Epidemiology of Covid-19 in a Long-Term Care Facility in King County, Washington.

BACKGROUND: Long-term care facilities are high-risk settings for severe outcomes from outbreaks of Covid-19, owing to both the advanced age and frequent chronic underlying health conditions of the residents and the movement of health care personnel among facilities in a region. METHODS: After identification on February 28, 2020, of a confirmed case of Covid-19 in a skilled nursing facility in King County, Washington, Public Health-Seattle and King County, aided by the Centers for Disease Control and Prevention, launched a case investigation, contact tracing, quarantine of exposed persons, isolation of confirmed and suspected cases, and on-site enhancement of infection prevention and control. RESULTS: As of March 18, a total of 167 confirmed cases of Covid-19 affecting 101 residents, 50 health care personnel, and 16 visitors were found to be epidemiologically linked to the facility. Most cases among residents included respiratory illness consistent with Covid-19; however, in 7 residents no symptoms were documented. Hospitalization rates for facility residents, visitors, and staff were 54.5%, 50.0%, and 6.0%, respectively. The case fatality rate for residents was 33.7% (34 of 101). As of March 18, a total of 30 long-term care facilities with at least one confirmed case of Covid-19 had been identified in King County. CONCLUSIONS: In the context of rapidly escalating Covid-19 outbreaks, proactive steps by long-term care facilities to identify and exclude potentially infected staff and visitors, actively monitor for potentially infected patients, and implement appropriate infection prevention and control measures are needed to prevent the introduction of Covid-19.

COVID-19 in a Long-Term Care Facility - King County, Washington, February 27-March 9, 2020.

On February 28, 2020, a case of coronavirus disease (COVID-19) was identified in a woman resident of a long-term care skilled nursing facility (facility A) in King County, Washington.* Epidemiologic investigation of facility A identified 129 cases of COVID-19 associated with facility A, including 81 of the residents, 34 staff members, and 14 visitors; 23 persons died. Limitations in effective infection control and prevention and staff members working in multiple facilities contributed to intra- and interfacility spread. COVID-19 can spread rapidly in long-term residential care facilities, and persons with chronic underlying medical conditions are at greater risk for COVID-19-associated severe disease and death. Long-term care facilities should take proactive steps to protect the health of residents and preserve the health care workforce by identifying and excluding potentially infected staff members and visitors, ensuring early recognition of potentially infected patients, and implementing appropriate infection control measures.

Evaluation of electronic ambulatory care data for influenza-like illness surveillance, Washington State.

A growing number of outpatient providers utilize electronic health records (EHR) to identify patient visits for influenza-like illness (ILI) but no standard query guidance exists. We applied an ILI definition validated for emergency department data to EHR from outpatient networks and found ILI visits highly correlated with influenza laboratory detections. Incorporating ambulatory EHR into our ILI surveillance system increased the capacity by more than 300%. Electronic ambulatory care data could be used to augment or replace public health surveillance systems traditionally reliant on manual reporting.

An automated system for public health surveillance of school absenteeism.

Public Health-Seattle & King County established an automated system for monitoring school absenteeism data from 18 of 19 public school districts in King County, Washington. The system receives a daily aggregate count of the number of students enrolled and absent, stratified by school district, school name, and grade. A name and unique identifier are provided for each school and district, as well as the level (eg, elementary, middle, high, alternative, other) and zip code of each school. Files are transmitted to the health department daily and include data from the previous school day. Public Health-Seattle & King County developed a series of visualizations that summarize the data by day, week, and month for each level of stratification. The automated system for collecting and monitoring school absenteeism data was more acceptable, simple, timely, complete, and useful relative to traditional manual data collection methods.

A Population-Based Intervention to Improve Care Cascades of Patients With Hepatitis C Virus Infection.

