Prevalence of serologic markers for hepatitis B and C viruses in Brazilian blood donors and incidence and residual risk of transfusion transmission of hepatitis C virus

BACKGROUND: We evaluate the current prevalence of serologic markers for hepatitis B virus (HBV) and hepatitis C virus (HCV) in blood donors and estimated HCV incidence and residual transfusion‐transmitted risk at three large Brazilian blood centers. STUDY DESIGN AND METHODS: Data on whole blood and platelet donations were collected from January through December 2007, analyzed by center; donor type; age; sex; donation status; and serologic results for hepatitis B surface antigen (HBsAg), antibody to hepatitis B core antigen (anti‐HBc), and anti‐HCV. HBV and HCV prevalence rates were calculated for all first‐time donations. HCV incidence was derived including interdonation intervals that preceded first repeat donations given during the study, and HCV residual risk was estimated for transfusions derived from repeat donors. RESULTS: There were 307,354 donations in 2007. Overall prevalence of concordant HBsAg and anti‐HBc reactivity was 289 per 100,000 donations and of anti‐HCV confirmed reactivity 191 per 100,000 donations. There were significant associations between older age and hepatitis markers, especially for HCV. HCV incidence was 3.11 (95% confidence interval, 0.77‐7.03) per 100,000 person‐years, and residual risk of HCV window‐phase infections was estimated at 5.0 per million units transfused. CONCLUSION: Improvement in donor selection, socioeconomic conditions, and preventive measures, implemented over time, may have helped to decrease prevalence of HBV and HCV, relative to previous reports. Incidence and residual risk of HCV are also diminishing. Ongoing monitoring of HBV and HCV markers among Brazilian blood donors should help guide improved recruitment procedures, donor selection, laboratory screening, and counseling strategies.     

Prevalence,incidence, and residual risk of major blood‐borne infections among apheresis collections to the American Red Cross Blood Services, 2004 through 2008

BACKGROUND: The number of apheresis collections increased significantly in recent years; however, data on viral marker rates among these collections are lacking. STUDY DESIGN AND METHODS: Apheresis collection data for 2004 to 2008 were analyzed. All collections were tested for antibodies and viral RNA for human immunodeficiency virus (HIV) and hepatitis C virus (HCV), hepatitis B surface antigen (HBsAg), antibody to hepatitis B core antigen (anti‐HBc), antibody to human T‐lymphotropic virus (anti‐HTLV), and other markers. HBsAg‐confirmed‐positive but anti‐HBc–nonreactive units were further verified by HBV DNA testing. RESULTS: From 2004 to 2008, apheresis collections for double red blood cells (R2) increased by 294% to a total of 37% of all apheresis collections. Marker rates (/100,000) among all apheresis collections were 1.41, 7.83, 2.04, and 0.28, for HIV, HCV, HBsAg, and HTLV. Among R2 collections, rates (/100,000) were 6‐ to 13‐fold higher than among non‐R2 collections for HIV (3.50 vs. 0.53), HCV (21.84 vs. 1.96), and HBsAg (5.83 vs. 0.44), but not HTLV (0.53 vs. 018). First‐time male R2 donors accounted for 25% to 100% of positivity but only 1% to 5% of the total number of apheresis collections. Incidence (/100,000 person‐years) and residual risk estimates among repeat apheresis donors between 2007 and 2008 for HIV were 3.82 and 1:1.0 million, for HCV were 1.53 and 1:3.2 million, and for HBsAg were 4.85 and 1:200,000. These estimates were comparable to those among repeat whole blood donors. CONCLUSION: The risk of major blood‐borne infections among current apheresis collections was low; however, an upward trend in the viral marker frequency among apheresis donations was attributable to the contribution of first‐time, male R2 donors.     

