Healthcare-associated Pneumonia Definition Research Articles

2177. Institutional Prevalence of Drug-Resistant Pathogens in Community-Acquired Pneumonia

Abstract Background Community-acquired pneumonia (CAP) is a leading cause of hospitalizations and plays a major role in mortality. The previous Infectious Diseases Society of America (IDSA) definition of healthcare-associated pneumonia (HCAP) was found to be neither sensitive nor specific for identifying drug-resistant pathogens including methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa (PsA) as a cause of CAP, and use is no longer supported by current guidelines. The 2019 IDSA guidelines for CAP management emphasizes the need for clinician understanding of local epidemiology data to guide selection of appropriate treatment. The primary objective of this study was to determine the prevalence of MRSA and PsA CAP at our institution. Methods This was a retrospective observational study of patients admitted to our 870-bed public hospital with a CAP or HCAP diagnosis within 48 hours of admission between March 2016 and March 2021. The primary outcome of prevalence of CAP caused by MRSA or PsA was determined by comparing the number of blood and adequate sputum cultures with MRSA or PsA to total reviewed cases. Secondary outcomes included the percentage of initial antibiotic regimens involving a broad-spectrum agent, percentage of initial broad-spectrum regimens de-escalated within 72 hours if indicated, and duration of CAP antibiotic treatment. Results A total of 220 patients were included. MRSA or PsA was isolated in 1.36% of adequate sputum cultures collected (n=3/35) and in no collected blood cultures (n=0/208). The local prevalence of CAP caused by MRSA or PsA among the analyzed sample was 1.36% (n=3/220) (Table 1). MRSA nares screening tests were completed in 10% of cases, 4.5% of which were positive (n=1/22). Secondary end point results are presented in Table 2.Table 1.Prevalence of MRSA and PsA in CAP Based on Culture DataTable 2.Secondary Outcome Data Conclusion The overall prevalence of CAP caused by MRSA or PsA among admitted patients is low at Parkland Hospital. Further research is needed to identify local risk factors associated with CAP caused by drug-resistant pathogens. Disclosures All Authors: No reported disclosures.

Prospective Evaluation of a Novel Treatment Algorithm for Health Care-Associated Pneumonia

Background The current health care–associated pneumonia (HCAP) model may be too broad, leading to inappropriate use of broad-spectrum antibiotics. As a result, therapeutic algorithms, such as what Maruyama et al validated, have been developed for a more specific therapy. Our study aims to validate this algorithm in our patient population. Methods This is a single-center, prospective, cohort study, with a historical control cohort. The prospective cohort followed an outlined algorithm to determine empiric therapy as compared with a historical cohort, which followed the standard of care. Prospective cohort patients were categorized as low versus high risk based on the algorithm and started on empiric community-acquired pneumonia (CAP) or HCAP regimens, respectively. Primary objectives included length of stay and initial empiric failure. Secondary objectives included patients treated with CAP versus HCAP regimens, intravenous to oral conversion time, antibiotic duration, and incidence of acute kidney injury. Results There was no difference in the primary outcomes of length of stay and initial empiric regimen. Secondary outcomes were significant for elevated frequency of empiric CAP regimens compared with HCAP regimens and shorter antibiotic duration. Conclusions The current definition of HCAP may be too expansive leading to the overuse of broad-spectrum antibiotics. Risk stratification based on the presence of multidrug-resistant risk factors and severity of illness may prove to be a useful assessment tool in determining targeted empiric therapy and limit the propagation of bacterial resistance.

Risk factors to predict drug-resistant pathogens in hemodialysis-associated pneumonia.

