Etiologies of Acute Respiratory Tract Infections

Abstract

A case-control method was used in the Dutch trial, and ILI was defined as an “acute onset of illness” (duration of prodromal stage, 3‐4 days) and the presence of at least 1 of the following symptoms: cough, rhinitis, sore throat, frontal headache, retrosternal pain, or myalgia. ARTI was defined as an acute respiratory illness other than ILI with at least 1 of the following symptoms: cough, rhinitis, or sore throat. Nose and throat swab specimens were obtained from case patients and control subjects, and viral cultures and PCR tests were performed for detection of adenovirus, coronavirus, enterovirus, hMPV, influenza virus, parainfluenza virus, rhinovirus, and respiratory syncytial virus (RSV), as well as for Mycoplasma pneumoniae, Chlamydophila pneumoniae, and Chlamydophila psittaci. Bacterial cultures of throat swab specimens were also performed to detect all bacterial pathogens that are known to potentially cause “community-acquired” respiratory infection. The findings were then semiquantitatively classified into 5 groups: no colonies, sporadic colonies, few colonies, several colonies, or many colonies.