Analyzing actual risk in malaria-deferred donors through selective serologic testing.

BACKGROUND: Approximately 150,000 US blood donors are deferred annually for travel to malaria-endemic areas. However, the majority do not travel to the high-risk areas of Africa associated with transfusion-transmitted malaria (TTM) but visit low-risk areas such as Mexico. This study tests for Plasmodium infection among malaria-deferred donors, particularly those visiting Mexico. STUDY DESIGN AND METHODS: Blood donors deferred for malaria risk (travel, residence, or previous infection) provided blood samples and completed a questionnaire. Plasma was tested for Plasmodium antibodies by enzyme immunoassay (EIA); repeat-reactive (RR) samples were considered positive and tested by real-time polymerase chain reaction (PCR). Accepted donors provided background testing data. RESULTS: During 2005 to 2011, a total of 5610 malaria-deferred donors were tested by EIA, including 5412 travel deferrals. Overall, 88 (1.6%) were EIA RR; none were PCR positive. Forty-nine (55.7%) RR donors previously had malaria irrespective of deferral category, including 34 deferred for travel. Among 1121 travelers to Mexico, 90% visited Quintana Roo (no or very low risk), but just 2.2% visited Oaxaca/Chiapas (moderate or high risk). Only two Mexican travelers tested RR; both previously had malaria not acquired in Mexico. CONCLUSIONS: Travel to Mexico represents a large percentage of US donors deferred for malaria risk; however, these donors primarily visit no- or very-low-risk areas. No malaria cases acquired in Mexico were identified thereby supporting previous risk estimates. Consideration should be given to allowing blood donations from U.S. donors who travel to Quintana Roo and other low-risk areas in Mexico. A more effective approach to preventing TTM would be to defer all donors with a history of malaria, even if remote.

A 25-year study of the clinical and histologic outcomes of hepatitis C virus infection and its modes of transmission in a cohort of initially asymptomatic blood donors.

BACKGROUND: A total of 738 volunteer blood donors who were positive for anti-hepatitis C virus (HCV) were assessed for risk factors and outcomes for up to 15 years within the study and up to 54 years from the estimated onset of infection. METHODS: A third-generation recombinant immunoblot assay (RIBA) was performed to distinguish true from false anti-HCV reactivity. Findings of HCV polymerase chain reaction classified subjects as having chronic HCV infection or as having recovered. Liver biopsy specimens were staged by Ishak fibrosis score and graded by histologic activity index. RESULTS: Of 738 anti-HCV-positive subjects, 469 (64%) had positive RIBA results, 217 (29%) had negative results, and 52 (7%) had indeterminate results. Primary independent risk factors were injection drug use (odds ratio [OR], 35.0; P < .0001), blood transfusion (OR, 9.9; P < .0001), and intranasal cocaine use, including 79 "snorters" who repeatedly denied injection drug use or blood transfusion (OR, 8.5; P < .0001). Classification and regression tree and random forest analyses confirmed these risk factors. A total of 384 RIBA-positive donors (82%) were HCV RNA positive; of these, liver biopsy specimens from 185 (48%) showed no fibrosis in 33%, mild fibrosis in 52%, bridging fibrosis in 12%, and cirrhosis in 2% a mean duration of 25 years after infection. Analysis of 63 repeat biopsy specimens showed that 8% progressed ≥2 Ishak stages over 5 years (mean progression, 0.06 Ishak stages/year). CONCLUSIONS: Injection drug use and blood transfusion before 1990 are dominant risk factors for HCV acquisition; intranasal cocaine use may be a surreptitious route of parenteral spread. After a mean of 25 years of HCV infection, histologic outcomes were relatively mild: 85% had no or mild fibrosis, and only 2% had cirrhosis. Nearly one-fifth spontaneously recovered.

The clinical relevance of persistent recombinant immunoblot assay-indeterminate reactions: insights into the natural history of hepatitis C virus infection and implications for donor counseling.

BACKGROUND: Recombinant immunoblot assay (RIBA) is used to determine the specificity of antibody to hepatitis C virus (anti-HCV). The RIBA result is recorded as positive, negative, or indeterminate. The interpretation and significance of RIBA-indeterminate reactions are unclear. We addressed the clinical relevance of these reactions in the context of the natural history of HCV infection in a prospectively followed cohort of anti-HCV-positive blood donors. STUDY DESIGN AND METHODS: Donor demographics, exposure history, and humoral and cell-mediated immunity (CMI) were compared in 15 RIBA-indeterminate subjects, nine chronic HCV carriers, and eight spontaneously recovered subjects. Serum samples were tested for anti-HCV by a quantitative, liquid luciferase immunoprecipitation system (LIPS). CMI was assessed by interferon-γ enzyme-linked immunosorbent spot assay. RESULTS: In the LIPS assay, the sum of antibody responses to six HCV antigens showed significant (p < 0.001) stepwise diminution progressing from chronic carriers to spontaneously recovered to RIBA-indeterminate subjects. CMI responses in RIBA-indeterminate subjects were similar to spontaneously recovered subjects and greater than chronic carriers and controls (p < 0.008). A parenteral risk factor was identified in only 13% of RIBA-indeterminate subjects compared to 89% of chronic carriers and 87% of spontaneously recovered subjects. RIBA-indeterminate donors were older than the other groups. CONCLUSION: The CMI and LIPS results suggest that persistent RIBA-indeterminate reactions represent waning anti-HCV responses in persons who have recovered from a remote HCV infection. In such cases, detectable antibody may ultimately disappear leaving no residual serologic evidence of prior HCV infection, as reported in a minority of long-term HCV-recovered subjects.

