COVID-19 Case Investigation and Contact Tracing in Central Washington State, June-July 2020.

OBJECTIVE: To evaluate participation in COVID-19 case investigation and contact tracing in central Washington State between June 15 and July 12, 2020. METHODS: In this retrospective observational evaluation we combined SARS-CoV-2 RT-PCR and antigen test reports from the Washington Disease Reporting System with community case investigation and contact tracing data for 3 health districts (comprising 5 counties) in central Washington State. All 3 health districts have large Hispanic communities disproportionately affected by COVID-19. RESULTS: Investigators attempted to call all referred individuals with COVID-19 (n = 4,987); 71% were interviewed. Of those asked about close contacts (n = 3,572), 68% reported having no close contacts, with similar proportions across ethnicity, sex, and age group. The 968 individuals with COVID-19 who named specific contacts (27% of those asked) reported a total of 2,293 contacts (mean of 2.4 contacts per individual with COVID-19); 85% of listed contacts participated in an interview. CONCLUSIONS: Most individuals with COVID-19 reported having no close contacts. Increasing community engagement and public messaging, as well as understanding and addressing barriers to participation, are crucial for CICT to contribute meaningfully to controlling the SARS-CoV-2 pandemic.

Factors Related to Pertussis and Tetanus Vaccination Status Among Foreign-Born Adults Living in the United States.

Pertussis is a common vaccine-preventable disease (VPD) worldwide. Its reported incidence has increased steadily in the United States, where it is endemic. Tetanus is a rare but potentially fatal VPD. Foreign-born adults have lower tetanus-diphtheria-pertussis (Tdap) and tetanus-diphtheria (Td) vaccination coverage than do U.S.-born adults. We studied the association of migration-related, socio-demographic, and access-to-care factors with Tdap and Td vaccination among foreign-born adults living in the United States. The 2012 and 2013 National Health Interview Survey data for foreign-born respondents were analyzed. Multivariable logistic regression was conducted to calculate prevalence ratios and 95% confidence intervals, and to identify variables independently associated with Tdap and Td vaccination among foreign-born adults. Tdap and Td vaccination status was available for 9316 and 12,363 individuals, respectively. Overall vaccination coverage was 9.1% for Tdap and 49.8% for Td. Younger age, higher education, having private health insurance (vs. public insurance or uninsured), having visited a doctor in the previous year, and region of residence were independently associated with Tdap and Td vaccination. Among those reporting a doctor visit, two-thirds had not received Tdap. This study provides further evidence of the need to enhance access to health care and immunization services and reduce missed opportunities for Tdap and Td vaccination for foreign-born adults in the United States. These findings apply to all foreign-born, irrespective of their birthplace, citizenship, language and years of residence in the United States. Addressing vaccination disparities among the foreign-born will help achieve national vaccination goals and protect all communities in the United States.

Viral shedding and clinical illness in naturally acquired influenza virus infections.

BACKGROUND: Volunteer challenge studies have provided detailed data on viral shedding from the respiratory tract before and through the course of experimental influenza virus infection. There are no comparable quantitative data to our knowledge on naturally acquired infections. METHODS: In a community-based study in Hong Kong in 2008, we followed up initially healthy individuals to quantify trends in viral shedding on the basis of cultures and reverse-transcription polymerase chain reaction (RT-PCR) through the course of illness associated with seasonal influenza A and B virus infection. RESULTS: Trends in symptom scores more closely matched changes in molecular viral loads measured with RT-PCR for influenza A than for influenza B. For influenza A virus infections, the replicating viral loads determined with cultures decreased to undetectable levels earlier after illness onset than did molecular viral loads. Most viral shedding occurred during the first 2-3 days after illness onset, and we estimated that 1%-8% of infectiousness occurs prior to illness onset. Only 14% of infections with detectable shedding at RT-PCR were asymptomatic, and viral shedding was low in these cases. CONCLUSIONS: Our results suggest that "silent spreaders" (ie, individuals who are infectious while asymptomatic or presymptomatic) may be less important in the spread of influenza epidemics than previously thought.