Prevalence of viral markers among first-time Arab blood donors in Kuwait

BACKGROUND: The aim of this study was to assess the effect of blood donation modes on the prevalence of viral markers among Arab first-time blood donors in Kuwait. STUDY DESIGN AND METHODS: Donor ethnic background was classified as Kuwaiti nationals and non-Kuwaiti Arabs. A total of 26,874 donors were screened in 2002 for the following viral markers: hepatitis C virus antibody (anti-HCV), hepatitis B surface antigen (HBsAg), anti-hepatitis B core antigen (HBc), human immunodeficiency virus-1 and -2 antibody (anti-HIV-1 and -2), HIV p24, and human T lymphotropic virus-I and -II antibody (anti-HTLVI/II). All samples positive for the presence of anti-HBc were tested for anti-HBs. Among these donors, 12,798 were first-time donors of which 74 percent were replacement and 26 percent were volunteers. RESULTS: The prevalence of HCV among replacement donors was significantly higher than the volunteer group. The difference between the two modes of blood donations, however, was not significant for HBsAg. The prevalence of anti-HCV among Kuwaiti national and non-Kuwaiti Arab first-time donors was 0.8 and 5.4 percent, respectively, whereas the prevalence of HBsAg was 1.1 and 3.5 percent, respectively, with the difference being significant at a p level of <0.0001. The difference observed for prevalence of anti-HBc among Kuwaiti national and non-Kuwaiti Arab donors (17 and 33.3%, respectively) was significant (p < 0.0001). Among first-time donors, 13.7 percent were positive for the presence of anti-HBs, indicating that 13.7 percent of the total Arab donor population might have had a previous infection and possible immunity to hepatitis B virus (HBV). CONCLUSION: A high prevalence of HBV and HCV was found among non-Kuwaiti Arab donors. The prevalence of anti-HCV was only significantly higher among replacement versus volunteer first-time donors. Therefore, there is a need to develop a strategic plan that incorporates the diverse background of the blood donors living in Kuwait.     

Potential increased risk of virus transmission due to exclusion of older donors because of concern over Creutzfeldt-Jakob disease. The National Heart, Lung, and Blood Institute Retrovirus Epidemiology Donor Study

BACKGROUND: Concern over the theoretical possibility of disease transmission via blood from donors who develop Creutzfeldt-Jakob disease has led to proposals to exclude older individuals from donating plasma for further manufacture into pooled plasma donations. The impact of extending this age-deferral policy to blood donors was examined with respect to the risk for known transmissible viruses. STUDY DESIGN AND METHODS: Demographic characteristics and confirmed prevalence rates (/10(5) first-time donations) and incidence rates (/10(5) person-years for repeat donors) for viral markers were compared for donors < 50 years old (n = 1,259,805 [85%]) and > or = 50 years old (n = 219,856 [15%]) and for donors < 60 years old (n = 1,409,176 [95%]) and > or = 60 years old (n = 70,485 [5%]). Incidence rates were combined with infectious window-period estimates for each virus, to calculate the risk of virus transmission per 10(6) donations. RESULTS: Unadjusted prevalence rates were significantly greater for younger than for older donor groups for human immunodeficiency virus (HIV), hepatitis B surface antigen (HBsAg), and hepatitis C virus (HCV) (p < or = 0.05). Incidence rates (and transmission risk estimates) for HBsAg were significantly higher in the < 50 donor group than in the > or = 50 group (p < or = 0.05), and those for HIV, human T-lymphotropic virus, and HCV were not significantly higher (p > 0.05). Blanket removal of donors over the age of 50 would potentially lead to the following significant increases in the risk of infected units: HIV, 12 percent; HCV, 21 percent; and hepatitis B virus (HBsAg), 22 percent. CONCLUSION: Removal of donors over the age of 60 would not significantly affect the risk of infected units. Deferral of donors > or = 50 years of age from whole-blood donations for unfounded concerns about Creutzfeldt-Jakob disease could have adverse effects on both blood availability and safety.     

