Incidence of West Nile virus infection in the Dallas-Fort Worth metropolitan area during the 2012 epidemic.

The 2012 West Nile virus (WNV) epidemic was the largest since 2003 and the North Texas region was the most heavily impacted. We conducted a serosurvey of blood donors from four counties in the Dallas-Fort Worth area to characterize the epidemic. Blood donor specimens collected in November 2012 were tested for WNV-specific antibodies. Donors positive for WNV-specific IgG, IgM, and neutralizing antibodies were considered to have been infected in 2012. This number was adjusted using a multi-step process that accounted for timing of IgM seroreversion determined from previous longitudinal studies of WNV-infected donors. Of 4971 donations screened, 139 (2·8%) were confirmed WNV IgG positive, and 69 (1·4%) had IgM indicating infection in 2012. After adjusting for timing of sampling and potential seroreversion, we estimated that 1·8% [95% confidence interval (CI) 1·5-2·2] of the adult population in the Dallas-Fort Worth area were infected during 2012. The resulting overall estimate for the ratio of infections to reported WNV neuroinvasive disease (WNND) cases was 238:1 (95% CI 192-290), with significantly increased risk of WNND in older age groups. These findings were very similar to previous estimates of infections per WNND case, indicating no change in virulence as WNV evolved into an endemic infection in the United States.

Transfusion-transmitted babesiosis in Washington State: first reported case caused by a WA1-type parasite.

Most cases of babesiosis reported in the United States have been tickborne and caused by Babesia microti, the etiologic agent of all previously described transfusion-transmitted cases. A 76-year-old man with the first recognized case of transfusion-transmitted infection with the recently identified WA1-type Babesia parasite is described. The subject received multiple blood transfusions in 1994. Indirect immunofluorescent antibody testing of serum from 57 blood donors implicated a 34-year-old man (WA1 titer, 1:65,536) whose donation had been used for packed red cells. Isolates of the organisms that infected the recipient and the donor, both of whom were spleen-intact residents of Washington State, were obtained by hamster inoculation. The DNA sequence of a 536-bp region of the nuclear small subunit-rRNA gene of both isolates was identical to that of WA1 (isolated in 1991 from the index WA1 case-patient). Effective measures for preventing transmission of babesiosis by blood transfusion are needed.

Seroprevalence to Bartonella quintana among patients at a community clinic in downtown Seattle.

In 1993, an outbreak of 10 cases of Bartonella quintana bacteremia occurred among homeless, alcoholic, human immunodeficiency virus (HIV)-negative persons in Seattle. To estimate the prevalence of past exposure B. quintana among this population, a serosurvey was conducted in 1994 among patients at a downtown Seattle clinic. Microimmunofluorescent titers to B. quintana in 192 clinic patients were compared with titers in 199 age- and sex-matched Seattle volunteer blood donors. Titers > or = 64 were detected in 20% (39/192) of clinic patients compared with 2% (4/199) of blood donors (P<.001). Among clinic patients, alcohol abuse was independently associated in multivariate analysis with titers > or = 64 (odds ratio, 3.3; 95% confidence interval, 1.6-6.9). Of the 39 patients with B. quintana titers > or = 64, 24 (62%) also had titers > or = 64 to Bartonella henselae, indicating serologic cross-reactivity between Bartonella species. These results suggest that a substantial proportion of this indigent, inner-city Seattle population was infected with B. quintana.

Hepatitis C virus (HCV) infection in bone marrow transplant patients after transfusions from anti-HCV-positive blood donors.

