Absence of risk factors for false-positive test results in blood donors with a reactive test result in an automated treponemal test (PK-TP) for syphilis

BACKGROUND: Screening and confirmatory serologic tests for syphilis are known to generate false-positive results in low-risk populations, which include blood donors. This study assessed whether conditions previously reported to cause biological false-positive (BFP) test results for syphilis are relevant to contemporary syphilis testing of blood donors and the extent to which seropositive donors report a history of syphilis. STUDY DESIGN AND METHODS: A history of conditions reported to be associated with BFP syphilis tests or a history of syphilis infection was assessed by a case-control study of donors with reactive and nonreactive automated treponemal test results, using an anonymous mail survey. Analysis of cases was stratified by fluorescent treponemal antibody absorption (FTA-ABS) result. RESULTS: Adjusted ORs (95% CIs) for reported BFP-associated conditions were 1.3 (0.8-2.1) for FTA-ABS-positive cases and 0.8 (0.3-1.9) for FTA-ABS-negative cases. Among responding blood donors, syphilis history was reported in 78 (51%) of 153 FTA-ABS-positive cases, 0 of 142 FTA-ABS-negative cases, and 3 (0.4%) of 716 automated treponemal test (PK-TP)-negative controls. CONCLUSION: Approximately half of donors with FTA-ABS-positive test results reported a syphilis history. There was no difference between reported BFP conditions for FTA-ABS-positive or FTA-ABS-negative cases and controls. This information may be useful when providing donors with better predonation or post-test counseling information about syphilis testing.     

Current value of serologic test for syphilis as a surrogate marker for blood-borne viral infections among blood donors in the United States

BACKGROUND: Serologic screening for syphilis has been justified in part as a surrogate marker for infections caused by other pathogens such as human immunodeficiency virus (HIV). This study assessed the current surrogate value of the test.
STUDY DESIGN AND METHODS: Testing results for blood donors with the American Red Cross Blood Services between January 1, 2006, and December 31, 2007, were analyzed. All donations were tested according to standard procedures for markers of HIV, hepatitis B virus (HBV), hepatitis C virus (HCV), human T-lymphotropic virus (HTLV), syphilis, and other infections. The frequency of window-period (w-p) infections interdicted by syphilis testing was estimated.
RESULTS: There were significantly higher frequencies of HIV, HCV, hepatitis B surface antigen (HBsAg), and HTLV confirmed-positive donations among those with positive syphilis test results, although the sensitivity of syphilis test positivity in these groups was low. Among more than 3 million repeat donors with complete testing through reactive donation confirmation for both syphilis and HIV (anti-HIV and HIV RNA), 225 seroconverted for syphilis but not for anti-HIV or HIV RNA and 83 converted for HIV (anti-HIV or HIV RNA) but not for syphilis, with only 1 who converted for both syphilis and HIV, resulting in an incidence ratio of 150 (95% confidence interval, 21-1080) and a sensitivity of 1.2 percent. No syphilis seroconverters converted for HCV, HBsAg, or anti-HTLV.
CONCLUSION: Syphilis testing presents no surrogate value for incident HCV, HBV, and HTLV infections and could only remove approximately 1 HIV w-p unit of every 148 million donations.     

Limited effectiveness of donor deferral registries for transfusion-transmitted disease markers

