(221) Hypermucoviscous Klebsiella: Rare Source of Severe Head and Neck Infections

Introduction: Hypermucoviscous Klebsiella pneumoniae emerged in East Asia in the 1980s and classically presents with liver abscess. While rare single case reports of head and neck infection with this organism have been reported, no larger series has described these patients.

Methods: Electronic medical records of three patients with hypermucoviscous (a.k.a. hypermucoid) Klebsiella neck abscesses were reviewed. MEDLINE search of “hypermucoid” and “hypermucoviscous” Klebsiella was reviewed for cases to determine year, age, race, comorbidity, presentation of disease, complications, antibiotic sensitivity, bacteria phenotype, and treatment course.

Results: Our three patients with hypermucoid Klebsiella deep neck abscesses had histories of diabetes and dental manipulation. Initial imaging underestimated the tenacious nature of the infection, necessitating serial imaging and serial surgical drainages and washouts. Hypermucoid variant was confirmed with positive string test. Two patients required tracheostomy and one esophageal perforation requiring stenting, but all survived. Mean length of stay was 47.6 days. Of 360 results from the MEDLINE search for hypermucoviscous Klebsiella, only eleven reported head and neck manifestations. Diabetes, Asian race, or recent travel to Asia were associated. Although 63% of strains were pansensitive to all antibiotics except Ampicillin, treatment required prolonged antibiotic course. 36% expressed rmpA transcription factor promoting capsule production. Severe infections resulted in intubation, tracheostomy, and death.

Conclusions: A rare and unusually aggressive infection usually seen in Asian patients and diabetics, hypermucoid Klebsiella deep neck abscesses require prolonged antimicrobial treatment, close monitoring for airway compromise, serial imaging, and repeat debridements.