Identify Drug-Resistant Pathogens in Patients with Community-Acquired Pneumonia

HIGHLIGHTS: What are the main findings? The identification of patients with CAP at high risk for resistant pathogens is of outstanding clinical interest due to the worse outcome of these patients. However, the HCAP classification and the scores proposed in literature to identify resistant pathogens in CAP are overly sensitive, leading to inappropriately broad-spectrum antibiotic use. What is the implication of the main finding? As suggested by the new IDSA/ATS guidelines, it is crucial to generate local data concerning DRP in order to identify and validate risk factors at a local level. Identification of new, rapid and specific diagnostic tests for DRP represents a clinical priority to improve the outcomes of CAP patients. ABSTRACT: A substantial increase in broad-spectrum antibiotics as empirical therapy in patients with community-acquired pneumonia (CAP) has occurred over the last 15 years. One of the driving factors leading to that has been some evidence showing an increased incidence of drug-resistant pathogens (DRP) in patients from a community with pneumonia, including methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa. Research has been published attempting to identify DRP in CAP through the implementation of probabilistic approaches in clinical practice. However, recent epidemiological data showed that the incidence of DRP in CAP varies significantly according to local ecology, healthcare systems and countries where the studies were performed. Several studies also questioned whether broad-spectrum antibiotic coverage might improve outcomes in CAP, as it is widely documented that broad-spectrum antibiotics overuse is associated with increased costs, length of hospital stay, drug adverse events and resistance. The aim of this review is to analyze the different approaches used to identify DRP in CAP patients as well as the outcomes and adverse events in patients undergoing broad-spectrum antibiotics.