Influenza C virus in U.S. children with acute respiratory infection 2016-2019.

Influenza C virus (ICV) is an orthomyxovirus related to influenza A and B, yet due to few commercial assays, epidemiologic studies may underestimate incidence of ICV infection and disease. We describe the epidemiology and characteristics of ICV within the New Vaccine Surveillance Network (NVSN), a Centers for Disease Control and Prevention (CDC)-led network that conducts population-based surveillance for pediatric acute respiratory illness (ARI). Nasal or/combined throat swabs were collected from emergency department (ED) or inpatient ARI cases, or healthy controls, between 12/05/2016-10/31/2019 and tested by molecular assays for ICV and other respiratory viruses. Parent surveys and chart review were used to analyze demographic and clinical characteristics of ICV+ children. Among 19,321 children tested for ICV, 115/17,668 (0.7 %) ARI cases and 8/1653 (0.5 %) healthy controls tested ICV+. Median age of ICV+ patients was 18 months and 88 (71.5 %) were ≤36 months. Among ICV+ ARI patients, 40 % (46/115) were enrolled in the ED, 60 % (69/115) were inpatients, with 15 admitted to intensive care. Most ICV+ ARI patients had fever (67.8 %), cough (94.8 %), or wheezing (60.9 %). Most (60.9 %) ARI cases had ≥1 co-detected viruses including rhinovirus, RSV, and adenovirus. In summary, ICV detection was rarely associated with ARI in children, and most ICV+ patients were ≤3 years old with co-detected respiratory viruses.

Chest CT Imaging Provides More Information Than Chest Radiography Alone in Determining Extent of Physiologic Impairment in Pulmonary Sarcoidosis.

BACKGROUND: Sarcoidosis staging primarily has relied on the Scadding chest radiographic system, although chest CT imaging is finding increased clinical use. RESEARCH QUESTION: Whether standardized chest CT scan assessment provides additional understanding of lung function beyond Scadding stage and demographics is unknown and the focus of this study. STUDY DESIGN AND METHODS: We used the National Heart, Lung, and Blood Institute study Genomics Research in Alpha-1 Antitrypsin Deficiency and Sarcoidosis cases of sarcoidosis (n = 351) with Scadding stage and chest CT scans obtained in a standardized manner. One chest radiologist scored all CT scans with a visual scoring system, with a subset read by another chest radiologist. We compared demographic features, Scadding stage, and CT scan findings and the correlation between these measures. Associations between spirometry results and Dlco, CT scan findings, and Scadding stage were determined using regression analysis (n = 318). Agreement between readers was evaluated using Cohen's κ value. RESULTS: CT scan features were inconsistent with Scadding stage in approximately 40% of cases. Most CT scan features assessed on visual scoring were associated negatively with lung function. Associations persisted for FEV1 and Dlco when adjusting for Scadding stage, although some CT scan feature associations with FVC became insignificant. Scadding stage was associated primarily with FEV1, and inclusion of CT scan features reduced significance in association between Scadding stage and lung function. Multivariable regression modeling to identify radiologic measures explaining lung function included Scadding stage for FEV1 and FEV1 to FVC ratio (P < .05) and marginally for Dlco (P < .15). Combinations of CT scan measures accounted for Scadding stage for FVC. Correlations among Scadding stage and CT scan features were noted. Agreement between readers was poor to moderate for presence or absence of CT scan features and poor for degree and location of abnormality. INTERPRETATION: CT scan features explained additional variability in lung function beyond Scadding stage, with some CT scan features obviating the associations between lung function and Scadding stage. Whether CT scan features, phenotypes, or endotypes could be useful for managing patients with sarcoidosis needs more study.

Reduced effectiveness of repeat influenza vaccination: distinguishing among within-season waning, recent clinical infection, and subclinical infection.

Studies have reported that prior-season influenza vaccination is associated with higher risk of clinical influenza infection among vaccinees. This effect might arise from incomplete consideration of within-season waning and recent infection. Using data from the US Flu Vaccine Effectiveness (VE) Network (2011-2012 to 2018-2019 seasons), we found that repeat vaccinees were vaccinated earlier in a season by one week. After accounting for waning VE, repeat vaccinees were still more likely to test positive for A(H3N2) (OR=1.11, 95%CI:1.02-1.21) but not for influenza B or A(H1N1). We found that clinical infection influenced individuals' decision to vaccinate in the following season while protecting against clinical infection of the same (sub)type. However, adjusting for recent clinical infections did not strongly influence the estimated effect of prior-season vaccination. In contrast, we found that adjusting for subclinical infection could theoretically attenuate this effect. Additional investigation is needed to determine the impact of subclinical infections on VE.

