Abstract Background While the epidemiology of acute respiratory illness (ARI) among those seeking medical care is well studied, less is known about ARI in non-medical settings (e.g., schools), especially in individuals not exhibiting ARI symptoms. We examined respiratory virus detections among asymptomatic students and staff in a public school district.Table 1:Frequency of Respiratory Viral Detection Among Respiratory Surveillance Swabs Collected from Students/Staff Reporting No Recent Acute Respiratory Illness SymptomsFigure 1:Viral Positivity Among Respiratory Surveillance Swabs Collected from Students/Staff Reporting No Recent Acute Respiratory Illness Symptoms, by Collection Month and School YearNote: Viral positivity defined as detection of ≥1 respiratory virus from a respiratory surveillance swab. Testing for the 2023-24 school year began in November 2023. Testing for the 2024-25 school year is ongoing. Methods Knowledge of Infectious Diseases in Schools (School KIDS) is a prospective respiratory virus surveillance program in a preK-12th grade public school district in Kansas City, MO. From 2023—2025, student/staff participants self-collected monthly anterior nares swabs. Specimens were tested by multiplex PCR for adenovirus, human metapneumovirus, influenza, parainfluenza, respiratory syncytial virus, rhinovirus/enterovirus (RV/EV), seasonal coronaviruses (sCoV), and SARS-CoV-2. Prior to specimen collection, participants were asked about ARI symptoms (cough, fever, congestion, runny nose, shortness of breath, sore throat, and wheezing) in the past 7 days. Specimens from participants with no ARI symptoms (i.e., asymptomatic) were included in the analysis. Differences between positive (detecting ≥1 virus) and negative specimens were assessed. We used multilevel logistic models to compare odds of viral detection adjusting for school-level and season.Figure 2:Proportion of Virus Detections in Respiratory Swabs Collected from Students/Staff Reporting No Recent Acute Respiratory Illness Symptoms by Specific VirusNote: the numbers above each bar indicate the frequency of positive detections. Of the 512 positive swabs, 27 had more than one virus detected. Therefore, total detected viruses were 543.Table 2:Adjusted Odds of Detecting ≥1 Respiratory Virus Among Respiratory Surveillance Swabs Collected from Students/Staff Reporting No Recent Acute Respiratory Illness Symptoms Results Of 5398 specimens collected from 2023—2025, 3502 (65%) were from asymptomatic participants. Viral positivity among these specimens was 15% (n=512/3502). Viral positivity varied by school level (Table 1) but overall showed little seasonal variation (Figure 1). Most commonly detected viruses were RV/EV (56%), sCoV (23%) and SARS-CoV-2 (7%) (Figure 2). Compared with staff from middle/high-schools, increased odds of viral positivity were observed for preK (OR: 18.9 4.9, 72.4), elementary (OR: 5.7 3.0, 10.7), and middle-school students (OR: 2.4 1.2, 4.7) (Table 2). Conclusion Viral detections in asymptomatic students and staff were frequent (15%), with relatively consistent positivity (for any virus) throughout the school year. Public health strategies to mitigate respiratory viral transmission including cough/hand hygiene and staying home while sick, among others, may reduce both symptomatic and asymptomatic transmission Disclosures Brian R. Lee, PhD, MPH, Merck: Grant/Research Support Rangaraj Selvarangan, PhD, Altona: Grant/Research Support|Biomerieux: Advisor/Consultant|Biomerieux: Grant/Research Support|Biomerieux: Honoraria|Cepheid: Grant/Research Support|Hologic: Grant/Research Support|Hologic: Honoraria|Meridian: Grant/Research Support|Qiagen: Grant/Research Support
Lee et al. (2026) studied this question.