BACKGROUND: Donor deferral registries (DDRs) detect repeat donations by previously deferred donors and prevent their release. The utility of DDRs has not been objectively demonstrated. STUDY DESIGN AND METHODS: A total of 10.2 million first-time donors to the American Red Cross from 1995 through 2002 were reviewed to identify donors deferred by screening tests for human immunodeficiency virus (HIV; 0.19% of donors), hepatitis C virus (HCV; 0.55%), and hepatitis B virus (HBV; 0.13%). All repeat-reactive (RR) donors were deferred despite confirmatory testing. Donors were notified and counseled about their test results and deferral. Their subsequent donation behavior was assessed. RESULTS: A total of 414 HIV-deferred donors (2.1%), 471 HCV-deferred donors (0.8%, p < 0.001 vs. HIV and HBV), and 222 HBV-deferred donors (1.6%, p < 0.01 vs. HIV) returned to donate despite their deferred status. For all three tests, confirmed-positive donors were less likely to return. Of donors originally confirmed positive, only 7 returning donors were negative by screening (thus the repeat donation interdicted from distribution by the DDR): 0 HIV RR donors, 2 of 36,092 HCV RR donors, and 5 of 8,404 HBV RR donors. Review of the laboratory results for the HCV donors and one HBV donor was consistent with originally false-positive confirmation tests. The four other HBV confirmed-positive donors were anti-hepatitis B core antigen-positive on their subsequent donation, which was discarded despite the DDR. CONCLUSION: Of 10.2 million donors, the DDR did not prevent the release of any potentially dangerous blood component due to inappropriate return of donors deferred for HIV, HCV, and HBV tests. The effectiveness of DDRs should be evaluated for other deferrals.     

Direct oral questions to blood donors: the impact on screening for human immunodeficiency virus

BACKGROUND: In December 1990, the Food and Drug Administration recommended that all United States blood centers implement a policy of asking prospective donors direct oral questions (DOQs) about human immunodeficiency virus (HIV) risk behaviors to increase the safety of the blood supply. STUDY DESIGN AND METHODS: To evaluate the impact of the DOQ policy, HIV-related deferral and HIV seroprevalence data were analyzed at four American Red Cross blood centers for the year before the policy change and the year after. An epidemiologic analysis with stratification was conducted, including the calculation of odds ratios (OR) and 95-percent CIs. RESULTS: Two of the four blood centers showed an overall significant increase in HIV-related deferral after implementation of the DOQ policy: OR = 4.04, (95% CI = 3.41, 4.76); OR = 2.93, (95% CI = 2.67, 3.21). The increase in HIV-related deferral was higher for women. HIV seroprevalence decreased at all four centers, including the two that did not see an increase in HIV-related deferrals. Seroprevalence declined by 14 percent in the two centers with increases in HIV-related deferral, which was neither significant nor attributable to DOQs. CONCLUSION: Given that HIV antibody screening cannot detect HIV-seronegative (but infectious) "window-period" donations, the deferral of at-risk donors may offer some additional protection to the blood supply. However, evidence was not found of an increase in safety of the blood supply as measured by HIV seroprevalence.     

The asymptomatic patient with a positive VDRL test

Although VDRL and RPR tests are excellent screens for syphilis, false-positive reactions do occur. A positive VDRL or RPR test must be confirmed with an FTA-ABS test. Patients with positive serologic tests should have a thorough physical examination to determine the stage of syphilis. A patient with a low-titer VDRL or RPR may have active disease and may require lumbar puncture to rule out neurosyphilis.     

Prevalence of circulating Treponema pallidum DNA and RNA in blood donors with confirmed-positive syphilis tests

BACKGROUND: Although there have been no well-documented cases of transfusion-transmitted syphilis in more than 30 years, serologic tests for syphilis (STS) continues to be required for donated blood. Previously, the methods for detecting viable spirochetes were dependent on the use of the rabbit infectivity test. DNA PCR and RNA RT-PCR were applied to assess the presence of Treponema pallidum DNA or RNA in blood donors with confirmed-positive results in STS. STUDY DESIGN AND METHODS: This case series describes T. pallidum DNA and RNA testing of platelet concentrates prepared from blood donors with reactive results in an automated treponemal screening test and positive test results in the fluorescent treponomal antibody absorption test. The first DNA test was specific for the T. palladium polA gene. The second DNA test was a multiplex PCR using a T. pallidum 47-kDa gene target. The RT-PCR for RNA used T. pallidum 16S rRNA as a template for production of a cDNA target. RESULTS: One hundred sixty-nine samples (including rapid plasma reagin [RPR]+ and RPR-) tested for T. pallidum DNA and/or RNA were negative. CONCLUSIONS: A lack of demonstrable T. pallidum DNA or RNA suggests that blood donors with confirmed-positive results in STS are unlikely to have circulating T. pallidum in their blood and that that their blood is unlikely to be infectious for syphilis.     

