Detection and Response to an HIV Cluster: People Living Homeless and Using Drugs in Seattle, Washington.

INTRODUCTION: The HIV epidemic in King County, Washington has traditionally been highly concentrated among men who have sex with men, and incidence has gradually declined over 2 decades. In 2018, King County experienced a geographically concentrated outbreak of HIV among heterosexual people who inject drugs. METHODS: Data sources to describe the 2018 outbreak and King County's response were partner services interview data, HIV case reports, syringe service program client surveys, hospital data, and data from a rapid needs assessment of homeless individuals and people who inject drugs. In 2020, the authors examined the impact of delays in molecular sequence analyses and cluster member size thresholds, for identifying genetically similar clusters, on the timing of outbreak identification. RESULTS: In 2018, the health department identified a North Seattle cluster, growing to 30 people with related HIV infections diagnosed in 2008-2019. In total, 70% of cluster members were female, 77% were people who inject drugs, 87% were homeless, and 27% reported exchanging sex. Intervention activities included a rapid needs assessment, 2,485 HIV screening tests in a jail and other outreach settings, provision of 87,488 clean syringes in the outbreak area, and public communications. A lower cluster size threshold and more rapid receipt and analyses of data would have identified this outbreak 4-16 months earlier. CONCLUSIONS: This outbreak shows the vulnerability of people who inject drugs to HIV infection, even in areas with robust syringe service programs and declining HIV epidemics. Although molecular HIV surveillance did not identify this outbreak, it may have done so with a lower threshold for defining clusters and more rapid receipt and analyses of HIV genetic sequences.

Foreign-Born Individuals with HIV in King County, WA: A Glimpse of the Future of HIV?

To better understand country of birth-related shifts in the demography of people newly diagnosed with HIV infection, we compared demographic and clinical characteristics of foreign-born and U.S.-born residents of King County, WA diagnosed with HIV from 2006 to 2015. The proportion of cases that were foreign-born increased from 23 to 34% during this time. Most foreign-born cases were born in Africa (34%), Latin America (32%), Asia (22%), or Europe (7%). Latin Americans and Asians were similar to U.S.-born individuals by HIV risk factor and gender, while Africans were more likely to be female and less often men who have sex with men. In 2015, approximately 15% of cases presumptively newly diagnosed in King County were foreign-born individuals who self-reported a pre-immigration HIV diagnosis. Increases in foreign-born individuals previously diagnosed out of country may lead to inaccuracy in the count of new diagnoses, including an over-estimate of community-acquired HIV in King County.

Integrating HIV Surveillance and Field Services: Data Quality and Care Continuum in King County, Washington, 2010-2015.

OBJECTIVES: To assess how integration of HIV surveillance and field services might influence surveillance data and linkage to care metrics. METHODS: We used HIV surveillance and field services data from King County, Washington, to assess potential impact of misclassification of prior diagnoses on numbers of new diagnoses. The relationship between partner services and linkage to care was evaluated with multivariable log-binomial regression models. RESULTS: Of the 2842 people who entered the King County HIV Surveillance System in 2010 to 2015, 52% were newly diagnosed, 41% had a confirmed prior diagnosis in another state, and 7% had an unconfirmed prior diagnosis. Twelve percent of those classified as newly diagnosed for purposes of national HIV surveillance self-reported a prior HIV diagnosis that was unconfirmed. Partner services recipients were more likely than nonrecipients to link to care within 30 days (adjusted risk ratio [RR] = 1.10; 95% confidence interval [CI] = 1.03, 1.18) and 90 days (adjusted RR = 1.07; 95% CI = 1.01, 1.14) of diagnosis. CONCLUSIONS: Integration of HIV surveillance, partner services, and care linkage efforts may improve the accuracy of HIV surveillance data and facilitate timely linkage to care.

Emerging Regional and Racial Disparities in the Lifetime Risk of Human Immunodeficiency Virus Infection Among Men who Have Sex With Men: A Comparative Life Table Analysis in King County, WA and Mississippi.

BACKGROUND: Little is known about the lifetime risk of human immunodeficiency virus (HIV) diagnosis among US men who have sex with men (MSM), trends in risk and how risk varies between populations. METHODS: We used census and HIV surveillance data to construct life tables to estimate the cumulative risk of HIV diagnosis among cohorts of MSM born 1940 to 1994 in King County, Washington (KC) and Mississippi (MS). RESULTS: The cumulative risk of HIV diagnosis progressed in 3 phases. In phase 1, risk increased among MSM in successive cohorts born 1940 to 1964. Among men born 1955 to 1965 (the peak risk cohort), by age 55 years, 45% of white KC MSM, 65% of black KC MSM, 22% of white MS MSM, and 51% of black MS MSM had been diagnosed with HIV. In phase 2, men born 1965 to 1984, risk of diagnosis among KC MSM declined almost 60% relative to the peak risk cohort. A similar pattern of decline occurred in white MS MSM, with a somewhat smaller decline observed in black MS MSM. In phase 3, men born 1985 to 1994, the pattern of risk diverged. Among white KC MSM, black KC MSM, and white MS MSM, HIV risk increased slightly compared with men born 1975 to 1984, with 6%, 14%, and 2% diagnosed by age 27 years, respectively. Among black MS MSM born 1985 to 1994, HIV risk rose dramatically, with 35% HIV diagnosed by age 27 years. CONCLUSIONS: The lifetime risk of HIV diagnosis has substantially declined among MSM in KC and among white MSM in MS, but is rising dramatically among black MSM in MS.

Comparison of In-Person Versus Telephone Interviews for Early Syphilis and Human Immunodeficiency Virus Partner Services in King County, Washington (2010-2014).

