Advances in diagnosis and treatment for respiratory infection by atypical pathogens

The incidence of atypical pneumonia is pretty high throughout the world,accounting for 15%-50% of the community-acquired pneumonia.Epidemiological studies have revealed that Mycoplasma pneumoniae (MP) ranks the top among the pathogens which are most likely to cause atypical pneumonia,while Chlamydia pneumoniae (CP) ranks the second and Legionella pneumophila (LP) the lowest.However,LP may induce outbreak of pneumonia with the highest mortality.Q fever pneumonia is also one type of atypical pneumonia,which is not commonly seen in clinic and rarely reported.Definite diagnosis of atypical pneumonia remains a difficult problem since specific clinical presentations are unavailable,with difficulties in culturing etiological agents,and low value of serum tests for diagnosis.Nevertheless,PCR assay seemed to be an important technique for early diagnosis of atypical pneumonia,provided that false positive rate was effectually reduced by strict quality control.Regarding to the therapeutic drugs,macrolides and quinolones are the most effective ones for the treatment of atypical pneumonia.Those drugs covering atypical pneumonia related pathogens are recommended for initial treatment for patients with community-acquired pneumonia.Moreover,patients who are suspected to have Legionella pneumophila infection are recommended to take quinolones to decrease mortality.