Incidence and Transmission of SARS-CoV-2 in US Child Care Centers After COVID-19 Vaccines.

Importance: SARS-CoV-2 surveillance studies in US child care centers (CCCs) in the post-COVID-19 vaccine era are needed to provide information on incidence and transmission in this setting. Objective: To characterize SARS-CoV-2 incidence and transmission in children attending CCCs (students) and their child care providers (CCPs) and household contacts. Design, Setting, and Participants: This prospective surveillance cohort study was conducted from April 22, 2021, through March 31, 2022, and included 11 CCCs in 2 cities. A subset (surveillance group) of CCPs and students participated in active surveillance (weekly reverse transcription-polymerase chain reaction [RT-PCR] swabs, symptom diaries, and optional baseline and end-of-study SARS-CoV-2 serologic testing), as well as all household contacts of surveillance students. Child care center directors reported weekly deidentified self-reported COVID-19 cases from all CCPs and students (self-report group). Exposure: SARS-CoV-2 infection in CCC students. Main Outcomes and Measures: SARS-CoV-2 incidence, secondary attack rates, and transmission patterns were determined from diary entries, self-reports to CCC directors, and case logs. Incidence rate ratios were measured using Poisson regression clustering on centers with a random intercept and unstructured matrix. Results: From a total population of 1154 students and 402 CCPs who self-reported cases to center directors, 83 students (7.2%; mean [SD] age, 3.86 [1.64] years; 55 male [66%]), their 134 household contacts (118 adults [mean (SD) age, 38.39 (5.07) years; 62 female (53%)], 16 children [mean (SD) age, 4.73 (3.37) years; 8 female (50%)]), and 21 CCPs (5.2%; mean [SD] age, 38.5 [12.9] years; 18 female [86%]) participated in weekly active surveillance. There were 154 student cases (13%) and 87 CCP cases (22%), as defined by positive SARS-CoV-2 RT-PCR or home antigen results. Surveillance students had a higher incidence rate than self-report students (incidence rate ratio, 1.9; 95% CI, 1.1-3.3; P = .01). Students were more likely than CCPs to have asymptomatic infection (34% vs 8%, P < .001). The CCC secondary attack rate was 2.7% to 3.0%, with the upper range representing possible but not definite secondary cases. Whether the index case was a student or CCP, transmission within the CCC was not significantly different. Household cumulative incidence was 20.5%, with no significant difference in incidence rate ratio between adults and children. Household secondary attack rates were 50% for children and 67% for adults. Of 30 household cases, only 5 (17%) represented secondary infections caused by 3 students who acquired SARS-CoV-2 from their CCC. Pre- and poststudy seroprevalence rates were 3% and 22%, respectively, with 90% concordance with antigen or RT-PCR results. Conclusions and Relevance: In this study of SARS-CoV-2 incidence and transmission in CCCs and students' households, transmission within CCCs and from children infected at CCCs into households was low. These findings suggest that current testing and exclusion recommendations for SARS-CoV-2 in CCCs should be aligned with those for other respiratory viruses with similar morbidity and greater transmission to households.

Fracture patterns, associated injuries, management, and treatment outcomes of 530 pediatric mandibular fractures.

BACKGROUND: Mandibular fractures account for up to 48.8% of pediatric facial fractures; however, there are a wide range of available treatment modalities, and few studies describe trends in adverse outcomes of these injuries. This study describes fracture etiology, pattern, management, and treatment outcomes in pediatric mandibular fracture patients. METHODS: A retrospective review was performed of patients under 18 years of age who were evaluated for mandibular fractures at a pediatric level I trauma center between 2006 and 2021. Variables studied included demographics, etiology, medical history, associated facial fractures, other associated injuries, treatments, and outcomes. RESULTS: A total of 530 pediatric patients with 829 mandibular fractures were included in the analysis. Most isolated mandibular fractures were treated with physical therapy (PT) and rest (n=253, 47.7%). Patients with combination fractures, specifically those involving the parasymphysis and angle, were 2.63 times more likely to undergo surgical management compared to patients with a single facial fracture (p<0.0001). Older age (p<0.001), gender (p=0.042), mechanism (p=0.008) and cause of injury (p=0.002), as well as specific fractures (e.g., isolated angle (p=0.001)) were more associated with adverse outcomes. The odds of adverse outcomes were higher for patients treated with CREF or ORIF compared to conservative management (OR=1.8; 95% Cl 1.0-3.2 and OR=2.1; 95% Cl 1.2-3.5, respectively). CONCLUSION: Fracture type, mechanism of injury, and treatment modality in pediatric mandibular fractures are associated with distinct rates and types of adverse outcomes. Large scale studies characterizing these injuries are critical for guiding physicians in the management of these patients.