Effects of oseltamivir treatment on duration of clinical illness and viral shedding and household transmission of influenza virus.

BACKGROUND: Large clinical trials have demonstrated the therapeutic efficacy of oseltamivir against influenza. We assessed the indirect effectiveness of oseltamivir in reducing secondary household transmission in an incident cohort of influenza index patients and their household members. METHODS: We recruited index outpatients whose rapid test results were positive for influenza from February through September 2007 and January through September 2008. Household contacts were followed up for 7-10 days during 3-4 home visits to monitor symptoms. Nose and throat swabs were collected and tested for influenza by reverse-transcription polymerase chain reaction or viral culture. RESULTS: We followed up 384 index patients and their household contacts. Index patients who took oseltamivir within 24 h of symptom onset halved the time to symptom alleviation (adjusted acceleration factor, 0.56; 95% confidence interval [CI], 0.42-0.76). Oseltamivir treatment was not associated with statistically significant reduction in the duration of viral shedding. Household contacts of index patients who had taken oseltamivir within 24 h of onset had a nonstatistically significant lower risk of developing laboratory-confirmed infection (adjusted odds ratio, 0.54; 95% CI, 0.11-2.57) and a marginally statistically significant lower risk of clinical illness (adjusted odds ratio, 0.52; 95% CI, 0.25-1.08) compared with contacts of index patients who did not take oseltamivir. CONCLUSIONS: Oseltamivir treatment is effective in reducing the duration of symptoms, but evidence of household reduction in transmission of influenza virus was inconclusive.

Factors affecting QuickVue Influenza A + B rapid test performance in the community setting.

Rapid diagnosis of influenza can facilitate timely clinical management. We evaluated the performance of the QuickVue Influenza A + B test (Quidel, San Diego, CA) in a community setting and investigated the factors affecting test sensitivity. We recruited 1008 subjects from 30 outpatient clinics in Hong Kong between February and September 2007. Each subject provided 2 pooled pairs of nose and throat swabs; 1 pair was tested by the QuickVue rapid test on site, and the other pair was sent to a laboratory for reference tests. Among 998 enrolled subjects with valid results, the rapid test had overall sensitivity of 0.68 and specificity of 0.96 compared with viral culture. Sensitivity for both influenza A and B was significantly higher for specimens with viral loads greater than 5 log(10) copies/mL. The QuickVue Influenza A + B test has similar sensitivity in point-of-care community settings to more controlled conditions.

Facemasks and hand hygiene to prevent influenza transmission in households: a cluster randomized trial.

BACKGROUND: Few data are available about the effectiveness of nonpharmaceutical interventions for preventing influenza virus transmission. OBJECTIVE: To investigate whether hand hygiene and use of facemasks prevents household transmission of influenza. DESIGN: Cluster randomized, controlled trial. Randomization was computer generated; allocation was concealed from treating physicians and clinics and implemented by study nurses at the time of the initial household visit. Participants and personnel administering the interventions were not blinded to group assignment. (ClinicalTrials.gov registration number: NCT00425893) SETTING: Households in Hong Kong. PATIENTS: 407 people presenting to outpatient clinics with influenza-like illness who were positive for influenza A or B virus by rapid testing (index patients) and 794 household members (contacts) in 259 households. INTERVENTION: Lifestyle education (control) (134 households), hand hygiene (136 households), or surgical facemasks plus hand hygiene (137 households) for all household members. MEASUREMENTS: Influenza virus infection in contacts, as confirmed by reverse-transcription polymerase chain reaction (RT-PCR) or diagnosed clinically after 7 days. RESULTS: Sixty (8%) contacts in the 259 households had RT-PCR-confirmed influenza virus infection in the 7 days after intervention. Hand hygiene with or without facemasks seemed to reduce influenza transmission, but the differences compared with the control group were not significant. In 154 households in which interventions were implemented within 36 hours of symptom onset in the index patient, transmission of RT-PCR-confirmed infection seemed reduced, an effect attributable to fewer infections among participants using facemasks plus hand hygiene (adjusted odds ratio, 0.33 [95% CI, 0.13 to 0.87]). Adherence to interventions varied. LIMITATION: The delay from index patient symptom onset to intervention and variable adherence may have mitigated intervention effectiveness. CONCLUSION: Hand hygiene and facemasks seemed to prevent household transmission of influenza virus when implemented within 36 hours of index patient symptom onset. These findings suggest that nonpharmaceutical interventions are important for mitigation of pandemic and interpandemic influenza. PRIMARY FUNDING SOURCE: Centers for Disease Control and Prevention.

