Use of Next-Generation Sequencing in a State-Wide Strategy of HIV-1 Surveillance: Impact of the SARS-COV-2 Pandemic on HIV-1 Diagnosis and Transmission.

BACKGROUND: The ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic posed an unpreceded threat to the management of other pandemics such as human immunodeficiency virus-1 (HIV-1) in the United States. The full impact of the SARS-CoV-2 pandemic on the HIV-1 pandemic needs to be evaluated. METHODS: All individuals with newly reported HIV-1 diagnoses from NC State Laboratory of Public Health were enrolled in this prospective observational study, 2018-2021. We used a sequencing-based recency assay to identify recent HIV-1 infections and to determine the days postinfection (DPI) for each person at the time of diagnosis. RESULTS: Sequencing used diagnostic serum samples from 814 individuals with new HIV-1 diagnoses spanning this 4-year period. Characteristics of individuals diagnosed in 2020 differed from those in other years. People of color diagnosed in 2021 were on average 6 months delayed in their diagnosis compared to those diagnosed in 2020. There was a trend that genetic networks were more known for individuals diagnosed in 2021. We observed no major integrase resistance mutations over the course of the study. CONCLUSIONS: SARS-CoV-2 pandemic may contribute to the spread of HIV-1. Public health resources need to focus on restoring HIV-1 testing and interrupting active, ongoing, transmission.

Measuring Success: Disease Intervention Specialists Performance Metrics and Outcome Assessments.

ABSTRACT: Disease intervention specialists (DIS) are the cornerstone of public health. However, the incremental gains of DIS-led interventions are difficult to detect at the population level. Health departments attempt to quantify the impact of key DIS activities through performance measures that assess how many and how quickly both patients are interviewed, and contacts are notified, tested, and treated. However, DIS work encompasses more than case finding and existing performance measures may not capture the full value DIS provide to health departments. In this article, we first describe how DIS investigations and contact tracing are conducted for sexually transmitted diseases and other communicable diseases to understand how the definition of effectiveness may vary by disease. Then, we examine the benefits and limitations of traditional performance measures using syphilis investigations as an example. Recognizing the limits of existing measures will improve our understanding of DIS impact and assist in the development of new measures of effectiveness that better represent the totality of DIS work.

Ten Years of Disseminated Gonococcal Infections in North Carolina: A Review of Cases From a Large Tertiary Care Hospital.

BACKGROUND: The detection and reporting of disseminated gonococcal infection (DGI) has been increasing across the United States. METHODS: We conducted a retrospective chart review of DGI case-patients diagnosed between 2010 and 2019 at a large tertiary care hospital in North Carolina. RESULTS: We identified 12 DGI case-patients (7 men and 5 women, aged 20 to 44 years), of whom 5 had Neisseria gonorrheae isolated from a sterile site (confirmed), 2 had N. gonorrheae detected at a nonsterile mucosal site and had clinical manifestations consistent with DGI (probable), and 5 did not have N. gonorrheae isolated from any site, but DGI was the most likely diagnosis (suspect). Among the 12 DGI case-patients, the most common manifestation was arthritis or tenosynovitis (n = 11); 1 patient had endocarditis. Half of the patients had significant underlying comorbidities or predisposing factors, including complement deficiency. Eleven of the 12 case-patients were hospitalized, and 4 required surgical intervention. CONCLUSIONS: This case series highlights the difficulty of making a definitive diagnosis of DGI, which could negatively affect reporting to public health authorities and hinder surveillance efforts to determine the true prevalence of DGI. A high index of suspicion is required, and a full diagnostic workup should be pursued in all cases of suspected DGI.

Intersection of Syphilis and Human Immunodeficiency Virus (HIV) Networks to Identify Opportunities to Enhance HIV Prevention.

