Outbreak of Respiratory Syncytial Virus Bronchiolitis in Italy

Yeoh et al.reported the impact of public health measures introduced during the coronavirus disease 2019 (COVID-19) pandemic on influenza and respiratory syncytial virus (RSV) detections in Western Australian children through winter 2020. A subsequent increase in RSV cases in 2020, with numbers exceeding the median seasonal peak from 2012 to 2019 and a higher median age of the affected cohort, has been reported as the results of a local, Australian prospective surveillance. Relaxed physical-distancing recommendations consequent to the reduction in COVID-19–related public health measures, together with the expanded cohort of RSV-naive patients, including an increased number of older children, coupled with waning population immunity have been considered as being responsible for this marked resurgence. Concerns were raised for RSV control in the Northern Hemisphere, where a shortened season was experienced during the 2020–2021 epidemic season [3]. Here, we report the data on an ongoing outbreak of bronchiolitis in Italy. Fourteen pediatric hospitals with a wide geographical distribution in Italy, part of the Italian Association of Pediatric Hospitals, provided numbers of hospital admissions due to bronchiolitis and RSV infections from the current (1 September to 30 November 2021) and, for comparison, from the previous seasonal epidemics (2019–2020 and 2020–2021). Data were extracted using the 10th edition of the International Classification of Diseases from the hospital's electronic medical record systems.