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Volume 32, Number 11—November 2026
Research
Five-Biomarker Definition for Hypervirulent Klebsiella pneumoniae Bloodstream Infection and Abscess Complications, Japan, 2022–2024
Naoki Watanabe
, Tomohisa Watari, Yoshihito Otsuka, and Tomoh Matsumiya
, Tomohisa Watari, Yoshihito Otsuka, and Tomoh Matsumiya
Table 1
Baseline characteristics of 207 patients with hypervirulent and classical Klebsiella pneumoniae bloodstream infections in a study of five-biomarker definition for hvKp, Japan, 2022–2024*
| Characteristics | hvKp, n = 28 | cKp, n = 179 | p value† |
|---|---|---|---|
| Demographic characteristics | |||
| Median age, y (IQR) | 76 (71–81) | 78 (69–85) | 0.64 |
| Sex | |||
| M | 21 (75) | 108 (60) | 0.15 |
| F | 7 (25) | 71 (40) | |
| Median body mass index (IQR), n = 201 |
21 (20–23) |
20 (18–24) |
0.65 |
| Underlying conditions | |||
| Median CCI score (IQR) | 2 (1–4) | 3 (2–5) | 0.15 |
| Diabetes, any | 9 (32) | 62 (35) | >0.99 |
| Chronic kidney disease | 3 (11) | 23 (13) | >0.99 |
| Liver disease | 1 (4) | 9 (5) | >0.99 |
| Solid tumor |
8 (29) |
64 (36) |
0.53 |
| Healthcare exposure | |||
| Indwelling device | 12 (43) | 114 (64) | 0.04 |
| Recent hospitalization | 12 (43) | 112 (63) | 0.06 |
| Prior antibiotic exposure |
9 (32) |
99 (55) |
0.02 |
| Infection characteristics | |||
| Onset classification | 0.30 | ||
| Healthcare-associated | 15 (54) | 114 (64) | |
| Community-acquired |
13 (46) |
65 (36) |
|
| Primary source of infection | 0.03 | ||
| Urinary tract | 7 (25) | 37 (21) | |
| Catheter-related | 0 (0.0) | 5 (3) | |
| Intraabdominal | 13 (46) | 83 (46) | |
| Respiratory | 4 (14) | 5 (3) | |
| Other | 1 (4) | 1 (<1) | |
| Unknown |
3 (11) |
48 (27) |
|
| Microbiological characteristics | |||
| Multidrug resistance | 3 (11) | 53 (30) | 0.04 |
| Polymicrobial bloodstream infection | 3 (11) | 42 (23) | 0.15 |
*Values are no. (%) except as indicated. CCI, Charlson comorbidity index; cKp, classical K. pneumoniae; hvKp, hypervirulent K. pneumoniae; IQR, interquartile range. †p values were calculated using Fisher exact test for categorical variables and Mann–Whitney U test for continuous variables and were provided for descriptive purposes.
Page created: September 16, 2026
Page updated: October 14, 2026
Page reviewed: October 14, 2026
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