BACKGROUND: Neurologic/neuromuscular disorders (NNMD) can aggravate respiratory viral infections, such as influenza, and lead to severe illness. We describe clinical outcomes and respiratory pathogen detections in children with NNMD hospitalized with severe acute respiratory illness (SARI).
METHODS: Surveillance for patients with SARI was conducted at three sentinel hospitals in the Minneapolis/St. Paul metropolitan area. Respiratory specimens collected from hospitalized patients with acute respiratory illness were tested by the state public health laboratory for 22 respiratory pathogens using individual and multiplexed real-time RT-PCR assays. Medical records were reviewed to collect demographic and clinical information. We compared severe outcomes (intensive care unit admission, mechanical ventilation, or death) and length of stay (LOS) by pathogen detected among three SARI patient groups: NNMD, other comorbidities, and no comorbidities. We used a multinomial logistic regression model to evaluate severe outcome and LOS by group, and Poisson regression to evaluate LOS by pathogen detection among children with NNMD, adjusting for age.
RESULTS: From September 2013-June 2015, 3,099 children <18 years with SARI were included: 511 (16.5%) had NNMD, 962 (31.0%) had other comorbidities, and 1,626 (52.5%) had no identified comorbidities. Overall, the presence of comorbidities increased with age. Children with NNMD were significantly older than those with other or no comorbidities (median age 3.0, 1.6 and 0.6 years, respectively, p<0.0001), and pathogen detection was slightly less frequent among children with NNMD (79.5%) compared with those with other or no comorbidities (87.2% and 86.3%, respectively, p<0.0001). Among children with NNMD, most commonly detected pathogens were rhinovirus/enterovirus (29%), respiratory syncytial virus (23%), metapneumovirus (10%), and parainfluenzaviruses (8%). In multivariable analysis, compared to children with no or other comorbidities, children with NNMD had a longer LOS (6.1 vs. 4.5 and 3.7 days, respectively, p<0.0001), and were more likely to have a severe outcome (aRR=2.3, 95% confidence interval [CI]: 1.7-3.0). Detection of a respiratory pathogen was not independently associated with comorbidity group; however, among children with NNMD, LOS was 26.2% longer among children with a pathogen detected (95% CI: 16.7-35.6% p<0.0001).
CONCLUSIONS: Children with SARI who have NNMD are at greater risk for severe outcome and a longer LOS, which may be further prolonged when a pathogen is detected. Children with NNMD represented 16% of the patient-population hospitalized for SARI and presented at an older age. A better understanding of the impact of respiratory-specific pathogens in patients with NNMD may help target preventive measures.