COVID-19 Surveillance and Investigations in Workplaces - Seattle & King County, Washington, June 15-November 15, 2020.

Workplace activities involving close contact with coworkers and customers can lead to transmission of SARS-CoV-2, the virus that causes COVID-19 (1,2). Information on the approach to and effectiveness of COVID-19 workplace investigations is limited. In May 2020, Public Health - Seattle & King County (PHSKC), King County, Washington established a COVID-19 workplace surveillance and response system to enhance COVID-19 contact tracing and identify outbreaks in workplaces. During June 15-November 15, 2020, a total of 2,881 workplaces in King County reported at least one case of COVID-19. Among 1,305 (45.3%) investigated workplaces,* 524 (40.3%) met the definition of a workplace outbreak.† Among 306 (58.4%) workplaces with complete data,§ an average of 4.4 employee COVID-19 cases¶ (median = three; range = 1-65) were identified per outbreak, with an average attack rate among employees of 17.5%. PHSKC and the Washington State Department of Health optimized resources by establishing a classification scheme to prioritize workplace investigations as high, medium, or low priority based on workplace features observed to be associated with increased COVID-19 spread and workforce features associated with severe disease outcomes. High-priority investigations were significantly more likely than medium- and low-priority investigations to have two or more cases among employees (p<0.001), two or more cases not previously linked to the workplace (p<0.001), or two or more exposed workplace contacts not previously identified during case interviews (p = 0.002). Prioritization of workplace investigations allowed for the allocation of limited resources to effectively conduct workplace investigations to limit the potential workplace spread of COVID-19. Workplace investigations can also serve as an opportunity to provide guidance on preventing workplace exposures to SARS-CoV-2, facilitate access to vaccines, and strengthen collaborations between public health and businesses.

Yield and Coverage of Active Case Finding Interventions for Tuberculosis Control:A Systematic Review and Meta-analysis.

Background: Active case finding (ACF) for tuberculosis (TB) is a key strategy to reduce diagnostic delays, expedite treatment, and prevent transmission. Objective: Our objective was to identify the populations, settings, screening and diagnostic approaches that optimize coverage (proportion of those targeted who were screened) and yield (proportion of those screened who had active TB) in ACF programs. Methods: We performed a comprehensive search to identify studies published from 1980-2016 that reported the coverage and yield of different ACF approaches. For each outcome, we conducted meta-analyses of single proportions to produce estimates across studies, followed by meta-regression to identify predictors. Findings. Of 3,972 publications identified, 224 met criteria after full-text review. Most individuals who were targeted successfully completed screening, for a pooled coverage estimate of 93.5%. The pooled yield of active TB across studies was 3.2%. Settings with the highest yield were internally-displaced persons camps (15.6%) and healthcare facilities (6.9%). When compared to symptom screening as the reference standard, studies that screened individuals regardless of symptoms using microscopy, culture, or GeneXpert®MTB/RIF (Xpert) had 3.7% higher case yield. In particular, microbiological screening (usually microscopy) as the initial test, followed by culture or Xpert for diagnosis had 3.6% higher yield than symptom screening followed by microscopy for diagnosis. In a model adjusted for use of Xpert testing, approaches targeting persons living with HIV (PLWH) had a 4.9% higher yield than those targeting the general population. In all models, studies targeting children had higher yield (4.8%-5.7%) than those targeting adults. Conclusion: ACF activities can be implemented successfully in various populations and settings. Screening yield was highest in internally-displaced person and healthcare settings, and among PLWH and children. In high-prevalence settings, ACF approaches that screen individuals with laboratory tests regardless of symptoms have higher yield than approaches focused on symptomatic individuals.

Evaluation of the Isoniazid Preventive Therapy Care Cascade Among HIV-Positive Female Sex Workers in Mombasa, Kenya.

BACKGROUND: Kenyan female sex workers (FSWs) have a high HIV prevalence, increasing their tuberculosis (TB) risk. Despite recommendations that HIV-positive individuals be offered isoniazid preventive therapy (IPT), uptake has been limited. METHODS: In this longitudinal cohort of HIV-positive FSWs, we retrospectively characterized the IPT care cascade between March 2000 and January 2010, including reasons for cascade loss or appropriate exit. Cascade success required completion of 6 months of IPT. Baseline characteristics were assessed as potential correlates of cascade loss using multivariable logistic regression. RESULTS: Among 642 HIV-positive FSWs eligible for IPT evaluation, median age was 31 years (IQR 26-35) with median CD4 lymphocyte count of 409 (IQR 292-604) cells per cubic millimeter. There were 249 (39%) women who successfully completed 6 months of IPT, 157 (24%) appropriately exited the cascade, and 236 (37%) were cascade losses. Most cascade losses occurred at symptom screen (38%, 90/236), chest radiograph evaluation (28%, 66/236), or during IPT treatment (30%, 71/236). Twenty-nine women were diagnosed with tuberculosis, including one after IPT initiation. Most women initiating IPT completed the course (71%, 249/351); <5% had medication intolerance. Younger women [<25 and 25-35 vs. >35 years; adjusted odds ratio (AOR) 2.65, 95% confidence interval (CI): 1.46 to 4.80 and AOR 1.78, 95% CI: 1.13 to 2.80, respectively], and those evaluated for IPT after antiretroviral availability in 2004 (AOR 1.92, 95% CI: 1.31 to 2.81), were more likely to be cascade losses. CONCLUSIONS: Implementation of IPT among HIV-positive FSWs in Kenya is feasible. However, significant losses along the IPT care cascade underscore the need for strategies improving retention in care.

