Predictive factors for pneumonia development and progression to respiratory failure in MERS-CoV infected patients

Abstract

Background: After the 2015 Middle East respiratory syndrome (MERS) outbreak in Korea, prediction of pneumonia development and progression to respiratory failure was emphasized in control of MERS outbreak.

Methods: MERS-CoV infected patients who were managed in a tertiary care center during the 2015 Korean MERS outbreak were reviewed. To analyze predictive factors for pneumonia development and progression to respiratory failure, we evaluated clinical variables measured within three days from symptom onset.

Results: A total of 45 patients were included in the study: 13 patients (28.9%) did not develop pneumonia, 19 developed pneumonia without respiratory failure (42.2%), and 13 progressed to respiratory failures (28.9%). The identified predictive factors for pneumonia development included age ≥45 years, fever ≥37.5 °C, thrombocytopenia, lymphopenia, CRP ≥ 2 mg/dL, and a threshold cycle value of PCR less than 28.5. For respiratory failure, the indicators included male, hypertension, low albumin concentration, thrombocytopenia, lymphopenia, and CRP ≥ 4 mg/dL (all P < 0.05). With ≥ two predictive factors for pneumonia development, 100% of patients developed pneumonia. Patients lacking the predictive factors did not progress to respiratory failure.

Conclusion: For successful control of MERS outbreak, MERS-CoV infected patients with ≥ two predictive factors should be intensively managed from the initial presentation.

Keywords: Disease progression; Middle East respiratory syndrome coronavirus; Pneumonia; Predictive factor; Respiratory failure.

Figure 1

The development and progression of pneumonia in patients with MERS-CoV infection depicted by time sequence MERS-CoV infected patients were divided into three groups: patients without the development of pneumonia (group 1), patients who developed pneumonia without respiratory failure (group 2), and pneumonia patients who progressed to respiratory failure (group 3). (a) Number of patients who developed pneumonia and who received endotracheal intubation due to respiratory failure by the days after symptom onset. Patients in group 3 developed pneumonia earlier than those in group 2, and progressed to respiratory failure sequentially. (b) Overall presentation of pneumonia development and progression. The development of pneumonia, desaturation, endotracheal intubation, and application of ECMO occurred step by step. Abbreviations: ECMO, extracorporeal membrane oxygenation.