Repeating the BinaxNOW antigen test for SARS-CoV-2 by two groups of readers within 30 minutes resulted in high concordance (98.9%) in 2,110 encounters. BinaxNOW test sensitivity was 77.2% (258/334) compared to real-time reverse transcription-polymerase chain reaction. Repeating antigen testing on the same day did not significantly improve test sensitivity while specificity remained high.Competing Interest StatementThe authors have declared no competing interest.Funding StatementThis work was funded by the Centers for Disease Control and Prevention.Author DeclarationsI confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.YesThe details of the IRB/oversight body that provided approval or exemption for the research described are given below:This activity was reviewed by CDC and was conducted consistent with applicable federal law and CDC policy. See e.g., 45 C.F.R. part 46.102(l)(2), 21 C.F.R. part 56; 42 U.S.C. 241(d); 5 U.S.C. 552a; 44 U.S.C. 3501 et seq.All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).YesI have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.YesData will be made available upon reasonable request.

Background Performance characteristics of SARS-CoV-2 antigen tests among children are limited despite the need for point-of-care testing in school and childcare settings. We describe children seeking SARS-CoV-2 testing at a community site and compare antigen test performance to real-time reverse transcription-polymerase chain reaction (RT-PCR) and viral culture.Methods Two anterior nasal specimens were self-collected for BinaxNOW antigen and RT-PCR testing, along with demographics, symptoms, and exposure information from individuals ≥5 years at a community testing site. Viral culture was attempted on residual antigen or RT-PCR positive specimens. Demographic and clinical characteristics, and the performance of SARS-CoV-2 antigen tests, were compared among children (<18 years) and adults.Results About one in ten included specimens were from children (225/2110); 16.4% (37/225) were RT-PCR positive. Cycle threshold values were similar among RT-PCR positive specimens from children and adults (22.5 vs 21.3, p=0.46) and among specimens from symptomatic and asymptomatic children (22.5 vs 23.2, p=0.39). Sensitivity of antigen test compared to RT-PCR was 73.0% (27/37) among specimens from children and 80.8% (240/297) among specimens from adults; among specimens from children, specificity was 100% (188/188), positive and negative predictive value were 100% (27/27) and 94.9% (188/198) respectively. Virus was isolated from 51.4% (19/37) of RT-PCR positive pediatric specimens; all 19 had positive antigen test results.Conclusions With lower sensitivity relative to RT-PCR, antigen tests may not diagnose all positive COVID-19 cases; however, antigen testing identified children with live SARS-CoV-2 virus.Competing Interest StatementThe authors have declared no competing interest.Funding StatementThis work was supported by the Centers for Disease Control and Prevention.Author DeclarationsI confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.YesThe details of the IRB/oversight body that provided approval or exemption for the research described are given below:This activity was reviewed by CDC and was conducted consistent with applicable federal law and CDC policy. See e.g., 45 C.F.R. part 46.102(l)(2), 21 C.F.R. part 56; 42 U.S.C. 241(d); 5 U.S.C. 552a; 44 U.S.C. 3501 et seq.All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).YesI have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.YesThe datasets generated during and analyzed during the current study are available from the corresponding author on reasonable request.

Children are capable of initiating COVID-19 transmission into households, but many questions remain about the impact of vaccination on transmission. Data from a COVID-19 Delta variant outbreak at an overnight camp in Texas during June 23-27, 2021 were analyzed. The camp had 451 attendees, including 364 youths aged <18 years and 87 adults. Detailed interviews were conducted with 92 (20.4%) of consenting attendees and 117 household members of interviewed attendees with COVID-19. Among 450 attendees with known case status, the attack rate was 41%, including 42% among youths; attack rates were lower among vaccinated (13%) than among unvaccinated youths (48%). The secondary attack rate was 51% among 115 household contacts of 55 interviewed index patients. Secondary infections occurred in 67% of unvaccinated household members and 33% of fully or partially vaccinated household members. Analyses suggested that household member vaccination and camp attendee masking at home protected against household transmission.

