Risk factor-based analysis of community-acquired pneumonia, healthcare-associated pneumonia and hospital-acquired pneumonia: Microbiological distribution, antibiotic resistance, and clinical outcomes

Abstract

Background Healthcare-associated pneumonia (HCAP) lies in the intersection of community-acquired pneumonia (CAP) and hospital-acquired pneumonia (HAP). Although HCAP is excluded from the revised HAP guideline, reassessment for HCAP is needed considering its heterogeneous characteristics. Methods The microbiological distribution, antibiotic resistance, and clinical outcomes in CAP, HCAP, and HAP were studied retrospectively. The susceptibility to standard CAP regimens (β-lactams plus macrolide or fluoroquinolone monotherapy) and rates of methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa (P. aeruginosa) infections were evaluated in the CAP group and HCAP subgroups. Results In total, 933 cases were included (CAP, n = 557; HCAP, n = 264; HAP, n = 112). In the CAP and HCAP cases, Streptococcus pneumoniae (7.4% vs. 5.7%) and P. aeruginosa (9.2% vs. 18.6%) were the most common gram-positive and gram-negative pathogens. Staphylococcus aureus (methicillin-resistant, 2.7%; methicillin-susceptible, 2.4%) and carbapenem-resistant Acinetobacter baumannii (20.5%) were the most common Gram-positive and Gram-negative pathogens in the HAP group, respectively. Higher susceptibility to levofloxacin was observed in CAP and HCAP isolates than that to β-lactam agents. However, levofloxacin non-susceptibility was significantly higher in long-term care facility (LTCF)-onset HCAP compared to community-onset HCAP (43.6% vs. 22.7%, P = 0.014). Conclusion HCAP showed higher rates of P. aeruginosa and MRSA infections than CAP. Empirical antipseudomonal therapy should be considered in the treatment of HCAP. Prior isolation of P. aeruginosa was the most important risk factor for P. aeruginosa infection.

Predictors of hospital mortality and multidrug-resistant pathogens in hospitalized pneumonia patients residing in the community

“…We found that patients’ background characteristics such as age; male sex; being underweight; residence in a nursing home or extended care facility; being bedridden; prior admission; immunosuppression; and comorbidities of heart failure, liver failure, and COPD, as well as severity of conditions at admission, including dehydration, respiratory failure, conscious disturbance, and hypotension were significantly associated with 30-day hospital mortality. These factors have been consistently reported in older studies in the late 1990s and in more recent studies [ [25] , [26] , [27] , [28] , [29] ]. Bedsores were further identified as an independent risk factor for mortality.…”

Gram-negative pulmonary infections – advances in epidemiology and diagnosis

“…The ever-increasing number of people living with chronic diseases and comorbidities, such as structural lung disease, diabetes, chronic kidney disease and immune suppression has also driven a higher risk for pneumonia caused by Gram-negative, often drug-resistant organisms [17 ▪▪ ,18]. Finally, recent antibiotics, being bed-bound or living in a long-term care facility, also maps to a higher risk for drug-resistant organisms in CAP [19].…”

Ten Issues for Updating in Community-Acquired Pneumonia: An Expert Review

“…The incidence of the different drug-resistant pathogens (DRP) in CAP is variable in different studies, ranging from 3.5% to 45% [141][142][143][144][145][146]. Several factors play a role, such as the year or location of the study, patient profiles, their risk factors, severity at presentation, etc.…”

“…Several factors play a role, such as the year or location of the study, patient profiles, their risk factors, severity at presentation, etc. (Table 7) [141][142][143][144][145][146]. The prevalence of DRP-CAP varies according to the region.…”

“…However, as with other infectious diseases, we do not have specific risk factors for the different DRPs causing CAP. Although we should consider an empirical antibiotic therapy (AET) for DTP in patients with a combination of certain risk factors such as those with chronic lung disease with recent antibiotic or steroid use, immunosuppression, receiving chronic invasive treatments or with close contact with home services [141][142][143][144]. The weight of each risk factor for a given pathogen is not equal.…”