BACKGROUND: Human immunodeficiency virus (HIV) and syphilis infection continue at disproportionate rates among minority men who have sex with men (MSM) in the United States. The integration of HIV genetic clustering with partner services can provide important insight into local epidemic trends to guide interventions and control efforts. METHODS: We evaluated contact networks of index persons defined as minority men and transgender women diagnosed with early syphilis and/or HIV infection between 2018 and 2020 in 2 North Carolina regions. HIV clusters were constructed from pol sequences collected through statewide surveillance. A combined "HIV-risk" network, which included persons with any links (genetic or sexual contact) to HIV-positive persons, was evaluated by component size, demographic factors, and HIV viral suppression. RESULTS: In total, 1289 index persons were identified and 55% named 1153 contacts. Most index persons were Black (88%) and young (median age 30 years); 70% had early syphilis and 43% had prevalent HIV infection. Most people with HIV (65%) appeared in an HIV cluster. The combined HIV-risk network (1590 contact network and 1500 cluster members) included 287 distinct components; however, 1586 (51%) were in a single component. Fifty-five percent of network members with HIV had no evidence of viral suppression. Overall, fewer index persons needed to be interviewed to identify 1 HIV-positive member without viral suppression (1.3 vs 4.0 for contact tracing). CONCLUSIONS: Integration of HIV clusters and viral loads illuminate networks with high HIV prevalence, indicating recent and ongoing transmission. Interventions intensified toward these networks may efficiently reach persons for HIV prevention and care re-engagement.

Pelvic Inflammatory Disease Trends Among Emergency Department Visits in North Carolina, 2008 to 2017.

BACKGROUND: Pelvic inflammatory disease (PID) is an infection of the upper female reproductive organs that can lead to infertility and ectopic pregnancies. It is a reportable condition in North Carolina (NC) but is likely underreported. We aimed to quantify PID diagnoses in NC emergency department (ED) visits. METHODS: The NC Disease Event Tracking and Epidemiology Collection Tool tracks all ED visits in NC. We identified PID diagnoses among women of reproductive age (15-44 years) between 2008 and 2017 using International Classification of Diseases, Ninth/Tenth Revision, Clinical Modification codes, and calculated the yearly proportion with PID diagnoses. We assessed the number of PID visits per patient each year, and the proportion of ED visits with a PID diagnosis by age, proportion of the patient's ZIP code living below the poverty line, insurance coverage, and NC provider region. RESULTS: The percent of women with PID decreased from 6189 (1.0%) in 2008 to 4337 (0.58%) in 2016 before increasing slightly to 4371 (0.61%) in 2017. We identified 54,502 (0.45%) ED visits among 51,847 (0.76%) women with ≥1 PID diagnosis code. Most (95.5%) women with PID had one ED visit during the calendar year. Each year, the proportion with PID was highest among women aged 20 to 24 years, covered under public insurance, from the most impoverished areas, and whose provider was in the Coastal region of NC. CONCLUSIONS: The percent with PID among women visiting EDs decreased between 2008 and 2017 in NC. Although this decline was observed across all demographics, disparities associated with PID continued to persist over time.

Effectiveness of Syphilis Partner Notification After Adjusting for Treatment Dates, 7 Jurisdictions.

BACKGROUND: Disease intervention specialists (DIS) prevent syphilis by ensuring treatment for patients' sex partners through partner notification (PN). Different interpretations of how to measure partners treated due to DIS efforts complicates PN evaluation. We measured PN impact by counting partners treated for syphilis after DIS interviewed the patient. METHODS: We reviewed data from early syphilis cases reported during the 2015-2017 period in 7 jurisdictions. We compared infected partners brought to treatment using the following: (1) DIS-assigned disposition codes or (2) all infected partners treated 0 to 90 days after the patient's interview (adjusted treatment estimate). Stratified analyses assessed patient characteristics associated with the adjusted treatment estimate. RESULTS: Disease intervention specialists interviewed 23,613 patients who reported 20,890 partners with locating information. Many of the 3569 (17.1%) partners classified by DIS as brought to treatment were treated before the patient was interviewed. There were 2359 (11.3%) partners treated 0 to 90 days after the patient's interview. Treatment estimates were more consistent between programs when measured using our adjusted estimates (range, 6.1%-14.8% per patient interviewed) compared with DIS-assigned disposition (range, 6.1%-28.3%). Treatment for ≥1 partner occurred after 9.0% of interviews and was more likely if the patient was a woman (17.9%), younger than 25 years (12.6%), interviewed ≤7 days from diagnosis (13.9%), HIV negative (12.6%), or had no reported history of syphilis (9.8%). CONCLUSIONS: Counting infected partners treated 0 to 90 days after interview reduced variability in reporting and facilitates quality assurance. Identifying programs and DIS who are particularly good at finding and treating partners could improve program impact.

