Seropositive Donations Research Articles

Blood discard rate in a blood center in Curitiba – Brazil. Ten years of study

IntroductionDevelopment of technologies to reduce transfusion risks of infectious diseases is a major characteristic of hemotherapy. Thus, each donation undergoes clinical and serological screening tests to ensure the donated blood do not offer risks to the receiver. ObjectiveEvaluate the prevalence of positive serology in blood donations rejected by Hemobanco (Curitiba – PR) in the period ranging from January 2003 to December 2012. MethodologyDuring the period studied, we observed the total number of donations and its division according to gender. We also analyzed the number of rejected donations due to seropositivity, considering the diseases investigated routinely in blood banks in Brazil, and the frequency of discards according to age groups. ResultsWithin the period studied, 399,280 donations were performed. 62.0% donors were male. Comparing 2003 to 2012, we noticed a significant decrease of discards, from 10.2% to 5.0%, respectively. There was a reduction of seropositivity for HIV, HBsAg and anti-HBc and an increase for Chagas Disease, hepatitis C, syphilis and HTLV. The age group with the highest prevalence for discards changed: it used to be the 40–59 years old group in 2003, and became the 20–39 years old group in 2012. ConclusionThere was an increase in the number of donations in Hemobanco and a decrease in total discards due to seropositive donations. Most donors were male. The most prevalent cause of discards only amongst seropositive donation discards is seropositivity for anti-HBc. There was a significant increase of donors aged between 20 and 39 years old.

Relative distribution of West Nile virus RNA in blood compartments: implications for blood donor nucleic acid amplification technology screening

Despite implementation of targeted individual-donor nucleic acid test (NAT) screening of blood donors for West Nile virus (WNV), three "breakthrough" WNV transfusion transmission cases were reported (2004-2008), suggesting that current plasma-based assays are unable to detect all WNV-infectious donations. A 2007 report found that 19 of 20 red blood cell components from WNV-infected donors contained 1 log higher viral load than plasma components. This study's aim was to further establish the value of screening whole blood relative to plasma for WNV RNA by generating differential viral loads on paired samples derived from blood screening tubes. WNV RNA-positive donors identified by routine NAT screening were enrolled and quantitative viral data were generated using cross-sectional (index-donation) and longitudinal (follow-up) specimens. A real-time reverse transcription-polymerase chain reaction viral load assay was used on both study sample sets and replicate qualitative NAT screening assays were also used on the longitudinal study samples. For the cross-sectional study, seronegative index donations (n = 29) had WNV RNA concentrations fourfold higher in plasma than in whole blood, whereas for seropositive donations (n = 13), the WNV RNA concentrations were 10-fold higher in whole blood than in plasma. All 10 longitudinal study participants were seropositive throughout the follow-up study; whole blood viral load was consistently greater than plasma viral load (mean difference, 343 copies; p < 0.001) up to 200 days after index. The improved sensitivity of WNV NAT using whole blood instead of plasma was confirmed, but appears to be limited to better detection in seropositive stages. However, the implication of these findings for blood screening requires further study to establish the infectivity of persistent whole blood viremia.

TRANSFUSION COMPLICATIONS: Seroprevalence of Babesia microti in blood donors from Babesia‐endemic areas of the northeastern United States: 2000 through 2007

BACKGROUND: Current estimates of 70 cases of transfusion‐transmitted Babesia microti, with 12 associated deaths, suggest that Babesia is a growing blood safety concern. The extent of Babesia infections among blood donors has not been well defined. To determine how common exposure to B. microti is among blood donors, a seroprevalence study was undertaken in the American Red Cross Northeast Division.STUDY DESIGN AND METHODS: Blood donations at selected blood drives in Connecticut and Massachusetts (2000 through 2007) were tested for the presence of immunoglobulin (Ig)G antibodies to B. microti using immunofluorescence assay. Geographic and temporal trends of B. microti seroprevalence were estimated for donor's zip code of residence.RESULTS: Overall, a 1.1% seroprevalence was identified in Connecticut, with the highest levels found in two Southeastern counties (Middlesex and New London). Observed seroprevalence for offshore islands of Massachusetts was 1.4%. Seropositive donations were identified from donors residing in all eight counties in Connecticut and three counties in Massachusetts. Although a seasonal peak was found between July and September, seropositive donations were identified in every month of the year.CONCLUSIONS: Foci of statistically higher B. microti seroprevalence among blood donors were observed; however, B. microti transfusion transmission risk exists for blood collected throughout Connecticut and portions of Massachusetts. Similarly, a seasonal peak was identified; nevertheless, seropositive donations were found year‐round. Thus, geographic and/or seasonal exclusion methods are insufficient to fully safeguard the blood supply from Babesia transmission. Steps should be taken to reduce risk of transfusion‐transmitted B. microti, perhaps through implementation of year‐round, regional testing.

