Mycoplasma pneumoniae infection is associated with subacute cough

Abstract

To the Editor: Cough, one of the most common reasons patients seek medical attention [1], is categorised according to duration. Acute cough lasts 8 weeks [2, 3]. Acute cough is usually due to viral infection; it is transient and self-limiting [4]. Chronic cough has a variety of causes that can be established in 88–100% of patients using a diagnostic algorithm [3]. In contrast, the aetiology of subacute cough remains poorly defined, although post-infectious cough, sinusitis, post-nasal drip and bronchial asthma are listed as possible causes [2, 3, 5, 6]. As subacute cough is often refractory to recommended therapies, a better understanding of its aetiology is needed. The present work examined a possible role for Mycoplasma pneumoniae infection in subacute cough. Between July 2010 and June 2011, patients who visited the Dept of Respiration at the Affiliated Hospital of Academy of Military and Medical Sciences (AHAMMS, Beijing, China) on their own initiative were screened and enrolled if they met the following criteria: cough was the only major complaint; cough was not associated with haemoptysis; cough had lasted for 3–8 weeks (determined by patient recall); chest radiography was normal; and age ≥15 years. Exclusion criteria included inpatient status, a prior history of lung or other systemic disease that could account for cough, current or past smoking, taking angiotensin-converting enzyme inhibitors, known immunodeficiency or pregnancy. Control subjects were enrolled from healthy medical staff in the department, their family members and relatives of patients who accompanied the patients. Control subjects had no cough for ≥1 month and were subject …