Epidemiology of hepatitis B in Canadian blood donors

BACKGROUND: The residual risk of hepatitis B is higher than for other markers such as human immunodeficiency virus and hepatitis C virus in nonendemic countries. Evaluating the potential for further risk reduction requires a better understanding of the relationship between donor selection criteria, immigration from endemic countries, and public health vaccination strategies. STUDY DESIGN AND METHODS: Age and sex trends of hepatitis B surface antigen (HBsAg)‐positive donors from 1997 to 2006 were analyzed using a Poisson model. All HBsAg‐positive donors in 2005/2006 plus four matched control donors for every HBsAg‐positive donor who participated were invited to participate in a risk factor interview and predictors of HBsAg positivity identified by logistic regression. A survey of 40,000 donors who did not react for all markers asked about vaccination history and country of birth. RESULTS: Most HBsAg‐positive donations were from first‐time donors (86%), have been decreasing in donors under the age of 30 (p < 0.01), and were correlated with geographic regions with more donors from higher‐prevalence countries (p < 0001). Birth in a higher‐prevalence country predicted HBsAg positivity (p < 0.01). Fifty‐six percent of donors reported being vaccinated for hepatitis including approximately 80 percent of donors under age 30 who reported being vaccinated as part of regular school programs. CONCLUSION: HBsAg‐positive donations are decreasing in donors under age 30, those most frequently vaccinated through provincial vaccination programs. HBsAg‐positive donations largely reflect immigration from high‐prevalence countries without other deferrable risk factors, mainly chronic cases that will be detected by current testing. Furthermore, risk of incident infections should decrease with increasing vaccination rates in donors, especially the younger cohort now receiving universal vaccination.     

Performance of an algorithm for the reentry of volunteer blood donors deferred due to false-positive test results for antibody to hepatitis B core antigen

BACKGROUND: Blood donor testing for antibody to hepatitis B core antigen (anti‐HBc) has been used in the United States for more than 20 years as a surrogate to prevent transmission by transfusion of non‐A,non‐B hepatitis, as a human immunodeficiency virus surrogate, and to reduce transmission of hepatitis B virus (HBV). Nonspecific anti‐HBc assays have caused deferral of hundreds of thousands of otherwise qualified donors. A more specific anti‐HBc test and a sensitive HBV DNA test should permit donor reentry after false‐positive anti‐HBc. STUDY DESIGN AND METHODS: A total of 1324 otherwise eligible volunteer donors, deferred for anti‐HBc reactivity on more than one occasion, were recruited from four collection facilities. They were tested using a licensed, more specific anti‐HBc test, a licensed hepatitis B surface antigen (HBsAg) test, and a licensed HBV DNA assay with a 95 percent limit of detection of not more than 10 copies per mL. RESULTS: From 11 to 32 percent of donors contacted by participating sites entered the study. Overall, 488 (37%) of the donors were negative on the more specific anti‐HBc test. The proportion of putative false‐positive samples varied according to the test responsible for the original deferral. A single donor, negative for the presence of anti‐HBc and HBsAg, was positive for the presence of HBV DNA in one of three replicates. Repeat testing of this donor 10 months later was negative for the presence of all markers of HBV infection, and the donor had a history of HBV vaccination with documented postimmunization anti‐HBs seroconversion 10 years before her anti‐HBc deferral, and was considered HBV DNA false positive. CONCLUSION: These data support reentry of donors with false‐positive anti‐HBc results on the relatively nonspecific assays that have been in use in the United States for more than 20 years.     

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.     

Hepatitis B e antigen in volunteer and paid blood donors

Sera from 200 volunteer donors and 200 paid blood donors, all positive for hepatitis B surface antigen (HBsAg), were tested for the presence of hepatitis B e antigen (HBeAg).HBeAg was detected in 31 HBsAg- positive paid donors (15%), and in 11 HBsAg-positive volunteer donors (5%) by agar gel diffusion. The presence of HBsAg was associated with higher titers of HBsAg. No significant difference was found in the prevalence of antibody to HBeAg (anti-HBe) in the two donor groups. Rheumatoid factor was not associated with the presence or absence of HBeAg or anti-HBe, indicating that HBeAg is probably not an anti-IgG. These data support the epidemiological evidence that paid blood donors appear to be more likely than volunteer donors to transmit hepatitis B virus infection to recipients of their blood.     