Impact of changes in viral marker screening assays

BACKGROUND: Monitoring the performance of routinely used infectious disease serologic tests is necessary to evaluate their effectiveness in identifying true-positive units and erroneously disqualifying safe blood donors. METHODS: With two large screening test data sets collected between 1991 and 1998 and between 1997 and 2000, the impact of changes in screening assays for HIV, HCV, and HBsAg was analyzed with regard to the prevalence of confirmed-positive, indeterminate, and confirmed-negative results and the deferral of donors with an indeterminate or negative results (donor loss). RESULTS: The prevalence of indeterminate results and donors loss increased significantly in the 6 months after introduction of an HIV-1/2 EIA. A second-generation HCV EIA increased the detection of confirmed-positive donations in repeat donors (p < 0.001) and increased the prevalence of indeterminate donations. Implementation of a third-generation HCV EIA resulted in a significant decrease in indeterminate results in first-time donors. Nonspecific test results increased when HBsAg test kits from a different manufacturer were introduced or different lots of HIV antibody screening test kits from the same manufacturer were used. CONCLUSION: Introduction of newly licensed versions of assays, switching kit manufacturers, and lot-to-lot variations have an impact on rates of deferrals of safe donors as well as sensitivity of routine screening. Before considering changes in screening tests, blood centers should be aware of, and evaluate, the potential impact on donor loss.     

Serologic test for syphilis as a surrogate marker for human immunodeficiency virus infection among United States blood donors

BACKGROUND: This study evaluated the usefulness of the serologic test for syphilis (STS) in preventing the transmission of human immunodeficiency virus (HIV), hepatitis B and C viruses, and human T- lymphotropic virus via the transfusion of seronegative, infectious window-period blood. STUDY DESIGN AND METHODS: Demographic and laboratory information on blood donations made between January 1992 and June 1994 in 18 American Red Cross regions was analyzed. It was assumed that the same proportion of HIV-positive and HIV-infectious window- period donations reacted on STS and were negative on other screening tests (hepatitis B and C viruses and human T-lymphotropic virus). This proportion multiplied by the estimated number of HIV-infectious window- period donations is the number of post-screening HIV-infectious donations removed by STS. RESULTS: Of 4,468,570 donations, 12,145 (0.27%) were STS positive and 377 (0.008%) were HIV positive. Among donations that were negative on other screening tests, STS-reactive donations were 12 times more likely to be HIV positive (odds ratio = 11.9; 95% CI = 5,26). However, of an estimated 13 infectious window- period donations, 0.2 would have been removed because of a reactive STS, at a cost of over $16 million. CONCLUSION: STS is a poor marker and a costly strategy for preventing post-screening HIV infections and other blood-borne diseases.     

Current prevalence and incidence of infectious disease markers and estimated window-period risk in the American Red Cross blood donor population

BACKGROUND: There has been continuing progress in measures to reduce the risk of transfusion-transmitted infection, including introduction of serologic tests of increased sensitivity and the recent implementation of investigational NAT in small pools of samples. STUDY DESIGN AND METHODS: Data relating to all blood donations to the American Red Cross have been consolidated into a single database. The prevalence of confirmed-positive test results for HBsAg, HCV, HIV, and HTLV were evaluated for each year for first-time donors from 1995 through 2001. Incidence rates for these infections were evaluated among repeat donors having at least two donations in a 2-year period. The frequencies of HIV-1 RNA- and HCV RNA-positive, seronegative donations were assessed for first-time and repeat donations. The relationship risk = (window period) x (incidence) was used to assess residual risk among repeat donations and to evaluate the incidence of HCV and HIV infection among first-time donors. RESULTS: During the study period, prevalence rates for all markers declined significantly over time: in 2001, the rates per 100,000 were 75.6 for HBsAg, 299 for HCV, 9.7 for HIV, and 9.6 for HTLV; the corresponding incidence rates (/100,000 person-years) were 1.267, 1.889, 1.554, and 0.239, respectively. Estimates of residual risk in donations from repeat donors (after NAT) for HCV and HIV were 1 per 1,935,000 and 1 per 2,135,000, respectively. However, incidence rates for these agents are approximately two times greater among first-time donors. For both HCV and HIV, NAT yield was concordant with that predicted by current window-period models. CONCLUSION: These data cover about half of all the whole blood collected in the United States. They suggest increasing improvement in transfusion safety and clearly define the benefit of pooled NAT.     

