Pharyngitis is one of the most common medical conditions for UC visits and can be caused by a variety of viral or bacterial pathogens. Diagnostic uncertainty can lead to provider/patient frustration and inappropriate under-/over-prescribing of antimicrobials. SPOTFIRE ST (Sore Throat) is a novel, rapid, CLIA-waived POC testing platform for 14 common bacterial and viral pathogens; however, the detection characteristics of a multi-plex PCR test in a real-world UC setting has not been evaluated fully.Figure 1.Age and Gender distribution of participants.Table 1.Pathogen Detection Results by Age Group. This prospective study was performed during peak respiratory illness season (Dec ‘24-Mar ‘25) at a single UC center (Madison, WI). Pediatric patients (PP) with fever (1-2 y) or pharyngitis (3-17 y) and adult patients (AP) with immunocompromising conditions or comorbid conditions with pharyngitis were eligible. After informed consent, research staff collected clinical information and an oropharyngeal swab from each participant. Specimens were tested using the SPOTFIRE ST machine according to instructions. Test results and survey data were recorded and analyzed using STATA (StataCorp, LLC).Table 2.Single Detection and Codetections Among Adult and Pediatric Patients. 200 (117 PP, 83 AP, Fig 1) patients were enrolled, of which 149 (74.5%) had 208 total detections. PP had significantly higher detection rates (85% vs. 60%, p< 0.001). Table 1 lists pathogen results by age group. PP were statistically more likely to have Group A Streptococcus (GAS), influenza B, and M. pneumoniae infections. Multiple pathogen detection was common (n=50 patients). PP were significantly more likely to have codetections (38% vs 7%, p< 0.001), including multi-virus and bacteria-virus codetections (Table 2). Pathogens with specific antimicrobial treatments (influenza, GAS) were significantly more likely to be found in PP (68% vs. 28%, p< 0.001). SPOTFIRE ST demonstrated high detection rates in patients presenting to an UC with acute pharyngitis. PP had significantly higher detection rates, differences in pathogen detection (GAS, influenza B, and M. pneumoniae), higher rates of co-detections, and higher rates of pathogen detections treatable with specific antimicrobials. This test may be most useful in PP to guide specific antimicrobial therapy and in AP to prevent unnecessary therapy for viral diseases. Alexander J. Lepak, MD, FIDSA, BioMerieux: Grant/Research Support Jonathan Temte, MD, PhD, bioMérieux: Grant/Research Support

PURPOSE:This study aims to identify symptoms that predict a high likelihood of viral infection, so these patients could be triaged for home care to avoid antibiotics. METHODS:We recruited adults presenting to US primary or urgent care sites with a chief complaint of cough and symptoms consistent with LRTI. Data collected included demographics, comorbidities, symptoms, and 46 viral and bacterial respiratory pathogens by PCR. Chi-square tests were done to evaluate the association between individual symptoms and viral versus bacterial infections. Symptoms with a p < 0.10 for the association were retained for logistic regression. We created four regression models using stepwise backward elimination at p < 0.20, with viral infection, bacterial infection, and mixed infection as the dependent variables. A simple risk score was created assigning positive and negative points for viral and bacterial symptoms. RESULTS:We enrolled 718 adults with acute cough and obtained valid PCR specimens for 618. Four symptoms were significantly more likely with viral infections and less common in bacterial: coryza, confusion, fever, and chest congestion. Three symptoms were more likely with bacterial infections and less likely with viral infections: presence of sputum, sputum that is colored, and double-sickening (feeling better but then worsening). A simple risk score identified patients with a low (29%), moderate (56%), or high (79%) likelihood of having only viral pathogens detected. CONCLUSIONS:Seven symptoms were identified that could help primary care clinicians distinguish between viral and bacterial LRTI. A simple risk score is proposed but requires prospective validation.

Background:Pharyngitis is a frequent cause of urgent care (UC) visits. The SPOTFIRE Sore Throat (SPOTFIRE ST) panel is a Clinical Laboratory Improvement Amendments-waived point-of-care test capable of detecting 14 common bacterial and viral pathogens from an oropharyngeal swab. We evaluated detection characteristics, antimicrobial prescribing, and clinician and patient perceptions associated with SPOTFIRE ST testing. Methods:We conducted a prospective, single-center study at an academic UC clinic. Eligible participants included 1-2-year-olds with fever, 3-17-year-olds with acute pharyngitis, and adult patients with acute pharyngitis and either immunocompromising or comorbid conditions. Clinical variables were collected, and specimens were tested according to SPOTFIRE ST instructions. Clinicians completed a pre-implementation survey, and clinicians and patients completed a postimplementation survey to assess perceptions and satisfaction with the test. Results:At least 1 detected pathogen occurred in 149/200 (74.5%) patients. Compared with adults, pediatric patients had higher detections (85% vs 60%; P < .001), statistically significantly higher detections of specifically Group A Streptococcus, influenza B, and M. pneumoniae, and higher detections of a pathogen with specific antimicrobial treatment (68% vs 28%; P < .001). Antibiotics were prescribed in only 7% of cases when a virus was detected. Stakeholders reported high satisfaction with SPOTFIRE ST testing and thought it useful in guiding clinical decisions. Conclusions:SPOTFIRE ST testing demonstrated a high proportion of detections with distinct differences between pediatric and adult patients with acute pharyngitis. The detection characteristics and high satisfaction indicate that this test is likely to be valued by clinicians and patients and may improve clinical assessment and antimicrobial prescribing. Clinical Trials Registration:ClinicalTrials.gov identifier. NCT06713642.

