RSV circulation during SARS-CoV-2 pandemic era: what happened in Italy

Background: In the northern hemisphere, Respiratory Syncytial Virus (RSV) is more frequently detected from December to February. In Italy, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) presented a peak in incidence from the end of December 2021 to February 2022. Aim(s): To evaluate how SARS-CoV-2 pandemic has influenced RSV circulation. Method(s): We evaluated 389 children, aged 0-18 years, admitted for respiratory tract infections from September 2021 to January 2022 throughout Italy, from the north to the south. Children underwent nasal washing from 1 to 3 days after hospitalization. A (RT)-PCR was developed for detecting 15 respiratory viruses, including RSV, influenza virus A and B, human coronavirus OC43, 229E, NL-63 and HUK1, adenovirus, rhinovirus, parainfluenza virus 1-3, human bocavirus and human metapneumovirus. Result(s): We detected a virus in 338 children (86.9%): RSV was found in 267 (68.7%), other viruses in 71 (18.3%). 51 children (13.1%) resulted negative. Dividing our observational period in two-week timeframes, we found that RSV showed an early peak from October to the first half of December 2021 compared to its usual seasonality. In a previous study, we have demonstrated that RSV circulation was incredibly low from September 2020 to January 2021, in contrast with what we found in the same period in 2021-2022. Comparing RSV and SARS-CoV-2 incidences, we found that these two viruses spread in opposite ways: when SARS-CoV-2 present an incidence peak, RSV circulation reduced and viceversa. Conclusion(s): The relationship between RSV and SARS-CoV-2 showed that viral interference plays a crucial role in their epidemiology.

Covid-19 in children: disease spectrum and risk factors

Introduction: Children infected with the severe acute respiratory coronavirus 2 (SARS-CoV-2) are mostly asymptomatic or mild symptomatic. Some children experience persistent symptoms after SARS-CoV-2 infection, which may be consistent with Long COVID. Aim(s): To assess the frequency of both acute and persisting Coronavirus disease (COVID-19) symptoms in children and to search for the presence of risk factors for acute or persisting COVID-19 symptoms. Method(s): We included 697 children, aged between 0 and 18 years, who had previous SARS CoV-2 infection. Children and parents were asked questions regarding symptoms in the acute phase of COVID-19 and also persistent symptoms (extending beyond or developing 30 days and 90 days after initial diagnosis). Result(s): 79,2% of children were symptomatic in the acute phase of COVID-19;the most common acute symptoms were fever (49,6%), cough (22,1%), headache (37,9%) and asthenia (25,8%). 26,8% of children reported symptoms 30 days after initial diagnosis and 10,2% of children presented symptoms 90 days after initial diagnosis;the most common reported symptom was asthenia respectively in 12,3% (after 30 days) and in 4,9% of children (after 90 days). Persisting symptoms after 30 days were mostly present in overweigh or obese girls (35,8% vs 64,2%, p-value 0,03) and in children with asthenia (41,3% vs 20,3, p-value 0,001) in the acute phase. Children with symptoms 90 days after initial diagnosis most frequently had asthenia in the acute phase. Conclusion(s): We confirm that SARS-CoV-2 infection in children is generally mild. Also children can experience persisting symptoms that are significantly more frequent if they have a symptomatic disease and asthenia.