Beyond Disease Intervention: Exploring an Expanded Role for Partner Services in the MATRix-NC Demonstration Project.

BACKGROUND: Disease intervention specialists (DIS) provide partner services for sexually transmitted infections (STIs). We assessed an expansion of DIS services for clients with HIV and/or syphilis, and contacts within their social and sexual networks. METHODS: Black and Latinx cisgender men and transgender women who have sex with men diagnosed with HIV and/or syphilis in 4 urban North Carolina counties were referred to designated DIS, who were trained to recruit clients as "seeds" for chain-referral sampling of sociosexual network "peers." All received HIV/STI testing and care; referrals for preexposure prophylaxis (PrEP) and social, behavioral, and non-STI medical services were offered. Participants completed baseline, 1-month, and 3-month computerized surveys. RESULTS: Of 213 cases referred to DIS from May 2018 to February 2020, 42 seeds (25 with syphilis, 17 with HIV) and 50 peers participated. Median age was 27 years; 93% were Black and 86% were cisgender men. Most peers came from seeds' social networks: 66% were friends, 20% were relatives, and 38% were cisgender women. Incomes were low, 41% were uninsured, and 10% experienced recent homelessness. More seeds than peers had baseline PrEP awareness; attitudes were favorable, but utilization was poor. Thirty-seven participants were referred for PrEP 50 times; 17 (46%) accessed PrEP by month 3. Thirty-nine participants received 129 non-PrEP referrals, most commonly for housing assistance, primary care, Medicaid navigation, and food insecurity. CONCLUSIONS: Chain-referral sampling from partner services clients allowed DIS to access persons with significant medical and social service needs, demonstrating that DIS can support marginalized communities beyond STI intervention.

Near Real-Time Identification of Recent Human Immunodeficiency Virus Transmissions, Transmitted Drug Resistance Mutations, and Transmission Networks by Multiplexed Primer ID-Next-Generation Sequencing in North Carolina.

BACKGROUND: The identification of recent human immunodeficiency virus (HIV) 1 infections among people with new HIV diagnoses is important to both tailoring and assessing the impact of HIV-1 prevention strategies. METHODS: We developed a multiplexed Primer ID-next-generation sequencing approach to identify recent infections by measuring the intrahost viral diversity over multiple regions of the HIV-1 genome, in addition to detecting drug resistance mutations (DRMs) and phylogenetically linked clusters. We summarize the field implementation of this all-in-one platform among persons with newly diagnosed HIV-1 by the North Carolina State Laboratory of Public Health in 2018. RESULTS: Overall, recent infection was identified in 94 (35%) of 268 patients with new HIV diagnoses. People <30 years old, and people who inject drugs were more likely to have diagnoses of recent infection. The reverse-transcriptase region K103N was the most commonly detected DRM (prevalence, approximately 15%). We found a total of 28 clusters, and persons with recent infection were more likely to be cluster members than were those with chronic infections (P = .03). CONCLUSIONS: We demonstrate the rapid identification of recent infection and pretreatment DRMs coupled with cluster analysis that will allow prioritization of linkage to care, treatment, and prevention interventions to those at highest risk of onward transmission.

Automated Digital Notification of COVID-19 Diagnoses Through Text and Email Messaging - North Carolina, December 2020-January 2021.

