Nonserogroup O1 Vibrio Cholerae in a Renal Transplant Patient

A 29-year-old male presented with vomiting, fever, and rigors for 2 days. He had a history of two deceased donor transplants, the first in 1999 that failed due to noncompliance, and the second in 2004 with delayed graft function. The patient complained of progressive erythema and pain of the left lower leg. He had missed a few doses of his prednisone and tacrolimus, but claimed to have taken his mycophenolate mofetil. One day prior to symptoms, the patient had gone fishing in the Mazon River near Joliet, Illinois. The Mazon River is a tributary of the Illinois River, which is the principal tributary of the Mississippi. He had to hike through woods to get to the river wearing only sandals and shorts. Examination of the leg showed confluent erythema that was below the knee. His left inguinal lymph nodes were mildly enlarged and tender. The patient was started on ceftriaxone but was changed to piperacillin/tazobactam after blood cultures grew gram-negative bacilli (Fig. 1). Both sets of blood cultures eventually grew Vibrio cholerae, which was confirmed by a reference laboratory. The antibiotic was changed to ciprofloxacin with defervescence and improvement of the cellulitis. Repeat cultures were negative and the patient was discharged on ciprofloxacin for 14 days. The Illinois Department of Public Health confirmed that the V. cholerae was a nonserogroup O1 isolate.FIGURE 1.: Gram stain of peripheral blood culture of patient showing gram-negative curved, motile rods.The non-O1 V. cholerae are distinct nontoxigenic strains that do not agglutinate in type-O1 or O139 antisera (1). These strains typically do not cause epidemic diarrhea but extraintestinal infections such as cellulitis, urinary tract, and pulmonary infection. Many documented cases of these non-O1 strains have environmental exposure to estuarine or coastal topography (2). Although most cases in the U.S. are nontoxigenic, two cases of toxigenic O1 serotypes were recently reported after Hurricanes Katrina and Rita in 2005. It appears that these strains are endemic to the Atlantic and Gulf coasts (3). In fact, from 1996–2005, 64 cases of toxigenic V. cholerae O1 were reported to the Centers for Disease Control and Prevention (4). Pitrak described a case of bacteremic cellulitis caused by nonserogroup O1 V. cholerae in a patient fishing in a freshwater inland lake in northern Illinois (2). Similarly, our patient was fishing in a tributary of the Illinois River with presumed introduction of bacteria through superficial excoriations resulting in bacteremia and cellulitis. Other cases of cellulitis caused by the same organism in Colorado and in Illinois suggest that the non-O1 V. cholerae may be more indigenous to certain inland bodies of water than was previously appreciated (5). Patients who develop severe extraintestinal Vibrio bacteremia are immunosuppressed (6). The preferred treatment of superficial Vibrio wound infection includes oral ciprofloxacin, trimethoprim/ sulfamethoxazole, or tetracycline. In deeper wounds, aminoglycosides, ciprofloxacin, or trimethoprim/sulfamethoxazole are recommended (7, 8). Transplant patients are at greater risk of infection with uncommon organisms. Because they may not present with typical clinical findings, it is important to consider unusual organisms, especially when there is poor response to empiric therapy. Vibrio cholerae is an exceedingly rare organism in the United States; however, if not treated early, it may be devastating in the immunocompromised transplant recipient. Micah R. Chan Division of Nephrology University of Wisconsin Madison, WI John D.