A method for estimating incidence rate of infectious diseases among first-time blood donors

BACKGROUND: In certain circumstances, there is no method for estimating incidence based on testing results on a single blood sample from first‐time blood donors, severely limiting the ability to assess the residual risk of blood‐borne infections among this donor subpopulation. STUDY DESIGN AND METHODS: Incidence rates were estimated for human immunodeficiency virus (HIV) and hepatitis C virus (HCV) among first‐time donors using the formula (P₂ ? P₁)/D, where P₁ is the prevalence among blood donations from first‐time donors of the minimum eligible ages for donation, P₂ is the prevalence among donations from first‐time donors of an older age group, and D is the age difference (in years) between the older and younger donor groups. RESULTS: Estimating incidence among first‐time donors using the proposed method based on a single test for anti‐HCV produced similar results to those based on HCV nucleic acid test (NAT) yield cases, by sex and in different periods. Comparison of the proposed method with HIV NAT yield also showed similar results although the small number of HIV NAT yield cases limits interpretation. CONCLUSIONS: The proposed method provides an alternative way for estimating incidence of certain blood‐borne infections among first‐time donors, provided that our assumptions are met. It helps residual risk assessment in donor populations where first‐time donors account for most of the donations and only one test result is available for each donor.     

A comparison of human immunodeficiency virus,hepatitis C virus,hepatitis B virus,and human T‐lymphotropic virus marker rates for directed versus volunteer blood donations to the American Red Cross during 2005 to 2010

BACKGROUND: At most US blood centers, patients may still opt to choose specific donors to give blood for their anticipated transfusion needs. However, there is little evidence of improved safety with directed donation when compared to volunteer donation. STUDY DESIGN AND METHODS: The percentage of directed donations made to the American Red Cross (ARC) from 1995 to 2010 was determined. Infectious disease marker rates for human immunodeficiency virus (HIV), hepatitis C virus (HCV), hepatitis B virus (HBV), and human T‐lymphotropic virus (HTLV) were calculated for volunteer and directed donations made from 2005 to 2010. Odds ratios (ORs) were calculated to compare marker‐positive rates of directed donations to volunteer donations. RESULTS: The percentage of donations from directed donors declined from 1.6% in 1995 to 0.12% in 2010. From 2005 to 2010, the ARC collected 38,894,782 volunteer and 69,869 directed donations. Rates of HIV, HCV, HBV, and HTLV for volunteer donations were 2.9, 32.2, 12.4, and 2.5 per 100,000 donations, respectively; for directed, the rates were 7.2, 93.0, 40.1, and 18.6 per 100,000. After demographics and first‐time or repeat status were adjusted for, corresponding ORs of viral marker positivity in directed versus volunteer donations were not significant for HIV, HBV, or HTLV and significant for HCV (OR, 0.7; 95% confidence interval, 0.50‐0.90). CONCLUSIONS: Directed donations have declined by 92% at the ARC since 1995, but have higher viral marker rates than volunteer donations. The difference can be explained in part by the effects of first‐time or repeat status of the donors. Patients considering directed donation should be appropriately counseled about the potential risks.     

