4
Diagnosis
3. Urinary Antigens
➤ We suggest NOT routinely testing urine for pneumococcal antigen
in adults with CAP (conditional recommendation, low quality
of evidence), except in adults with severe CAP (conditional
recommendation, low quality of evidence).
➤ We suggest NOT routinely testing urine for Legionella antigen
in adults with CAP (conditional recommendation, low quality of
evidence) except
1. in cases where indicated by epidemiological factors, such as association with a
Legionella outbreak or recent travel (conditional recommendation, low quality of
evidence), or
2. in adults with severe CAP (See Table 1) (conditional recommendation, low quality
of evidence).
➤ We suggest testing for Legionella urinary antigen and collecting
lower respiratory tract secretions for Legionella culture on
selective media or Legionella nucleic acid amplification testing in
adults with severe CAP (conditional recommendation, low quality
of evidence).
4. Respiratory Sampling
➤ When influenza viruses are circulating in the community, we
recommend testing for influenza with a rapid influenza molecular
assay (i.e., influenza nucleic acid amplification test), which is
preferred over a rapid influenza diagnostic test (i.e., antigen test)
(strong recommendation, moderate quality of evidence).