Hepatitis C virus (HCV) infection is common in the United States and leads to significant morbidity, mortality, and economic costs. Simplified screening recommendations and highly effective direct-acting antivirals for HCV present an opportunity to eliminate HCV. The objective of this study was to increase testing, linkage to care, treatment, and cure of HCV. This was an observational, prospective, population-based intervention program carried out between September 2014 and September 2018 and performed in three community health centers, three large multiclinic health care systems, and an HCV patient education and advocacy group in King County, WA. There were 232,214 patients included based on criteria of documented HCV-related diagnosis code, positive HCV laboratory test or prescription of HCV medication, and seen at least once at a participating clinical site in the prior year. Electronic health record (EHR) prompts and reports were created. Case management linked patients to care. Primary care providers received training through classroom didactics, an online curriculum, specialty clinic shadowing, and a telemedicine program. The proportion of baby boomer patients with documentation of HCV testing increased from 18% to 54% during the project period. Of 77,577 baby boomer patients screened at 87 partner clinics, 2,401 (3%) were newly identified HCV antibody positive. The number of patients staged for treatment increased by 391%, and those treated increased by 1,263%. Among the 79% of patients tested after treatment, 95% achieved sustained virologic response. Conclusion: A combination of EHR-based health care system interventions, active linkage to care, and clinician training contributed to a tripling in the number of patients screened and a more than 10-fold increase of those treated. The interventions are scalable and foundational to the goal of HCV elimination.

Accuracy and cost-effectiveness of cervical cancer screening by high-risk human papillomavirus DNA testing of self-collected vaginal samples.

OBJECTIVE: Estimate the accuracy and cost-effectiveness of cervical cancer screening strategies based on high-risk human papillomavirus (HPV) DNA testing of self-collected vaginal samples. MATERIALS AND METHODS: A subset of 1,665 women (age range, 18-50 y) participating in a cervical cancer screening study were screened by liquid-based cytology and by high-risk HPV DNA testing of both self-collected vaginal swab samples and clinician-collected cervical samples. Women with positive/abnormal screening test results and a subset of women with negative screening test results were triaged to colposcopy. On the basis of individual and combined test results, 5 screening strategies were defined. Estimates of sensitivity and specificity for cervical intraepithelial neoplasia grade 2 or worse were calculated, and a Markov model was used to estimate the incremental cost-effectiveness ratios for each strategy. RESULTS: Compared with cytology-based screening, high-risk HPV DNA testing of self-collected vaginal samples was more sensitive (68%, 95% CI = 58%-78% vs 85%, 95% CI = 76%-94%) but less specific (89%, 95% CI = 86%-91% vs 73%, 95% CI = 67%-79%). A strategy of high-risk HPV DNA testing of self-collected vaginal samples followed by cytology triage of HPV-positive women was comparably sensitive (75%, 95% CI = 64%-86%) and specific (88%, 95% CI = 85%-92%) to cytology-based screening. In-home self-collection for high-risk HPV DNA detection followed by in-clinic cytology triage had a slightly lower lifetime cost and a slightly higher quality-adjusted life year (QALY) expectancy than did cytology-based screening (incremental cost-effectiveness ratio of triennial screening compared with no screening was $9,871/QALY and $12,878/QALY, respectively). CONCLUSIONS: Triennial screening by high-risk HPV DNA testing of in-home, self-collected vaginal samples followed by in-clinic cytology triage was cost-effective.

Design of an Enhanced Public Health Surveillance System for Hepatitis C Virus Elimination in King County, Washington.

INTRODUCTION: With the goal of eliminating hepatitis C virus (HCV) as a public health problem in Washington State, Public Health-Seattle & King County (PHSKC) designed a Hepatitis C Virus Test and Cure (HCV-TAC) data system to integrate surveillance, clinical, and laboratory data into a comprehensive database. The intent of the system was to promote identification, treatment, and cure of HCV-infected persons (ie, HCV care cascade) using a population health approach. MATERIALS AND METHODS: The data system automatically integrated case reports received via telephone and fax from health care providers and laboratories, hepatitis test results reported via electronic laboratory reporting, and data on laboratory and clinic visits reported by 6 regional health care systems. PHSKC examined patient-level laboratory test results and established HCV case classification using Council of State and Territorial Epidemiologists criteria, classifying patients as confirmed if they had detectable HCV RNA. RESULTS: The data enabled PHSKC to report the number of patients at various stages along the HCV care cascade. Of 7747 HCV RNA-positive patients seen by a partner site, 5377 (69%) were assessed for severity of liver fibrosis, 3932 (51%) were treated, and 2592 (33%) were cured. PRACTICE IMPLICATIONS: Data supported local public heath surveillance and HCV program activities. The data system could serve as a foundation for monitoring future HCV prevention and control programs.