During October 3, 2020-January 9, 2021, North Carolina experienced a 400% increase in daily reported COVID-19 cases (1). To handle the increased number of cases and rapidly notify persons receiving a positive SARS-CoV-2 test result (patients), North Carolina state and local health departments moved from telephone call notification only to telephone call plus automated text and email notification (digital notification) beginning on December 24, 2020. Overall, among 200,258 patients, 142,975 (71%) were notified by telephone call or digital notification within the actionable period (10 days from their diagnosis date)* during January 2021, including at least 112,543 (56%) notified within 24 hours of report to North Carolina state and local health departments, a significantly higher proportion than the 25,905 of 175,979 (15%) notified within 24 hours during the preceding month (p<0.001). Differences in text notification by age, race, and ethnicity were observed. Automated digital notification is a feasible, rapid and efficient method to support timely outreach to patients, provide guidance on how to isolate, access resources, inform close contacts, and increase the efficiency of case investigation staff members.

Network Interconnectivity and Community Detection in HIV/Syphilis Contact Networks Among Men Who Have Sex With Men.

BACKGROUND: Despite persistent HIV and syphilis epidemics among men who have sex with men (MSM), the relationship between HIV and syphilis contact networks has not been well characterized. We aimed to measure interconnectivity between HIV and syphilis contact networks among MSM and identify network communities with heightened interconnectivity of the syphilis network with the HIV network. METHODS: Using contact-tracing data, we generated independent and combined HIV and syphilis networks for all MSM diagnosed with HIV or early syphilis, respectively, in North Carolina between 2015 and 2017. We treated the independent networks as layers and identified network communities, or groups of densely connected nodes, in the 2-layer network. We assessed interconnectivity by comparing the mean node degree among syphilis network members in the syphilis network alone versus the combined HIV/syphilis network, both overall and by network community. RESULTS: The syphilis network was interconnected with the HIV network, especially in network communities with younger median age, higher proportions of persons self-identifying as Black, non-Hispanic, and higher proportions of syphilis cases diagnosed at sexually transmitted disease clinics. CONCLUSIONS: Interconnected contact networks underlie HIV and syphilis epidemics among MSM, particularly among young, Black MSM. Intensified transmission prevention interventions within highly interconnected network communities may be particularly beneficial.

Unnamed Partners From Syphilis Partner Services Interviews, 7 Jurisdictions.

BACKGROUND: Reducing transmission depends on the percentage of infected partners treated; if many are missed, impact on transmission will be low. Traditional partner services metrics evaluate the number of partners found and treated. We estimated the proportion of partners of syphilis patients not locatable for intervention. METHODS: We reviewed records of early syphilis cases (primary, secondary, early latent) reported in 2015 to 2017 in 7 jurisdictions (Florida, Louisiana, Michigan, North Carolina, Virginia, New York City, and San Francisco). Among interviewed syphilis patients, we determined the proportion who reported named partners (with locating information), reported unnamed partners (no locating information), and did not report partners. For patients with no reported partners, we estimated their range of unreported partners to be between one and the average number of partners for patients who reported partners. RESULTS: Among 29,719 syphilis patients, 23,613 (80%) were interviewed and 18,581 (63%) reported 84,224 sex partners (average, 4.5; 20,853 [25%] named and 63,371 [75%] unnamed). An estimated 11,138 to 54,521 partners were unreported. Thus, 74,509 to 117,892 (of 95,362-138,745) partners were not reached by partner services (78%-85%). Among interviewed patients, 71% reported ≥1 unnamed partner or reported no partners; this proportion was higher for men who reported sex with men (75%) compared with men who reported sex with women only (65%) and women (44%). CONCLUSIONS: Approximately 80% of sex partners were either unnamed or unreported. Partner services may be less successful at interrupting transmission in networks for men who reported sex with men where a higher proportion of partners are unnamed or unreported.

HIV Outbreak Control With Effective Access to Care and Harm Reduction in North Carolina, 2017-2018.