Vaccine effectiveness of recombinant and standard dose influenza vaccines against influenza related hospitalization using a retrospective test-negative design.

BACKGROUND: Relative effectiveness of various vaccine formulations provide important input for vaccine policy decisions and provider purchasing decisions. We used electronic databases to conduct a test-negative case control study to determine relative vaccine effectiveness (rVE) of recombinant influenza vaccine (RIV4) compared with standard dose vaccines (SD-IIV4) against influenza hospitalization. METHODS: Adults 18-64 and ≥65 years of age hospitalized in a large U.S. health system (19 hospitals) in 2018-2019 and 2019-2020 who were clinically tested for influenza using reverse transcription polymerase chain reaction (RT-PCR) assays were included. The hospital system electronic medical record (EMR) and the state immunization registry were used to confirm influenza vaccination. Propensity scores with inverse probability weighting were used to adjust for potential confounders and determine rVE. RESULTS: Of the 14,590 individuals included in the primary analysis, 3,338 were vaccinated with RIV4 and 976 were vaccinated with SD-IIV4, with the balance of 10,276 being unvaccinated. Most participants were white (80 %), most (70 %) had a high-risk condition, just over half were female (54 %) and age 65 years or older (53 %). Overall RIV4 rVE was significant when adjusted for propensity scores with inverse probability weights (rVE = 31; 95 % CI = 11 %, 46 %). Among younger adults (18-64 years-old), overall rVE of RIV4 was significant (rVE = 29; 95 % CI = 4 %, 47 %). CONCLUSIONS: Over all adults, both RIV4 and SD-IIV4 were effective against influenza hospitalization, with RIV4 providing better protection compared with SD-IIV4 overall, for females, younger adults, and those with no high-risk conditions.

Reduced effectiveness of repeat influenza vaccination: distinguishing among within-season waning, recent clinical infection, and subclinical infection.

Studies have reported that prior-season influenza vaccination is associated with higher risk of clinical influenza infection among vaccinees. This effect might arise from incomplete consideration of within-season waning and recent infection. Using data from the US Flu Vaccine Effectiveness (VE) Network (2011-2012 to 2018-2019 seasons), we found that repeat vaccinees were vaccinated earlier in a season by one week. After accounting for waning VE, repeat vaccinees were still more likely to test positive for A(H3N2) (OR=1.11, 95%CI:1.02-1.21) but not for influenza B or A(H1N1). We found that clinical infection influences individuals' decision to vaccinate in the following season while protecting against clinical infection of the same (sub)type. However, adjusting for recent clinical infections did not strongly influence the estimated effect of prior-season vaccination. In contrast, we found that adjusting for subclinical infection could theoretically attenuate this effect. Additional investigation is needed to determine the impact of subclinical infections on VE.

Blood Inflammatory Biomarkers Differentiate Inpatient and Outpatient Coronavirus Disease 2019 From Influenza.

Background: The ongoing circulation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) poses a diagnostic challenge because symptoms of coronavirus disease 2019 (COVID-19) are difficult to distinguish from other respiratory diseases. Our goal was to use statistical analyses and machine learning to identify biomarkers that distinguish patients with COVID-19 from patients with influenza. Methods: Cytokine levels were analyzed in plasma and serum samples from patients with influenza and COVID-19, which were collected as part of the Centers for Disease Control and Prevention's Hospitalized Adult Influenza Vaccine Effectiveness Network (inpatient network) and the US Flu Vaccine Effectiveness (outpatient network). Results: We determined that interleukin (IL)-10 family cytokines are significantly different between COVID-19 and influenza patients. The results suggest that the IL-10 family cytokines are a potential diagnostic biomarker to distinguish COVID-19 and influenza infection, especially for inpatients. We also demonstrate that cytokine combinations, consisting of up to 3 cytokines, can distinguish SARS-CoV-2 and influenza infection with high accuracy in both inpatient (area under the receiver operating characteristics curve [AUC] = 0.84) and outpatient (AUC = 0.81) groups, revealing another potential screening tool for SARS-CoV-2 infection. Conclusions: This study not only reveals prospective screening tools for COVID-19 infections that are independent of polymerase chain reaction testing or clinical condition, but it also emphasizes potential pathways involved in disease pathogenesis that act as potential targets for future mechanistic studies.

