Emergent severe acute respiratory distress syndrome caused by adenovirus type 55 in immunocompetent adults in 2013: a prospective observational study

Abstract

Introduction: Since 2008, severe cases of emerging human adenovirus type 55 (HAdV-55) in immunocompetent adults have been reported sporadically in China. The clinical features and outcomes of the most critically ill patients with severe acute respiratory distress syndrome (ARDS) caused by HAdV-55 requiring invasive mechanical ventilation (IMV) and/or extracorporeal membrane oxygenation (ECMO) are lacking.

Methods: We conducted a prospective, single-center observational study of pneumonia with ARDS in immunocompetent adults admitted to our respiratory ICU. We prospectively collected and analyzed clinical, laboratory, radiological characteristics, sequential tests of viral load in respiratory tract and blood, treatments and outcomes.

Results: The results for a total of five consecutive patients with severe ARDS with confirmed HAdV-55 infection were included. All five patients were immunocompetent young men with a median age of 32 years. The mean time from onset to dyspnea was 5 days. Arterial blood gas analysis at ICU admission revealed profound hypoxia. Mean partial oxygen pressure/fraction of inspired oxygen was 58.1. Mean durations from onset to a single-lobe consolidation shown on chest X-rays (CXRs) and, from the first positive CXR to bilateral multilobar lung infiltrates, were 2 days and 4.8 days, respectively. The viral load was higher than 1 × 108 copies in three patients and was 1 × 104 in one patient. It was negative in the only patient who survived. The mean duration for noninvasive positive pressure ventilation (NPPV) failure and IMV failure were 30.8 hours and 6.2 days, respectively. Four patients received venovenous ECMO. Four (80%) of the five patients died despite receiving appropriate respiratory support.

Conclusions: HAdV-55 may cause severe ARDS in immunocompetent young men. Persistent high fever, dyspnea and rapid progression to respiratory failure within 2 weeks, together with bilateral consolidations and infiltrates, are the most frequent clinical manifestations of HAdV-55-induced severe ARDS. Viral load monitoring may help predict disease severity and outcome. The NPPV and IMV failure rates were very high, but ECMO may still be the respiratory support therapy of choice.

Trial registration: Clinicaltrials.gov NCT01585922. Registered 20 April 2012.

Figures

Figure 1

Radiographic findings and their relationship to viral load monitoring in patient 4. (Picture 1) Radiographs show widespread bilateral interstitial infiltrates at the onset of the disease. (Picture 2) The patient’s condition rapidly deteriorated within 3 days, and mechanical ventilation was required. (Picture 3) The patient’s adenoviral infection progressed, so supplementary oxygen was given on day 3 of admission. (Picture 4–8) Radiographs show gradual recovery with supportive therapy. Also shown are the trends of viral load detected with endotracheal aspirates (ETAs) and their relationship to radiological changes.

Figure 2

Dynamic changes on computed tomography scans for human adenovirus type 55 pneumonia in patient 3. Chest computed tomography scans taken on day 1 show a nodular shadow in the right upper lobe. The nodular shadow expanded dramatically within 3 days and was surrounded by ground-glass opacity on day 4. The lesion was diffuse in both lung fields on day 8. A cavity was observed on day 23, and the mediastinum window shows the formation of pulmonary abscess in the upper right lobe (red arrow). The lung abscess tested negative for Legionella, Staphylococcus and tuberculosis.

Figure 3

Changes in human adenovirus type 55 concentration measured in endotracheal aspirates from all five acute respiratory distress syndrome patients. Patient 4, whose viral DNA copies in ETA became negative, was the only patient who survived.