Retrospective comparison between non-treponemal and treponemal tests for screening of blood donors for syphilis and their correlation with donor history in a tertiary care teaching hospital

Background and objectivesTreponemal tests provide advantage of better detection during early, late and latent stages of syphilis with equal or higher sensitivity & specificity in comparison to non-treponemal tests. The objective of the present study was to analyse the level of concordance between treponemal and non-treponemal tests for donor screening and to correlate them with donor history.Materials and methodsRetrospective analysis of syphilis screening by treponemal (Chemiluminescence & TPHA) and non-treponemal tests (RPR) was done and donor history for high-risk behaviour and factors associated with false positivity were collected from post-donation counselling and collected data was coded and analysed.ResultsAmongst the 12,000 donors screened, reactivity rate by RPR, TPHA and Chemiluminescence was 0.45%, 0.8% and 1.17% respectively. There was discordance of 62% and 32% for reactive results by RPR and TPHA respectively when compared with Chemiluminescence. History of high-risk behaviour was present in ∼ 50% and 15% of donors with discordant results by RPR and TPHA respectively. Of 34 donors who were reactive only by Chemiluminescence and were followed up, 15% had history of high-risk behaviour and 56% had factors associated with false reactivity.ConclusionTreponemal tests showed high syphilis reactivity amongst blood donors as compared to non-treponemal tests most likely due to their ability to detect early, late and latent syphilis cases. This may confer added transfusion safety in centres dependent on replacement donors without NAT testing by identifying donors with high-risk history with negligible increase in discard rate due to false reactivity.     

The FTA-ABS test: a diagnostic help or hindrance?

The fluorescent treponemal antibody absorption (FTA-ABS) test, an excellent confirmatory treponemal test, has been used increasingly for syphilis screening and case detection. To evaluate its performance as an initial test, we did Venereal Disease Research Laboratory (VDRL) slide and FTA-ABS tests on 1,043 patients suspected of having syphilis. When retested in both a local and a reference laboratory, sera from 226 patients with borderline or reactive results demonstrated interlaboratory consistency for the VDRL but not the FTA-ABS. Borderline FTA-ABS results correlated poorly with the diagnosis of syphilis in both laboratories; a reactive FTA-ABS test correlated well only in the reference laboratory. Performance of the test appeared to be diminished by its use in a low-prevalence population and by seemingly minor alterations in the test procedure at the local laboratory.     

Assessment of motivations for return donation among deferred blood donors. American Red Cross ARCNET Study Group

BACKGROUND: The recent addition of a computerized donor deferral registry to American Red Cross blood donation procedures has enabled blood center staffs to identify, before donation, persons who attempt to donate despite previous deferral. The current study investigated reasons that deferred donors return to donate, despite having been notified that they are ineligible. STUDY DESIGN AND METHOD: Anonymous mail surveys requesting demographic information, details of last donation or attempted donation, and assessments of incentives for donating were sent to 311 donors presenting inappropriately at blood drives and 849 matched controls in three American Red Cross regions between April and July 1996. RESULTS: Responses were received from a total of 113 deferred donors and 388 matched controls. Analysis of the 49 permanently deferred donors indicated that they were more likely than controls to donate blood to receive test results or to be awarded community service credit. Responses also revealed that some deferred donors may return to donate blood because of a misunderstanding of the deferral message or erroneous recruitment by blood center staff. CONCLUSION: There is a need before donation for the provision of educational materials regarding the window period of infection and for careful consideration of the use of incentives to attract donors to blood centers. It is also important to provide to donors a clear and consistent message regarding their test results and deferral status.     