Conversion to low transfusion-related acute lung injury (TRALI)-risk plasma significantly reduces TRALI.

BACKGROUND: Transfusion-related acute lung injury (TRALI) is an uncommon but serious transfusion reaction. Studies have shown that the transfusion of HLA and HNA antibodies in donor plasma can lead to TRALI. Female donors are more likely to have such antibodies due to alloantigen exposure during pregnancy. Many blood suppliers have now implemented various TRALI risk reduction strategies to unknown effect. A retrospective analysis of TRALI reactions in plasma recipients before and after the conversion to low-TRALI-risk plasma (all-male donor plasma, male-predominant plasma, nulliparous female plasma, and HLA antibody-tested plasma) is reported. STUDY DESIGN AND METHODS: Transfusion reaction reports at three large hospitals 16 months before and 16 months after the conversion to low-TRALI-risk plasma were analyzed. Respiratory reactions were categorized as TRALI, possible TRALI, or other (e.g., transfusion-associated circulatory overload or allergic reactions). Reactions were reported as a percentage of total units transfused and rates for the two time periods were compared. Trends in reaction rates for other components were also compared. RESULTS: A total of 2156 transfusion reactions in association with 461,598 transfused blood components were reviewed. The incidence of combined TRALI or possible TRALI reactions, due to the transfusion of plasma, decreased from 0.0084% to zero (p = 0.052). The rate of TRALI or possible TRALI reactions in red blood cell and platelet recipients did not change significantly. CONCLUSION: The conversion to low-TRALI-risk plasma has reduced the incidence of TRALI reactions in plasma recipients.

Increased all-cause and cancer mortality in HTLV-II infection.

BACKGROUND: Human T-lymphotropic virus (HTLV)-I and HTLV-II cause chronic human retroviral infections, but few studies have examined the impact of either virus on survival among otherwise healthy individuals. The authors analyzed all-cause and cancer mortality in a prospective cohort of 155 HTLV-I, 387 HTLV-II, and 799 seronegative subjects. METHODS: Vital status was ascertained using death certificates, the US Social Security Death Index or family report, and causes of death were grouped into 9 categories. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using Cox proportional hazards models. RESULTS: After a median follow-up of 15.9 years, there were 105 deaths: 22 HTLV-I, 41 HTLV-II, and 42 HTLV-seronegative. Cancer was the predominant cause of death, resulting in 8 HTLV-I, 17 HTLV-II, and 15 HTLV-seronegative deaths. After adjustment for confounding, HTLV-I status was not significantly associated with increased all-cause mortality, though there was a positive trend (HR: 1.6, 95% CI: 0.8 to 3.1). HTLV-II status was strongly associated with increased all-cause (HR: 2.4, 95% CI: 1.4 to 4.4) and cancer mortality (HR: 3.8, 95% CI: 1.6 to 9.2). CONCLUSIONS: The observed associations of HTLV-II with all-cause and cancer mortality could reflect biological effects of HTLV-II infection, residual confounding by socioeconomic status or other factors, or differential access to health care and cancer screening.

Long-term increases in lymphocytes and platelets in human T-lymphotropic virus type II infection.

Human T-lymphotropic viruses types I and II (HTLV-I and HTLV-II) cause chronic infections of T lymphocytes that may lead to leukemia and myelopathy. However, their long-term effects on blood counts and hematopoiesis are poorly understood. We followed 151 HTLV-I-seropositive, 387 HTLV-II-seropositive, and 799 HTLV-seronegative former blood donors from 5 U.S. blood centers for a median of 14.0 years. Complete blood counts were performed every 2 years. Multivariable repeated measures analyses were conducted to evaluate the independent effect of HTLV infection and potential confounders on 9 hematologic measurements. Participants with HTLV-II had significant (P < .05) increases in their adjusted lymphocyte counts (+126 cells/mm(3); approximately +7%), hemoglobin (+2 g/L [+0.2 g/dL]) and mean corpuscular volume (MCV; 1.0 fL) compared with seronegative participants. Participants with HTLV-I and HTLV-II had higher adjusted platelet counts (+16 544 and +21 657 cells/mm(3); P < .05) than seronegatives. Among all participants, time led to decreases in platelet count and lymphocyte counts, and to increases in MCV and monocytes. Sex, race, smoking, and alcohol consumption all had significant effects on blood counts. The HTLV-II effect on lymphocytes is novel and may be related to viral transactivation or immune response. HTLV-I and HTLV-II associations with higher platelet counts suggest viral effects on hematopoietic growth factors or cytokines.