Objectives. To assess and control a potential outbreak of HIV among people who inject drugs in Western North Carolina.Methods. Disease intervention specialists offered testing for hepatitis B and hepatitis C, harm reduction materials, and linkage to care to 7 linked people recently diagnosed with HIV who also injected drugs. Contacts were offered the same services and HIV testing. HIV genotype analysis was used to characterize HIV spread. We assessed testing and care outcomes by using state surveillance information.Results. Disease intervention specialists contacted 6 of 7 linked group members and received information on 177 contacts; among 96 prioritized contacts, 42 of 96 (44%) were exposed to or diagnosed with hepatitis C, 4 of 96 (4%) had hepatitis B, and 14 of 96 (15%) had HIV (2 newly diagnosed during the investigation). HIV genotype analysis suggested recent transmission to linked group members and 1 contact. Eleven of 14 with HIV were virally suppressed following the outbreak response.Conclusions. North Carolina identified and rapidly responded to an HIV outbreak among people reporting injecting drugs. Effective HIV care, the availability of syringe exchange services, and the rapid response likely contributed to controlling this outbreak.

Ocular Syphilis and Human Immunodeficiency Virus Coinfection Among Syphilis Patients in North Carolina, 2014-2016.

BACKGROUND: Ocular syphilis (OS) has been associated with human immunodeficiency virus (HIV) coinfection previously. We compared demographic and clinical characteristics of syphilis patients with and without HIV to identify risk factors for developing OS. METHODS: We reviewed all syphilis cases (early and late) reported to the North Carolina Division of Public Health during 2014 to 2016 and categorized HIV status (positive, negative, unknown) and OS status based on report of ocular symptoms with no other defined etiology. We estimated prevalence ratios (PR) and 95% confidence intervals (CI) for OS by HIV status. Among syphilis patients with HIV, we compared viral loads and CD4 cell counts by OS status. We compared symptom resolution by HIV status for a subset of OS patients. RESULTS: Among 7123 confirmed syphilis cases, 2846 (39.9%) were living with HIV, 109 (1.5%) had OS, and 59 (0.8%) had both. Ocular syphilis was more prevalent in syphilis patients with HIV compared to HIV-negative/unknown-status patients (PR, 1.8; 95% CI, 1.2-2.6). Compared with other patients with HIV, the prevalence of OS was higher in patients with viral loads greater than 200 copies/mL (1.7; 1.0-2.8) and in patients with a CD4 count of 200 cells/mL or less (PR, 2.3; 95% CI, 1.3-4.2). Among 11 patients with severe OS, 9 (81.8%) were HIV-positive. Among 39 interviewed OS patients, OS symptom resolution was similar for HIV-positive (70.0%) and HIV-negative/unknown-status (68.4%) patients. CONCLUSIONS: Syphilis patients with HIV were nearly twice as likely to report OS symptoms as were patients without documented HIV. Human immunodeficiency virus-related immunodeficiency possibly increases the risk of OS development in co-infected patients.

Depression, ART Adherence, and Receipt of Case Management Services by Adults with HIV in North Carolina, Medical Monitoring Project, 2009-2013.

Depression among persons with HIV is associated with antiretroviral therapy (ART) interruption and discontinuation, virological failure, and poor clinical and survival outcomes. Case management services can address needs for emotional counseling and other supportive services to facilitate HIV care engagement. Using 2009-2013 North Carolina Medical Monitoring Project data from 910 persons engaged in HIV care, we estimated associations of case management utilization with "probable current depression" and with 100% ART dose adherence. After weighting, 53.2% of patients reported receiving case management, 21.7% reported depression, and 87.0% reported ART adherence. Depression prevalence was higher among those reporting case management (24.9%) than among other patients (17.6%) (p < 0.01). Case management was associated with depression among patients living above the poverty level [adjusted prevalence ratio (aPR), 2.05; 95% confidence interval (CI) 1.25-3.36], and not among other patients (aPR, 1.01; 95% CI 0.72-1.43). Receipt of case management was not associated with ART adherence (aPR, 1.00; 95% CI 0.95-1.05). Our analysis indicates a need for more effective depression treatment, even among persons receiving case management services. Self-reported ART adherence was high overall, though lower among persons experiencing depression (unadjusted prevalence ratio, 0.92; 95% CI 0.86-0.99). Optimal HIV clinical and prevention outcomes require addressing psychological wellbeing, monitoring of ART adherence, and effective case management services.

A Comparison of Syphilis Partner Notification Outcomes by Reported Use of Internet-based Apps to Meet Sex Partners in North Carolina, 2013-2016.

