Bartonella Infection Presenting With Prolonged Fever in a Pediatric Renal Transplant Recipient

摘要

Bartonella henselae infection is a common zoonosis acquired from cats. In immunocompetent individuals, it can present with a broad range of clinical symptoms including short lasting fever, regional lymphadenopathy, prolonged fever of unknown origin and hepatic or splenic granulomas. Bartonella infection in immunocompromised patients is more likely to present with a systemic illness. We describe an adolescent kidney transplant recipient who presented with prolonged fever without a focus fever of unknown origin caused by Bartonella infection. This case highlights the fact that Bartonella henselae infection must be considered in immunocompromised patients, including transplant recipients, with unexplained fever. Introduction Bartonella henselae infection is a common zoonosis transmitted by cats. Immunocompromised hosts tend to follow an atypical course with prolonged fever and systemic involvement. It may be difficult to differentiate from other causes of fever. Vigilant search for this infection is necessary to make a diagnosis. Case Report A 16-year-old Caucasian female with history of fever for one week was admitted to the renal service. She complained of back and neck pain for three days prior to the onset of fever. The family recalled that the patient had a maximum temperature of 38.5°C at home. She had been given acetaminophen with limited antipyretic effects. Vomiting and loose stools developed one day before hospital admission. The patient was born with complex cloacal anomalies and obstructive uropathy requiring multiple surgical procedures for her uro-genital malformations. She received a non-related live donor kidney transplant 19 months before this admission. At the time of transplantation, her cytomegalovirus (CMV) and Epstein Barr virus (EBV) antibodies were negative and positive respectively. The donor was positive for both CMV and EBV. The patient received CMV immunoglobulin and valganciclovir prophylaxis after the transplant. She had never experienced a rejection episode. She had been admitted several times for lymphocele drainage before this admission. Her immunosuppression included prednisone 5 mg daily, mycophenolate mofetil 750 mg twice daily and tacrolimus 2.5 mg twice daily. She was also receiving cotrimoxazole at night for urinary tract infection prophylaxis due to the need for self-catheterization through a Mitrofanoff catheterizable stoma. She did not have any history of traveling to a foreign country. There were three adult cats and a dog in the household. She had also played with stray cats but she reported no recent bite or scratch by her cats. There was no other animal exposure or history of potential tick exposure. Vital signs at time of admission were as follows: temperature 38.9°C, pulse 116 per minute, and blood pressure 113/69 mmHg. She weighed 47.4 kg and her height was 149.5 cm. On physical examination, she was mildly ill looking without signs of dehydration. No lymphadenopathy, rashes or skin lesions were detected. Her ear, nose and throat examinations were normal. She also had normal respiratory and cardiovascular examinations except for mild tachycardia. Abdominal examination showed no hepatomegaly, but her spleen was palpable 4 cm below the left costal margin. She had a Mitrofanoff catheterizable stoma in her lower abdomen; this appeared normal.She was empirically started on intravenous piperacillin sodium/tazobactam and itraconazole to cover for bacterial or fungal infection. Post-transplant lymphoproliferative disease was also considered and immunosuppression was decreased. Her EBV viral load by polymerase chain reaction (PCR) showed 150 to 15,999 copies/ml whole blood on day 2 of admission. This is a level that has not typically been associated with clinical disease in transplant patient. Ultrasound of her abdomen upon admission showed a small collection of fluid in the pelvis and a normal appearing renal allograft. It also revealed a normal appearing liver, a poorly visualized gallblad