Capnocytophaga canimorus infection and acute renal failure

The bacterium Capnocytophaga canimorus , a mouth commensal of cats and dogs, is an unusual cause of septicaemia in human beings. Human infection usually follows animal bites or licking of broken skin. We wish to report a case complicated by acute renal failure and to review the literature with regard to renal involvement. A previously well 56-year-old man, without any recent animal bite, presented with a 2 days' history of malaise, fever and dyspnoea. He rapidly developed multiple organ failure requiring ventilatory and circulatory support. Bacilli were seen within neutrophils in a conventionally Wright-stained peripheral blood smear made on the patient's admission to hospital. Gram-staining revealed intracellular Gram-negative rods. Treatment with piperacillin and gentamicin began. The organism was later identified as C. canimorus , sensitive to penicillins, resistant to gentamicin. On transfer to our unit for haemodialysis, the patient's APACHE-II score was 30. Serum creatinine was 560 mu mol/l and the WBC count was 18.6 x 10 super(9)/l (85% neutrophils). Target cells and Howell-Jolly bodies were later noted in blood films. Abdominal ultrasound examination revealed an abnormal spleen with an irregular, possibly infarcted, lower pole. The extremities became gangrenous, requiring below-knee amputations and disarticulation of the left-hand. Ultrasound scanning of the splenic bed revealed a collection of cystic and solid material with little residual splenic tissue. The patient was discharged from hospital 6 weeks after admission with normal renal function.