In March 1992, 12 bone marrow transplant patients at the Fred Hutchinson Cancer Research Center received blood components from donors who were anti-HCV-nonreactive by first generation ELISA but whose serum later tested anti-HCV-reactive to a second generation ELISA. All these blood components were further tested for anti-HCV using a second-generation RIBA and for HCV RNA by polymerase chain reaction. Recipient sera were tested for HCV RNA prior to and following blood component infusion. Blood components from four donors were positive for HCV RNA. All recipients of HCV RNA-positive blood components became viremic on the first day tested post-infusion. In addition, two recipients of HCV RNA-negative blood components tested HCV RNA-positive both pre- and post-infusion. Viremia persisted up to the time of death or day 100 in five of the six patients who were HCV RNA-positive post-transplant. No HCV RNA-positive recipient developed symptomatic acute hepatitis, and only two had aminotransferase elevations consistent with chronic hepatitis. We conclude that HCV RNA-positivity in blood components accurately predicts transmission of virus. Infection with HCV did not adversely affect short-term patient outcome following bone marrow transplantation.

Capacity of the store-regulator in maintaining iron balance.

There is evidence that iron stores alter iron absorption to meet body iron needs. In this study, quantitative aspects of this regulation of iron balance are examined. Two male subjects, one with low and one with average iron stores, were given additional dietary iron over 500 days. Changes in iron stores were monitored by plasma ferritin measurements, and the ferritin estimate of stores was validated at the end of the study by bleeding to the point of iron deficiency. The subject with low iron stores increased his ferritin by 39 micrograms/L or 0.8 mg/day, whereas the subject with average iron stores had no significant change. It is concluded that the mechanism by which stores regulate food iron absorption has a capacity of about 1 mg/day, sufficient to meet usual physiological needs, with the exception of pregnancy, as well as the ability to resist increase in stores above normal despite an iron rich diet.

Guidelines for blood utilization review.

Hospitals are required by accrediting agencies to perform blood utilization review. Specific areas that must be addressed are the ordering, distribution, handling, dispensing, and administration of blood components. Monitoring the effects of transfusion on patients is also required. The format of the review process and the criteria for appropriate blood utilization must be developed by each institution. This article provides examples of areas that can be reviewed and procedures that may be used. However, the suggested laboratory values must not be interpreted as defining indications or criteria for transfusion. Each transfusion committee, or its equivalent, is responsible for developing its own institutional blood utilization procedures and audit criteria. Review and approval by the medical staff prior to implementation are essential. The procedures must also be reviewed and revised on a regular basis.

Transfusion-transmitted viral infections other than hepatitis and human immunodeficiency virus infection. Cytomegalovirus, Epstein-Barr virus, human herpesvirus 6, and human parvovirus B19.

During the last decade, there has been a sharp increase in the number of tests routinely used to screen all volunteer whole blood donations for evidence of transfusion-transmissible infection. These measures have had a dramatic effect on improvements in transfusion safety, especially as far as hepatitis viruses and the human immunodeficiency virus are concerned. Although all blood donations are not routinely screened for evidence of possible transmissibility of cytomegalovirus, some are, since there is now a clearer understanding of the categories of patients in whom this infection must be avoided. Recent studies have also pointed to a role for leukocyte filtration of transfusion products as an alternative to donor screening for selected patients at risk of cytomegalovirus infection. With regard to other viruses, knowledge about the relevance of Epstein-Barr virus, human herpesvirus 6, and parvovirus to blood product safety is incomplete. Until their pathogenicity, if any, in transfusion recipients is known, recommendations about special handling of blood products because of concern for these viruses is premature.

Recombinant immunoblot and polymerase chain reaction testing in volunteer whole blood donors screened by a multi-antigen assay for hepatitis C virus antibodies.

The purpose of this study was to compare the results of supplementary testing of volunteer whole blood donors who had been screened by the first hepatitis C virus antibody assay licensed in the United States with results from donors screened by a newer, more sensitive, multi-antigen assay. In contrast to the earlier assay, the multi-antigen assay incorporates a recombinant hepatitis C virus antigen, c22-3, which is encoded by a structural region of the viral genome. Supplementary testing included a second-generation recombinant immunoblot assay and a highly sensitive polymerase chain reaction assay for evidence of hepatitis C virus genomic RNA. A comparison of supplementary test results reveals a higher percentage of donors screened by the newer assay to be indeterminate on recombinant immunoblot (34.4% vs. 6.4%, p < 0.05). Furthermore, polymerase chain reaction testing of donors with indeterminate blot results shows that 14 percent have evidence of viral RNA. For this reason, counseling of donors with indeterminate patterns on immunoblot must include informing them of the possibility that they are infected.

