Chart 4. Advantages and disadvantages of using biomarkers in infectious diseases.

Advantages
Provide information that is specific to infections requiring antibiotics
High levels in bacterial infections and low levels in viral infections
Levels increase rapidly in bacterial infections
Response does not depend on the organism
Levels may be altered at disease onset, before clinical and radiological abnormalities
May help define prognosis
Improve the yield of severity scores
Help monitor therapeutic response
May be more specific than clinical manifestations
May help reduce antibiotic use without adverse consequences
Disadvantages
Results may conflict with careful clinical assessment
Previous use of antibiotics may rapidly reduce levels and lead to false-negative findings
May not differentiate between pneumonia caused by atypical pathogens and viral pneumonia
Do not always recognize influenza complicated by bacterial infection
Do not distinguish between chemical aspiration pneumonia and secondary bacterial aspiration pneumonia

Adapted from Müller et al. ⁵²