Atypical Bacterial Pneumonia

Excerpt

Pneumonia is a lower respiratory tract infection that primarily affects the pulmonary parenchyma. Viruses, fungi, and bacteria can all cause pneumonia. Atypical bacterial pneumonia is caused by bacterial species less frequently associated with pneumonia compared to typical bacterial species, such as Gram-positive Streptococcus pneumoniae or Staphylococcus aureus. These atypical bacteria are also more difficult to detect using traditional Gram stain and standard culture methods. Examples of atypical bacteria include Mycoplasma pneumoniae, Chlamydia (formerly Chlamydophila) pneumoniae, and Legionella species. Similar to typical bacterial pneumonia, the severity of pneumonia can range from mild to life-threatening, with uncomplicated disease resolving with outpatient antibiotics and complicated cases progressing to septic shock, acute respiratory distress syndrome, and death. Atypical bacterial pneumonia affects all age groups and can account for up to 40% of community-acquired pneumonia cases. M. pneumoniae alone is estimated to account for over 2 million cases and 100,000 hospitalizations in the United States. Atypical bacterial pneumonia can cause mortality in both adults and children, and epidemics may occur every few years. Atypical bacteria are known to cause a disproportionate disease burden in children older than 5 and adolescents. These bacteria can initially present subacutely and progress to constitutional symptoms. Proper evaluation of suspected atypical bacterial pneumonia, including a detailed history, physical examination, and targeted investigations, is crucial for the interdisciplinary management of this condition.

Please see StatPearls' companion resource, "Bacterial Pneumonia," for further information.