How to identify respiratory pathogens in primary health care - a review on the benefits, prospects and pitfalls in using point of care tests.

Purpose: Respiratory tract infections are among the most common reasons for consultations in primary health care (PHC) settings. In this review, we aim to provide an overview of diagnostic tests for selected respiratory pathogens useful in PHC.

Methods: We performed a PubMed search on diagnostic tests for influenza virus, respiratory syncytial virus (RSV), Severe Acute Respiratory Syndrome Coronavirus type 2 (SARS-CoV-2), Streptococcus pneumoniae, Legionella pneumophila, Mycoplasma pneumoniae and Bordetella pertussis. We then selected and summarized clinical trials, meta-analyses and systematic reviews published between May 1994 and April 2025 relevant to PHC.

Results: Diagnostic tests are useful if the test result will guide subsequent clinical management. Polymerase chain reaction (PCR) tests have high diagnostic accuracy but are not always available in PHC. Accurate rapid antigen detections tests (RADTs) are required to have a sensitivity of at least 80% and a specificity of at least 97% and are available for influenza virus, RSV and SARS-CoV-2 as are urinary antigen tests for Streptococcus pneumoniae and Legionella pneumophila. In contrast, due to the lack of appropriate RADTs, infections with Mycoplasma pneumoniae or Bordetella pertussis typically require PCR tests.

Conclusion: From a clinical perspective, the differentiation between viral and bacterial infections and the accurate identification of the specific causative agent may guide medical interventions including antimicrobial therapy. From a diagnostic perspective, adequate microbiologic sampling and careful interpretation of laboratory test results in a clinical context are central requirements.