Preliminary findings of a randomized trial of non-pharmaceutical interventions to prevent influenza transmission in households.

BACKGROUND: There are sparse data on whether non-pharmaceutical interventions can reduce the spread of influenza. We implemented a study of the feasibility and efficacy of face masks and hand hygiene to reduce influenza transmission among Hong Kong household members. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a cluster randomized controlled trial of households (composed of at least 3 members) where an index subject presented with influenza-like-illness of <48 hours duration. After influenza was confirmed in an index case by the QuickVue Influenza A+B rapid test, the household of the index subject was randomized to 1) control or 2) surgical face masks or 3) hand hygiene. Households were visited within 36 hours, and 3, 6 and 9 days later. Nose and throat swabs were collected from index subjects and all household contacts at each home visit and tested by viral culture. The primary outcome measure was laboratory culture confirmed influenza in a household contact; the secondary outcome was clinically diagnosed influenza (by self-reported symptoms). We randomized 198 households and completed follow up home visits in 128; the index cases in 122 of those households had laboratory-confirmed influenza. There were 21 household contacts with laboratory confirmed influenza corresponding to a secondary attack ratio of 6%. Clinical secondary attack ratios varied from 5% to 18% depending on case definitions. The laboratory-based or clinical secondary attack ratios did not significantly differ across the intervention arms. Adherence to interventions was variable. CONCLUSIONS/SIGNIFICANCE: The secondary attack ratios were lower than anticipated, and lower than reported in other countries, perhaps due to differing patterns of susceptibility, lack of significant antigenic drift in circulating influenza virus strains recently, and/or issues related to the symptomatic recruitment design. Lessons learnt from this pilot have informed changes for the main study in 2008. TRIAL REGISTRATION: ClinicalTrials.gov NCT00425893 HKClinicalTrials.com HKCTR-365.

Performance measures for pneumonia: are they valuable, and are process measures adequate?

PURPOSE OF REVIEW: Pneumonia has been the target of large national initiatives to measure and report quality of care. Measures of pneumonia care are now being used for public reporting and pay-for-performance in an effort to increase provider accountability for healthcare quality in the USA. Increasingly, concerns have been raised about the potential for unintended consequences of performance measurement and reporting that might lead to patient harm. RECENT FINDINGS: Since 1999, there have been substantial improvements in performance on measures of pneumonia processes of care, and patient clinical outcomes have improved. The association between improved clinical outcomes and processes of care for pneumonia, however, is not clear based on available national data. The increasing use of process measures for hospital accountability has created the continual need to re-evaluate the relationship between processes being measured and desired patient outcomes. While there is little direct evidence of unintended consequences of performance measurement, concerns have been raised about the potential for direct or indirect harm to patients. SUMMARY: Measuring processes of care for pneumonia is feasible and appears to have accelerated the pace of quality improvement. There is an ongoing need to develop new measures of pneumonia quality that focus on patient outcomes, care transitions, and efficiency of care.

Evaluating adverse events after vaccination in the Medicare population.

