Viral etiology of respiratory tract infection in patients with hematologic malignancy

  Background  Patients with hematological malignancies are prone to complicate respiratory viral infections due to low immunity, and clinicians are prone to ignore such infections.

  Objective  To investigate the viral etiological characteristics of respiratory tract infection in patients with hematological malignancies.

  Methods   Throat swab specimens were collected from 442 patients with respiratory infections admitted to the Fifth Medical Center of Chinese PLA General Hospital from October 2018 to January 2020, and clinical data were recorded. The sample included 229 patients with hematological malignancies complicated by respiratory infections and 213 patients with respiratory infections alone. The collected throat swab samples were tested for respiratory viral nucleic acids by real-time PCR for eight viruses: influenza virus (IFV), parainfluenza virus (PIV), respiratory syncytial virus (RSV), metapneumovirus (MPV), human bocavirus (HBoV), adenovirus (ADV), human coronavirus (HCoV) and rhinovirus (HRV).

  Results   The viral positive rate (48.03% vs 34.27%, P=0.003) and viral load (29.65 ± 4.07 vs 31.51 ± 3.58, P＜0.001) in the patients with hematological malignancies complicated by respiratory infection were significantly higher than those in the patients with respiratory infection alone. The viral positive rates from high to low in patients with hematologic malignancies and respiratory infections ranked as IFV (14.85%), RSV (12.66%), HRV (5.68%), HCoV (3.49%), MPV (3.06%), PIV (2.18%), ADV (0.87%), and HBoV (0.00%). White blood cell (WBC) and lymphocyte count (LYM) decreased in patients positive for different hematological malignancies, especially in patients with acute myeloid leukemia (AML) (0.77 0.36, 1.23 × 10⁹/L vs 1.08 0.63,1.60 × 10⁹/L, P=0.037).

  Conclusion   The susceptibility of patients with hematological malignancies complicated with respiratory infection is significantly higher than that of patients with respiratory infection alone, mainly with IFV, RSV and HRV infections. AML respiratory virus-positive patients have a lower LYM than negative patients.