Vaccine effectiveness of recombinant and standard dose influenza vaccines against outpatient illness during 2018-2019 and 2019-2020 calculated using a retrospective test-negative design.

Newer influenza vaccine formulations have entered the market, but real-world effectiveness studies are not widely conducted until there is sufficient uptake. We conducted a retrospective test-negative case-control study to determine relative vaccine effectiveness (rVE) of recombinant influenza vaccine or RIV4, compared with standard dose vaccines (SD) in a health system with significant RIV4 uptake. Using the electronic medical record (EMR) and the Pennsylvania state immunization registry to confirm influenza vaccination, VE against outpatient medically attended visits was calculated. Immunocompetent outpatients ages 18-64 years seen in hospital-based clinics or emergency departments who were tested for influenza using reverse transcription polymerase chain reaction (RT-PCR) assays during the 2018-2019 and 2019-2020 influenza seasons were included. Propensity scores with inverse probability weighting were used to adjust for potential confounders and determine rVE. Among this mostly white and female cohort of 5,515 individuals, 510 were vaccinated with RIV4 and 557 were vaccinated with SD, with the balance of 4,448 (81%) being unvaccinated. Adjusted influenza VE estimates were 37% overall (95% CI = 27, 46), 40% (95% CI = 25, 51) for RIV4 and 35% (95% CI = 20, 47) for standard dose vaccines. Overall, rVE of RIV4 compared to SD was not significantly higher (11%; 95% CI = -20, 33). Influenza vaccines were moderately protective against medically attended outpatient influenza during the 2018-2019 and 2019-2020 seasons. Although the point estimates are higher for RIV4, the large confidence intervals around VE estimates suggest this study was underpowered to detect significant rVE of individual vaccine formulations.

Effect of mild COVID-19 on health-related quality of life.

Background: Little is known about the effects of a mild SARS-CoV-2 infection on health-related quality of life. Methods: This prospective observational study of symptomatic adults (18-87 years) who sought outpatient care for an acute respiratory illness, was conducted from 3/30/2020 to 4/30/2021. Participants completed the Short Form Health Survey (SF-12) at enrollment and 6-8 weeks later, to report their physical and mental health function levels as measured by the physical health and mental health composite scores (PHC and MHC, respectively). PHC and MHC scores for COVID-19 cases and non-COVID cases were compared using t-tests. Multivariable regression modeling was used to determine predictors of physical and mental health function at follow-up. Results: Of 2301 enrollees, 426 COVID-19 cases and 547 non-COVID cases completed both surveys. PHC improved significantly from enrollment to follow-up for both COVID-19 cases (5.4 ± 0.41; P < 0.001) and non-COVID cases (3.3 ± 0.32; P < 0.001); whereas MHC improved significantly for COVID-19 cases (1.4 ± 0.51; P < 0.001) and decreased significantly for non-COVID cases (-0.8 ± 0.37; P < 0.05). Adjusting for enrollment PHC, the most important predictors of PHC at follow-up included male sex (ß = 1.17; SE = 0.5; P = 0.021), having COVID-19 (ß = 1.99; SE = 0.54; P < 0.001); and non-white race (ß = -2.01; SE = 0.70; P = 0.004). Adjusting for enrollment MHC, the most important predictors of MHC at follow-up included male sex (ß = 1.92; SE = 0.63; P = 0.002) and having COVID-19 (ß = 2.42; SE = 0.67; P < 0.001). Conclusion: Both COVID-19 cases and non-COVID cases reported improved physical health function at 6-8 weeks' convalescence; whereas mental health function improved among COVID-19 cases but declined among non-COVID cases. Both physical and mental health functioning were significantly better among males with COVID-19 than females.

Incidence and visual outcomes of acute endophthalmitis post intravitreal injection of anti-vascular endothelial growth factors in a single referral center.

