Clinical Features and Risk Factors Associated With 30-Day Mortality in Patients With Pneumonia Caused by Hypervirulent Klebsiella pneumoniae (hvKP)

Abstract

Background Reports on metastatic or invasive infections by hypervirulent Klebsiella pneumoniae (hvKP) have increased recently. However, the effects of its virulence on clinical course and outcomes in pneumonia patients have rarely been addressed. We assessed and compared the clinical features of hvKp and classic K. pneumoniae (cKP) strains isolated from patients with pneumonia caused by K. pneumoniae . We also investigated the effects of virulence factors and the K. pneumoniae capsular serotypes K1 and K2 on mortality. Methods In this retrospective study, we enrolled 91 patients diagnosed as having pneumonia caused by K. pneumoniae and obtained their demographic and clinical data from medical records. We evaluated genes for K1 and K2, antimicrobial susceptibility, and the virulence genes rmpA, iutA, entB, ybtS, kfu, mrkD , and allS . Strains that possessed rmpA and iutA were defined as hvKP (N=39), while the remaining were classified as cKP (N=52). Odds ratio (OR) for the risk factors associated with 30-day mortality was calculated using the binary logistic regression model. Results The 30-day mortality in all patients was 23.1%; it was 17.9% (7/39) in the hvKP group and 26.9% (14/52) in the cKP group ( P =0.315). Bacteremia (OR=38.1; 95% confidence interval [CI], 2.5–570.2), altered mental status (OR=8.8; 95% CI, 1.7–45.0), and respiratory rate >30 breaths/min (OR=4.8; 95% CI, 1.2–20.0) were independent risk factors for 30-day mortality in all patients. Conclusions Our results suggest that hypervirulence determinants do not have a significant effect on 30-day mortality in patients with pneumonia caused by K. pneumoniae .

Epidemiological Features of Klebsiella pneumoniae Infection in the Hepatobiliary System of Patients in Yantai, China, Based on Clinical and Genetic Analyses

“…As an opportunistic pathogen, cKP mainly causes infection in hosts who are immunocompromised, or who have existing barrier breakdown (eg, intravascular devices, an endotracheal tube or surgical wounds). 5 HvKP is best described as a virulent pathogen. Distinguishing characteristics of hvKP include community-acquired infections in healthy individuals of any age, multiple sites of infection and a tendency for metastatic dissemination to various sites (eye, lung, central nervous system).…”

Clinical and Microbiological Characteristics of Klebsiella pneumoniae Bloodstream Infection in a Chinese Hospital: Hypervirulent and Multiclonal

“… 23 Similarly, Hwang et al recently reported that the 30-day mortality in patients with cKP pneumonia (26.9%) was higher than that in patients with hvKP pneumonia (17.9%). 32 This might be attributed to patients in the cKP subgroup usually having more and much severe underlying diseases, as well as greater age. Additionally, a higher percentage (43.2% in cKP vs 10.3% in hvKP) of a history of hospitalization in recent 90 days may be partially contributed to the higher mortality in the cKP subgroup.…”

Current Positioning against Severe Infections Due to Klebsiella pneumoniae in Hospitalized Adults

“…Hypervirulent strains of K. pneumoniae can cause a syndrome of pneumonia with invasive and metastatic infections, such as bacteremia, liver abscess and necrotizing fasciitis, whereas the traditional syndrome is associated with pneumonia, urinary tract infection or infection at abdominal or surgical sites, with ulterior bacteremia [ 60 ].…”

“…Patients with pneumonia caused by K. pneumoniae , either community-acquired or nosocomial, can have worse outcomes given certain risk factors. Hwang et al reported that patients with bacteremia, altered mental status or respiratory rates over 22 breaths per minute presented higher mortality [ 60 ]. Mortality rates appear to be similar for traditional or hypervirulent clinical syndromes [ 60 ].…”

“…Hwang et al reported that patients with bacteremia, altered mental status or respiratory rates over 22 breaths per minute presented higher mortality [ 60 ]. Mortality rates appear to be similar for traditional or hypervirulent clinical syndromes [ 60 ].…”