COVID‐19 complicated by postinfectious bronchiolitis obliterans and pulmonary aspergillosis in an infant

To the Editor, We present a case of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection in a 2‐week‐old infant, requiring mechanical ventilation and paediatric intensive care (ICU) support, complicated by invasive pulmonary aspergillosis and post‐infectious bronchiolitis obliterans (PIBO). A 2‐week‐old girl (ex‐38 + 2 weeks' gestation) was transferred to a referral children's hospital with fevers, irritability and reduced oral intake, and tested positive for SARS‐CoV‐2. Following 48 h of antibiotics and negative blood and CSF cultures, she was discharged home with close monitoring. She was re‐admitted after 3 days with rapidly escalating respiratory distress requiring mechanical ventilation. She was initially treated with remdesivir (5 mg/kg loading dose, then 2.5 mg/kg daily for total 10 days) and dexamethasone (0.15mg/kg for 8 days) with some clinical improvement. Right upper lobe (RUL) collapse with widespread interstitial changes were noted on serial chest X‐rays (Figure 1A). She was mechanically ventilated a total of 28 days. Chest X‐ray showed progression of COVID‐19 pneumonitis. The presence of areas of hyperinflation with attenuated vascular markings and reticular markings raised possibility of PIBO (Figure 1B). Prophylactic azithromycin (10mg/kg three times/weekly) and hypertonic saline (HTS) with chest physiotherapy were commenced. Given the apparent clinical response to dexamethasone, the child underwent a 6‐week steroid course and was weaned off both steroid and respiratory support. Concurrently, intravenous immunoglobulin (IVIG) and daily prophylactic trimethoprim/sulfamethoxazole (2 mg/kg trimethoprim component) were commenced. The child's ICU course was complicated by ventilator‐associated pneumonia with growth of Acinetobacter pitti, and subsequently invasive pulmonary aspergillosis. Thick secretions noted on flexible bronchoscopy cultured Aspergillus fumigatus and treated initially with liposomal amphotericin B. The diagnosis was confirmed via a rigid laryngo‐bronchoscopy (LBO) with biopsy of an invasive tracheal plaque (Figure 1D). Intravenous voriconazole (9 mg/kg every 12 h) and nebulised amphotericin B (12.5mg three times weekly) were commenced. CPAP was weaned to room air at 11 weeks of age. Repeat bronchoscopy demonstrated RUL bronchomalacia and resolution of plaques. Immune function screening including T&B lymphocyte subsets and immunoglobulins (IgA, IgG, and IgM) was normal. No pathogenic variants were identified on genetic testing for interstitial lung disorders or primary immunodeficiency. She was discharged home at 3.5 months of age with prophylactic azithromycin and trimethoprim/sulfamethoxazole, HTS and posaconazole. She completed six doses of monthly IVIG. Sleep study was normal at 7 months old. A repeat computed tomography chest demonstrated improvement in volume loss of RUL consistent with resolved aspergillosis infection. However, interlobular septal thickening, subsegmental atelectasis and mosaic attenuation was noted in keeping with a PIBO diagnosis. Whilst SARS‐CoV‐2 infection in children is predominantly a mild disease, very young age is associated with risk of more severe