Salmonella sepsis caused by a platelet transfusion from a donor with a pet snake

Salmonella sepsis caused by a platelet transfusion from a donor with a pet snake

T R ANSFUSION JOURNAL CLUB Mindy Goldmgn, Christopher Hillyer, and Sunny Dzik, Abstract Editors Accumulation of prion protein in tonsil and appen...

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Mindy Goldmgn, Christopher

Hillyer, and Sunny Dzik, Abstract Editors

Accumulation of prion protein in tonsil and appendix: Review of tissue samples. D.A. Hilton, A.C. Ghani, L. Conyers, eta/. BMJ 325:633-634, 2002. Variant Creutzfeldt-Jacob disease (vCJD) was first recognized in 1996 and is thought to be linked to ingestion of the bovine spongiform encephalopathy agent, which was endemic in UK herds from 1980 to 1989. There have been 115 deaths because of vCJD to date. Given the long incubation period of prion diseases, there is much uncertainty about the possible number of future cases, with recent estimates of total cumulative incidence ranging from 20.5 to 4,000 cases in the United Kingdom. Accumulation of prion protein (PrPsc) in lymphoid tissues occurs before the onset of clinical symptoms in both human and animal spongiform encephalopathies, although the precise sensitivity and specificity of this method and the duration of the preclinical phase are unknown. A sensitivity of 87% and specificity of 94% were shown in sheep exposed to scrapie. Three patients who subsequently developed vCJD had appendectomies in the preclinical stage of their disease; in 2 of the 3 cases, PrPsc was detectable on retrospective analysis. In this study, the authors screened 11,228 appendectomy and tonsillectomy samples removed in the United Kingdom between 1995 and 1999, using immunohistochemistry with 2 monoclonal antibodies against PrPsc. Samples were from patients age 10 to 50 at the time of their surgery and were predominantly appendectomy samples from patients 20 to 29 years old. Two thousand nine hundred ten samples were excluded because of an inadequate amount of lymphoid tissue. One appendix showed an accumulation of PrPsc. The estimated prevalence was 120 per lo6 or 1 in 8,333, with an enormous 95% confidence interval of 1 in 1,111 to 1 in 2 million for people in the study age group. A much larger study would be necessary to obtain a more-precise estimate of prevalence. Fresh tissue obtained in a prospective study would be necessary fos confirmation .of positive samples by animal transmission studies. Unfortunately, the enormous confidence interval allows both optimists and pessimists to hold on to their estimates based on various epideniiological models. (M.G.) Salmonella sepsis caused by a platelet transfusion from a donor with a pet snake. M. Jafari, J. Forsberg, R.O. Gilcher, eta/. N Engl J Med 347:1075-1078, 2002. The authors report 2 episodes of sepsis because of Sulmoin recipients of a single platelet donation that had been divided into 2 units. The first recipient was a 51-year-old woman with acute promyelocytic leukemia who received a platelet transfusion while asymptomatic but neutropenic. During the transfusion she developed temperature of 4O”C, nausea, vomiting, and chills. She was started on broad-spectrum antibiotics. Six hours later, she developed septic shock with hypotension, anuria, and respiratory distress. Two days after transnella entericu





fusion, blood cultures were positive for gram-negative bacilli that were eventually identified as Salmonella. The patient recovered from the septic episode with intensive supportive care. The second recipient was a 50-year-old woman admitted for severe upper gastrointestinal bleeding and hypotension caused by esophagitis, gastritis, and gastric ulcers. She had thrombocytopenia as a result of cirrhosis and hypersplenism associated with alcoholism and chronic hepatitis C. She developed fever, chills, tachycardia, and respiratory distress within 1 hour of transfusion. Despite antibiotics and aggressive supported care, she died of refractory septic shock and hemorrhage. Salmonella enterica was grown from her blood cultures as well as culture of the infused platelets. Because this second patient was transfused 1 day after patient 1, the fatal reaction could have been avoided if transfusion-associated sepsis had been suspected in the first case. The donor was a 47-year-old man who had donated multiple whole blood and apheresis units. He was well at the time of donation and on a postdonation evaluation several days later. However, on further questioning, it was determined that he was the owner of a pet boa constrictor. A stool sample from the boa grew S enterica of the same serotype isolated from both patients and the second platelet product. Pulsed-field gel electrophoresis revealed identical patterns in the isolates from both patients, the platelet unit, and the snake. A blood culture and stool culture from the donor taken several days after the donation showed no pathogenic organisms. The authors hypothesize that the donor had an episode of asymptomatic bacteremia at the time of donation? Reptiles are increasingly pop&u pets and their fecal carriage rates for Salmonella species may be as high as 90%. Salmonella sepsis from platelet transfusion has been described in a case of occult osteomyelitis in a donor and in a case of asymptomatic bacteremia 5 days after mild gastroenteritis. These reports show that unusual bacterial species may be involved in transfusion associated:sepsis and that the prompt recognition, treatment, and reporting of these infections to blood suppliers is critical. (M.G.) The frequency of bleeding complications in patients with haematological malignancy following the introduction of a stringent prophylactic platelet transfusion policy. C.R. Callow, R. Swindell, W. Randall, et al. Br J Haematol 118:677-682, 2002. There is considerable variability in the transfusion trigger used for prophylactic platelet transfusions. Both the Royal College of Physicians Consensus Conference in 1997 and the Practice Guidelines of the American Society of Clinical Oncol-

Vol 17, No 2 (April), 2003:pp 163-168

Copyright 2003, Elsevier Inc. All rights reserved. 0887-7963/03/l 702-$30.00/O doi:10.1053/tmrv.2003.50010