BACKGROUND: The relative effectiveness of in-person versus telephone interviews for human immunodeficiency virus (HIV)/sexually transmitted disease partner services (PS) is uncertain. METHODS: We compared outcomes of in-person versus telephone PS interviews for early syphilis (ES) and newly diagnosed HIV in King County, Washington from 2010 to 2014. We used multivariable Poisson regression to evaluate indices (number of partners per original patient [OP]) for partners named, notified, tested, diagnosed, and treated (ES only). Analyses controlled for OP age, sex, race/ethnicity, sexual orientation, time to interview, place of diagnosis, and staff performing interviews. RESULTS: For ES, 682 and 646 OPs underwent in-person and telephone interviews, respectively. In-person syphilis PS were associated with higher indices of partners named (in-person index [IPI], 3.43; telephone index [TI], 2.06; adjusted relative risk [aRR], 1.68; 95% confidence interval [CI], 1.55-1.82), notified (IPI, 1.70; TI, 1.13; aRR, 1.39; 95% CI, 1.24-1.56), tested (IPI, 1.15; TI, 0.72; aRR, 1.34; 95% CI, 1.16-1.54), and empirically treated (IPI, 1.03; TI, 0.74; aRR, 1.19; 95% CI, 1.03-1.37), but no difference in infected partners treated (IPI, 0.28; TI, 0.24; aRR, 0.93; 95% CI, 0.72-1.21). For HIV, 358 and 489 OPs underwent in-person and telephone interviews, respectively. In-person HIV PS were associated with higher indices of partners named (IPI, 1.87; TI, 1.28; aRR, 1.38; 95% CI, 1.18-1.62), notified (IPI, 1.38; TI, 0.92; aRR, 1.24; 95% CI, 1.03-1.50), and newly diagnosed with HIV (IPI, 0.10; TI, 0.05; aRR, 2.17; 95% CI, 1.04-4.50), but no difference in partners tested (IPI, 0.61; TI, 0.48; aRR, 1.15; 95% CI, 0.88-1.52). CONCLUSIONS: Although in-person syphilis PS were associated with some increased PS indices, they did not increase the treatment of infected partners. In contrast, in-person HIV PS resulted in increased HIV case finding. These data support prioritizing in-person PS for HIV and suggest that in-person PS for syphilis may not have major public health benefit.

Achieving the Goals of the National HIV/AIDS Strategy: Declining HIV Diagnoses, Improving Clinical Outcomes, and Diminishing Racial/Ethnic Disparities in King County, WA (2004-2013).

BACKGROUND: The US National HIV/AIDS Strategy defines national objectives related to HIV prevention and care. The extent to which US cities are meeting those objectives is uncertain. METHODS: We analyzed King County, WA, HIV surveillance data collected between 2004 and 2013. The study population included 9539 persons diagnosed as having and living with HIV infection and 3779 persons with newly diagnosed HIV infection. RESULTS: Between 2004 and 2013, the rate of new HIV diagnosis decreased from 18.4 to 13.2 per 100,000 residents (decline of 28%); AIDS diagnosis rates declined 42% from 12 to 7 per 100,000; and age-adjusted death rates decreased from 27 to 15 per 1000 persons living with HIV/AIDS (decline of 42%; P<0.0001 for all 3 trends). The rate of new HIV diagnosis declined 26% among men who have sex with men (MSM; P=0.0002), with the largest decline occurring in black MSM (44%). Among 8679 individuals with laboratory results reported to National HIV Surveillance System from 2006 through 2013, viral suppression (viral load<200 copies/mL) increased from 45% to 86% (P<0.0001), with all racial/ethnic groups achieving greater than 80% viral suppression in 2013. INTERPRETATION: The rates of new HIV diagnosis, AIDS diagnoses, and mortality in persons living with HIV in King County, WA, have significantly declined over the last decade. These changes have occurred concurrent with a dramatic increase in HIV viral suppression and have affected diverse populations, including MSM and African American MSM. These findings demonstrate substantial local success in achieving the goals of the National HIV/AIDS Strategy.

Evaluating New Definitions of Acute and Early HIV Infection from HIV Surveillance Data.

BACKGROUND: The U.S. HIV staging system is being revised to more comprehensively track early and acute HIV infection (AHI). We evaluated our ability to identify known cases of AHI using King County (KC) HIV surveillance data. METHODOLOGY: AHI cases were men who have sex with men (MSM) with negative antibody and positive pooled nucleic acid amplification (NAAT) tests identified through KC testing sites. We used KC surveillance data to calculate inter-test intervals (ITI, time from last negative to first positive test) and the serologic algorithm for recent HIV seroconversion (STARHS). For surveillance data, AHI was defined as an ITI of ≤ 30 days and early infection as an ITI ≤ 180 days or STARHS recent result. Dates of last negative HIV tests were obtained from lab reports in the HIV surveillance system or data collected for HIV Incidence Surveillance. RESULTS: Between 2005 and 2011, 47 MSM with AHI were identified by pooled NAAT. Of the 47 cases, 36% had ITI < 1 day, 60% had an ITI < 30 days, and 70% (95% CI=55-82%) had an ITI ≤ 6 months and would have been identified as early HIV infection. Of the 47, 38% had STARHS testing and 94% were STARHS recent. CONCLUSION: MSM with known AHI were not identified by proposed definitions of AHI and early infection. These known AHI cases were frequently missed by HIV surveillance because concurrent negative antibody tests were not reported. Successful implementation of the revisions to the HIV staging system will require more comprehensive reporting.