Results
A total of 3699 patients had RPA sent within 48 hours of hospital admission in the study period (01/01/15 – 12/31/19). Among these patients, 2192 had a positive RPA and were included in the study. One thousand eight hundred thirty-one patients had only a single virus detected (Group A), while 361 had more than one virus detected (group B). Thirty-seven patients had three or more virus detected, four patients had four or more virus detected, and one patient had six viruses detected in the RPA.
A total of 2595 viruses were identified in the RPA of the included patients (including all the coinfections). Rhino enterovirus comprised almost half of all the viruses identified (n=1278, 49.2%). Proportion of other viruses included respiratory syncytial virus (n=422, 16.2%), parainfluenza virus (n=222, 8.5%), metapneumovirus (n=140, 5.3%), influenza virus (n=151, 5.8%), coronavirus (n=193, 7.4%), adenovirus (n=189, 7.2%). Among the patient with two virus coinfections, the most common combination was Rhino/enterovirus and respiratory syncytial virus (22.4%). The other common combinations were Rhino/enterovirus and adenovirus (17.4%), Rhino/enterovirus and parainfluenza virus (13.8%) and Rhino/enterovirus and coronavirus (8%). (Table 1)
The median age of the study population was 15.9 months (IQR 3.8, 43.8). Patients who had coinfection were significantly younger (11.3 [IQR 4.3, 25.1]) than patients hospitalized with single virus infection (17.0 [IQR 3.7, 48.8]), p= 0.001. There was a higher proportion of infants (50.9%) among patients who had coinfection, as compared to patients with single viral infection (41.3%), p <0.001. There was no difference in gender distribution or racial distribution in the two groups. Children with coinfection had an overall lower median weight; however, there was no significant difference in the body mass index or percentage of obese patients in the two groups. Overall positive urine culture was detected in 8.2% of total patients at the time of admission, while positive blood and respiratory culture were detected in 2.0% and 2.5%, respectively. A much higher proportion of patients with coinfection had a positive respiratory culture within 24 hours of hospital admission (4.7%) as compared to only 2.1% in patients with a single viral infection, p= 0.004. There was no significant difference in the patients who had positive blood culture or positive urine culture at the time of admission. Asthma was the most prevalent comorbidity and was present in 463 (21.1%) of the total patients. There was, however, no significant difference in the diagnosis of asthma between the two groups. Similarly, the two groups were similar in terms of the proportion of patients who were premature, had congenital heart disease, or had a pre-existing diagnosis of developmental delay. There was, however, a higher proportion of patients with single viral infection (4.0%) who had an oncologic diagnosis as compared to patients with coinfection and had an oncologic diagnosis (1.6%), p= 0.02. (Table No 2)
Overall, oral antibiotics were prescribed to 155 patients in the study population (7.0%), and intravenous antibiotics were prescribed to 646 patients (29.4%) within six hours of hospital admission. There was no difference in the proportion of patients who were prescribed oral or intravenous antibiotics among the two groups. The median intravenous antibiotic duration in the study population was one day (IQR 0, 2), and 24 patients (1%) received antibiotics that were prescribed at the time of admission, for five or more days. There was no difference between the two groups in terms of antibiotic duration. 60.7% of the patients received a chest x-ray (CXR) during the hospitalization. A higher proportion of patients with coinfection (66.4%) received CXR compared to patients with single virus infection (59.5%), p= 0.01. There was no difference in the number of chest x-rays performed during hospitalization in the two groups. Overall, 8.1% of the study population had a Pediatric Emergency Response Team (PERT) activation during the hospitalization, and this proportion was higher in patients with coinfection (11.6%) as compared to patients with single viral infection (7.4%), p= 0.007. Only six patients out of all included patients had “code blue” (cardiac arrest) during their hospitalization, and there was no difference in the two groups. The median cost of care for hospitalization of patients with viral -related illnesses was $ 2468.59 (IQR $ 1452.27, $ 4754.90). There was a significant difference in the two groups with a higher median cost of care ($ 2934.89) in patients with co-viral infections compared to patients with single viral infection ($ 2381.14), p= 0.002. (Table No 3). The difference in cost of care however did not persist on multi variable linear regression after accounting for confounders (parameter estimate 1.1104 coinfection versus single infection, P value 0.052) (data not shown)
Overall, 41.1% of the patients required intermediate level admission in the hospital, and 23.4% required ICU admission. There was no significant difference in the proportion of patients requiring intermediate or ICU admission among the two groups. Among the patient who required ICU admission, the median length of stay was 1.9 days (IQR 0.91, 4.76). There was no significant difference in the ICU length of stay between the two groups. A significantly higher proportion of patients with coinfection required initiation of high flow cannula (145/361, 40.1%) compared to patients with single viral infection (28.0%), p <0.001. This difference remained significant on multi variable logistic regression after accounting for confounders (p<0.001, data not shown). Similarly, a higher proportion of patients with coinfection (8.2%) required intubation compared to patients with single viral infection (5.6%); this difference, however, was not statistically significant, p= 0.07. The overall median duration of intubation for patients who required intubation was six days (IQR 2, 9). This was comparable in the two groups. The median hospital length of stay for the study population was two days (IQR 1, 4), and patients with coinfection stayed in the hospital for a significantly longer duration (3[IQR 1, 5] vs. 2 [IQR 1, 4], p= 0.0003). A total of seven patients died during hospitalization, with an overall mortality rate of 0.3%. There was no difference in mortality between the two groups. (Table No 4). The difference in hospital length of stay in the two groups were significant on multi variable linear regression with a parameter estimate of 1.116 for coinfection versus single infection, p=0.01 (data not shown).