A 36-year-old Haitian female presented with a four-month history of “pus like drainage from a left abdominal wall opening”. It began with left flank pain followed by a “bump” in that area which progressed to a chronic draining fistula. There was associated lumbar back pain,aggravated by walking and relieved by lying on her side, with subjective intermittent fevers and chills. Physical examination revealed an afebrile healthy female with a 1 cm by 3cm fistula draining brown purulent material from her left lateral abdominal wall. Labs were remarkable for a normocytic anemia without leukocytosis and a negative HIV test. Computer Tomography of the abdomen and pelvis demonstrated L3-L4 osteomyelitis, bilateral psoas myositis, a fistulous tract extending to the left lateral abdominal wall, with gas in the right psoas muscle. MRI confirmed fistula but also demonstrated epidural, paraspinal and bilateral psoas abscesses. Interventional radiology guided drainage of the psoas abscess yielded pus speciating to KP resistant to Ampicillin. Patient received antibiotics for six weeks with notable clinical improvement.
Since the mid 1980s ,a distinct clinical syndrome of liver abscesses and metastatic infections emerged ,due to hypervirulent KP(hvKP) with a preponderance of cases in the Asian Pacific rim. This disease with high morbidity and mortality is now on the rise in the Caribbean,North and South America. HVKP belongs to serotype K1 or K2, and possesses the ability to more efficiently acquire iron, resulting in increased capsule production thereby conferring to it the hallmark feature of this strain, which is the ability to create metastatic deposits to spine, epidural space and psoas muscles. The reported manifestations of this disease range from liver abscesses,endopthalmitis,necrotizing soft tissue infections to osteomyelitis in young healthy hosts.There is limited data on the epidemiology of this entity but genetic versus geographic theories have been proposed with a study of KP liver abscesses, by Rahimian et al in two hospitals in New York favoring genetic component by demonstrating that 78.3% of patients were Asians. Colonization particularly intestinal appears to be a critical prerequisite for infection however the route of entry remains unclear. Despite the limited information about this disease process, it is known that these strains are susceptible to most antibiotics but are uniformly resistant to ampicillin. There is no rapid and reliable test to identify the strain.
Health care professionals especially those in areas of the US, such as Brooklyn, where there are large immigrant populations, must be made aware of this devastating hvKP. Early recognition of this pathogen would lead to improved patient outcomes, and would prompt aggressive vigilance for metastatic deposits.All in all, much work needs to be done on the search for a rapid diagnostic test, and greater understanding of epidemiology of this distinctive pathogen.