Self-reported symptoms associated with West Nile virus infection in RNA-positive blood donors

BACKGROUND: In 2003, West Nile virus (WNV) nucleic acid amplification testing (NAT) was implemented to detect potentially infected donors. Of more than 5.3 million donations screened prospectively by the American Red Cross during the epidemic periods of 2003 and 2004, 974 were NAT-reactive and 519 confirmed-positive. A subset of both the confirmed-positive and the false-positive groups was assessed for demographic characteristics, symptoms, and symptom reporting relative to date of donation. STUDY DESIGN AND METHODS: All donors with initial WNV NAT-reactive results were invited to participate in a study that included a demographic, symptom, and date-of-symptom questionnaire. WNV confirmed-positive cases were compared to false-positive controls for comparison of frequency of symptom reporting before, on the day of, and after donation. RESULTS: Enrolled cases and controls were similar in all characteristics except cases were more likely to live in rural areas. Symptoms were reported by 61 percent of cases versus 20 percent of controls, with 74 percent of symptoms reported by cases within the 14 days after donation. The frequency of headache and fever reported together in the 7 days before donation was not significantly different between cases and controls; only the individual frequencies of headache, eye pain, and new rash during this time were significantly different. The most commonly reported symptoms, after adjustment for symptom reporting by controls, were headache, new rash, and generalized weakness; these symptoms were reported by 25 percent of cases. CONCLUSIONS: The demographic characteristics of infected donors reflected the rural nature of the 2003 to 2004 WNV epidemics. This study suggests that asking donors about predonation headache and fever had no detectable contribution to blood safety.     

Prevalence of selected viral infections among temporarily deferred donors who returned to donate blood: American Red Cross blood donor study

BACKGROUND: Health history questions are introduced into the predonation interview to identify blood donors believed to pose a higher risk of infectious diseases to recipients. This study assesses the current impact of some of those questions. STUDY DESIGN AND METHODS: Donor deferral and donation data were extracted from a research database of the American Red Cross. The prevalence of hepatitis B surface antigen or antibodies to human immunodeficiency virus, hepatitis C virus, or human T-lymphotropic virus was obtained for different groups of donors who were temporarily deferred in 2000 through 2001 and later returned to donate blood in 2000 through 2003. The results were compared with either first-time or repeat donors in 2000 through 2003, while controlling for differences in sex, age, and year of donation. RESULTS: Of donors temporarily deferred in 2000 through 2001 who had had no donation or deferral during the previous 2 years, only 22.08 percent subsequently returned to donate blood in 2000 through 2003. Donations from returning donors who had been deferred for potential infectious disease risk did not show a higher prevalence for any of the viral markers when those with no donation or deferral during the previous two years were compared with first-time donations, and those with prior donation were compared with repeat donations. CONCLUSION: Blood donors temporarily deferred in 2000 through 2001 for potential risk of viral infection who later returned to donate blood did not appear to pose a higher risk compared to first-time or repeat donors. The effectiveness of some of the currently used deferral questions in reducing viral risks warrants further study.     

Yield of HCV and HIV-1 NAT after screening of 3.6 million blood donations in central Europe

BACKGROUND: HCV and HIV-1 NAT of all blood donations was initiated at our institutions in January 1997 to reduce the residual risk of transfusion-transmitted virus infections. The yield of NAT after testing more than 3.6 million donations in central Europe is reported. STUDY DESIGN AND METHODS: Automated pipetting instruments were used to pool up to 96 donor samples including those that were antibody reactive. To compensate for dilution of the individual donor samples by pooling, viruses were enriched from the pools by centrifugation at 48,000 x g. A commercial PCR (Cobas Amplicor, Roche) and an in-house PCR were applied for HCV and HIV-1 amplification, respectively. RESULTS: Six HCV and 2 HIV-1 PCR confirmed-positive, antibody-negative donations (yield, 1 in 600,000 and 1 in 1.8 million, respectively) were identified. Thirty-nine and 11 multiple-time donors seroconverted for HCV and HIV, respectively, and look-back procedures were initiated. Archived samples from preseroconversion donations were thawed and retested by single-sample PCR and remained negative. The recipients of the blood components were traced and tested. All traced recipients were negative for HCV and HIV antibodies. CONCLUSION: The yield of NAT in central European Red Cross blood donors was less than expected from theoretical calculations for American and German multiple-time donors. Look-back procedures for HCV and HIV indicated that no donation given before seroconversion of the donor was missed by minipool PCR. Sensitivity of minipool PCR testing after virus enrichment seems to be sufficiently high to close the diagnostic window almost completely.     