BACKGROUND: Partner notification services (PNS) remain the backbone of syphilis control. The popularity of Internet-based apps to meet sex partners among early syphilis (ES) patients may hinder the success of PNS if partners cannot be located. METHODS: We compared demographic and clinical characteristics between male ES patients indicating sex with men (MSM) and reported in North Carolina between 2013 and 2016 by reported use of an Internet-based app to meet sex partners (app user). We used multivariable log-binomial regression to assess the association between app usage and ES exposure notification of 1 or more sex partner. RESULTS: Among 3414 MSM ES patients, 58.6% were app users. App users were more frequently white (33.2% vs 27.3%; P = 0.003), younger (median, 28 years vs 30 years; P = 0.0002) and less frequently human immunodeficiency virus coinfected (54.1% vs 58.2%; P = 0.02) compared to non-app users. Overall, 94.9% of app users and 89.6% of non-app users reported 1 or more sex partner. App users reported 2.5 times more locatable and 2.7 times more unlocatable sex partners than non-app users. Similar proportions of app (23.6%) and non-app users (25.0%) reported only unlocatable partners (P = 0.4). App usage was not associated with ES exposure notification of 1 or more sex partner (adjusted risk ratio, 0.99; 95% confidence interval, 0.87-1.13). CONCLUSIONS: We observed no difference in the proportion of locatable partners or likelihood of notifying 1 or more sex partner of exposure among MSM ES patients, by reported use of Internet-based apps to meet sex partners. Partner notification services continues to be an important mechanism to locate and assure treatment for sex partners in this population.

Repeat Human Immunodeficiency Virus Testing by Transmission Risk Group and Rurality of Residence in North Carolina.

BACKGROUND: Understanding of repeat human immunodeficiency virus (HIV) testing (RHT) is limited and the impact of rural residence as a potential barrier to RHT is unknown. Rural populations are of particular interest in the Southeastern United States because of their disproportionate HIV burden. METHODS: We used HIV surveillance data from publicly funded HIV testing sites in North Carolina to assess repeat testing by transmission risk group and residential rurality in a retrospective cohort study. Linear binomial regression models were used to estimate adjusted, 1-year cumulative incidences and cumulative incidence differences comparing RHT within transmission risk populations by level of rurality. RESULTS: In our total study population of 600,613 persons, 19,275 (3.2%) and 9567 (1.6%) self-identified as men who have sex with men (MSM) and persons who inject drugs (PWID), respectively. A small minority, 13,723 (2.3%) resided in rural ZIP codes. Men who have sex with men were most likely to repeat test (unadjusted, 1-year cumulative incidence after an initial negative test, 16.4%) compared with PWID (13.2%) and persons who did not identify as either MSM or PWID (13.6%). The greatest effect of rurality was within PWID; the adjusted, 1-year cumulative incidence of RHT was 6.4 (95% confidence interval, 1.4-11.4) percentage points higher among metropolitan versus rural PWID. CONCLUSIONS: One-year cumulative incidence of RHT was low among all clients of publicly funded HIV testing sites in North Carolina, including MSM and PWID for whom annual testing is recommended. Our findings suggest a need for public health efforts to increase access to and support for RHT, particularly among rural PWID.

Screening Veterans for Syphilis: Implementation of the Reverse Sequence Algorithm.

We evaluated the syphilis reverse sequence algorithm (RSA) in a Veteran Affairs facility, finding 5.5% reactive Treponema pallidum enzyme immunoassay (EIA) tests. In a subset of EIA+/VDRL-/TP-PA+ cases, 48% were previously treated. Of veterans with unknown/no prior therapy, only 45% had documentation of subsequent treatment, suggesting suboptimal interpretation of RSA results.

Increases in Ocular Syphilis-North Carolina, 2014-2015.

