Mycoplasma pneumoniae and community-acquired pneumonia

Background. Community-acquired pneumonia is an important cause of mortality and hospitalization in all age groups. In temperate climates, Mycoplasma p neumoniae is a common respiratory pathogen causing pneumonia. Information o n human Mycoplasma infection in India is scarce. Methods We aimed to determine the frequency of Mycoplasma pneumoniae infect ion among patients with community acquired pneumonia in a prospective cross -sectional study. The assessment included clinical and radiological evaluat ion followed by microbiological evaluation for the specific pathogen. Micro biological investigations included aerobic and anaerobic blood culture, ant i-Mycoplasma IgM antibody detection by gelatin particle agglutination test and ELISA, culture of respiratory tract secretions for Mycoplasma pneumonia e and other organisms, and detection of specific Mycoplasma pneumoniae anti gen by indirect immunofluorescence. Results. Sixty-two patients (42 men and 20 women; mean age 41.7 years) with community-acquired pneumonia were investigated prospectively. They include d 42 immunocompetent and 20 immunocompromised patients. Six patients had de finitive evidence of Mycoplasma pneumoniae infection and an additional 16 p atients had a probable diagnosis. In all, 22 (35.5) patients with pneumonia had Mycoplasma pneumoniae infection. Of these, 12 patients belonged to the immunocompromised group and 10 to the immunocompetent group. Patients with Mycoplasma pneumoniae infection also had secondary bacterial infection as evidenced by organisms isolated from blood in 50% and from respiratory trac t secretions in 68%. Conclusion. Community-acquired pneumonia has a polymicrobial aetiology, of which the prevalence of Mycoplasma pneumoniae is 35%. The study has two imp lications: (i) Mycoplasma pneumoniae infection is frequently associated wit h secondary bacterial infection; and (ii) initial empirical antibiotic ther apy for community-acquired pneumonia in India must include antibiotics with activity against Mycoplasma pneumoniae.