Genital Shedding of Resistant Human Immunodeficiency Virus-1 Among Women Diagnosed With Treatment Failure by Clinical and Immunologic Monitoring.

Background. The accumulation of human immunodeficiency virus (HIV) resistance mutations can compromise treatment outcomes and promote transmission of drug-resistant virus. We conducted a study to determine the duration and evolution of genotypic drug resistance in the female genital tract among HIV-1-infected women failing first-line therapy. Methods. Treatment failure was diagnosed based on World Health Organization (WHO) clinical or immunologic criteria, and second-line therapy was initiated. Stored plasma and genital samples were tested to determine the presence and timing of virologic failure and emergence of drug resistance. The median duration of genital shedding of genotypically resistant virus prior to regimen switch was estimated. Results. Nineteen of 184 women were diagnosed with treatment failure, of whom 12 (63.2%) had confirmed virologic failure at the switch date. All 12 women with virologic failure (viral load, 5855-1 086 500 copies/mL) had dual-class resistance in plasma. Seven of the 12 (58.3%) had genital HIV-1 RNA levels high enough to amplify (673-116 494 copies/swab), all with dual-class resistance. The median time from detection of resistance in stored samples to regimen switch was 895 days (95% confidence interval [CI], 130-1414 days) for plasma and 629 days (95% CI, 341-984 days) for genital tract secretions. Conclusions. Among women diagnosed with treatment failure using WHO clinical or immunologic criteria, over half had virologic failure confirmed in stored samples. Resistant HIV-1 RNA was shed in the genital tract at detectable levels for ≈1.7 years before failure diagnosis, with steady accumulation of mutations. These findings add urgency to the ongoing scale-up of viral load testing in resource-limited settings.

Genital HSV Shedding among Kenyan Women Initiating Antiretroviral Therapy.

OBJECTIVES: Genital ulcer disease (GUD) prevalence increases in the first month of antiretroviral treatment (ART), followed by a return to baseline prevalence by month 3. Since most GUD is caused by herpes simplex virus type 2 (HSV-2), we hypothesized that genital HSV detection would follow a similar pattern after treatment initiation. METHODS: We conducted a prospective cohort study of 122 HSV-2 and HIV-1 co-infected women with advanced HIV disease who initiated ART and were followed closely with collection of genital swab specimens for the first three months of treatment. RESULTS: At baseline, the HSV detection rate was 32%, without significant increase in genital HSV detection noted during the first month or the third month of ART. HIV-1 shedding declined during this period; no association was also noted between HSV and HIV-1 shedding during this period. CONCLUSION: Because other studies have reported increased HSV detection in women initiating ART and we have previously reported an increase in GUD during early ART, it may be prudent to counsel HIV-1 infected women initiating ART that HSV shedding in the genital tract may continue after ART initiation.

Antiretroviral treatment interruptions predict female genital shedding of genotypically resistant HIV-1 RNA.

OBJECTIVES: Resistant viruses may emerge in the female genital tract during antiretroviral therapy (ART). Our objective was to identify predictors of drug-resistant HIV-1 RNA in genital secretions after initiation of nonnucleoside reverse transcriptase inhibitor-based therapy. DESIGN: We conducted a prospective cohort study with periodic evaluation of plasma and genital swab samples for HIV-1 RNA levels and antiretroviral resistance mutations. METHODS: First-line ART was initiated in 102 women. Plasma and genital HIV-1 RNA levels were measured at months 0, 3, 6, and 12. Genotypic resistance testing was performed for samples from all participants with RNA >1000 copies per milliliter at month 6 or 12. Cox regression analysis was used to identify factors associated with incident genital tract resistance. RESULTS: Detectable genital tract resistance developed in 5 women, all with detectable plasma resistance (estimated incidence, 5.5/100 person-years of observation). Treatment interruption >48 hours, adherence by pill count, adherence by visual analog scale, and baseline plasma viral load were associated with incident genital tract resistance. In multivariate analysis, only treatment interruption was associated with risk of detectable genital tract resistance (adjusted hazard ratio: 14.2; 95% confidence interval: 1.3 to 158.4). CONCLUSIONS: Treatment interruption >48 hours during nonnucleoside reverse transcriptase inhibitor-based therapy led to a significantly increased risk of detecting genotypically resistant HIV-1 RNA in female genital tract secretions. Patient- and program-level interventions to prevent treatment interruptions could reduce the risk of shedding-resistant HIV-1 during ART.