Diagnostic Tests for Agents of Community- Acquired Pneumonia Essay

Worldwide, lower respiratory tract infections are the major cause of death due to an infectious disease. Community-acquired pneumonia (CAP) is possibly the most important infectious disease that is encountered in clinical practice. Most forms of community-acquired pneumonia (CAP) are treatable. There is consensus that the selection of antimicrobial agents is notably simplified if the pathogen is defined. This article will focus on how aetiological tests can be used to guide antibiotic therapy in adult patients with CAP. The role of aetiological testing for antimicrobial therapy in CAP A major role of aetiological testing in CAP is to enable the use of pathogen-directed therapy, and thus reduce the use of broad-spectrum antibiotics and improve the outcome in patients. It has been suggested that the antibiotic therapy should be started within 4 h of hospital admission [4, 8], hence rapid tests with a shorter analysis time can be used to influence the choice of first-line antibiotic therapy. Rapid tests include, sputum gram strain, urinary antigen tests, and real-time PCR for respiratory pathogens. Less rapid tests, such as cultures, conventional PCR for respiratory pathogens, and serology, may provide useful information that may support ongoing antibiotic therapy, support narrowing of broad-spectrum therapy, and support therapy changes in case of treatment failure [3]. Culture of blood and respiratory specimens may be important for the identification of unexpected or uncommon CAP aetiologies that the empirical treatment does not cover for, e.g., Pseudomonas spp., methicillin-resistant S. aureus, and other highly resistant pathogens. Culture remains a cornerstone of the diagnostic techniques, as it can provide information abou... ...ing to the BTS and Swedish guidelines [7,8]. Suggested strategy for diagnostic testing A strategy for diagnostic testing in hospitalized CAP patients is presented in Table 3. It is based on disease severity and presence/absence of prior antibiotic therapy. Conclusion In order to cure CAP patients without causing unnecessary side effects and without contributing to the development of antibiotic resistance, antibiotic therapy should be carefully selected. Although patients with severe CAP should be treated with broad-spectrum antibiotics, patients with non-severe CAP should preferably receive pathogen-directed therapy. While rapid aetiological tests may be useful for targeting initial pathogen-directed therapy, non-rapid tests may support switch from broad- to narrow-spectrum antibiotic therapy and support therapy changes in the case of treatment failure.