The B.1.1.529 (Omicron) variant, first detected in November 2021, was responsible for a surge in U.S. infections with SARS-CoV-2, the virus that causes COVID-19, during December 2021-January 2022 (1). To investigate the effectiveness of prevention strategies in household settings, CDC partnered with four U.S. jurisdictions to describe Omicron household transmission during November 2021-February 2022. Persons with sequence-confirmed Omicron infection and their household contacts were interviewed. Omicron transmission occurred in 124 (67.8%) of 183 households. Among 431 household contacts, 227 were classified as having a case of COVID-19 (attack rate [AR] = 52.7%).(†) The ARs among household contacts of index patients who had received a COVID-19 booster dose, of fully vaccinated index patients who completed their COVID-19 primary series within the previous 5 months, and of unvaccinated index patients were 42.7% (47 of 110), 43.6% (17 of 39), and 63.9% (69 of 108), respectively. The AR was lower among household contacts of index patients who isolated (41.2%, 99 of 240) compared with those of index patients who did not isolate (67.5%, 112 of 166) (p-value <0.01). Similarly, the AR was lower among household contacts of index patients who ever wore a mask at home during their potentially infectious period (39.5%, 88 of 223) compared with those of index patients who never wore a mask at home (68.9%, 124 of 180) (p-value <0.01). Multicomponent COVID-19 prevention strategies, including up-to-date vaccination, isolation of infected persons, and mask use at home, are critical to reducing Omicron transmission in household settings.

BACKGROUND: Performance characteristics of SARS-CoV-2 antigen tests among children are limited despite the need for point-of-care testing in school and childcare settings. We describe children seeking SARS-CoV-2 testing at a community site and compare antigen test performance to real-time reverse transcription-polymerase chain reaction (RT-PCR) and viral culture. METHODS: Two anterior nasal specimens were self-collected for BinaxNOW antigen and RT-PCR testing, along with demographics, symptoms, and exposure information from individuals ≥5 years at a community testing site. Viral culture was attempted on residual antigen or RT-PCR-positive specimens. Demographic and clinical characteristics, and the performance of SARS-CoV-2 antigen tests, were compared among children (<18 years) and adults. RESULTS: About 1 in 10 included specimens were from children (225/2110); 16.4% (37/225) were RT-PCR-positive. Cycle threshold values were similar among RT-PCR-positive specimens from children and adults (22.5 vs 21.3, P = .46) and among specimens from symptomatic and asymptomatic children (22.5 vs 23.2, P = .39). Sensitivity of antigen test compared to RT-PCR was 73.0% (27/37) among specimens from children and 80.8% (240/297) among specimens from adults; among specimens from children, specificity was 100% (188/188), positive and negative predictive values were 100% (27/27) and 94.9% (188/198), respectively. Virus was isolated from 51.4% (19/37) of RT-PCR-positive pediatric specimens; all 19 had positive antigen test results. CONCLUSIONS: With lower sensitivity relative to RT-PCR, antigen tests may not diagnose all positive COVID-19 cases; however, antigen testing identified children with live SARS-CoV-2 virus.

We evaluated the performance of self-collected anterior nasal swab (ANS) and saliva samples compared with healthcare worker-collected nasopharyngeal swab specimens used to test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We used the same PCR diagnostic panel to test all self-collected and healthcare worker-collected samples from participants at a public hospital in Atlanta, Georgia, USA. Among 1,076 participants, 51.9% were men, 57.1% were >50 years of age, 81.2% were Black (non-Hispanic), and 74.9% reported >1 chronic medical condition. In total, 8.0% tested positive for SARS-CoV-2. Compared with nasopharyngeal swab samples, ANS samples had a sensitivity of 59% and saliva samples a sensitivity of 68%. Among participants tested 3-7 days after symptom onset, ANS samples had a sensitivity of 80% and saliva samples a sensitivity of 85%. Sensitivity varied by specimen type and patient characteristics. These findings can help physicians interpret PCR results for SARS-CoV-2.

OBJECTIVE: To evaluate the risk of adverse birth outcomes among adults who use electronic cigarettes (e-cigarettes) before and during pregnancy. METHODS: Data from the 2016-2018 PRAMS (Pregnancy Risk Assessment Monitoring System) were used to assess the association between e-cigarette use during the 3 months before and last 3 months of pregnancy among 79,176 individuals with a recent live birth and the following birth outcomes: preterm birth, small for gestational age, and low birth weight (LBW). Adjusted prevalence ratios were generated using average marginal predictions from multivariable logistic regression models. Models were stratified by prenatal combustible cigarette smoking and frequency of e-cigarette use (daily or less than daily use). RESULTS: In the 3 months before pregnancy, 2.7% (95% CI 2.6-2.9%) of respondents used e-cigarettes; 1.1% (95% CI 1.0-1.2%) used e-cigarettes during the last 3 months of pregnancy. Electronic cigarette use before pregnancy was not associated with adverse birth outcomes. Electronic cigarette use during pregnancy was associated with increased prevalence of LBW compared with nonuse (8.1% vs 6.1%; adjusted prevalence ratio 1.33; 95% CI 1.06-1.66). Among respondents who did not also smoke combustible cigarettes during pregnancy (n=72,256), e-cigarette use was associated with higher prevalence of LBW (10.6%; adjusted prevalence ratio 1.88; 95% CI 1.38-2.57) and preterm birth (12.4%; adjusted prevalence ratio 1.69; 95% CI 1.20-2.39). When further stratified by frequency of e-cigarette use, associations were seen only for daily users. CONCLUSION: E-cigarette use during pregnancy, particularly when used daily by individuals who do not also smoke combustible cigarettes, is associated with adverse birth outcomes.

