Factors Contributing to Symptom Duration and Viral Reduction in Outpatient Children With Respiratory Syncytial Virus Infection

Abstract

Background: We investigated the association between age, duration of clinical symptoms and viral shedding in outpatient children infected with respiratory syncytial virus (RSV) in Japan. Methods: Outpatients younger than 2 years of age, with suspected RSV infection between 2014 and 2018, were enrolled in the study. Following informed consent, nasal samples were collected at first and second clinic visits (with 0–9 days gap). RSV-A or -B infection and viral load were determined by real-time polymerase chain reaction. Clinical symptoms were recorded at first clinic visit, and fever and symptoms were recorded at home for up to 8 days. Association between clinical symptoms and patient characteristics, such as age, sex and birth weight, were analyzed using ordered logistic regression analysis. The association between viral reduction and estimated shedding period was examined using linear regression analysis. Results: Among the 205 cases enrolled in the study, no difference was found in patient characteristics between RSV-A and -B infection. Duration of fever was prolonged with increased age. Duration of rhinorrhea and cough was shorter in females than in males and in groups with birth weight ≥3 kg than in those with <2.5 kg. Daily viral reduction increased and estimated viral elimination period decreased with age. Conclusions: Fever duration was found to increase while viral shedding decreased with patient age.

Molecular Epidemiology of Respiratory Syncytial Virus during 2019–2022 and Surviving Genotypes after the COVID-19 Pandemic in Japan

“…Through our investigations, we reported several new genotypes of NA1, NA2, BA7, BA8, BA9, and BA10, and found that a newly reported genotype in Canada, ON1, was imported to Japan in 2013 [14,18,26]. In addition to molecular epidemiology, we reported that RSV seasonality in Japan moves from winter to summer [24] and another report on clinical virology showed that patient age contributes to symptom duration and viral reduction in outpatients [27]. This study was also conducted as a part of this investigation, and samples were collected from various prefectures in Japan through our own network.…”

Age-Dependent Clinical Characteristics of Acute Lower Respiratory Infections in Young Hospitalized Children with Respiratory Syncytial Virus Infection

“… 1 The infection occurs in all age groups, but most children are infected at or before 2 years of age. 2 Patients with HRSV bronchiolitis usually present with two to four days of upper respiratory tract symptoms such as fever, rhinorrhea, and congestion, followed by lower respiratory tract symptoms such as increasing cough, wheezing, and increased respiratory effort. 3 However, it is not clear whether lower respiratory tract infections (LRTI) caused by HRSV cause different clinical manifestations in children of different ages.…”

Comparative analysis of Respiratory Syncytial Virus frequency rates and viral load in different patient cohorts in a University Hospital in São Paulo, Brazil, over an eight-year period (2005–2013)

“…Viral load measurement provides valuable information regarding the replication kinetics of the virus, shedding patterns, and host immune responses, all of which can significantly affect disease outcomes and transmission potential. 7 , 8 Assessment of the viral load can provide valuable insights into the patterns and impact of RSV infection, contributing to the establishment of effective strategies for prevention, treatment, and control. Current treatment options are supportive; however, antiviral trials are ongoing and new preventive options are available.…”