BACKGROUND: To describe the incidence and factors predicting visual outcome in patients with infectious endophthalmitis following intravitreal anti-VEGF injection. METHODS: Retrospective, single-site, cohort study. Patients with acute endophthalmitis within 6 weeks of intravitreal anti-VEGF injection who were referred to our practice after inciting injection or were injected by us between January 2010 and July 2017 were included. All patients received intravitreal antibiotics with either vitreous/anterior chamber tap (TAP) or pars plana vitrectomy. Visual outcomes pre/post treatment, baseline variables (age, gender, ocular disease) and cultures results were studied. RESULTS: Seventy eyes of 69 patients were included. Presenting VA was the strongest factor associated with final visual outcome after adjusting for other variables including culture status and baseline VA (p = .0002). Cultures were positive in 62.8% of eyes and were associated with worse visual outcome (p = .0087). Growth of Streptococcus or microorganisms other than coagulase negative Staphylococci (CNS) was also associated with worse prognosis, regardless of baseline and presenting VA (p = .0002). The crude incidence of post-injection endophthalmitis was 0.028% in our practice (40 eyes in 143,628 injections) during the study time. No significant difference was found between pre-filled bevacizumab versus ranibizumab or aflibercept drawn from a vial. CONCLUSIONS: In a large, single center, retrospective study, the incidence of acute endophthalmitis post anti-VEGF injection was relatively low. Worse visual acuity at presentation of endophthalmitis and growth of Streptococcus or organisms other than CNS were associated with the worst visual outcomes.

Population-based hospitalization burden estimates for respiratory viruses, 2015-2019.

BACKGROUND: Acute respiratory infections (ARIs) result in millions of illnesses and hundreds of thousands of hospitalizations annually in the United States. The responsible viruses include influenza, parainfluenza, human metapneumovirus, coronaviruses, respiratory syncytial virus (RSV), and human rhinoviruses. This study estimated the population-based hospitalization burden of those respiratory viruses (RVs) over 4 years, from July 1, 2015 to June 30, 2019, among adults ≥18 years of age for Allegheny County (Pittsburgh), Pennsylvania. METHODS: We used population-based statewide hospital discharge data, health system electronic medical record (EMR) data for RV tests, census data, and a published method to calculate burden. RESULTS: Among 26,211 eligible RV tests, 67.6% were negative for any virus. The viruses detected were rhinovirus/enterovirus (2552; 30.1%), influenza A (2,299; 27.1%), RSV (1082; 12.7%), human metapneumovirus (832; 9.8%), parainfluenza (601; 7.1%), influenza B (565; 6.7%), non-SARS-CoV-2 coronavirus (420; 4.9% 1.5 years of data available), and adenovirus (136; 1.6%). Most tests were among female (58%) and White (71%) patients with 60% of patients ≥65 years, 24% 50-64 years, and 16% 18-49 years. The annual burden ranged from 137-174/100,000 population for rhinovirus/enterovirus; 99-182/100,000 for influenza A; and 56-81/100,000 for RSV. Among adults <65 years, rhinovirus/enterovirus hospitalization burden was higher than influenza A; whereas the reverse was true for adults ≥65 years. RV hospitalization burden increased with increasing age. CONCLUSIONS: These virus-specific ARI population-based hospital burden estimates showed significant non-influenza burden. These estimates can serve as the basis for several areas of research that are essential for setting funding priorities and guiding public health policy.

Estimating the burden of adult hospitalized RSV infection including special populations.

BACKGROUND: Numerous studies in the U.S. have made estimates of the RSV burden among adults that vary widely due to differences in methodology, reliance on influenza surveillance, which does not adequately capture all RSV clinical symptoms, and lack of diagnostic methods to identify RSV when viral loads are low. Nevertheless, accurate burden estimates can inform healthcare planning, resource allocation and potentially, RSV vaccine policy. METHODS: A simple method combined with statewide and local hospitalization, medical record and U.S. Census data were used to estimate population-based RSV hospitalization burden among adults ages 18-64 years, ≥65 years, and including immunocompetent, immunocompromised and pregnant individuals during 2015-2018 for Allegheny County, Pennsylvania. Economic burden of hospitalization was estimated using state-provided average hospitalization charges for comparisons across patient groups. RESULTS: The largest burden was borne by adults ≥ 65 years of age whose rates per 100,000 population of that age group (939/100,000) were 7.0-9.0 times those of adults 18-64 years of age (118/100,000). Immunosuppressed patients bore the greatest relative burden of RSV hospitalizations (1,288-1,562/100,000 immunosuppressed individuals). RSV burden ranged from 0 to 808/100,000 pregnant women. Average total charges for RSV hospitalization in Allegheny County across all adults increased from $39 million in 2015-2016 to $57 million in 2016-2017 to $89 million in 2017-2018, due to both increased average charges for an acute respiratory hospitalization and increased numbers of RSV cases. CONCLUSIONS: These RSV burden estimates add to the body of knowledge to guide public health policy makers and offer a method for simply and easily producing population-based burden estimates.