Association between school closure and subsequent absenteeism during a seasonal influenza epidemic.

BACKGROUND: Mathematical models suggest that social distancing measures, such as school closures, may mitigate community transmission during an influenza pandemic. Because closures are disruptive to schools and families, they are rarely employed during seasonal influenza outbreaks. A rare circumstance enabled us to examine the association between school closure and absenteeism during a seasonal influenza outbreak when half of King County, Washington public schools closed for a winter recess 19-23 February 2007, while half remained open for all or part of the week. METHODS: Using absenteeism as a proxy for influenza activity, we tested the hypothesis that schools on break would experience lower rates of post-break absenteeism than schools remaining open. We conducted daily retrospective and prospective surveillance from 5 February-9 March 2007 in schools on break (n = 256) and in session (n = 205). We use generalized estimating equations with Poisson distribution to evaluate whether mean absenteeism after the break differed between schools on break and those in session, adjusting for baseline absenteeism and repeated measurements by schools over time. RESULTS: Results indicate no difference in post-break absenteeism in schools on break compared with schools that remained in session (relative risk = 1.07 [95% confidence interval = 0.96-1.20]). This result held in elementary schools (1.00 [0.91-1.10]), where absenteeism patterns are thought to be most representative of community influenza activity. CONCLUSION: We did not find that school closure during a seasonal influenza outbreak reduced subsequent absenteeism. However, limitations in this "natural experiment" hampered our ability to detect a benefit if one truly was present.

Carbon monoxide epidemic among immigrant populations: King County, Washington, 2006.

OBJECTIVES: We investigated an outbreak of carbon monoxide (CO) poisoning after a power outage to determine its extent, identify risk factors, and develop prevention measures. METHODS: We reviewed medical records and medical examiner reports of patients with CO poisoning or related symptoms during December 15 to 24, 2006. We grouped patients into households exposed concurrently to a single source of CO. RESULTS: Among 259 patients with CO poisoning, 204 cases were laboratory confirmed, 37 were probable, 10 were suspected, and 8 were fatal. Of 86 households studied, 58% (n = 50) were immigrant households from Africa (n = 21), Asia (n = 15), Latin America (n = 10), and the Middle East (n = 4); 34% (n = 29) were US-born households. One percent of households was European (n = 1), and the origin for 7% (n = 6) was unknown. Charcoal was the most common fuel source used among immigrant households (82%), whereas liquid fuel was predominant among US-born households (34%). CONCLUSIONS: Educational campaigns to prevent CO poisoning should consider immigrants' cultural practices and languages and specifically warn against burning charcoal indoors and incorrect ventilation of gasoline- or propane-powered electric generators.

Completeness of reporting of rabies postexposure prophylaxis in King County, Washington.

The completeness of rabies postexposure prophylaxis (PEP) reporting was evaluated in King County, Washington State. Information on rabies immune globulin prescriptions was obtained from hospital pharmacies associated with emergency departments in King County from 2003 to June 2006. Rabies immune globulin is given at the initiation of rabies PEP which is usually started at emergency departments. Because pharmacies are not regular sources of rabies PEP reporting, we compared pharmacy cases with cases reported via routine passive surveillance methods. A capture-recapture method was used to calculate the estimated number of unreported cases from all sources. Reporting completeness was calculated by dividing the number of cases reported via routine surveillance with the sum of reported and estimated unreported cases. Seventy-one unreported rabies PEP cases were identified by comparing previously reported cases with pharmacy cases. A total of 128 cases were estimated to have been missed by the surveillance system. Overall reporting completeness was 62 percent increasing to almost 80 percent in 2005 and 2006. Our findings illustrate the importance of evaluating surveillance systems and suggest that it may be useful to institute active rabies PEP surveillance with emergency departments in addition to continuing educating healthcare providers and facilities about reporting.