Demonstrable parasitemia among Connecticut blood donors with antibodies to Babesia microti

Reports of transfusion-transmitted Babesia microti have risen steadily during the past several years, reflecting a concurrent increase in US cases of human babesiosis. Although several studies have measured B. microti antibodies in blood donors, little is known about associated parasitemia and the inherent risk of transmitting the parasite by transfusion. Donations from blood donors located in Babesia-endemic and nonendemic areas of Connecticut were tested for B. microti antibodies from July through September. Subsequently, an additional blood sample was collected from selected seropositive donors and tested by nested polymerase chain reaction (PCR) for B. microti nucleic acids. A total of 3490 donations, 1745 each from endemic and nonendemic areas, were tested for B. microti antibodies; 30 (0.9%) were confirmed as positive and seroprevalence rates peaked in July. Significantly more seropositive donations were from endemic areas (24, 1.4%) than nonendemic areas (6, 0.3%). Ten (53%) of 19 seropositive donors subsequently tested by PCR were positive. B. microti seroprevalence was highest in those areas of Connecticut where the parasite is endemic. More than half of seropositive donors tested had demonstrable parasitemia, indicating that many are at risk for transmitting B. microti by blood transfusion. Three donors were identified as parasitemic in October, suggesting that donors may be at risk for transmitting the parasite outside of the peak period of community-acquired infection.

False-negative testing errors in routine viral marker screening of blood donors. For the Retrovirus Epidemiology Donor Study.

The contribution of testing errors to the risk of virus transmission by transfusion depends on the rate of false-negative testing errors and the prevalence of infected seropositive donations. Although the false-negative testing error rate has been estimated at 0.1 to 1 percent on the basis of proficiency studies, it has not previously been measured in routine donor screening. A 1991 to 1995 database containing 5,153,153 donations from 1.5 x 10(6) donors (including autologous donors) was searched to identify donors who tested seropositive for HIV, HCV, HTLV-I or II and who attempted subsequent donations. The false-negative rate in routinely screened follow-up donations was determined, and false-negative cases were investigated to identify the cause. Subsequent donations (n = 2015) by 1224 donors with confirmed-positive results were identified. Eleven (0.5%) of these donations did not react in EIA. Ten of the 11 false-negative cases were attributable to borderline-reactive donations. On subsequent donations, there were borderline-nonreactive results on HTLV-I (2 cases), first-generation HCV (5 cases), and second-generation HCV (3 cases) EIAs. The final case was strongly reactive for HCV in a second-generation EIA on two donations (signal-to-cutoff [S:C] ratio >3.5), followed by a baseline nonreactive result on a third donation (S:C = 0.05). False-negative testing results occur infrequently during routine infectious-disease donor screening. Although most false-negative results occurred with borderline-reactive HTLV-II samples and/or early-generation HCV EIAs, frank technical errors (e.g., sample mixup or failure to add sample to EIA well) also occur at a low rate (0.05%; 95% CI, 0-1.5%). Process enhancements designed to reduce errors (e.g., enhanced automation of data management and testing systems and process controls for EIAs) are warranted to detect and prevent false-negative results.

Séropositivité VIH dans les dons de sang : prévalence, risque résiduel et épidémiologie

As it has been observed since the beginning of anti-HIV screening in blood donations, the rate of seropositive donations has been still decreasing during these 4 last years: 0.090/1000 in 1991 to 0.042/1000 in 1994. This decrease has been observed in blood donations from first-time donors (0.38 to 0.17/1000) and from regular donors (0.060 to 0.030/1000). However, the residual risk from cellular components, such as it is estimated, seems to be stable. The proportion of blood donations positive for both anti-HIV and anti-HBc was constantly decreasing from year to year: 63% between 1985 and 1988 and 25% in 1994. The repartition of seropositive donors into sex, ages and at-risk groups during this recent period was the same as previously observed.

Duration of time from onset of human immunodeficiency virus type 1 infectiousness to development of detectable antibody. The HIV Seroconversion Study Group.