PURPOSE: Post-licensure observational studies using large linked databases can provide important data about whether adverse events are associated with vaccines, but databases that have been used may not have sufficient statistical power to examine rare events, and may underrepresent the elderly. We assessed the utility of Medicare data for evaluating adverse events after influenza and pneumococcal vaccines, by using an example involving selected clinical conditions, and evaluating aspects of data quality relevant to vaccine safety analyses. METHODS: We used 2001 data from the National Claims History File and Enrollment Database to determine if hospitalization for urinary tract infection (not likely associated with vaccination) or for cellulitis and abscess of the upper arm and forearm is associated with vaccination. RESULTS: For influenza vaccine, the 7-day period after vaccination did not demonstrate an elevation in hospitalization with cellulitis and abscess of the upper arm and forearm; for pneumococcal vaccine, a clear peak was evident. No increase in urinary tract infection was found after either influenza or pneumococcal vaccine. Having a prior Medicare claim for pneumococcal vaccine within 5 years was a risk factor for hospitalization with cellulitis and abscess of the upper arm and forearm (relative risk, 2.6; 95% confidence limits (CL), 1.3, 5.0). CONCLUSIONS: Medicare data are a useful source for evaluating adverse events after vaccination. Screening analyses can be performed using administrative data, but medical record review to validate diagnoses will often be needed for rigorous study of vaccine-adverse event associations.

Antibiotics for bacteremic pneumonia: Improved outcomes with macrolides but not fluoroquinolones.

BACKGROUND: The questions of whether the use of antibiotics that are active against atypical organisms is beneficial in the treatment of community-acquired pneumonia and of the potential mechanisms of any beneficial effects remain unresolved. Proposed mechanisms include activity against atypical organisms vs the immunomodulatory effects of these antibiotics. The study of outcomes of a large cohort of patients with bacteremic pneumonia provides a unique opportunity to address these questions by excluding patients with primary atypical infection. METHODS: We reviewed data from the charts of 2,209 Medicare patients who were admitted to hospitals across the United States from either home or a nursing facility with bacteremic pneumonia between 1998 and 2001. Patients were stratified according to the type of antibiotic treatment. Multivariate modeling was performed to assess the relationship between the class of antibiotic used and several outcome variables. RESULTS: The initial use of any antibiotic active against atypical organisms was independently associated with a decreased risk of 30-day mortality (odds ratio [OR], 0.76; 95% confidence interval [CI], 0.59 to 0.98; p = 0.03) and hospital admission within 30 days of discharge (OR, 0.67; 95% CI, 0.51 to 0.89; p = 0.02). Further analysis revealed that the benefits of atypical treatment were associated with the use of macrolides, but not the use of fluoroquinolones or tetracyclines, with macrolides conferring lower risks of in-hospital mortality (OR, 0.59; 95% CI, 0.40 to 0.88; p = 0.01), 30-day mortality (OR, 0.61; 95% CI, 0.43 to 0.87; p = 0.007), and hospital readmission within 30 days of discharge (OR, 0.59; 95% CI, 0.42 to 0.85; p = 0.004). CONCLUSIONS: Initial antibiotic treatment including a macrolide agent is associated with improved outcomes in Medicare patients hospitalized with bacteremic pneumonia. These results have implications regarding the mechanism by which the use of a macrolide for treatment of pneumonia is associated with improved outcomes.

Asthma prevention in urbanites.

OBJECTIVES: The purpose of this intervention was to evaluate the efficacy of low-literacy asthma education and the provision of free asthma controller medications to persons living in the urban inner-city. METHODS: The intervention was conducted as a series of three studies. A health educator from the Johnson Health Center (JHC) performed chart reviews in the first two studies to identify urban asthma patients with frequent emergency department (ED) visits. The third study evaluated participants from the community-at-large who came to the ED for episodic asthma care. Free controller medications and education were provided to participants in all three studies. RESULTS: Emergency department utilization, inpatient admissions, and consumer medical costs were greatly reduced in all three studies during the 5-year intervention period. Lung function improved, and participants reported an improved quality of life. CONCLUSION: The provision of free asthma controller medications resulted in greatly improved asthma management and reduced costs. There was no evidence that an asthma education component per se produced any of the changes.

In-hospital observation after antibiotic switch in pneumonia: a national evaluation.