BackgroundAfter the concept of healthcare associated pneumonia (HCAP) was introduced in 2005 by the American Thoracic Society/Infectious Disease Society of America (ATS/IDSA), pneumonia in hemodialysis patients has been classified as HCAP. Even though there are several risk factors and scoring systems of drug-resistant pathogens (DRPs) in HCAP, the risk factors for DRPs in hemodialysis-associated pneumonia are unclear.MethodsPatients who were admitted to our tertiary care hospital from January 2005 to December 2010 were screened by a discharge diagnosis of pneumonia. Patients were enrolled if they fulfilled the definition of HCAP according to the 2005 ATS/IDSA guidelines.ResultsA total of 530 subjects were diagnosed with HCAP, of whom 48 (9.1 %) received regular hemodialysis (HD group) and the other 482 did not (non-HD group). The most common pathogens in HD group were Pseudomonas aeruginosa and methicillin resistant Staphylococcus aureus (MRSA). There was a similar distribution of Gram-negative bacilli infections between the two groups except for Haemophilus influenzae and Citrobacter species. The incidence of DRPs was not significantly different between the two groups (HD vs. non-HD, 35.4 vs. 39.2 %, p = 0.607). Wound care, severe pneumonia and an age of more than 70 years were significant risk factors for DRPs. The area under the operating cure of predicting DRPs was 0.727 (0.575–0.879, p = 0.01).ConclusionP. aeruginosa and MRSA were the most important pathogens in hemodialysis-associated pneumonia. Wound care, severe pneumonia and old age were significant risk factors for DRPs.

Multidrug-resistant pathogens in patients with pneumonia coming from the community.

Identification of patients with multidrug-resistant (MDR) pathogens at initial diagnosis is essential for the appropriate selection of empiric treatment of patients with pneumonia coming from the community. The term Healthcare-Associated Pneumonia (HCAP) is controversial for this purpose. Our goal is to summarize and interpret the data addressing the association of MDR pathogens and community-onset pneumonia. Most recent clinical studies conclude that HCAP risk factor does not accurately identify resistant pathogens. Several risk factors related to MDR pathogens, including new ones that were not included in the original HCAP definition, have been described and different risk scores have been proposed. The present review focuses on the most recent literature assessing the importance of different risk factors for MDR pathogens in patients with pneumonia coming from the community. These included generally MDR risk factors, specific risk factors related to methicillin-resistant Staphylococcus aureus or Pseudomonas aeruginosa and clinical scoring systems develop to assess the MDR risk factors and its application in clinical practice. Different MDR risk factors and prediction scores have been recently developed. However, further research is needed in order to help clinicians in distinguishing between different MDR pathogens causing pneumonia.

Healthcare-associated pneumonia: Who is truly at risk for multidrug-resistant pathogens?

In 2005, joint guidelines issued by the American Thoracic Society (ATS) and the Infectious Diseases Society of America (IDSA) provided the first definition of healthcare-associated pneumonia (HCAP).[1][1] This new classification was added to the existing classes of community-acquired pneumonia (CAP

A Critical Evaluation of Healthcare-Associated Pneumonia and the Need for Anti-pseudomonal Therapy, Including Double Coverage

In 2005, healthcare-associated pneumonia (HCAP) was described as a distinct entity, reflecting the concern that patients with HCAP have mortality rates and microbiologic culprits more akin to patients with hospital-acquired pneumonia (HAP) and, thus, warrant treatment similar to HAP, including empiric broad spectrum antibiotics. Increasing evidence suggests that the HCAP definition and criteria are insufficient predictors of which patients are at highest risk of being infected with a multi-drug resistant organism (MDRO); this lack of accuracy leads to overuse of broad spectrum antibiotics. New risk stratification schemes have been proposed that may supplant our current reliance on HCAP criteria for identifying patients who may be infected with an MDRO. Regardless of the risk stratification method used, antibiotic decisions must account for local MDRO prevalence rates. In settings where P. aeruginosa resistance to anti-pseudomonal therapies is high or in patients who are critically ill, empiric combination therapy for P. aeruginosa may be considered. However, therapy should be narrowed to a single agent once an effective agent has been identified from culture susceptibility data.

