respect to provider degree (MD/DO or NP/PA; p>0.25). More treatment errors occurred in private practice/health maintenance organisations compared to STD or family planning clinics (p<0.0001), emergency departments (p<0.0001), or community health centers/hospital clinics (p=0.0004). Among physicians, no differences were identified with respect to years since residency graduation (p>0.25). More treatment errors occurred with family medicine physicians compared to OB/GYN (p=0.0225) and emergency medicine physicians (p=0.0101), but not compared to paediatricians or internists see Abstract P5-S6.34 table 1. Abstract P5-S6.34 Table 1 Analysis to date Controls (n, %) Cases (n, %t) p Value Provider degree u2003NP/PA 49 (45%) 30 (41%) NS u2003MD/DO 59 (55%) 43 (59%) Practice location u2003Private practices/HMOs 22 (18%) 41 (56%) Reference u2003STD clinics 15 (13%) 0 <0.0001 u2003Emergency departments 40 (33%) 11 (15%) <0.0001 u2003Community health centers/hospital clinics 43 (36%) 21 (29%) 0.0004 Residency graduation year u2003After 2000 27 (47%) 15 (39%) NS u20031990s 16 (28%) 13 (33%) u2003Before 1990 14 (25%) 11 (28%) Physician specialty u2003Family Medicine 5 (9%) 11 (24%) Reference u2003Paediatrics 3 (5%) 5 (11%) NS u2003Internal Medicine 10 (18%) 10 (22%) NS u2003OB/GYN 18 (32%) 7 (16%) 0.0225 u2003Emergency Medicine 20 (36%) 7 (16%) 0.0101 Conclusions Although gonorrhoea treatment errors were rare, specific practice locations and physician specialties were significantly associated with gonorrhoea treatment errors, suggesting important opportunities for educational intervention. Further studies may determine reasons for errors, relative importance of provider factors, and what systems support accurate treatment.