Repeating the BinaxNOW antigen test for SARS-CoV-2 by two groups of readers within 30 minutes resulted in high concordance (98.9%) in 2,110 encounters. BinaxNOW test sensitivity was 77.2% (258/334) compared to real-time reverse transcription-polymerase chain reaction. Same day antigen testing did not significantly improve test sensitivity while specificity remained high.

BACKGROUND: To inform prevention strategies, we assessed the extent of SARS-CoV-2 transmission and settings in which transmission occurred in a Georgia public school district. METHODS: During December 1, 2020-January 22, 2021, SARS-CoV-2-infected index cases and their close contacts in schools were identified by school and public health officials. For in-school contacts, we assessed symptoms and offered SARS-CoV-2 RT-PCR testing; performed epidemiologic investigations and whole-genome sequencing to identify in-school transmission; and calculated secondary attack rate (SAR) by school setting (e.g., sports, elementary school classroom), index case role (i.e., staff, student), and index case symptomatic status. RESULTS: We identified 86 index cases and 1,119 contacts, 688 (63.1%) of whom received testing. Fifty-nine (8.7%) of 679 contacts tested positive; 15 (17.4%) of 86 index cases resulted in ≥2 positive contacts. Among 55 persons testing positive with available symptom data, 31 (56.4%) were asymptomatic. Highest SAR were in indoor, high-contact sports settings (23.8%, 95% confidence interval [CI] 12.7, 33.3), staff meetings/lunches (18.2%, CI 4.5-31.8), and elementary school classrooms (9.5%, CI 6.5-12.5). SAR was higher for staff (13.1%, CI 9.0-17.2) versus student index cases (5.8%, CI 3.6-8.0) and for symptomatic (10.9%, CI 8.1-13.9) versus asymptomatic index cases (3.0%, CI 1.0-5.5). CONCLUSIONS: Indoor sports may pose a risk to the safe operation of in-person learning. Preventing infection in staff members, through measures that include COVID-19 vaccination, is critical to reducing in-school transmission. Because many positive contacts were asymptomatic, contact tracing should be paired with testing, regardless of symptoms.

BACKGROUND: Although many viral respiratory illnesses are transmitted within households, the evidence base for SARS-CoV-2 is nascent. We sought to characterize SARS-CoV-2 transmission within US households and estimate the household secondary infection rate (SIR) to inform strategies to reduce transmission. METHODS: We recruited laboratory-confirmed COVID-19 patients and their household contacts in Utah and Wisconsin during March 22-April 25, 2020. We interviewed patients and all household contacts to obtain demographics and medical histories. At the initial household visit, 14 days later, and when a household contact became newly symptomatic, we collected respiratory swabs from patients and household contacts for testing by SARS-CoV-2 rRT-PCR and sera for SARS-CoV-2 antibodies testing by enzyme-linked immunosorbent assay (ELISA). We estimated SIR and odds ratios (OR) to assess risk factors for secondary infection, defined by a positive rRT-PCR or ELISA test. RESULTS: Thirty-two (55%) of 58 households had evidence of secondary infection among household contacts. The SIR was 29% (n = 55/188; 95% confidence interval [CI]: 23-36%) overall, 42% among children (<18 years) of the COVID-19 patient and 33% among spouses/partners. Household contacts to COVID-19 patients with immunocompromised conditions had increased odds of infection (OR: 15.9, 95% CI: 2.4-106.9). Household contacts who themselves had diabetes mellitus had increased odds of infection (OR: 7.1, 95% CI: 1.2-42.5). CONCLUSIONS: We found substantial evidence of secondary infections among household contacts. People with COVID-19, particularly those with immunocompromising conditions or those with household contacts with diabetes, should take care to promptly self-isolate to prevent household transmission.