Promotion of high school blood donations: testing the efficacy of a videotaped intervention.

"Life to Life," an 11-minute videotape based on social learning principles, was used by 10 blood centers in presentations to 4970 high school students one week before school blood drives. At each school, some students saw the videotape and others attended a blood center's customary presentation. Students also completed a brief questionnaire assessing donation attitudes, donation history, and intent to donate. The videotape accounted for a relative increase of 18.7 percent in donations even when other factors were not controlled for. Results were analyzed with logistic models and showed a consistently positive effect over all models used. For students who had never donated, the estimated odds ratio for actual donation (videotape:control) was 1.528. When the model included both type of presentation and ethnicity, the relative increase in donation over that after the blood centers' usual presentation was 69.8 percent for first-time donors. Among previous donors considered alone, the effect on donation was not significant. Whatever their donor history, students who viewed the videotape showed significantly more positive attitudes toward donation and had greater intention to donate than students who saw the blood centers' standard presentations. These results suggest that this videotape is a useful tool for recruitment of high school blood donors.

Reducing the risk for transfusion-transmitted cytomegalovirus infection.

OBJECTIVE: To define the groups of patients at risk for transfusion-transmitted cytomegalovirus infection and to define the methods to reduce this risk. DATA SOURCES: English-language publications on transfusion medicine. STUDY SELECTION AND DATA EXTRACTION: Studies were selected that described cytomegalovirus infection in transfusion-dependent patients. Special attention was paid to reports that included observations about the prevalence and clinical manifestations of cytomegalovirus infection and recommendations for the prevention of infection. DATA SYNTHESIS: Some patients with impaired immune responses who have never been exposed to cytomegalovirus are at risk for transfusion-transmitted cytomegalovirus infection. This infection, which is associated with substantial morbidity and mortality, can be avoided by additional screening of blood donors or by special processing of components for transfusion. CONCLUSIONS: Transfusion products that are unlikely to transmit cytomegalovirus infection can be prepared by filtration to remove leukocytes or can be obtained by selecting donors who are seronegative for antibodies to cytomegalovirus. These products are indicated for certain groups of immunosuppressed patients, including pregnant women who are cytomegalovirus seronegative, premature infants of low birth weight who are born to cytomegalovirus-seronegative mothers, cytomegalovirus-seronegative recipients of allogeneic bone marrow transplants from cytomegalovirus-seronegative donors, and cytomegalovirus-seronegative patients with the acquired immunodeficiency syndrome (AIDS).

Use of leukocyte-depleted platelets and cytomegalovirus-seronegative red blood cells for prevention of primary cytomegalovirus infection after marrow transplant.

Seventy-seven cytomegalovirus (CMV)-seronegative marrow transplant patients were randomized in a prospective controlled trial comparing the use of leukocyte-depleted platelets plus CMV-seronegative red blood cells with standard unscreened blood products for the prevention of primary CMV infection during the first 100 days after transplant. Eligible patients included CMV-seronegative patients undergoing autologous transplant or seronegative patients undergoing allogeneic transplant for aplastic anemia or non-hematologic malignancy who had seronegative marrow donors. Patients and marrow donors were serologically screened for CMV and randomized before conditioning for transplant and followed for CMV infection with weekly cultures of throat, urine, and blood and with weekly CMV serologies until day 100 after transplant. Leukocyte-depleted platelets were prepared by centrifugation, a procedure that removed greater than 99% of leukocytes. There were no CMV infections observed in 35 evaluable treatment patients compared with seven infections in 30 evaluable control patients (P = .0013). There was no statistically significant difference in the mean number of platelet concentrates in the treatment patients (164 concentrates) compared with the control patients (126 concentrates). Leukocyte-depleted platelets plus CMV-seronegative red blood cells are highly effective in preventing primary CMV infection after marrow transplant.