Surveillance cultures in healthcare-associated pneumonia

This review explores the usefulness of surveillance cultures in healthcare-associated pneumonia (HCAP). The definition of HCAP is controversial. Causative micro-organisms of HCAP resemble those found in hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP). Some types of surveillance cultures have proven useful in hospitalized patients. Whereas numerous studies have investigated the role of surveillance cultures in VAP, one may wonder whether surveillance culture implementation should belong in HCAP management guidelines. Studies exploring the usefulness of obtaining surveillance cultures in VAP are numerous, but are mostly retrospective, observational and/or quasi-experimental in nature. Surveillance cultures may be useful for antibiotic guidance, but positive predictive value and specificity of surveillance cultures are low, obviously negatively impacting on cost effectiveness, especially in the large population at risk for HCAP. On the other hand, multidrug-resistance is increasing and surveillance cultures for methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci in ICU-admitted patients appeared useful and cost-effective. Furthermore, surveillance cultures for the presence of multidrug-resistant Gram-negative bacilli might be useful for antibiotic guidance. Currently, neither community-acquired pneumonia, HCAP, HAP nor VAP guidelines incorporate surveillance cultures. In the future, surveillance cultures in populations at risk for HCAP may be able to differentiate HCAP from other kinds of pneumonia and authorize its reason for existence.

Development and validation of a clinical risk score for predicting drug‐resistant bacterial pneumonia in older Chinese patients

Health care-associated pneumonia (HCAP) and drug-resistant bacterial pneumonia may not share identical risk factors. We have shown that bronchiectasis, recent hospitalization and severe pneumonia (confusion, blood urea level, respiratory rate, low blood pressure and 65 year old (CURB-65) score ≥ 3) were independent predictors of pneumonia caused by potentially drug-resistant (PDR) pathogens. This study aimed to develop and validate a clinical risk score for predicting drug-resistant bacterial pneumonia in older patients. We derived a risk score by assigning a weighting to each of these risk factors as follows: 14, bronchiectasis; 5, recent hospitalization; 2, severe pneumonia. A 0.5 point was defined for the presence of other risk factors for HCAP. We compared the areas under the receiver-operating characteristics curve (AUROC) of our risk score and the HCAP definition in predicting PDR pathogens in two cohorts of older patients hospitalized with non-nosocomial pneumonia. The derivation and validation cohorts consisted of 354 and 96 patients with bacterial pneumonia, respectively. PDR pathogens were isolated in 48 and 21 patients in the derivation and validation cohorts, respectively. The AUROCs of our risk score and the HCAP definition were 0.751 and 0.650, respectively, in the derivation cohort, and were 0.782 and 0.671, respectively, in the validation cohort. The differences between our risk score and the HCAP definition reached statistical significance. A score ≥ 2.5 had the best balance between sensitivity and specificity. Our risk score outperformed the HCAP definition to predict pneumonia caused by PDR pathogens. A history of bronchiectasis or recent hospitalization is the major indication of starting empirical broad-spectrum antibiotics.

Editorial Commentary: Healthcare-Associated Pneumonia: Where Do We Go Next?

Editorial Commentary: Healthcare-Associated Pneumonia: Where Do We Go Next?

The definition of healthcare-associated pneumonia (HCAP) is insufficient for the medical environment in Japan: a comparison of HCAP and nursing and healthcare-associated pneumonia (NHCAP)