Analysis of sample‐to‐cutoff ratios on chemiluminescent immunoassays used for blood donor screening highlights the need for serologic confirmatory testing

BACKGROUND: High sample‐to‐cutoff (s/co) ratios on hepatitis C virus antibody (anti‐HCV) screening immunoassays (IAs) are indicative of confirmed‐positive results and, according to some reports, can be used to determine anti‐HCV status without the need for confirmatory testing. The purpose of this study was to determine whether s/co ratios on hepatitis B surface antigen (HBsAg), antibody to human immunodeficiency virus Types 1 and 2 (anti‐HIV‐1/2), anti‐HCV, and antibody to human T‐lymphotropic virus Types I and II (anti‐HTLV‐I/II) chemiluminescent immunoassays (ChLIAs) can be used to discriminate between biologic false‐reactive (BFR) and confirmed‐positive results. STUDY DESIGN AND METHODS: In a blood donor population the s/co ratio distributions for BFR and confirmed‐positive results were compared for the Abbott PRISM HBsAg, HIV O Plus, HCV, and HTLV‐I/II ChLIAs to determine the extent of overlap between the two distributions for each assay. RESULTS: The s/co ratio distributions for BFR and confirmed results overlapped in the range of 10.00 to 60.00, 1.00 to 6.00, 3.00 to 15.00, and 1.00 to 100.00 for the PRISM HIV O Plus, HCV, HTLV‐I/II, and HBsAg assays, respectively. CONCLUSION: Although high s/co ratios were predictive of confirmed‐positive results in all four assays, a number of confirmed‐positive samples gave low values while some biologic false‐positive samples showed high values. As the s/co ratio distributions for BFR and confirmed‐positive results overlapped for all four PRISM assays, this study highlights the importance of serologic confirmatory testing and the need for caution when using screening IA results to assign a final donor status.     

New hepatitis B virus mutant form in a blood donor that is undetectable in several hepatitis B surface antigen screening assays

BACKGROUND: Envelope mutant forms of hepatitis B virus (HBV), impairing HBV antibody recognition, have been reported with mutations in single or multiple sites of the hepatitis B surface antigen (HBsAg) group- specific "a" determinant. Blood donors infected with such an HBsAg mutant form of HBV may escape detection by HBsAg screening assays and therefore may affect the safety of the blood supply. CASE REPORT: A repeat blood donor became HBsAg-reactive in an enzyme immunoassay. Confirmatory testing yielded negative results for HBsAg in a radioimmunoassay and in four enzyme immunoassays used in blood donor screening. The specificity of the HBsAg reactivity in the first enzyme immunoassay was confirmed by HBsAg neutralization with antibody to HBsAg. Additional HBV confirmatory test results were positive for antibody to hepatitis B core antigen and antibody to hepatitis B e antigen; negative for antibody to HBsAg and for hepatitis B e antigen; and positive for HBV DNA. DNA sequence analysis of the "a" determinant region of HBsAg revealed amino acid substitutions from Q (Gln) to R (Arg) at codon 129 and from M (Met) to T (Thr) at codon 133. CONCLUSION: This case illustrates the presence of HBsAg mutant forms of HBV in a West European blood donor population that were undetected by several HBsAg screening assays. Adaptation of HBsAg screening is indicated to overcome deficiencies in sensitivity in detecting HBsAg mutant forms of HBV. Screening for antibody to hepatitis B core antigen or HBV DNA may also detect blood donors infected with HBsAg mutant forms of HBV     

Temporal trends in the prevalence of HIV and other transfusion-transmissible infections among blood donors in northern Thailand, 1990 through 2001

BACKGROUND: Thailand's epidemic of HIV infection, which began in 1988, has primarily involved heterosexual transmission of the virus. This study describes changes in prevalence of HIV and other infectious diseases among blood donors in northern Thailand from 1990 through 2001. STUDY DESIGN AND METHODS: Serologic screening results and demographic data were analyzed from 276,066 donors screened at two blood collection facilities in Chiang Mai, Thailand, from 1990 through 2001. RESULTS: The HIV prevalence peaked in 1991 to 1993 at 4.04 percent and then declined to 0.38 percent in 2001. The overall prevalence of HIV infection was 2.16 percent; HIV prevalence was higher among male (2.24%) than among female (0.64%) donors, in first-time donors, and in replacement volunteer donors. The majority of the donors were men and first-time donors throughout this study. The prevalence of antibodies to syphilis decreased significantly in both men and women. However, the prevalence of antibodies to HCV and HBsAg were stable. CONCLUSIONS: The declining HIV prevalence from 1990 through 2001 among blood donors in two large blood banks in northern Thailand indicates significant progress toward recruitment of a safer donor population in a developing country despite a major HIV and AIDS epidemic involving the general population.     

