1. Poster THP 55; Contact: David Katz, dkatz7@u.washington.edu
Sexually Transmitted Disease Partner Services Increase HIV Testing among Partners of Men Who Have Sex with Men
David A. Katz1,2, Teal R. Bell3, Julia C. Dombrowski1,2, Roxanne P. Kerani1,2, Mark R. Aubin3, Zandt Bryan3, David A. Kern4, David D. Heal3, Matthew R. Golden1,2
University of Washington1, Seattle, WA; Public Health – Seattle & King County2, Seattle, WA; Washington State Department of Health3, Olympia, WA; Chicago Department of Public Health4, Chicago, IL
Abstract
BACKGROUND: Men who have sex with men (MSM) with bacterial sexually transmitted diseases (STDs) are at elevated risk for HIV infection. We instituted and evaluated a program promoting HIV testing through public health STD partner services (PS).
METHODS: In May 2012, health departments in Washington State revised PS programs to provide PS to all MSM with early syphilis, gonorrhea, or chlamydial infection and promote HIV testing among MSM and their partners as an explicit, measured PS objective. We compared the number of partners tested for and newly diagnosed with HIV following notification of exposure to the index STD case before (January 2010-April 2012) and during the revised program (May 2012-December 2015) using Poisson regression. Analyses adjusted for index STD, county of residence, and HIV status and, for case-finding, statewide HIV incidence among MSM.
RESULTS: In the intervention period, 8695 (71%) of 12,204 MSM STD cases received PS and provided information for a total of 13,600 partners, compared with 2994 (63%) of 4740 cases and 5974 partners pre-intervention (p<0.001 for both). The number of partners tested for HIV per interviewed index case increased from (760/2994) pre-intervention to (3703/8695) during the intervention [adjusted incidence rate ratio (aIRR)=1.63, 95%CI= ]. The number of partners newly diagnosed with HIV per interviewed index was stable ( pre-intervention vs during; aIRR=1.05, 95%CI= ). In multivariable analysis, index diagnosis with urethral gonorrhea, pharyngeal gonorrhea, and early syphilis and residence outside King County were associated with new HIV diagnosis in partners (p<0.01 for all). Of 52 new partner HIV diagnoses during the intervention, 44 (85%) occurred following initial PS interview with the index.
CONCLUSIONS: Promoting HIV testing among partners of MSM diagnosed with STDs through PS was feasible and increased HIV testing but not case-finding. Fewer than one new HIV case was identified for every 100 index cases receiving PS.
Background
US CDC estimates that 16% of men who have sex with men (MSM) living with HIV are unaware of their infection
MSM with bacterial sexually transmitted diseases (STDs) and their partners are at elevated risk for HIV infection
STD partner services (PS) provide an opportunity to ensure these high risk men are tested for HIV, yet:
Few public health departments provide PS to persons with STDs other than syphilis and HIV and
HIV testing is generally not an explicit and measured objective of STD PS
We previously found that promoting HIV testing through STD PS is effective at increasing testing among MSM (Katz et al, AIDS Patient Care STD 2016)
The effectiveness of promoting HIV testing among partners of MSM with STDs has not been evaluated
Objective
We instituted and evaluated a program promoting HIV testing among partners of MSM with STDs through public health STD partner services in Washington State.
Methods
Partner Services Intervention
Medical providers in Washington State complete STD case report forms that include gender of sex partner, allowing health departments to identify MSM for potential intervention
In May 2012, health departments in WA revised PS programs to:
Provide PS to all MSM with gonorrhea (GC) or chlamydial infection (CT) [already provided PS for all early syphilis]
Promote HIV testing among sex partners of MSM as an explicit and measured STD PS objective
Low intensity PS model: most interviews by phone and minimal field investigation, particularly for GC/CT
Data Sources
WA State HIV/STD surveillance data, 1/1/ /31/2015
STD surveillance and partner services data are matched with HIV surveillance data (eHARS) as follows:
Weekly automated probabilistic matching algorithm based on legal and alias names, date of birth, and sex
Bimonthly manual review of STD cases without eHARS match but with indication of HIV infection in STD surveillance data
Outcomes & Analyses
Pre/post analysis comparing outcomes among partners of MSM diagnosed during pre-intervention and intervention periods:
Pre-Intervention = January 2010 – April 2012
Intervention = May 2012 – December 2015
Compared partners elicited, HIV tested, and newly HIV diagnosed per index case interviewed for PS using Poisson regression
Compared test positivity (% newly diagnosed of those tested) using chi-square tests and logistic regression
Adjusted analyses included index STD, county of residence, HIV status and, for case-finding, statewide HIV incidence among MSM
Number needed to interview (NNTI) = number index cases interviewed ÷ outcome of interest
Results
Characteristics of 16,944 MSM Diagnosed with Bacterial STDs in Washington State, January 2010-December 2015
^Early syphilis = primary, secondary, or early latent. GC = gonorrhea. CT = chlamydial infection.