PURPOSE: To evaluate the clinical benefit of in-hospital observation after the switch from intravenous (IV) to oral antibiotics in a large Medicare population. Retrospective studies of relatively small size indicate that the practice of in-hospital observation after the switch from IV to oral antibiotics for patients hospitalized with community-acquired pneumonia (CAP) is unnecessary. METHODS: We performed a retrospective examination of the US Medicare National Pneumonia Project database. Eligible patients were discharged with an ICD-9-CM diagnosis consistent with community-acquired pneumonia and divided into 2 groups: 1) a "not observed" cohort, in which patients were discharged on the same day as the switch from IV to oral antibiotics and 2) an "observed for 1 day" cohort, in which patients remained hospitalized for 1 day after the switch from IV to oral antibiotics. We compared clinical outcomes between these 2 cohorts. RESULTS: A total of 39,242 cases were sampled, representing 4341 hospitals in all 50 states and the District of Columbia. There were 5248 elderly patients who fulfilled eligibility criteria involving a length of stay of no more than 7 hospital days (2536 "not observed" and 2712 "observed for 1 day" patients). Mean length of stay was 3.8 days for the "not observed" cohort and 4.5 days for the "observed for 1 day" cohort (P <.0001). There was no significant difference in 14-day hospital readmission rate (7.8% in the "not observed" cohort vs 7.2% "observed for 1 day" cohort, odds ratio 0.91; 95% confidence interval [CI] 0.74-1.12; P =.367) and 30-day mortality rate (5.1% "not observed" cohort vs 4.4% in the "observed for 1 day" cohort, odds ratio 0.86; 95% CI, 0.67-1.11; P =.258) between the "not observed" and "observed for 1 day" cohorts. CONCLUSIONS: Our analysis of the US Medicare Pneumonia Project database provides further evidence that the routine practice of in-hospital observation after the switch from IV to oral antibiotics for patients with CAP may be avoided in patients who are clinically stable although these findings should be verified in a large randomized controlled trial.

Volume, quality of care, and outcome in pneumonia.

BACKGROUND: The establishment of minimum volume thresholds has been proposed as a means of improving outcomes for patients with various medical and surgical conditions. OBJECTIVE: To determine whether volume is associated with either quality of care or outcome in the treatment of pneumonia. DESIGN: Retrospective cohort study. SETTING: 3243 hospitals participating in the National Pneumonia Quality Improvement Project in 1998 and 1999. PATIENTS: 13,480 patients with pneumonia cared for by 9741 physicians. MEASUREMENTS: The association between the annual pneumonia caseload of physicians and hospitals and adherence to quality-of-care measures and severity-adjusted in-hospital and 30-day mortality rates. RESULTS: Physician volume was unrelated to the timeliness of administration of antibiotics and the obtainment of blood cultures; however, physicians in the highest-volume quartile had lower rates of screening for and administration of influenza (21%, 19%, 20%, and 12% for quartiles 1 through 4, respectively; P < 0.01) and pneumococcal (16%, 13%, 13%, and 9% for quartiles 1 through 4, respectively; P < 0.01) vaccines. Among hospitals, the percentage of patients who received antibiotics within 4 hours of hospital arrival was inversely related to pneumonia volume (72%, 64%, 60%, and 56% for quartiles 1 through 4, respectively; P < 0.01), while selection of antibiotic, obtainment of blood cultures, and rates of immunization were similar. Physician volume was not associated with in-hospital or 30-day mortality rates. Odds ratios for in-hospital mortality rates rose with increasing hospital volume (1.14 [95% CI, 0.87 to 1.49], 1.34 [CI, 1.03 to 1.75], and 1.32 [CI, 0.97 to 1.80] for quartiles 2 to 4, respectively); however, odds ratios for 30-day mortality rates were similar. LIMITATIONS: This study was limited to Medicare beneficiaries 65 years of age and older. Ascertainment of some measures of the quality of care and severity of illness depended on the documentation practices of the physician. CONCLUSION: Among both physicians and hospitals, higher pneumonia volume is associated with reduced adherence to selected guideline recommendations and no measurable improvement in patient outcomes.

Understanding keys to successful implementation of electronic decision support in rural hospitals: analysis of a pilot study for antimicrobial prescribing.

