To analyze the clinical characteristics of respiratory syncytial virus (RSV) pneumonia in children in Southwest Shandong, and explore the factors associated with severe RSV pneumonia occurrence.

Retrospective analysis was conducted on the clinical data of 252 cases of RSV pneumonia admitted to the Department of Pediatrics at Affiliated Hospital of Jining Medical University from October 2021 to September 2022. According to the severity of the condition, the cases were categorized into mild pneumonia group(n=168) and severe pneumonia group(n=84). A comparative analysis of the clinical data of the 2 groups was performed, and a multivariate Logistic regression analysis was used to identify the risk factors associated with the occurrence of severe RSV pneumonia.

The study included 252 cases of RSV pneumonia, with 156 boys (61.90%) and 96 girls (38.10%), resulting in a male-to-female ratio of 1.63∶1. The 3 age groups with the highest RSV infection rates were aged ≤3 months (60.32%, 152/252), 3-6 months (21.83%, 55/252), and 6 months to 1 year (7.94%, 20/252). Of the total, 146 patients (57.94%) had a history of contact with respiratory infectious diseases became ill after exposure to respiratory infections (caregivers or co-residents underwent respiratory infections), 38 patients (15.08%) had underlying diseases. The differences between the severe RSV pneumonia group and the mild RSV pneumonia group were statistically significant in terms of anemia (19.05%, 10.12%), fever (55.95%, 29.76%), wheezing (57.14%, 39.88%), and having underlying disease (28.57%, 8.33%) (χ²=3.92, 16.23, 6.73, 17.91, all P<0.05). Patients in the severe RSV pneumonia group had a longer hospital stay [(8.86±3.71)d, (7.67±1.95)d], and a higher proportion of requiring oxygen therapy (65.48%, 14.29%), intravenous immunoglobulin therapy (38.10%, 5.95%), and glucocorticoid therapy (38.10%, 25.00%) compared to the mild RSV group. These differences were statistically significant (t=3.32, χ²=68.19, 41.66, 4.63, all P<0.05). Compared to the mild RSV group, the severe RSV pneumonia group had higher white blood cell count [(8.66±3.58)×10⁹/L], C-reactive protein level [1.16(0.25, 12.19)mg/L], lactate dehydrogenase level [(353.09±113.89)U/L], and α-hydroxybutyrate dehydrogenase level [(272.80±89.65)U/L] compared to mild RSV group [(7.86±2.40)×10⁹/L, 0.57(0.26, 2.35)mg/L, (288.29±73.13)U/L, (223.02±49.39)U/L], with statistically significant differences (t=2.09, Z=2.22, t=5.40, 5.60, all P<0.05). The variables that showed statistical significance in the univariate analysis were then subjected to multivariate Logistic analysis, which showed that fever, wheezing, presence of underlying disease and elevated lactate dehydrogenase level were independent risk factors for the development of severe RSV pneumonia (OR=18.019, 2.564, 4.275, 2.348, all P<0.05).

RSV pneumonia can occur in children of all age groups and is particularly prevalent in infants under 1 year old. The presence of underlying disease, fever, wheezing and elevated lactate dehydrogenase level are independent risk factors for the development of severe RSV pneumonia.