Healthcare-associated pneumonia (HCAP) is a new concept of pneumonia, which was proposed in the ATS/IDSA guidelines. The guidelines explain that HCAP patients should be treated with broad-spectrum antimicrobial drugs directed at multidrug-resistant pathogens. However, in Japan, there are many elderly people who received in-home care service. These patients seemed to be consistent with the concept of HCAP, but they did not meet the definition of HCAP. Therefore, the Japanese Respiratory Society modified the definition of HCAP according to the medical environmental in Japan. We retrospectively observed HCAP patients and nursing home and healthcare-associated pneumonia (NHCAP) patients who were hospitalized during 24 months at the Japanese Red Cross Nagasaki Genbaku Hospital (Nagasaki, Japan). Patient background, disease severity, identified pathogens, initial antibiotic regimens, and outcomes were compared. A total of 108 patients (77 HCAP and 31 NHCAP except HCAP patients) were evaluated. Of NHCAP except HCAP patients, 27 (87.1 %) were above 3 in the ECOG PS score. There were almost no significant differences between the two groups in characteristics, pneumonia severity, identified bacteria, initial antibiotic regimens, and response rate of initial antibiotic therapy. Although the in-hospital mortality of HCAP patients and NHCAP except HCAP patients was 9.1 % and 19.4 %, respectively, this difference did not reach statistical significance (P > 0.05). Our study suggested that, in the criteria of HCAP, some Japanese patients, who were consistent with the concept of HCAP, were classified as community-acquired pneumonia (CAP). Therefore, there is a need to change the definition of HCAP according to the medical environment in Japan.

Comparison of clinical characteristics between healthcare-associated pneumonia and community-acquired pneumonia in patients admitted to secondary hospitals

BackgroundSince healthcare-associated pneumonia (HCAP) is heterogeneous, clinical characteristics and outcomes are different from region to region. There can also be differences between HCAP patients hospitalized in secondary or tertiary hospitals. This study aimed to evaluate the clinical characteristics of HCAP patients admitted into secondary community hospitals. MethodsThis was a retrospective study conducted in patients with HCAP or community-acquired pneumonia (CAP) hospitalized in two secondary hospitals between March 2009 and January 2011. ResultsOf a total of 303 patients, 96 (31.7%) had HCAP. 42 patients (43.7%) resided in a nursing home or long-term care facility, 36 (37.5%) were hospitalized in an acute care hospital for ≥ 2 days within 90 days, ten received outpatient intravenous therapy, and eight attended a hospital clinic or dialysis center. HCAP patients were older. The rates of patients with CURB-65 scores of 3 or more (22.9% vs. 9.1%; p=0.001) and PSI class IV or more (82.2% vs. 34.7%; p<0.001) were higher in the HCAP group. Drug-resistant pathogens were more frequently detected in the HCAP group (23.9% vs. 0.4%; p<0.001). However, Streptococcus pneumoniae was the most common pathogen in both groups. The rates of antibiotic change, use of inappropriate antibiotics, and failure of initial antibiotic therapy in the HCAP group were significantly higher. Although the overall survival rate of the HCAP group was significantly lower (82.3% vs. 96.8%; p<0.001), multivariate analyses failed to show that HCAP itself was a prognostic factor for mortality (p=0.826). Only PSI class IV or more was associated with increased mortality (p=0.005). ConclusionsHCAP should be distinguished from CAP because of the different clinical features. However, the current definition of HCAP does not appear to be a prognostic for death. In addition, the use of broad-spectrum antibiotics for HCAP should be reassessed because S. pneumoniae was most frequently identified even in HCAP patients.

Clinical Scoring for Risk of Resistant Organisms in Pneumonia: Right Idea, Wrong Interpretation

