Aetiological agents of community acquired pneumonia

Sir,

The article of Asghar's et al1 about bacterial pneumonia during Hajj. They reported that most common aetiological agents were Candida albicans (27.5%), Pseudomonas aeruginosa (20.9%) and Legionella pneumophila (14.3%) in their community acquired pneumonia (CAP) patients. We disagree with this information, because it is known that most common aetiological agents of CAP are Streptococcus pneumoniae, Haemophilus influenzae, Moroxella catarrhalis and atypical agents (Mycoplasma, Legionella, Chlamydia and viruses).

Defintive aetiologic diagnosis of CAP is still uncertain. In general, Pseudomanas spp. is expected in hospital acquired settings while Candida pneumonia in immunocompetent individuals is very rare in community acquired settings3. Many factors may be related with the high rate of Candida and Pseudomanas spp. isolations in their patients suspected to have pneumonia. Isolation of Candida from the respiratory tract is common4. Because of a reasonably high occurrence of yeasts colonizing the respiratory region, diagnosis of Candida pneumonia should not be made based on only clinical, bacteriological and radiographic findings. The diagnosis could be done with lung biopsy findings or mannan test for definitive diagnosis of Candida pneumonia.

Most of their Candida and Pseudomonas isolates may be respiratory tract colonizing microorganism. So, they should clarify as to how they differentiated the causative agents from the colonized microbial agents.