RSV Detection and Antibiotic Prescribing Decisions for Pediatric Respiratory Tract Infections

Boracchini R, Brigadoi G, Salvadori S, et al. JAMA Netw Open. 2026;9(3):e260409. doi:10.1001/jamanetworkopen.2026.0409

Key Points

Question  Are respiratory syncytial virus (RSV) antigen rapid diagnostic tests (Ag-RDTs) in primary care associated with reduced inappropriate antibiotic prescribing in children with suspected viral lower respiratory tract infections (VLRTIs), including bronchiolitis?

Findings  In this cohort study of 256 children aged 9 to 36 months in Italy, implementing RSV Ag-RDTs in clinical practice was associated with a reduction in unnecessary antibiotic use. Overall, RSV Ag-RDTs were associated with a mean reduction in antibiotic prescribing for VLRTIs and bronchiolitis compared with clinically diagnosed cohorts.

Meaning  The findings suggest incorporating RSV Ag-RDTs into pediatric care may support more appropriate antibiotic prescribing and could help reduce antibiotic overuse.

Abstract

Importance  Respiratory syncytial virus (RSV) is a leading cause of pediatric viral lower respiratory tract infections (VLRTIs), often leading to inappropriate antibiotic use. Although rapid antigen diagnostic tests (Ag-RDTs) support clinical diagnosis, their effect on antibiotic prescribing in community settings remains uncertain.

Objective  To evaluate the association of RSV Ag-RDT implementation with antibiotic prescribing practices for infants and children assessed for LRTIs.

Design, Setting, and Participants  This retrospective cohort study used data from a community-based primary care setting involving family pediatricians in Italy participating in the Pedianet network. Data were collected between December 2023 and May 2024 from children aged 9 to 36 months with symptoms of VLRTI who underwent RSV Ag-RDT during the 2023-2024 respiratory epidemiologic season and historical matched cohorts.

Exposure  Children with RSV-positive and RSV-negative Ag-RDT results were compared with each other and with matched historical (2022-2023) and contemporaneous (2023-2024) cohorts of children with clinically diagnosed VLRTIs or bronchiolitis who did not undergo laboratory testing.

Main Outcomes and Measures  The primary outcome was antibiotic prescribing within 14 days of diagnosis. Prescriptions associated with suspected or confirmed bacterial infections (such as elevated C-reactive protein levels or documented coinfections) were excluded. Relative risks (RRs) and 95% CIs were estimated using log-binomial regression models.

Bar Graphs of Antibiotic Prescription Rates and Forest Plots
Illustrating Risk of Receiving at Least 1 Antibiotic Prescription
Within 14 Days of the Episode, by Detection of Infection

Results  Among 256 cases (median age, 15.06 [IQR, 11.61-22.72] months; 133 males [51.95%]), 79 (30.86%) were RSV positive and 177 (69.14%) were RSV negative. These 2 groups were comparable in age, with RSV-negative children slightly younger (median age, 14.95 [IQR, 11.66-22.67] vs 15.34 [IQR, 11.40-23.10] months), and in sex distribution, with a higher proportion of females among RSV-positive cases (41 [51.90%] vs 82 [46.33%]). Antibiotic prescribing was lower in RSV-positive than RSV-negative children (0.18 [95% CI, 0.10-0.25] vs 0.29 [95% CI, 0.22-0.35] prescriptions per 10 person-days) and was associated with a reduction in risk of receiving an antibiotic prescription (RR, 0.52; 95% CI, 0.33-0.83). Implementation of RSV Ag-RDT was associated with lower antibiotic use for VLRTIs compared with a matched untested cohort (RR, 0.54 [95% CI, 0.44-0.66] in 2022-2023 and 0.61 [95% CI, 0.50-0.75] in 2023-2024) and for bronchiolitis in 2022-2023 (RR, 0.56 [95% CI, 0.33-0.95]) but not in 2023-2024 (RR, 0.75 [95% CI, 0.42-1.33]). Reductions were greater among RSV-positive cases: for VLRTIs, the RR was 0.33 (95% CI, 0.20-0.52) in 2022-2023 and 0.41 (95% CI, 0.25-0.67) in 2023-2024; for bronchiolitis, the RR was 0.33 (95% CI, 0.15-0.76) in 2022-2023, but the reduction was not significant in 2023-2024 (RR, 0.43 [95% CI, 0.18-1.00]).

Conclusions and Relevance  In this cohort of 256 VLRTI cases, the findings suggest that RSV contributed to a broad range of VLRTIs across ages and that RSV Ag-RDT was a useful outpatient antimicrobial stewardship tool, particularly in bronchiolitis. Combined with universal immunoprophylaxis, widespread Ag-RDT use may improve diagnostic accuracy, resource allocation, and clinical outcomes.

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