Bacterial contamination of platelet concentrates: results of a prospective multicenter study comparing pooled whole blood-derived platelets and apheresis platelets.

BACKGROUND: The GERMS Group initiated a prospective multicenter study to assess prevalence and nature of bacterial contamination of pooled buffy-coat platelet concentrates (PPCs) and apheresis platelet concentrates (APCs) by routine screening with a bacterial culture system. STUDY DESIGN AND METHODS: In nine centers overall, 52,243 platelet (PLT) concentrates (15,198 APCs, 37,045 PPCs) were analyzed by aerobic and anaerobic cultures (BacT/ALERT, bioMérieux). RESULTS: In 135 PLT concentrates (PCs; 0.26%), bacteria could be identified in the first culture (0.4% for APCs vs. 0.2% for PPCs; p < 0.001). In 37 (0.07%) of these PC units, the same bacteria strain could be identified in a second culture from the sample bag and/or the PC unit. The rate of confirmed-positive units did not differ significantly between APC (0.09%; 1/1169) and PPC units (0.06%; 1/1544). Bacteria from skin flora (Propionibacterium acnes, Staphylococcus epidermidis) were the most prevalent contaminants. Median times to first positive culture from start of incubation were 0.7 and 3.7 days in aerobic and anaerobic cultures for confirmed-positive units. With a "negative-to-date" issue strategy, most PC units (55%) had already been issued by time of the first positive culture. CONCLUSION: The rate of confirmed bacterial contamination of PC units was low. Nevertheless, clinicians must be aware of this risk. The risk of bacterial contamination does not warrant universal preference of APCs. It must be questioned whether routine bacterial screening by a culture method can sufficiently prevent contaminated products from being transfused due to the delay until a positive signal in the culture system and due to false-negative results.

[Late infectious complications after high-dose therapy and autologous blood stem cell transplantation]. / Späte infektiöse Komplikationen nach Hochdosistherapie und autologer Blutstammzelltransplantation.

AIM: Only a few data on frequency and character of late infectious complications after high-dose therapy (HDT) and autologous blood stem cell transplantation (ASCT) have been published. This prospective study was carried out to identify potential predictive factors for late infections (occurring after discharge following HDT) and to clarify the usefulness of prophylactic measures. PATIENTS AND METHODS: Clinical data of 192 consecutive patients treated with HDT and ASCT in a single hospital were analyzed on late infectious complications. After discharge following HDT, the 166 evaluable patients (84 with hematologic malignancies, 82 with solid tumors) had been examined and interviewed on infections every 4-12 weeks after ASCT. For Pneumocystis carinii prophylaxis, inhalation with pentamidine or oral cotrimoxazole was used for 3-4 months following ASCT. RESULTS: In the first 6 months following ASCT (after discharge) we saw on average one infectious episode per patient (median, range 0-6), usually light infections (mostly banal upper airway infections). 17 patients had to be treated in hospital for infectious (15 of whom with hematologic malignancies), three of whom (only with hematologic malignancies) died in spite of intensive care as a result of pneumonias due to opportunistic causative agents (mainly Pneumocystis carinii [PcP]). In the second half of the year after ASCT, five patients (with hematologic malignancies) had to be hospitalized due to infections. No further infection-related death occurred. Early documented infections (pneumonia, bacteremia or Clostridium difficile colitis) were associated with an increased risk for late serious infections. Zoster occurred in 18% of patients within 12 months, more frequently after increased pretreatment (25% vs. 11% after less pretreatment), most frequently in patients with relapsed lymphomas (32%). CONCLUSIONS: Significant late infectious complications after ASCT are uncommon. Patients with hematologic malignancies have a significantly increased risk of more serious infections and should be observed carefully. For risk patients with hematologic malignancies and possibly solid tumors, a strict PcP prophylaxis is required. Patients with relapsed lymphomas could possibly be treated preventively against zoster with low-dose aciclovir to reduce the extent of zoster disease. Each patient should be informed carefully that early signs of zoster require an effective zoster treatment as soon as possible.