For persons newly infected with the human immunodeficiency virus type 1 (HIV-1), the time from the onset of infectivity to the development of detectable HIV-1 antibody is unknown. Persons who donate blood during this period account for nearly all instances of HIV-1 transmission from HIV-1 antibody-screened blood transfusions. To estimate the window period from infectivity to HIV-1 antibody positivity, 701 HIV-1-seropositive blood donors who made a previous seronegative donation at 40 United States blood centers were studied. The HIV-1 antibody status was determined for at least one recipient of blood from the seronegative donation preceding the seropositive donation made by 182 of the 701 donors. There were 39 seropositive recipients of blood from these 182 donors. Three donors were excluded from further analysis because the seropositive recipients of their blood had other HIV-1 risk factors or had HIV-1 infection before transfusion. The final study population comprised the remaining 179 donors, of whom 36 (20%) transmitted HIV-1 infection to recipients. When the interval between the seropositive donation and the preceding seronegative donation was less than 180 days, 46 percent of the donors transmitted HIV-1. In contrast, when that interval exceeded 540 days, only 2 percent transmitted HIV-1. A mathematical model was developed to explain the relationship between the probability that the previous seronegative donation occurred during the donor's window period of infectiousness, and hence transmitted HIV-1, as a function of both the window period and the duration between the seropositive and previous seronegative donations. This model indicated that the transmission data were most consistent with an average window period of 45 days. Assuming a log-normal window period distribution, it was estimated with 95 percent certainty that at least 90 percent of persons had a window period of less than 141 days. The window period averages 45 days, with few, if any, donors remaining infectious and seronegative for longer than 6 months.

Screening of blood donors for idiopathic CD4+ T‐lymphocytopenia

The recent recognition of idiopathic CD4+ T-lymphocytopenia (ICL) had led to concern that an unknown immunodeficiency virus may be transmissible by transfusion. To evaluate the prevalence and significance of low CD4+ values among blood donors, CD4+ data on 2030 blood donors who were negative for antibody to human immunodeficiency virus type 1 (HIV-1) were compiled. Those with CD4+ values below ICL cutoffs (< 300 CD4+ T cells/microL, or < 20% CD4+ T cells) were recalled for follow-up investigations. Serial CD4+ data on 55 homosexual men who seroconverted during prospective follow-up and data on 139 anti-HIV-1-positive blood donors initially evaluated in 1986 were reviewed as well. Five seronegative donors (0.25%) had absolute CD4+ counts < 300 cells per microL and/or < 20 percent. On follow-up, all five donors had immunologic findings within normal ranges, lacked HIV risk factors, and tested negative for HIV types 1 and 2 and human T-lymphotropic virus type I and II infections by antibody and polymerase chain reaction assays. Four of five donors reported transient illness shortly after their low CD4+ count donations. The median interval from HIV-1 seroconversion to an initial CD4+ value below ICL CD4+ cutoffs was 63 months for infected homosexual men. Of 139 HIV-1-infected blood donors studied 1 to 2 years after seropositive donations, 34 (24%) had CD4+ counts < 300 cells per microL and/or < 20 percent. Low CD4+ counts are rare among anti-HIV-1-negative volunteer blood donors and are generally associated with transient illnesses. If any unknown virus progresses similarly to HIV-1, CD4+ count donor screening would be a poor surrogate for its detection.

Human T-Cell Lymphotropic Virus Infection among Blood Donors in South Florida

Knowledge of the epidemiologic pattern of human T-lymphotropic virus (HTLV) in the United States is being enlarged by blood donor screening. We tested stored sera from 29,937 donations made in South Florida in 1984-1985. Twenty-three donors were confirmed as seropositive, a prevalence of 0.8 per 1,000 donations. Specificity was supported by serologic retesting and virus culture of 11 donors located for follow-up. Sex- and age-specific prevalences did not differ significantly; blacks, however, accounted for 65% of seropositive donations. Within South Florida, one section of Miami had a prevalence of 4.5 per 1,000 donations, significantly above the 0.1 to 1.1 per 1,000 rates for other parts. An epidemiologic association with known HTLV-I endemic areas could account for most infections; all seven typed isolates were characterized as HTLV-I. Exposures, however, were diverse, sometimes multiple, and had no necessary relationship to personal lifestyle. This finding suggests that sources of infection were varied. Seropositive family members emphasize familial clustering of HTLV-I infection.

Epidemiologic study of HIV serology in blood donors from 5 departments in northeastern France (1985-1989)

Between July 1985 and June 1989, the prevalence of HIV antibody was studied in 503,019 blood donations tested in 5 administrative areas ("departments") of north east France: 91 seropositive donations (donors) were detected (prevalence: 0.18%). The prevalence was 0.41% in 1985, 0.22% in 1986, 0.14% in 1987, 0.10% in 1988 and 0.11% in 1989: in each year, it was found lower than the national prevalence. 14 (15.4%) of the 91 seropositive donors were females, and the prevalences of HIV antibody in blood donations from female and male donors were 0.07% and 0.26% respectively. All seropositive donors were younger than 50 and 83 (91.2%) younger than 40. The prevalence of HIV antibody was higher in blood units at first donation (occasional donors) as compared with blood units collected from regular donors (0.60% versus 0.09%). The prevalence of HIV antibody was higher in blood donations from military donors as compared with donations from civilian donors (0.49% versus 0.07% in 1987, 1988 and 1989). Most seropositive military donors were young male recruits of the national armed forces conscription system. We believe that these recruits are subjects with risk factors which must be taken into account for the determination of national blood supply policies.