2.3.1 Clinical manifestations and laboratory findings
Among the 623 patients with RSV infection identified in this study, the medical data of 597 were collected successfully and analyzed. The comorbidity rate was 2.9% in the 0–4 years old group, 0% in 5–17 years old group, 22.4% in 18–44 years old group, and 57.2% in ≥60 years old group; and presented an approximately rising trend as age increasing (p < 0.001). Among the children with 0 to 4 years of age, the most common symptoms were cough (95.8%), fever (87.8%), sputum production (61.0%), rhinorrhea (42.9%), nasal congestion (33.5%), dyspnea (12.3%), and sore throat (11.6%), whereas among the adults 60 years of age or older, the most common symptoms were cough (88.8%), sputum production (82.9%), fever (74.8%), dyspnea (52.6%), sore throat (18.4%), and rhinorrhea (17.1%). Notably, almost more than half of patients with RSV infection aged ≥60 years eventually developed dyspnea in their clinical course (52.6%; Table 1).
There were some differences in blood analysis observed between the younger children and the elderly adults with RSV. The elderly patients frequently developed lymphopenia (5.1% for 0–4 yr, 41.5% for ≥60 yr, p<0.001), neutrophilia (15.1% for 0–4 yr, 71.2% for ≥60 yr, p<0.001), and elevated C-reactive protein (CRP; 23.2% for 0–4 yr, 73.6% for ≥60 yr, p<0.001), which indicated that there might be co-existing bacterial infection in these elderly patients besides RSV infection. However, the younger child patients were more likely to develop elevated aspartate aminotransferase (AST) levels (34.9% for 0–4 yr, 13% for ≥60 yr, p<0.001) and/or an elevated creatine kinase MB fraction (CKMB; 30.4% for 0–4 yr, 2.5% for ≥60 yr, p<0.001), which suggested that acute heart injuries may have occurred (Table 2).
Radiographic findings showed that the older the age of the patients with RSV infection was, the larger the proportion of pneumonia (23.2% for 0–4 yr, 59.2% for ≥60 yr, p<0.001). Furthermore, about 50% of the abnormal radiographic findings involved bilateral lung in children and adults (Table 2).