To the Editor—In their recent article, Shorr and colleagues present a new clinical tool to predict risk of drug-resistant bacterial pneumonia in patients presenting to emergency departments [1]. Improving risk assessment and minimizing inappropriate antibiotic use are necessary given the increasing prevalence of resistant pathogens and the risk of selecting for further resistance through overuse of broad-spectrum antibiotics, but this new risk score has several weaknesses. A weighted risk score is an attractive strategy to improve clinical decision making, but the authors overstate its advantages over the existing healthcare-associated pneumonia (HCAP) definition. Although the authors assert that their new risk score is superior to HCAP criteria because it incorporates weighting of risk factors, the cutoff of 0 turns the risk score into a dichotomous tool by which the presence of any risk factor yields a score considered positive rather than a stratified risk score. Under this conclusion, the predictive ability of the new tool is comparable (but not superior) to the current HCAP definition. Using a dichotomous risk tool ignores the information contained in a scoring system, and such a tool cannot be compared directly with the HCAP criteria. To compare the two, cutoff points should be contrasted for persons meeting 1, 2, or more HCAP or risk score criteria. The authors could further improve the predictive ability of their score by presenting likelihood ratios for each of the risk scores of the new tool. The authors present single positive and negative predictive values based on a risk score of 0, but these statistics could be calculated for other scores as well. Because of the effect of prevalence on the performance of diagnostic tests, we are concerned that the prevalence of drug-resistant pathogens reported in the study is inaccurate due to verification bias that occurs when the action of performing a test is affected by the pretest probability of disease [2]. The authors report a 47% prevalence of drug-resistant pathogens, likely an overestimation. A medical history suggesting a person had high risk for drug-resistant bacterial infection might influence physicians’ decisions to obtain cultures, a criterion for inclusion in the study. Persons without significant healthcare exposure might be deemed low-risk by clinicians, who would not order cultures, leading to underrepresentation of these patients in this study. Verification bias results in overestimation of the sensitivity and underestimation of the specificity of the new risk score. Unfortunately it is difficult to confirm that verification bias has occurred; however, the authors could have performed sensitivity analyses or controlled for culture collection to assess this problem. Finally, the most appropriate cutoff for risk score is determined by weighing the costs of further testing or broad-spectrum antibiotic use in patients who do not need them against benefits of appropriate early therapy in those infected with drug-resistant pathogens. This balance will depend on the clinical characteristics and risk factors of the patients, societal views of medical care, and economic considerations. Although the HCAP definition reaches an imperfect balance, the authors’ clinical risk score fails to improve upon that standard.

Is healthcare-associated pneumonia a distinct entity needing specific therapy?

Healthcare-associated pneumonia (HCAP) was introduced in 2005 by American Thoracic Society/Infectious Diseases Society of America guidelines as a new entity of pneumonia, resembling nosocomial pneumonia rather than community-acquired pneumonia (CAP) in terms of frequency of multidrug-resistant (MDR) pathogens and outcomes, thus requiring broad spectrum initial antimicrobial coverage in order to prevent inadequate treatment and, as a consequence, excess mortality. This concept continues to be a subject of controversy. Main concerns relate to the definition of HCAP, the true frequency of MDR pathogens, and the impact of MDR pathogens on outcomes. Definitions of HCAP and the relative frequencies of HCAP defining subgroups were highly variable. All studies demonstrated an increased severity of pneumonia at presentation and an excess mortality from HCAP as compared to CAP. The incidence of MDR pathogens in different observational studies was slightly increased but generally low in most studies originating from Europe, South Korea, Canada, and Japan. However, the data do not support a causal relationship of MDR incidence and excess mortality. Instead, after adjustment for confounders, mortality might be related to hidden or documented treatment restrictions in elderly and severely disabled patients. Accordingly, HCAP guideline concordant antimicrobial treatment did not improve outcomes. The HCAP concept is based on varying definitions poorly predictive of MDR pathogens. The incidence of MDR pathogens is far lower than supposed in the original guideline document, and MDR pathogens do not seem to be the main cause of excess mortality. Broad antimicrobial coverage does not alter outcomes. As the HCAP concept results in a tremendous overtreatment without any evidence for improved outcomes, it should not be implemented in clinical practice prior to clear evidence that it is superior to a careful assessment of individual risk factors for MDR pathogens.

UNDERSTANDING THE HEALTH CARE-ASSOCIATED PNEUMONIA (HCAP) DEFINITION

PURPOSE: Health care associated pneumonia (HCAP) has recently been described as a new and distinct entity. Certain risk factors included in the HCAP definition are associated with multi-drug resistant (MDR) pathogens. Therefore, our objective was to assess the recommended HCAP definition in order to identify MDR pathogens.