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.     

The increasing prevalence of serologic markers for syphilis among Chinese blood donors in 2008 through 2010 during a syphilis epidemic

BACKGROUND: In China, the growing syphilis epidemic parallels the spread of human immunodeficiency virus (HIV) in the general population. This study evaluated the prevalence and incidence of serologic markers for syphilis among donors at five Chinese blood centers. STUDY DESIGN AND METHODS: We examined whole blood and apheresis donations collected from January 2008 through December 2010. Postdonation testing of syphilis was conducted using two different Treponema pallidum antibody enzyme‐linked immunosorbent assay kits. The prevalence of serologic markers for syphilis (%), and the rate of coinfection with HIV‐1/2, hepatitis B virus (HBV), and hepatitis C virus (HCV) were calculated. A multivariable logistic regression analysis was conducted examining donor characteristics associated with positive syphilis serology. Seroconversion rate and syphilis incidence were estimated. RESULTS: Of 801,511 donations, 60% were from first‐time donors and 40% were from repeat donors. There was a significant increase in syphilis serologic markers among first‐time donors with 0.41, 0.45, and 0.57% positivity over 3 years (p < 0.001). Approximately 2.8, 0.8, and 0.5% of HIV‐1/2–, HBV‐, and HCV‐positive donations also tested reactive for syphilis. Logistic regression results suggest that first‐time donors were nine times more likely to be syphilis positive than repeat donors. Higher syphilis positivity was associated with donors older than 25 years and with less education. Estimated incidence among repeat donations was 33 (95% confidence interval, 29‐39) per 100,000 person‐years. CONCLUSION: The increase in syphilis serologic prevalence reflected the syphilis epidemic in the general population. Without screening, most of these syphilis‐positive donations would get into the blood supply. Thus, during a syphilis epidemic, continued syphilis screening of blood donations may be important to maintain blood safety and public health.     

Geographic risk factors for viral hepatitis and cytomegalovirus infection among United States Armed Forces blood donors

In an effort to determine whether residence in a foreign country increases the risk of hepatitis B and C and cytomegalovirus (CMV) infection in United States (US) Armed Forces blood donors, 5719 volunteer donors at four US Navy blood banks were evaluated. Most participants were repeat donors (68%) and were young (mean age, 25 years), male (88%), and white (80%), black (10%), or Hispanic (7%). Birth outside of the United States was reported by 6 percent of subjects, and 34 percent had lived in a foreign country for more than 3 months. Twenty (0.3%) subjects had hepatitis B surface antigen (HBsAg), and 100 (1.7%) had antibody to hepatitis B core antigen (anti-HBc). Thirty-four (0.6%) were repeatably reactive in enzyme-linked immunosorbent assay for antibody to hepatitis C virus (anti-HCV); 11 (0.2%) had anti-HCV in immumoblot assay. Of the 3484 donors tested for anti-CMV, 1117 (32.1%) were positive. When demographic characteristics were controlled for both anti-HBc and anti-CMV seropositivies were independently associated in male blood donors with residence in the Philippines. Geographic factors were not associated with HBsAg and anti-HCV positivity. These findings indicate that the prevalence of serologic markers for viral hepatitis is low in military blood donors, but that residence in the Western Pacific is a risk factor for hepatitis B and CMV infection.     

Current incidence and residual risk of hepatitis B infection among blood donors in the United States

