Severe Pneumonia and Pediatric Acute Respiratory Distress Syndrome Caused by HCoV NL 63 and Respiratory Syncytial Virus Coinfection With Favorable Outcome

To the Editors: NL63 coronavirus (HCoV NL63) was first described during the SARS-CoV outbreak in 2004, since then it has been reported infrequently in children. Data on coinfection with human covid NL 63 and respiratory syncytial virus (RSV) is sparse. We report 2 cases of HCoV NL63 and RSV coinfection causing pediatric acute respiratory distress syndrome (PARDS). Case 1: A 10-month-old baby, immunized for age, predominantly breastfed, wt-6 kg, who was admitted for pneumonia and PARDS. For worsening respiratory distress and impending failure, he had to be intubated and ventilated. His initial oxygenation index (OI) was 12 and progressed to 22 (severe PARDS). Chest radiograph showed bilateral heterogeneous opacities (Fig. 1). Respiratory viral panel showed coinfection of RSV and human covid NL 63 virus. In view of severe viral pneumonia and severe PARDS, we started him on intravenous dexamethasone @0.15 mg per kg and tapered over 3 weeks. The child responded and showed clinical and radiological improvement (OI decreased from 22→16→8→5→4). The child also had multiple organ dysfunction syndrome (MODS) (shock, acute kidney injury, transaminitis, all were managed conservatively and improved).FIGURE 1.: Admission chest x-ray of case 1 showing bilateral haziness (left >> right lung).Case 2: An 8-month-old girl, immunized for age, presented with fever, cough and fast breathing for 5 days. She was initially put on CPAP. In view of worsening distress, she was intubated within 24 hours and shifted to PICU and mechanically ventilated. She received IV ceftriaxone and ribavirin. She developed transudative pleural effusion on day 2 of admission. She was classified as a case of moderate PARDS. She also developed MODS (AKI, transaminitis) which were managed conservatively. Her respiratory viral panel showed coinfection with RSV and HCov NL 63 virus. Gradually, her OI decreased from 8→5→below 4 over a week, and MODS also resolved. She was successfully extubated after 8 days. HCoV NL 63 was first isolated during 2004. By, 2006, the incidence had decreased to 6% of all respiratory cases, RSV being the most common (48% cases).1 It occurs predominantly in the winter season.2 In children, it causes self-limiting mild to moderate respiratory disease, but has the potential to cause severe disease in immunocompromised children.1,3 Recently, there have been no cases of severe pneumonia ARDS published due to HCoV NL 63. The epidemic potential remains unclear. In a recent study, the incidence was estimated to be 21% among all corona virus, Coinfection with other viruses is common.3 In case 1 with severe pneumonia, severe PARDS and MODS, complicated with underlying vitamin-D deficiency, anemia and undernutrition, having a successful patient outcome was a challenging task. To our best knowledge, there have been no case reports on severe infection and disease caused by HCoV NL 63 in children recently. The child showed improvement with the addition of steroids, prone positioning and other supportive care. In contrast, case 2 improved without steroids. Adult case reports in HCoV NL 63 induced pneumonia, seen in immunocompromised patients have shown adverse outcomes despite the usage of steroids.4 Little is known about the consequences of RSV-HCoV NL 63 coinfection. Li et al5 concluded that there was no difference in the severity of illness in RSV infection vs RSV-HCoV NL 63 coinfection but in RSV-metapneumovirus coinfection severity of illness was high. We noticed that coinfection with RSV and human covid NL 63 virus resulted in increased severity of respiratory illness. ACKNOWLEDGMENTS We acknowledge the contribution of our nursing staff in the management of these cases and successful outcome.