INTRODUCTION:The association of C-reactive protein (CRP) with cough duration and severity has not been evaluated in a contemporary US population of patients with acute lower respiratory tract infection (LRTI). METHODS:We identified outpatients with less than 2 weeks of cough plus at least one lower respiratory or systemic symptom. The duration of illness, demographics, signs, symptoms, CRP and PCR for 46 pathogens were assessed. Duration and severity of cough were tracked using a paper diary plus responses to text messages. We classified CRP as low (<5 mg/L), moderate (5-19 mg/L) and high (≥20 mg/L). RESULTS:A total of 575 patients had valid CRP data and 503 had both valid CRP and PCR data. Patients with a CRP ≥20 mg/L were more likely (p<0.001) to have any bacterial detection (34.4%) or a mixed detection (37.7%) than viral infection (19.7%) or no detection (7.2%). Patients with elevated CRP were also more likely to have a likely bacterial pathogen detected (61.2% vs 37.8%, p<0.001) and were more likely to have a clinician label their illness as moderate or severe (53.7% vs 26.0%, p<0.001). Patients with a CRP ≥20 mg/L had a longer duration of illness than those with a lower CRP (18.5 vs 16.1 days, p=0.026) as well as a greater overall severity of cough (29.9 vs 23.0 points, p=0.001). In multivariable analysis, CRP ≥20 mg/L was the strongest independent predictor of a likely bacterial pathogen (adjusted OR 3.21, 95% CI 1.61 to 6.40). DISCUSSION:CRP ≥20 mg/L has a strong, independent association with the presence of bacterial pathogen in patients with acute LRTI and predicts longer duration and severity of illness. Further research is warranted to understand the impact of CRP on antibiotic prescribing and patient outcomes.

School-based outbreaks often precede increased incidence of acute respiratory infections in the greater community. We conducted acute respiratory infection surveillance among children to elucidate commonly detected pathogens in school settings and their unique characteristics and epidemiological patterns. The ORegon CHild Absenteeism due to Respiratory Disease Study (ORCHARDS) is a longitudinal, laboratory-supported, school-based, acute respiratory illness (ARI) surveillance study designed to evaluate the utility of cause-specific student absenteeism monitoring for early detection of increased activity of influenza and other respiratory viruses in schools from kindergarten through 12th grade. Eligible participants with ARIs provided demographic, epidemiologic, and symptom data, along with a nasal swab or oropharyngeal specimen. Multipathogen testing using reverse-transcription polymerase chain reaction (RT-PCR) was performed on all specimens for 18 respiratory viruses and 2 atypical bacterial pathogens (Chlamydia pneumoniae and Mycoplasma pneumoniae). Between 5 January 2015 and 9 June 2023, 3498 children participated. Pathogens were detected in 2455 of 3498 (70%) specimens. Rhinovirus/enteroviruses (36%) and influenza viruses A/B (35%) were most commonly identified in positive specimens. Rhinovirus/enteroviruses and parainfluenza viruses occurred early in the academic year, followed by seasonal coronaviruses, RSV, influenza viruses A/B, and human metapneumovirus. Since its emergence in 2020, SARS-CoV-2 was detected year-round and had a higher median age than the other pathogens. A better understanding of the etiologies, presentations, and patterns of pediatric acute respiratory infections can help inform medical and public health system responses.