Estimating the burden of adult hospitalized RSV infection using local and state data - methodology.

Respiratory syncytial virus (RSV) is becoming increasingly recognized as a serious threat to vulnerable population subgroups. This study describes the statistical analysis plan for a retrospective cohort study of adults hospitalized for acute respiratory infection (ARI) to estimate the population burden of RSV especially for groups such as the elderly, pregnant women and solid organ transplant patients. Disease burden estimates are essential for setting vaccine policy, e.g., should RSV vaccine become available, burden estimates may inform recommendations to prioritize certain high-risk groups. The study population is residents of Allegheny County, Pennsylvania ≥18 years of age who were hospitalized in Pennsylvania during the period September 1, 2015-August 31, 2018. Data sources will include U.S. Census, Pennsylvania Health Care Cost Containment Council (PHC4) and the electronic medical record for the health system to which the hospitals belong. The algorithm involves: 1) ARI-associated hospitalizations in PHC4 data; 2) adjustment for ARI hospitalizations among county residents but admitted to hospitals outside the county; and 3) RSV detections from respiratory viral panels. Key sensitivity analyses will adjust for undertesting for viruses in the fall and spring quarters. The results will be population-based estimates, stratified by age and risk groups. Adjusting hospitalization data using a multiplier method is a simple means to estimate the impact of RSV in a given area. This algorithm can be applied to other health systems and localities to estimate RSV and other respiratory pathogen burden in adults, to estimate burden following introduction of RSV vaccine and to make cost-effectiveness estimates.

Agreement among sources of adult influenza vaccination in the age of immunization information systems.

INTRODUCTION: Many vaccination studies rely on self-reported vaccination status, with its inherent biases. Accuracy of influenza vaccination self-report has been evaluated periodically, typically using the medical record as the gold standard. The burgeoning of electronic medical records (EMRs) and immunization information systems (IISs) and the rise of adult vaccine administration in community pharmacies suggest the need for a reevaluation of self-reported vaccination status. METHODS: Vaccination data from self-report, the state IIS, the health system EMR and other sources were compared for participants in outpatient and inpatient influenza vaccine effectiveness studies for four seasons (2016-2017 to 2019-2020). Agreement among the sources was calculated along with sensitivity and specificity. Tests for trend assessed changes in completeness of the Pennsylvania - Statewide IIS (PA-SIIS) data over time. RESULTS: With self-report as the gold standard, agreement with the local EMR, PA-SIIS, and all sources was 62%, 77% and 85%, respectively. Sensitivity of the EMR was 42% (95% CI = 41, 43) and specificity was 91% (90, 92). With PA-SIIS-as the gold standard, agreement with the local EMR and all sources was 77% and 78%, respectively. Sensitivity of all sources combined was 96% (95, 97) and specificity was (63% (62, 64). Capture of influenza vaccinations in the IIS has not consistently improved over time, with a significant increase among children (P = 0.001), no change among working-age adults and a decrease among older adults (P = 0.004). However, PA-SIIS provided the largest percentage of verified vaccines (69.3%) compared with EMR (43.3%) and other sources (12.4%). CONCLUSION: Both self-report and PA-SIIS are good estimates of actual vaccine uptake. When high accuracy data are required, such as for vaccine effectiveness studies, triangulation using multiple sources should be conducted.

Comparison of local influenza vaccine effectiveness using two methods.