BACKGROUND: This study used two approaches to estimate the current incidence of hepatitis B virus (HBV) in a US donor population.
METHODS: HBV incidence was estimated through the hepatitis B surface antigen (HBsAg) yield approach and the seroconversion method. Residual risk was estimated by the incidence–window period model. HBsAg yield refers to an HBsAg confirmed-positive, antibody against hepatitis B core antigen (anti-HBc)–nonreactive donation, adjusted for false-positive neutralization results. The number of HBsAg-seroconverting repeat donors divided by total number of person-years of evaluation or the HBsAg yield rate divided by HBsAg yield window gave rise to incidence estimates.
RESULTS: The seroconversion and the yield approach, respectively, gave an incidence estimate of 3.41 or 3.43 per 10⁵ person-years. Using a revised infectious window period of 38 or 30 days for current HBsAg assays, the current residual risk for HBV was respectively estimated for 2006 to 2008 at 1 in 282,000 or 1 in 357,000 donations from the seroconversion approach and 1 in 280,000 or 1 in 355,000 donations from the yield approach. With the same database and methods, this is a decrease from 1 in 86,000 to 1 in 110,000 observed in 1997 to 1999.
CONCLUSIONS: Current HBV incidence and residual risk are lower than earlier estimates, especially in the youngest donors, but remain higher in the absence of HBV nucleic acid test than those for human immunodeficiency virus or hepatitis C virus (HCV). In addition to the exclusion of HBsAg false-positive donors, the reduction could reflect shortened window periods and decreased incidence rates due to vaccination or other reasons.     

Age-related donor return patterns among first-time blood donors in the United States

BACKGROUND: Committed repeat donors are vital to the continued success of blood collections, yet the effect of age of first-time (FT) donation on return behavior is poorly described. Sixteen-year-old donors are increasingly allowed to donate and have the highest rates of adverse events, which negatively impacts return behavior.
STUDY DESIGN AND METHODS: Annual cohorts of allogeneic FT donors from 2005 and 2006 were selected within the American Red Cross system and followed for 25 and 13 months, respectively. Return and total yield rates among different age groups were compared.
RESULTS: A total of 2.3 million FT donors from 2005 and 2006 gave 4.2 million donations during the study. Sixteen- to 19-year old FT donors made up 41% of the FT donor base in 2005 and 16-, 17-, 18-, and 19-year-olds, respectively, had initial return rates of 62, 52, 35, and 28% and yield rates of 2.0, 1.76, 1.51, and 1.41 over 13 months. Multivariate analysis of FT yield rates shows that younger (16 and 17 years) and older (50+ years) donors, males, blood group O donors, and those without any initial adverse reaction are most likely to return. Increasing severity of donor adverse reactions correlated with a reduction in yield and return rates.
CONCLUSION: FT 16-year-old donors had the highest return and yield rates despite the negative impact of increased adverse event rates. Donation at young age is critical to building a cadre of committed repeat donors but donor reactions must be addressed to ensure the donors' well-being and to sustain return behavior.     

Patterns of age- and sex-specific prevalence of major blood-borne infections in United States blood donors, 1995 to 2002: American Red Cross blood donor study

BACKGROUND: The American Red Cross has been maintaining a research database of all blood donations, including all testing results for infectious disease markers, since 1995. This study analyzes the temporal trends of major blood-borne infections among blood donors. STUDY DESIGN AND METHODS: Temporal trends for age- and sex-specific prevalence of human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV), and syphilis infections in US blood donors were analyzed based on linear trend or time series model or other models as appropriate. RESULTS: From 1995 to 2002, significant declines have been observed for infections that used to be at relatively higher levels. Declines in prevalence were slower among first-time donations than repeat donations. There was an increase in prevalence of anti-HCV among first-time male donors of 50 to 59 years of age. Anti-HIV prevalence appeared to have increased among first-time male donors of 30 to 39 years of age since 2000. CONCLUSION: Different sex and age groups showed various patterns of decline and even signs of increase. The increasing prevalence among some age and sex groups may merit further investigation.     

Hepatitis B core antibody (anti-HBc) in blood donors in the United States: implications for surrogate testing programs

In order to evaluate the operational implications of excluding donated blood with antibody to hepatitis B core antigen (anti-HBc), the American Red Cross tested 107,473 voluntary blood donations for anti-HBc in 72 test sites during a 1-week period. The system-wide prevalence of anti-HBc was 2.60 percent, with a range of 0.55 to 6.38 percent, depending on geographic region. For the American Red Cross, which collects approximately one-half of the blood supply in the United States, excluding donated blood with anti-HBc would result in a loss of approximately 159,500 units during the first year.     