BACKGROUND AND OBJECTIVES: Limited data exist on severe acute respiratory syndrome coronavirus 2 in children. We described infection rates and symptom profiles among pediatric household contacts of individuals with coronavirus disease 2019. METHODS: We enrolled individuals with coronavirus disease 2019 and their household contacts, assessed daily symptoms prospectively for 14 days, and obtained specimens for severe acute respiratory syndrome coronavirus 2 real-time reverse transcription polymerase chain reaction and serology testing. Among pediatric contacts (<18 years), we described transmission, assessed the risk factors for infection, and calculated symptom positive and negative predictive values. We compared secondary infection rates and symptoms between pediatric and adult contacts using generalized estimating equations. RESULTS: Among 58 households, 188 contacts were enrolled (120 adults; 68 children). Secondary infection rates for adults (30%) and children (28%) were similar. Among households with potential for transmission from children, child-to-adult transmission may have occurred in 2 of 10 (20%), and child-to-child transmission may have occurred in 1 of 6 (17%). Pediatric case patients most commonly reported headache (79%), sore throat (68%), and rhinorrhea (68%); symptoms had low positive predictive values, except measured fever (100%; 95% confidence interval [CI]: 44% to 100%). Compared with symptomatic adults, children were less likely to report cough (odds ratio [OR]: 0.15; 95% CI: 0.04 to 0.57), loss of taste (OR: 0.21; 95% CI: 0.06 to 0.74), and loss of smell (OR: 0.29; 95% CI: 0.09 to 0.96) and more likely to report sore throat (OR: 3.4; 95% CI: 1.04 to 11.18). CONCLUSIONS: Children and adults had similar secondary infection rates, but children generally had less frequent and severe symptoms. In two states early in the pandemic, we observed possible transmission from children in approximately one-fifth of households with potential to observe such transmission patterns.

BACKGROUND: Improved understanding of SARS-CoV-2 spectrum of disease is essential for clinical and public health interventions. There are limited data on mild or asymptomatic infections, but recognition of these individuals is key as they contribute to viral transmission. We describe the symptom profiles from individuals with mild or asymptomatic SARS-CoV-2 infection. METHODS: From March 22 to April 22, 2020 in Wisconsin and Utah, we enrolled and prospectively observed 198 household contacts exposed to SARS-CoV-2. We collected and tested nasopharyngeal (NP) specimens by RT-PCR two or more times during a 14-day period. Contacts completed daily symptom diaries. We characterized symptom profiles on the date of first positive RT-PCR test and described progression of symptoms over time. RESULTS: We identified 47 contacts, median age 24 (3-75) years, with detectable SARS-CoV-2 by RT-PCR. The most commonly reported symptoms on the day of first positive RT-PCR test were upper respiratory (n=32, 68%) and neurologic (n=30, 64%); fever was not commonly reported (n=9, 19%). Eight (17%) individuals were asymptomatic at the date of first positive RT-PCR collection; two (4%) had preceding symptoms that resolved and six (13%) subsequently developed symptoms. Children less frequently reported lower respiratory symptoms (age <18: 21%, age 18-49: 60%, age 50+ years: 69%; p=0.03). CONCLUSIONS: Household contacts with lab-confirmed SARS-CoV-2 infection reported mild symptoms. When assessed at a single time-point, several contacts appeared to have asymptomatic infection; however, over time all developed symptoms. These findings are important to inform infection control, contact tracing, and community mitigation strategies.

CDC, the Food and Drug Administration (FDA), state and local health departments, and public health and clinical stakeholders are investigating a nationwide outbreak of e-cigarette, or vaping, product use-associated lung injury (EVALI) (1). CDC has published recommendations for health care providers regarding EVALI (2-4). Recently, researchers from Utah and New York published proposed diagnosis and treatment algorithms for EVALI (5,6). EVALI remains a diagnosis of exclusion because, at present, no specific test or marker exists for its diagnosis, and evaluation should be guided by clinical judgment. Because patients with EVALI can experience symptoms similar to those associated with influenza or other respiratory infections (e.g., fever, cough, headache, myalgias, or fatigue), it might be difficult to differentiate EVALI from influenza or community-acquired pneumonia on initial assessment; EVALI might also co-occur with respiratory infections. This report summarizes recommendations for health care providers managing patients with suspected or known EVALI when respiratory infections such as influenza are more prevalent in the community than they have been in recent months (7). Recommendations include 1) asking patients with respiratory, gastrointestinal, or constitutional symptoms about the use of e-cigarette, or vaping, products; 2) evaluating those suspected to have EVALI with pulse oximetry and obtaining chest imaging, as clinically indicated; 3) considering outpatient management for clinically stable EVALI patients who meet certain criteria; 4) testing patients for influenza, particularly during influenza season, and administering antimicrobials, including antivirals, in accordance with established guidelines; 5) using caution when considering prescribing corticosteroids for outpatients, because this treatment modality has not been well studied among outpatients, and corticosteroids could worsen respiratory infections; 6) recommending evidence-based treatment strategies, including behavioral counseling, to help patients discontinue using e-cigarette, or vaping, products; and 7) emphasizing the importance of annual influenza vaccination for all persons aged >/=6 months, including patients who use e-cigarette, or vaping products.