Transfusion therapy: associated risks and alternative approaches.

Transfusion therapy has been the mainstay for treating the anemia of end-stage renal disease (ESRD). Recently, several factors, including the awareness of associated risks, especially the transmission of blood-borne diseases and the transient treatment effect with regard to reversal of anemic symptoms, have caused a reassessment of transfusion therapy. Recombinant human erythropoietin (epoetin) has emerged as the alternative treatment, capable of sustained reversal of anemia without the associated risks of transfusions. The result of epoetin therapy has been marked improvement in the quality of life of ESRD patients. However, the advent of this therapy has also changed the nurse's role in caring for ESRD patients, as new medical management issues are identified and supportive care is tailored to the individual patient.

Prevalence of human immunodeficiency virus type 1 p24 antigen in U.S. blood donors--an assessment of the efficacy of testing in donor screening. The HIV-Antigen Study Group.

BACKGROUND: We performed a multicenter study in 1989 to determine whether screening whole-blood donors for human immunodeficiency virus type 1 (HIV-1) p24 antigen would improve transfusion safety by identifying carriers of the virus who are seronegative for HIV-1 antibody. METHODS: More than 500,000 donations were tested at 13 U.S. blood centers with test kits from two manufacturers. Units found repeatedly reactive were retested in a central laboratory; if the results were positive, they were confirmed by a neutralization assay. A subgroup of units was also tested for HIV-1 by the polymerase chain reaction. Selected donors confirmed or not confirmed as having p24 antigen were contacted for follow-up interviews to identify risk factors and undergo retesting for HIV-1 markers. RESULTS: Positive tests for p24 antigen were confirmed by neutralization in five donors (0.001 percent of all donations tested), all of whom were also positive for HIV-1 antibody and HIV-1 by polymerase chain reaction. Three of the antigen-positive donors had other markers of infectious disease that would have resulted in the exclusion of their blood; two had risk factors for HIV-1 that should have led to self-exclusion. Of 220 blood units with repeatedly reactive p24 antigen whose presence could not be confirmed by neutralization (0.04 percent of the donations studied), none were positive for HIV-1 antibody, HIV-1 by polymerase chain reaction (120 units tested), or virus culture (76 units tested)--attesting to the specificity of confirmatory neutralization. CONCLUSIONS: The finding that no donation studied was positive for p24 antigen and negative for HIV-1 antibody suggests that screening donors for p24 antigen with tests of the current level of sensitivity would not add substantially to the safety of the U.S. blood supply.

Guidelines for transfusion support in patients undergoing coronary artery bypass grafting. Transfusion Practices Committee of the American Association of Blood Banks.

We have reviewed the impact of evolving issues in coronary artery bypass grafting (CABG) on transfusion support for these patients. Issues include increased awareness of transfusion risks, reappraisal of traditional indicators triggering transfusion, and evolving alternatives to homologous blood transfusion such as autologous blood and pharmacologic therapy. These issues have been prompted by programs, such as the National Institutes of Health Consensus Conferences, to provide physicians with guidelines for appropriate use of blood components. However, evidence suggests that transfusion practice in coronary artery bypass grafting procedures remains variable and does not take into account the results of recently published clinical studies. We have therefore developed guidelines and recommendations for transfusion support in patients undergoing coronary artery bypass grafting. In summary, they are the following. 1. Institutions with coronary artery bypass grafting programs should establish a multidisciplinary approach to use a combination of interventions designed to minimize homologous blood exposure. 2. Prophylactic transfusion of plasma and platelets are of no benefit and therefore carry an unnecessary risk to the patient. 3. Special request products such as designated blood donation from first-degree relatives should not be used because of the risk of transfusion-associated graft versus host disease. 4. For support of intravascular volume, crystalloids or colloids should be used because they do not have the potential to transmit infection.