NAT screening of viral infections in donors enhances blood safety

The first experience in introducing the nucleic acid amplification technique (NAT) in an Indian blood service as compared with the established European practice is analyzed. Examination of 12,224 donor blood samples revealed 217 (1.78%) persons with markers of infections, including 8 (0.065%) persons only with markers of viral genome, without serological signs of infections. In India, enzyme immunoassay-negative NAT-positive donations were tens of times more detectable than in the developed countries, which is associated with the epidemiological features and the large (more than 50%) proportion of paid donors. By taking into account the fact that 4.6% of the preserved blood doses are annually rejected as defective in the Russian Federation, as evidenced by the screening of markers of infections, the introduction of NAT may be expected to reveal a large proportion of donors in the period of both a "seronegative window" and chronic carriers of hepatitis B virus with its blood content. Both intralaboratory monitoring using the certified standards and the laboratory work quality system as a whole are a necessary condition for introducing NAT into a blood service.     

The United States Trypanosoma cruzi Infection Study: evidence for vector-borne transmission of the parasite that causes Chagas disease among United States blood donors

BACKGROUND: Screening US blood donors for Trypanosoma cruzi infection is identifying autochthonous, chronic infections. Two donors in Mississippi were identified through screening and investigated as probable domestically acquired vector‐borne infections, and the US T. cruzi Infection Study was conducted to evaluate the burden of and describe putative risk factors for vector‐borne infection in the United States. STUDY DESIGN AND METHODS: Blood donors who tested enzyme‐linked immunosorbent assay repeat reactive and positive by radioimmunoprecipitation assay, and whose mode of infection could not be identified, were evaluated with a questionnaire to identify possible sources of infection and by additional serologic and hemoculture testing for T. cruzi infection. RESULTS: Of 54 eligible donors, 37 (69%) enrolled in the study. Fifteen (41%) enrollees had four or more positive serologic tests and were considered positive for T. cruzi infection; one was hemoculture positive. Of the 15, three (20%) donors had visited a rural area of an endemic country, although none had stayed for 2 or more weeks. All had lived in a state with documented T. cruzi vector(s) or infected mammalian reservoir(s), 13 (87%) reported outdoor leisure or work activities, and 11 (73%) reported seeing wild reservoir animals on their property. CONCLUSION: This report adds 16 cases, including one from the Mississippi investigation, of chronic T. cruzi infection presumably acquired via vector‐borne transmission in the United States to the previously reported seven cases. The estimated prevalence of autochthonous infections based on this study is 1 in 354,000 donors. Determining US foci of vector‐borne transmission is needed to better assess risk for infection.     

Hepcidin as a diagnostic marker of iron deficiency in blood donors

BackgroundBlood donors are prone to have iron deficiency. The aim of this study was to determine utility of serum hepcidin as an indicator of iron deficiency in blood donors.MethodsA total of 200 voluntary, healthy blood donors were included in the study. Donors were categorized into four groups according to the donation frequency. Group I: (n = 50) who donated for the first time, or those who have not donated in the past 2 years (reactivated donors). Group II: (n = 50), who donated blood for the second time and had donated once in the previous 12 months. Group III: (n = 50), who donated blood for third time and had donated twice in the previous 12 months. Group IV: (n = 50) who donated blood for the fourth time and had donated thrice in the previous 12 months. Sera of study participants were evaluated for serum ferritin and serum hepcidin levels based on enzyme linked immunosorbent assay.ResultsSerum hepcidin concentration ranged 2.36?15734 pg/mL. Serum hepcidin and serum ferritin were found to be lowest in group IV donors. When serum ferritin concentration of less than 15 ng/mL was considered as gold standard for diagnosing iron deficiency, AUCROC for serum hepcidin as a diagnostic test of iron deficiency was found to be 0.715. Serum hepcidin showed statistical significant correlation with donation frequency(p = 0 .005) and serum ferritin (p = 0.01). Sensitivity and specificity of serum hepcidin was found to be 77.8 %, 79.6 % respectively.ConclusionEffectiveness of Serum hepcidin as a diagnostic marker of iron deficiency still needs to be determined.     

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.