OBJECTIVES: To explore women's knowledge, attitudes, and beliefs about adverse outcomes associated with smoking during pregnancy and which outcomes might motivate cessation; to explore reactions to graphic warnings depicting 2 adverse outcomes. METHODS: Twelve focus groups were conducted with women of childbearing age who were current smokers. RESULTS: Participants had low to moderate awareness of many outcomes and believed it was acceptable to smoke in the first trimester before knowledge of pregnancy. Perceived susceptibility to outcomes was low. Motivators included risk-focused information, especially serious risks to the baby (eg, stillbirth, SIDS). Graphic warnings produced strong reactions, especially the warning with a real photo. CONCLUSIONS: Despite barriers to reducing rates of smoking during pregnancy, educational information and photos depicting babies' risks could motivate women to quit.

OBJECTIVE: To assess current and former smokers' reactions to US warning labels as a baseline for comparison to new labels. METHODS: The mail-in Consumer- Styles survey was sent to a representative sample of US adult consumers in 2010 (N = 10,328). RESULTS: Among current smokers, 51.5% (95% CI: 47.5-55.5) reported that they had 'never/rarely' seen or looked closely at the labels in the past 30 days. Current smokers (91.1%) reported that warning labels never stopped them from having a cigarette (95% CI: 89.1- 93.1) and that the labels had no effect on their likelihood of quitting (75.5%; 95% CI: 71.6-79.4). CONCLUSIONS: Current warning labels do not make smokers think about the risks of smoking or have an effect on their likelihood of forgoing cigarettes or quitting.

OBJECTIVE: To determine prevalence of smoking, quit ratios, and home smoking rules among Hispanics residing in colonias in El Paso, Texas. METHODS: Face-to-face interviews with 1485 Hispanic adults. GeoFrame field enumeration methods were used to develop a sampling frame from households in randomly selected colonias. RESULTS: The overall percent of current cigarette smoking was 14.6% (95% CI 12.4 to 16.8); Over 55% of smokers reported a serious quit attempt. Participants overwhelmingly reported that smoking was not allowed in their homes. CONCLUSIONS: Prevalence estimates for current smoking and restriction in the home were similar to those reported for recent national surveys.

OBJECTIVES: We sought to modify an instrument and to use it to collect information on smoking knowledge, attitudes, beliefs, and behaviors among Hispanics/Latinos, and to adapt survey methods to obtain high participation levels. METHODS: Promotoras (outreach workers) conducted face-to-face interviews with 1485 Hispanic adults (July 2007-April 2008). The project team used Geo-Frame field enumeration methods to develop a sampling frame from households in randomly selected colonias (residential areas along the Texas-Mexico border that may lack some basic necessities (e.g. portable water), in El Paso, Texas. RESULTS: The revised questionnaire included 36 unchanged items from the State Adult Tobacco Survey, 7 modified items, and 17 new items focusing on possible culturally specific quitting methods, secondhand smoke issues, and attitudes and knowledge about tobacco use that might be unique for Hispanic/Latino groups. The eligibility rate was 90.2%, and the conservative combined completed screener and interview response rate was 80.0%. CONCLUSIONS: Strategic, targeted, carefully designed methods and surveys can achieve high reach and response rates in hard-to-reach populations. Similar procedures could be used to obtain cooperation of groups who may not be accessible with traditional methods.

Current cigarette smoking combined with ever use of other tobacco products (lifetime polytobacco use) is important to examine as users may be at greater risk for illicit drug use, nicotine addiction, and adverse health outcomes. We determined estimates and patterns of lifetime polytobacco use and conducted multivariable analyses to determine demographic, family and friend, psychosocial, and lifestyle factors associated with use among a sample of Canadian young adults. Overall prevalence was 36.3% for current cigarette use; 10.1% for current cigarette use only and 26.2% for lifetime polytobacco use. Among polytobacco users, current cigarette use and ever cigar use was most frequent (67.2%). For males, the final model contained demographic, family and friends, and lifestyle factors. For females, the final model also included psychosocial factors. Illicit drug use was the strongest significant predictor for lifetime polytobacco use among males. We found gender specific differences when comparing lifetime polytobacco users to current cigarette-only users, in particular; male lifetime polytobacco users were more likely to use drugs and alcohol. Interventions focusing on individual substances should consider addressing combinations of use.