Current American Academy of Pediatrics Red Book recommendations note that detection of S. pneumoniae is not useful in children because asymptomatically colonized children may have positive test results.
S. pneumoniae vaccine may cause false positive results up to 10 days after vaccination.
Administration of antibiotics might influence the test results for S. pneumoniae.
A negtive result does not exclude an S. pneumoniae infection. The result of this test as well as culture, serology, or other antigen detection methods should be used in conjunction with clinical findings to make an accurate diagnosis.
A negative result does not exclude the possibility of a Legionella infection, as it can be caused by other serogroups and Legionella species. There is no single satisfactory laboratory test for Legionnaires' Disease. Therefore, culture results, PCR, serology, and/or antigen detection methods should be used in conjunction with clinical findings to make an accurate diagnosis.
False results may occur from highly basic (pH>=9) urine and give false positive S. pneumoniae results. Water-based personal lubricant might result in false positive L. pneumophila when found in the sample at hight levels.