Number of STDs diagnosed annually, in particular extragenital STDs, increased during intervention period
STD Partner Services Process from Index Case STD Diagnosis through New HIV Diagnosis in Partners
HIV Testing and Case-Finding among Partners of MSM with Bacterial STDs – Total Number per Year
Results (cont.)
HIV Testing and HIV Case-Finding among Partners of MSM with Bacterial STDs – Number per Interviewed Index Case
IRR = incidence rate ratio. Adjusted analyses included index STD diagnosis, county of residence, HIV status and, for new HIV diagnosis, statewide HIV incidence among MSM.
Fewer partners were elicited per interviewed index case during intervention (p<0.001)
Intervention was associated with a 1.63-fold increase in the number of partners tested for HIV per interviewed case (p<0.001)
After adjusting for confounding, the number of partners newly HIV-diagnosed per index case (i.e. case-finding) remained stable (p=0.83)
HIV incidence among MSM decreased over time and had a large effect on IRR
Most new HIV diagnoses in partners occurred following PS interview
Pre-intervention: 19 (68%) of 28 total new HIV diagnoses
During intervention: 44/52 (85%)
In multivariable analysis, index diagnosis with urethral gonorrhea, pharyngeal gonorrhea, and early syphilis and residence outside King County were associated with new HIV diagnosis in partners (p<0.01 for all)
Number of Index Cases Needed to Interview (NNTI) to Newly Diagnose One Partner with HIV by Index Case STD*
*During intervention period. STDs not mutually exclusive.
Limitations
Index cases may have notified partners and partners may have tested for HIV in the absence of PS; difficult to determine the direct effect of PS
Relied primarily on self-reported outcomes
HIV incidence decreased and STD diagnoses increased during the study period, possibly affecting ability to detect increase in HIV case-finding
Increased use of geosocial networking apps (e.g. Grindr) over the study period affected partner-seeking behaviors and the ability of DIS to elicit contactable partners
Observational study so cannot adjust for all potential confounding
Summary
Refocusing STD PS was associated with increased receipt of PS among MSM with bacterial STDs and an increase in the number of partners to be reached
Despite a decrease in the number of partners elicited per interviewed case, the number of partners HIV tested per interviewed case increased substantially and HIV case-finding remained stable
Most new HIV diagnoses in partners occur following PS intervention with index cases
Fewer than 1 new HIV case was identified for every 100 index cases receiving PS
Number needed to interview to diagnose 1 partner with HIV was lowest for early syphilis or urethral gonorrhea
Residence outside Washington State’s core metropolitan county was associated with new HIV diagnosis in partners
Conclusions
Promoting HIV testing among partners of MSM diagnosed with STDs through PS increased HIV testing but not case-finding
Prioritizing MSM with specific STDs or in certain settings for PS may increase efficiency of HIV case-finding
Health departments should consider partner HIV testing, in addition to increased index patient HIV testing and recruitment for PrEP:
As additional explicit outcomes of STD PS and
When considering expanding PS to MSM with GC and CT
Acknowledgments
This program and its evaluation were supported by the U.S. Centers for Disease Control and Prevention (CDC PS and 3H25PS004364), the Washington State Department of Health, and Public Health – Seattle & King County. This evaluation was also supported by the the University of Washington Center for AIDS Research, a National Institutes of Health-funded program (P30 AI027757).
Characteristic
Pre-Intervention
Intervention
Jan 2010-Apr 2012
May 2012-Dec 2015 N %
Total cases in MSM
4740 -
12204
Sexually transmitted infection
Early syphilis^
897
19%
1672
14%
Urethral GC
1147
24%
2484
20%
Rectal GC
732
15%
2308
Pharyngeal GC
626
13%
2511
21%
Urethral CT
1335
28%
2487
Rectal CT
898
3580
29%
Pharyngeal CT
126 3%
715 6%
Diagnosed in King County (incl. Seattle)
3427
72%
8885
73%
HIV co-infected
1571
33%
3782
31%
IRR
.78 ( )
1.68 ( )
.64 ( )
.80 ( )
Adjusted IRR
.81 ( )
1.63 ( )
1.05 ( )
1.28 ( )
Pre-Intervention
4740 STD cases in MSM
2994 (63%) interviewed for PS
5974 partners elicited
4632 (78%) HIV-neg or unknown
760 (16%) HIV tested
28 (3.7%) newly HIV-diagnosed
Intervention
12204 STD cases in MSM
8695 (71%) interviewed for PS
13600 partners elicited
11065 (81%) HIV-neg or unknown
3703 (33%) HIV tested
52 (1.4%) newly HIV-diagnosed
Outcome
Definition
Ascertainment
Partner
Individual, named sex partner reported by index
Recorded by PS staff
Partner HIV tested
HIV tested after notification of STD exposure
Self-report by case or partner or medical record review
Partner newly HIV diagnosed
Newly HIV-diagnosed after notification of exposure