BACKGROUND: In some settings, research methods to determine influenza vaccine effectiveness (VE) may not be appropriate because of cost, time constraints, or other factors. Administrative database analysis of viral testing results and vaccination history may be a viable alternative. This study compared VE estimates from outpatient research and administrative databases. METHODS: Using the test-negative, case-control design, data for 2017-2018 and 2018-2019 influenza seasons were collected using: 1) consent, specimen collection, RT-PCR testing and vaccine verification using multiple methods; and 2) an administrative database of outpatients with a clinical respiratory viral panel combined with electronic immunization records. Odds ratios for likelihood of influenza infection by vaccination status were calculated using multivariable logistic regression. VE = (1 - aOR) × 100. RESULTS: Research participants were significantly younger (P < 0.001), more often white (69% vs. 59%; P < 0.001) than non-white and less frequently enrolled through the emergency department (35% vs. 72%; P < 0.001) than administrative database participants. VE was significant against all influenza and influenza A in each season and both seasons combined (37-49%). Point estimate differences between methods were evident, with higher VE in the research database, but insignificant due to low sample sizes. When enrollment sites were separately analyzed, there were significant differences in VE estimates for all influenza (66% research vs. 46% administrative P < 0.001) and influenza A (67% research vs. 49% administrative; P < 0.001) in the emergency department. CONCLUSIONS: The selection of the appropriate method for determining influenza vaccine effectiveness depends on many factors, including sample size, subgroups of interest, etc., suggesting that research estimates may be more generalizable. Other advantages of research databases for VE estimates include lack of clinician-related selection bias for testing and less misclassification of vaccination status. The advantages of the administrative databases are potentially shorter time to VE results and lower cost.

Proposed clinical indicators for efficient screening and testing for COVID-19 infection using Classification and Regression Trees (CART) analysis.

The introduction and rapid transmission of SARS-CoV-2 in the United States resulted in methods to assess, mitigate, and contain the resulting COVID-19 disease derived from limited knowledge. Screening for testing has been based on symptoms typically observed in inpatients, yet outpatient symptoms may differ. Classification and regression trees recursive partitioning created a decision tree classifying participants into laboratory-confirmed cases and non-cases. Demographic and symptom data from patients ages 18-87 years enrolled from March 29-June 8, 2020 were included. Presence or absence of SARS-CoV-2 was the target variable. Of 832 tested, 77 (9.3%) tested positive. Cases significantly more often reported diarrhea (12 percentage points (PP)), fever (15 PP), nausea/vomiting (9 PP), loss of taste/smell (52 PP), and contact with a COVID-19 case (54 PP), but less frequently reported sore throat (-27 PP). The 4-terminal node optimal tree had sensitivity of 69%, specificity of 78%, positive predictive value of 20%, negative predictive value of 97%, and AUC of 76%. Among those referred for testing, negative responses to two questions could classify about half (49%) of tested persons with low risk for SARS-CoV-2 and would save limited testing resources. Outpatient symptoms of COVID-19 appear to be broader than the inpatient syndrome.Initial supplies of anticipated COVID-19 vaccines may be limited and administration of first such available vaccines may need to be prioritized for essential workers, the most vulnerable, or those likely to have a robust response to vaccine. Another priority group could be those not previously infected. Those who screen out of testing may be less likely to have been infected by SARS-CoV-2 virus thus may be prioritized for vaccination when supplies are limited.

Using Capture-Recapture Methods to Estimate Influenza Hospitalization Incidence Rates.

BACKGROUND: Accurate population estimates of disease incidence and burden are needed to set appropriate public health policy. The capture-recapture (C-R) method combines data from multiple sources to provide better estimates than is possible using single sources. METHODS: Data were derived from clinical virology test results and from an influenza vaccine effectiveness study from seasons 2016-2017 to 2018-2019. The Petersen C-R method was used to estimate the population size of influenza cases; these estimates were then used to calculate adult influenza hospitalization burden using a Centers for Disease Control and Prevention (CDC) multiplier method. RESULTS: Over all seasons, 343 influenza cases were reported in the clinical database and 313 in the research database. Fifty-nine cases (17%) reported in the clinical database were not captured in the research database, and 29 (9%) cases in the research database were not captured in the clinical database. Influenza hospitalizations were higher among vaccinated (58%) than the unvaccinated (35%) in the current season and were similar among unvaccinated (51%) and vaccinated (49%) in the previous year. Completeness of the influenza hospitalization capture was estimated to be 76%. The incidence rates for influenza hospitalizations varied by age and season and averaged 307-309 cases/100,000 adult population annually. CONCLUSION: Using Capture-Recapture methods with more than one database, along with a multiplier method with adjustments improves the population estimates of influenza disease burden compared with relying on a single data source.