Klebsiella pneumoniae Invasive Syndrome without Liver Abscess: A Case Report

BACKGROUND Klebsiella pneumoniae invasive syndrome (KPIS), a rare severe multi-site infection, typically caused by hypervirulent Klebsiella pneumonia, has a high mortality rate, usually ranging from 10% for antimicrobial-sensitive strains to 24% for resistant strains, and often requires prolonged treatment. Most cases have been reported in East Asia, with a handful documented in India, to date. The incidence is also rising in Western countries. CASE REPORT We report the case of a 45-year-old Indian man who presented with fever, low back pain, and asymmetric arthralgia for the past 20 days, along with new acute-onset right-sided hemiparesis and slurred speech. Laboratory test results were significant for elevated leukocyte counts and inflammatory markers (ESR and CRP). MRI of the brain revealed multiple lesions, with accompanying hemorrhage and edema at grey white-matter junction. PET-CT revealed septic collections at multiple sites, including the spleen, kidney, left knee joint, and L5-L6 vertebrae, along with paravertebral and psoas abscesses. Cultures of vertebral abscess confirmed Klebsiella pneumoniae, with a positive string test, consistent with a hypermucoviscous phenotype; however, genetic testing for hypervirulent genes could not be performed, due to unavailability. Given these findings, KPIS diagnosis was likely. Treatment was 6 weeks of antibiotics, empiric vancomycin and gentamicin, followed by de-escalation to amoxicillin-clavulanic acid. CONCLUSIONS KPIS can occur in immunocompetent hosts and should be considered in cases of unexplained systemic inflammation with multifocal abscesses. Hepatic involvement, while characteristic, is not essential for diagnosis. When genotypic testing is unavailable, a positive string test can serve as a useful surrogate marker for identifying hypervirulent strains.