Syphilis, human immunodeficiency virus infection, and targeting prevention

To examine the interaction between syphilis and human immunodeficiency virus-type 1 (HIV-1) infection in Oklahoma, we conducted an unlinked HIV seroprevalence survey using serum specimens submitted to the Oklahoma State Department of Health for serologic test for syphilis. Of specimens with positive results from fluorescent treponemal antibody absorption test (FTA-ABS), 6.3% were HIV-1 seropositive compared to 0.8% of those that had negative results from FTA-ABS. Among specimens positive for syphilis, HIV-1 seropositivity was found almost exclusively among those from persons 20 to 39 years of age and more often among those from men than those from women (9.9% vs 1.3%). Of syphilis-positive specimens from 20- to 39-year-old men, 17.6% were HIV-1 seropositive. In Oklahoma, an area with a relatively low overall prevalence of HIV-1 infection, targeting prevention efforts to young adults who test positive for syphilis should be an efficient way to reach some persons at high risk for HIV-1 infection.     

Hepatitis B virus (HBV) DNA screening of blood donations in minipools with the COBAS AmpliScreen HBV test

BACKGROUND: The risk of hepatitis B virus (HBV) transmission by blood transfusion (estimated at 1 in 63,000-1 in 205,000 units in the United States) exceeds that of hepatitis C virus (HCV) or human immunodeficiency virus (HIV). Reduction of window-period HBV transmissions through detection of HBV DNA-positive units by minipool nucleic acid testing (MP NAT) would be expected to decrease this risk. STUDY DESIGN AND METHODS: A large multicenter study of the COBAS AmpliScreen HBV test (Roche Molecular Systems) was conducted on minipools of 24 blood donation specimens. The yield of HBV DNA-positive, hepatitis B surface antigen (HBsAg)-negative window-period donations was determined relative to current and newly licensed HBsAg assays. Donors with selected HBV DNA, HBsAg, and anti-hepatitis B core antigen (HBc) results were further evaluated. RESULTS: The detection rate of window-period units was 1 in 352,451 (95% confidence interval, 1 in 2,941,176-1 in 97,561). Assay specificity was high (99.9964%). HBV DNA was detected in 84 percent of HBsAg-positive, anti-HBc-positive donations by MP NAT and in 94 percent when individual-donation (ID) NAT was added. HBV DNA was detected in 0.03 percent of HBsAg-negative, anti-HBc-positive donations by MP NAT and in 0.41 percent when ID NAT was added. CONCLUSIONS: Implementation of HBV MP NAT will provide an increment in safety relative to HBV serologic screening, similar to that for HCV and in excess of that for HIV. Our data indicate that the implementation of HBV MP NAT would likely interdict 39 HBV window-period units and prevent 56 cases of transfusion-transmitted HBV infection annually. The current data indicate that HBV MP NAT should not lead to discontinuation of anti-HBc testing but that discontinuation of HBsAg testing with retention of anti-HBc testing may be possible.     

Review of the standard tests for syphilis and evaluation of a new commercial elisa,the syphilis bio-enzabead test

To date, there are eight serologic tests considered Standard for the serodiagnosis of syphilis; however, the syphilis Bio-EnzaBead test is the first commercially available enzyme-linked immunosorbent assay (ELISA) for the confirmation of a reactive nontreponemal test result in the serodiagnosis of syphilis. The Bio-EnzaBead has a sensitivity of 95.2% in untreated syphilis when read at 405 nm with 80% of the 1 + optical density (OD) used as the breakpoint OD between reactive and nonreactive results. This sensitivity is comparable to the sensitivity of the microhemag-glutination assay (MHA-TP) of 97.6% in untreated syphilis. The specificity of the syphilis Bio-EnzaBead when read as described above is 94.7%, compared with the 99.3% of the MHA-TP and the 98.1% of the fluorescent treponemal antibody-absorption (FTA-ABS) test. Heating of the specimens did not adversely affect the test outcome, and it eliminated background readings seen with the negative control beads.     

