Incidence, Etiology, and Outcomes of Community-Acquired Pneumonia: A Population-Based Study

Abstract

BackgroundThe microbial etiology of community-acquired pneumonia (CAP) is often unclear in clinical practice, and previous studies have produced variable results. Population-based studies examining etiology and incidence are lacking. This study examined the incidence and etiology of CAP requiring hospitalization in a population-based cohort as well as risk factors and outcomes for specific etiologies.MethodsConsecutive admissions due to CAP in Reykjavik, Iceland were studied. Etiologic testing was performed with cultures, urine-antigen detection, and polymerase chain reaction analysis of airway samples. Outcomes were length of stay, intensive care unit admission, assisted ventilation, and mortality.ResultsThe inclusion rate was 95%. The incidence of CAP requiring hospitalization was 20.6 cases per 10000 adults/year. A potential pathogen was detected in 52% (164 of 310) of admissions and in 74% (43 of 58) with complete sample sets. Streptococcuspneumoniae was the most common pathogen (61 of 310, 20%; incidence: 4.1/10000). Viruses were identified in 15% (47 of 310; incidence: 3.1/10000), Mycoplasmapneumoniae were identified in 12% (36 of 310; incidence: 2.4/10000), and multiple pathogens were identified in 10% (30 of 310; incidence: 2.0/10000). Recent antimicrobial therapy was associated with increased detection of M pneumoniae (P < .001), whereas a lack of recent antimicrobial therapy was associated with increased detection of S pneumoniae (P = .02). Symptoms and outcomes were similar irrespective of microbial etiology.ConclusionsPneumococci, M pneumoniae, and viruses are the most common pathogens associated with CAP requiring hospital admission, and they all have a similar incidence that increases with age. Symptoms do not correlate with specific agents, and outcomes are similar irrespective of pathogens identified.

Emerging Resistance of Gram Negative Pathogens in Community-Acquired Pneumonia

“…[36][37][38] Novel molecular techniques studies expanded the microbiological identification in 38 to 87% of cases with CAP. [39][40][41][42] Geographic heterogeneity is also common at different levels and represents a challenge to define a "one size fits all" strategy. Studies performed in the United States have shown a higher prevalence of GNB compared with European studies.…”

Clinical Utility of Methicillin‐Resistant Staphylococcus aureus Nasal Screening for Antimicrobial Stewardship: A Review of Current Literature

“…Both guidelines advocate for early discontinuation of empirical anti‐MRSA therapy based on negative culture results because failure to detect S. aureus on culture is strong evidence of the absence of S. aureus . An alternative means of detecting MRSA is particularly valuable in pneumonia, where a suitable respiratory specimen for culture is obtained only 30–50% of the time …”

“…5,31 An alternative means of detecting MRSA is particularly valuable in pneumonia, where a suitable respiratory specimen for culture is obtained only 30-50% of the time. [32][33][34][35] The performance of MRSA nasal screening to predict MRSA pneumonia was reviewed comprehensively in a recent meta-analysis of 22 studies that included a total of 5243 patients. 36 In this meta-analysis, MRSA nasal screening had a pooled sensitivity of 70.9%, specificity of 90.3%, PPV of 44.8%, and NPV of 96.5% for MRSA pneumonia.…”

Air Pollutants and Hospital Visits for Pneumonia: A Case-crossover Study in Qingdao, China.

“…Smoking, irregular lifestyles, chronic diseases, and weakened immune systems could increase the risk of pneumonia occurs. Although considerable progress has made in understanding and treatment of pneumonia over the past years [4,5], further research is still needed to explore risk factors and more effective treatment to reduce the occurrence of such events.…”