Electronic clinical decision support systems (CDSS) have been hailed for their potential to improve clinical outcomes. Using a pretest/posttest design, an Internet-based CDSS designed to optimize antimicrobial prescribing was pilot tested for community-acquired pneumonia in 5 rural hospitals in southwestern Idaho. An antimicrobial management team was created in each hospital to address clinicians' perception of excessive time required for direct use of the CDSS. In pooled hospital data, agreement with CDSS recommendations improved to a statistically significant level. However, inspection of data at the individual hospital level demonstrated that almost all improvement occurred in a single hospital. Failure in the other hospitals appeared to be primarily a consequence of organizational and cultural barriers. These barriers are discussed to understand keys for successful future implementation of CDSS in rural hospitals, drawing on experience with cultural barriers from other industries, specifically aviation.

Antimicrobial prophylaxis for surgery: an advisory statement from the National Surgical Infection Prevention Project.

In January 2003, leadership of the Medicare National Surgical Infection Prevention Project hosted the Surgical Infection Prevention Guideline Writers Workgroup meeting. The objectives were to review areas of agreement among the published guidelines for surgical antimicrobial prophylaxis, to address inconsistencies, and to discuss issues not currently addressed. The participants included authors from most of the published North American guidelines for antimicrobial prophylaxis and several specialty colleges. The workgroup reviewed currently published guidelines for antimicrobial prophylaxis. Nominal group process was used to draft a consensus paper that was widely circulated for comment. The consensus positions of the workgroup include that infusion of the first antimicrobial dose should begin within 60 minutes before surgical incision and that prophylactic antimicrobial agents should be discontinued within 24 hours of the end of surgery. This advisory statement provides an overview of other issues related to antimicrobial prophylaxis including specific suggestions regarding antimicrobial selection.

Administration of first hospital antibiotics for community-acquired pneumonia: does timeliness affect outcomes?

PURPOSE OF REVIEW: Associations between processes of care for hospitalized community-acquired pneumonia patients and clinical outcomes are important because of the high incidence of such admissions and substantial related mortality. Several studies have examined these associations. RECENT FINDINGS: Large retrospective studies of older patients have demonstrated associations between time to first dose as short as 4 h and length of stay and mortality during and after hospitalization. Results of smaller studies have been less consistent. The association appears to be strongest among older patients who have not received antibiotics prior to arrival at the hospital. SUMMARY: A significant and causal relationship appears to exist between antibiotic timing and improved outcomes, especially among older patients. Even modest improvements in timeliness of antibiotic administration could impact a substantial number of lives because of the high incidence of community-acquired pneumonia hospitalization.

Blood culture and susceptibility results and allergy history do not influence fluoroquinolone use in the treatment of community-acquired pneumonia.

STUDY OBJECTIVE: To determine the influence of blood culture and susceptibility results and antimicrobial allergy history on fluoroquinolone use in the treatment of community-acquired pneumonia. DESIGN: Retrospective analysis of medical records. SETTING: Centers for Medicare and Medicaid Services, Seattle, Washington. PATIENTS: A total of 10,275 Medicare beneficiaries hospitalized with the diagnosis of pneumonia received antimicrobial treatment within 24 hours of admission. Of these patients, 288 had blood cultures positive for pneumococcus and were matched one-to-one with patients with negative blood and sputum cultures. MEASUREMENTS AND MAIN RESULTS: Antimicrobial use at the beginning and end of hospitalization, culture and susceptibility results, and patient allergies were recorded retrospectively and compared between two matched groups: patients with blood cultures positive for Streptococcus pneumoniae and those whose blood and sputum cultures were negative. Neither culture and susceptibility results nor allergy history affected the rate of fluoroquinolone use. Despite infection due to penicillin-susceptible pneumococci and no penicillin allergy, patients received therapy with fluoroquinolones (26.7%) as frequently as those with culture-negative pneumonia (34.9%; p=0.401). CONCLUSION: Fluoroquinolones are prescribed despite microbiologic confirmation of penicillin-susceptible pneumococcal pneumonia in the absence of penicillin allergy. These prescribing patterns may contribute to selection pressure associated with fluoroquinolone-resistant gram-positive and gram-negative bacteria.