Objectives: To describe the symptoms, duration, severity, and microbiology of lower respiratory tract infection (LRTI) in outpatients. Methods: Prospective cohort study of adults in US primary or urgent care with a chief complaint of cough and symptoms consistent with LRTI. Baseline data included demographics, signs, symptoms, and PCR for 46 viruses and bacteria. The severity of symptoms reported for <= 28 days follow-up via diary and text message. The Bronchitis severity score assessed severity at baseline; overall severity was defined as the area under the symptom severity curve. Results: Of 718 patients with complete baseline data, 618 had valid PCR results, and 443 were followed until symptoms resolved. Of those with valid PCR, 100 (16.2%) had 1+ viruses detected, 211 (34.1%) had 1+ bacteria, and 168 (27.2%) had both. Symptoms more likely with viral or mixed infection included feverishness (36.7-38.4% vs. 18.5%), chills or sweats (36.0-38.1% vs. 17.9%), being generally unwell (78.2- 81.3% vs. 64.9%), and myalgias (42.7-48.2% vs. 28.6%). Coloured sputum (42.9% vs. 23.2-29.5%) was more common with a bacterial infection. The mean duration of cough was 14.7 days with viruses (95% CI: 13.2-16.2), 17.3 with bacteria (95% CI: 15.9-18.6), 16.9 with mixed infection (95% CI: 15.2-18.6), and 18.4 with no detection (95% CI: 16.1-20.8). Overall severity of cough was lower for viral infections (20.9 points, 95% CI: 18.6-23.3) than for other groups (range 24.2-26.3). The most common potential bacterial pathogens were Haemophilus influenza (28.0%), Moraxella catarrhalis (16.2%), and Streptococcus pneumoniae (10.2%), whereas the most common viral pathogens were rhinovirus (17.3%), influenza (12.8%), SARS-CoV-2 (11.5%), and seasonal coronaviruses (8.1%). Discussion: The mean duration of cough was 16.4 days. Consistent with European studies, the type of infection or potential pathogen was not an important predictor of the duration or severity of LRTI.

Abstract Background The potential benefits of using rapid influenza diagnostic tests (RIDTs) in urgent care facilities for clinical care and prescribing practices are understudied. We compared antiviral and antibiotic prescribing, imaging, and laboratory ordering in clinical encounters with and without RIDT results. Methods We compared patients with acute respiratory infection (ARI) symptoms who received an RIDT and patients who did not at 2 urgent care facilities. Primary analysis using 1-to-1 exact matching resulted in 1145 matched pairs to which McNemar 2 × 2 tests were used to assess the association between the likelihood of prescribing, imaging/laboratory ordering, and RIDT use. Secondary analysis compared the same outcomes using logistic regression among the RIDT-tested population between participants who tested negative (RIDT(−)) and positive (RIDT(+)). Results Primary analysis revealed that compared to the non-RIDT-tested population, RIDT(+) patients were more likely to be prescribed antivirals (OR, 10.23; 95% CI, 5.78–19.72) and less likely to be prescribed antibiotics (OR, 0.15; 95% CI, .08–.27). Comparing RIDT-tested to non-RIDT-tested participants, RIDT use increased antiviral prescribing odds (OR, 3.07; 95% CI, 2.25–4.26) and reduced antibiotic prescribing odds (OR, 0.52; 95% CI, .43–.63). Secondary analysis identified increased odds of prescribing antivirals (OR, 28.21; 95% CI, 18.15–43.86) and decreased odds of prescribing antibiotics (OR, 0.20; 95% CI, .13–.30) for RIDT(+) participants compared with RIDT(−). Conclusions Use of RIDTs in patients presenting with ARI symptoms influences clinician diagnostic and treatment decision-making, which could lead to improved patient outcomes, population-level reductions in influenza burden, and a decreased threat of antibiotic resistance.

Background Influenza viruses pose significant disease burdens through seasonal outbreaks and unpredictable pandemics. Existing surveillance programs rely heavily on reporting of medically attended influenza (MAI). Continuously monitoring cause-specific school absenteeism may identify local acceleration of seasonal influenza activity. The Oregon Child Absenteeism Due to Respiratory Disease Study (ORCHARDS; Oregon, WI) implements daily school-based monitoring of influenza-like illness-specific student absenteeism (a-ILI) in kindergarten through Grade 12 schools and assesses this approach for early detection of accelerated influenza and other respiratory pathogen transmission in schools and surrounding communities. Methods Starting in September 2014, ORCHARDS combines automated reporting of daily absenteeism within six schools and home visits to school children with acute respiratory infection (ARI). Demographic, epidemiological, and symptom data are collected along with respiratory specimens. Specimens are tested for influenza and other respiratory viruses. Household members can opt into a supplementary household transmission study. Community comparisons are possible using a pre-existing and highly effective influenza surveillance program, based on MAI at five family medicine clinics in the same geographical area. Results Over the first 5 years, a-ILI occurred on 6634 (0.20%) of 3,260,461 student school days. Viral pathogens were detected in 64.5% of 1728 children with ARI who received a home visit. Influenza was the most commonly detected virus, noted in 23.3% of ill students. Conclusion ORCHARDS uses a community-based design to detect influenza trends over multiple seasons and to evaluate the utility of absenteeism for early detection of accelerated influenza and other respiratory pathogen transmission in schools and surrounding communities.