BACKGROUND: Ocular syphilis is an inflammatory eye disease due to Treponema pallidum infection. In the United States, syphilis rates have increased since 2000; clusters of ocular syphilis were reported in 2015. We investigated ocular syphilis in North Carolina to describe the epidemiology and clinical course of disease. METHODS: We reviewed syphilis cases reported to North Carolina during 2014-2015 and abstracted information from health department interviews for cases with ocular symptoms and no other defined etiology. To assess duration and severity of ocular symptoms, we also reviewed medical records and conducted structured interviews. We compared the prevalence of ocular manifestations among reported syphilis cases by demographic and clinical characteristics. RESULTS: Among 4232 syphilis patients, 63 (1.5%) had ocular syphilis: 21 in 2014 and 42 in 2015, a 100% increase. Total syphilis cases increased 35% through 2015. No patient with ocular syphilis named another ocular syphilis patient as a sex partner. Patients presented in all syphilis stages; 24 (38%) were diagnosed in primary or secondary syphilis. Ocular manifestations were more prevalent among syphilis patients who were male, aged ≥40 years, white, and infected with human immunodeficiency virus. No risk behaviors were associated with ocular syphilis. Among 39 interviewed patients, 34 (87%) reported reduced vision during infection; 12 (31%) reported residual visual symptoms posttreatment. CONCLUSIONS: In North Carolina, ocular syphilis increased from 2014 to 2015 and may be due to increased recognition of ocular manifestations, or a true increase in ocular syphilis. Many ocular syphilis patients experienced vision loss; however, most improved posttreatment.

The Number of Interviews Needed to Yield New Syphilis and Human Immunodeficiency Virus Cases Among Partners of People Diagnosed With Syphilis, North Carolina, 2015.

Compare syphilis investigation yield among patient groups using number needed to interview. GOAL: To increase investigation efficiency. STUDY DESIGN: Retrospective review of North Carolina 2015 syphilis investigations, using the number of cases needed to interview (NNTI) and the total number of cases and contacts needed to interview (TNTI) to compare yield of new syphilis and human immunodeficiency virus diagnoses between patient groups. RESULTS: We reviewed 1646 early syphilis cases and 2181 contacts; these yielded 241 new syphilis cases (NNTI, 6.9; TNTI, 16.4) and 38 new human immunodeficiency virus cases (NNTI, 43). Interviews of women (prevalence difference [PD] = 6%, 95% confidence interval [CI], 12-16), patients <30 years old (PD = 5%, 95% CI, 1-8), and patients with titer >1:16 (PD = 5%, 95% CI, 1-9) yielded more new syphilis cases in our adjusted model; no other patient factors increased investigation yield. CONCLUSIONS: The NNTI and TNTI are useful measures of efficiency. Prioritizing early syphilis investigation by gender, rapid plasmin reagin titer, and age provides small increases in efficiency; no other factors increased efficiency.

Influence of Detection Method and Study Area Scale on Syphilis Cluster Identification in North Carolina.

BACKGROUND: Identifying geographical clusters of sexually transmitted infections can aid in targeting prevention and control efforts. However, detectable clusters can vary between detection methods because of different underlying assumptions. Furthermore, because disease burden is not geographically homogenous, the reference population is sensitive to the study area scale, affecting cluster outcomes. We investigated the influence of cluster detection method and geographical scale on syphilis cluster detection in Mecklenburg County, North Carolina. METHODS: We analyzed primary and secondary syphilis cases reported in North Carolina (2003-2010). Primary and secondary syphilis incidence rates were estimated using census tract-level population estimates. We used 2 cluster detection methods: local Moran's I using an areal adjacency matrix and Kulldorff's spatial scan statistic using a variable size moving circular window. We evaluated 3 study area scales: North Carolina, Piedmont region, and Mecklenburg County. We focused our investigation on Mecklenburg, an urban county with historically high syphilis rates. RESULTS: Syphilis clusters detected using local Moran's I and Kulldorff's scan statistic overlapped but varied in size and composition. Because we reduced the scale to a high-incidence urban area, the reference syphilis rate increased, leading to the identification of smaller clusters with higher incidence. Cluster demographic characteristics differed when the study area was reduced to a high-incidence urban county. CONCLUSIONS: Our results underscore the importance of selecting the correct scale for analysis to more precisely identify areas with high disease burden. A more complete understanding of high-burden cluster location can inform resource allocation for geographically targeted sexually transmitted infection interventions.