The American Red Cross donor hemovigilance program: complications of blood donation reported in 2006.

BACKGROUND: The American Red Cross (ARC) initiated a comprehensive donor hemovigilance program in 2003. We provide an overview of reported complications after whole blood (WB), apheresis platelet (PLT), or automated red cell (R2) donation and analyze factors contributing to the variability in reported complication rates in our national program. STUDY DESIGN AND METHODS: Complications recorded at the collection site or reported after allogeneic WB, apheresis PLT, and R2 donation procedures in 36 regional blood centers in 2006 were analyzed by univariate and multivariate logistic regression. RESULTS: Complications after 6,014,472 WB, 449,594 PLT, and 228,183 R2 procedures totaled 209,815, 25,966, and 12,282 (348.9, 577.5, and 538.3 per 10,000 donations), respectively, the vast majority of which were minor presyncopal reactions and small hematomas. Regional center, donor age, sex, and donation status were independently associated with complication rates after WB, PLT, and R2 donation. Seasonal variability in complications rates after WB and R2 donation correlated with the proportion of donors under 20 years old. Excluding large hematomas, the overall rate of major complications was 7.4, 5.2, and 3.3 per 10,000 collections for WB, PLT, and R2 procedures, respectively. Outside medical care was recorded at similar rates for both WB and automated collections (3.2 vs. 2.9 per 10,000 donations, respectively). CONCLUSION: The ARC data describe the current risks of blood donation in a model multicenter hemovigilance system using standardized definitions and reporting protocols. Reported reaction rates varied by regional center independently of donor demographics, limiting direct comparison of different regional blood centers.

Pasteurella multocida bacteremia in asymptomatic plateletpheresis donors: a tale of two cats.

BACKGROUND: Bacterial contamination of platelet (PLT) concentrates occurs in 1 in 1000 to 1 in 3000 components and has been a leading cause of transfusion-associated morbidity and mortality. Two cases of Pasteurella multocida bacteremia in asymptomatic plateletpheresis donors are reported. Clinical outcomes were profoundly different, emphasizing the importance of robust methods to detect bacterial contamination. CASE REPORTS: The first case occurred before the implementation of bacterial testing of PLTs. A plateletpheresis component was collected from a 70-year-old man and transfused to an 88-year-old man, who developed rigors, tachycardia, and hypotension within 15 minutes of the start of the transfusion. Cardiopulmonary arrest ensued and he expired 6 hours after transfusion. Blood cultures collected after transfusion and cultures of the PLT component were positive for the presence of P. multocida. Investigation revealed that a feral cat had bitten the donor 100 minutes before his donation. He had not reported the event to the donor room staff. The second case involved a 74-year-old woman who developed a flulike syndrome 2 days after plateletpheresis donation. P. multocida was isolated in routine bacterial culture of her PLT component. The donor had several feral cats, and although there was no history of bite or scratch, one cat liked to lick her hands, which were chapped from gardening. CONCLUSION: Occult bacteremia with P. multocida transmitted by feral cats was the source of PLT contamination in two cases over 3 years. Bacterial testing of PLTs is critical in the prevention of transfusion-acquired sepsis and allows the identification and treatment of asymptomatic bacteremic donors.

Radiofrequency identification technology can standardize and document blood collections and transfusions.

BACKGROUND: We evaluated the potential for radiofrequency (RF) transponder microchips to standardize and document key steps in the blood collection and transfusion process. STUDY DESIGN AND METHODS: Using the blood center's standard operating procedures for blood collections, we programmed a laptop computer and 10 multiwrite 256-byte RF microchips to prompt operators to enter data for key steps in blood collection. Before collections, RF microchips were attached to blood collection sets at the blood center. In parallel with actual collections, we added data to the microchips with the computer and a hand-held scanner-programmer. After labeling, we shipped the RF microchip-tagged blood units to the hospital where unit-related data (whole blood number, ABO and Rh, expiration date, special laboratory test results) were uploaded from the RF microchip to the transfusion service's information system. The microchip was subsequently used as a cross-match label for blood unit-recipient matching. RESULTS: Data were successfully uploaded to the RF microchip at key steps during blood collections. Software programs in the laptop computer and hand-held scanner-programmer successfully prompted operators to enter key data. At any stage in a blood collection, authorized operators were able to review electronic records of prior steps using the laptop computer or by scanning the microchip attached to the blood bag. Unit-related data were successfully transferred to the hospital transfusion service through the RF microchip. These data were successfully incorporated in the RF microchip cross-match label, which was used to confirm recipient-blood unit matching at the bedside. CONCLUSION: RF microchips can collect key data during blood collections, facilitate information transfer from the blood center to the hospital, and confirm recipient-blood unit matching at the bedside before transfusions.