Profile of blood donors with serologic tests reactive for the presence of syphilis in São Paulo, Brazil

BACKGROUND: Syphilis screening of blood donors is a common practice worldwide, but very little is known about the meaning of a positive serologic test for syphilis in blood donors and the risk profile of these donors. The aim of this study was to determine the demographic characteristics and risk behaviors of blood donors with recent and past syphilis and their implications for blood bank testing and deferral strategies.
STUDY DESIGN AND METHODS: Demographic characteristics, category of donation, number of previous donations, sexual behavior, and history of sexually transmitted diseases were reviewed comparing blood donors with recent and past syphilis from January 1, 1999, to December 31, 2003.
RESULTS: A total of 2439 interviews were reviewed, including 2161 (88.6%) donors with past and 278 (11.4%) with recent syphilis infection. Factors associated with recent infection included younger age (≤20 years odds ratio [OR], 36.5; 95% confidence interval [CI], 15.8-84.1), two previous donations (OR, 2.7; 95% CI, 1.9-3.9), male-male sex (homosexual OR, 8.2; 95% CI, 3.2-20.8; and bisexual OR, 11.4; 95% CI, 3.6-36.3), two or more partners in the past 12 months (OR, 2.3; 95% CI, 1.3-4.0), symptoms for syphilis (OR, 4.5; 95% CI, 2.8-7.1), and human immunodeficiency virus (HIV) seropositivity (OR, 39.6; 95% CI, 4.6-339.8). Community donors were also associated with recent syphilis infection (OR, 1.5; 95% CI, 1.2-1.9) compared to replacement donors.
CONCLUSION: Sexual history, including male-male sex and multiple partners, were strongly associated with recent syphilis infection, which in turn was strongly associated with HIV. Continuous and vigilant surveillance that includes assessing sexual history and other factors associated with syphilis are needed to guide blood safety policies.     

Associations between West Nile virus infection and symptoms reported by blood donors identified through nucleic acid test screening

BACKGROUND: Blood collected in the United States and Canada is screened for West Nile virus (WNV) using nucleic acid testing (NAT). The role that donor-reported symptoms of infection disclosed at or shortly after donation may play in enhancing blood safety has been debated. Little data are available on subsequent manifestations of WNV-specific disease outcomes in viremic donors.
STUDY DESIGN AND METHODS: Donors with initially reactive NAT results were informed by telephone and asked to complete symptom interviews. The questionnaires are focused on three time periods: the week before, the day of, and the 2 weeks after donation. Symptoms and risk factors were compared between confirmed-positive and false-positive donors (classified based on confirmatory NAT and serology). Additional analyses comparing confirmed-positive symptomatic and asymptomatic donors were conducted.
RESULTS: A total of 423 of 536 initially reactive donors were interviewed between 2003 and 2006: 292 confirmed-positive for WNV and 131 false-positive. Individual symptoms were not significant predictors of WNV infection, except skin rash in the week before donation (odds ratio [OR], 3.0; 95% confidence interval [CI], 1.2-7.9) and body aches in the period after donation (OR, 2.8; 95% CI, 1.1-7.4). Specific combinations of symptoms were not good predictors of infection, but donors with three or more concurrent symptoms before donation were more likely to have WNV infection (OR, 2.5; 95% CI, 1.2-5.1). Demographic characteristics, predonation symptoms, and serology profiles in confirmed-positive donors did not predict postdonation symptom severity. Thirty-five confirmed-positive donors (12%) sought medical care for WNV infection, with two hospitalizations, but no cases of neuroinvasive disease.
CONCLUSION: The number rather than type of symptoms is associated with confirmed WNV infection, but the overall predictive value is low. Very few infected donors develop clinically significant disease.