Efficacy of individual nucleic acid amplification testing in reducing the risk of transfusion‐transmitted hepatitis B virus infection in Switzerland,a low‐endemic region

BACKGROUND: The risk of transfusion‐transmitted hepatitis B virus (HBV) in Switzerland by testing blood donors for hepatitis B surface antigen (HBsAg) alone has been historically estimated at 1:160,000 transfusions. The Swiss health authorities decided not to introduce mandatory antibody to hepatitis B core antigen (anti‐HBc) testing but to evaluate the investigation of HBV nucleic acid testing (NAT). STUDY DESIGN AND METHODS: Between June 2007 and February 2009, a total of 306,000 donations were screened routinely for HBsAg and HBV DNA by triplex individual‐donation (ID)‐NAT (Ultrio assay on Tigris system, Gen‐Probe/Novartis Diagnostics). ID‐NAT repeatedly reactive donors were further characterized for HBV serologic markers and viral load by quantitative polymerase chain reaction. The relative sensitivity of screening for HBsAg, anti‐HBc, and HBV DNA was assessed. The residual HBV transmission risk of NAT with or without anti‐HBc and HBsAg was retrospectively estimated in a mathematical model. RESULTS: From the 306,000 blood donations, 31 were repeatedly Ultrio test reactive and confirmed HBV infected, of which 24 (77%) and 27 (87%) were HBsAg and anti‐HBc positive, respectively. Seven HBV‐NAT yields were identified (1:44,000), two pre‐HBsAg window period (WP) donations (1:153,000) and five occult HBV infections (1:61,000). Introduction of ID‐NAT reduced the risk of HBV WP transmission in repeat donors from 1:95,000 to 1:296,000. CONCLUSIONS: Triplex NAT screening reduced the HBV WP transmission risk approximately threefold. NAT alone was more efficacious than the combined use of HBsAg and anti‐HBc. The data from this study led to the decision to introduce sensitive HBV‐NAT screening in Switzerland. Our findings may be useful in designing more efficient and cost‐effective HBV screening strategies in low‐prevalence countries.     

Human immunodeficiency virus prevalence, incidence, and residual risk of transmission by transfusions at Retrovirus Epidemiology Donor Study-II blood centers in Brazil

BACKGROUND: In Brazil nationally representative donor data are limited on human immunodeficiency virus (HIV) prevalence, incidence, and residual transfusion risk. The objective of this study was to analyze HIV data obtained over 24 months by the Retrovirus Epidemiology Donor Study‐II program in Brazil. STUDY DESIGN AND METHODS: Donations reactive to third‐ and fourth‐generation immunoassays (IAs) were further confirmed by a less‐sensitive (LS) IA algorithm and Western blot (WB). Incidence was calculated for first‐time (FT) donors using the LS‐EIA results and for repeat donors with a model developed to include all donors with a previous negative donation. Residual risk was projected by multiplying composite FT and repeat donor incidence rates by HIV marker–negative infectious window periods. RESULTS: HIV prevalence among FT donors was 92.2/10⁵ donations. FT and repeat donor and composite incidences were 38.5 (95% confidence interval [CI], 25.6‐51.4), 22.5 (95% CI, 17.6‐28.0), and 27.5 (95% CI, 22.0‐33.0) per 100,000 person‐years, respectively. Male and community donors had higher prevalence and incidence rates than female and replacement donors. The estimated residual risk of HIV transfusion transmission was 11.3 per 10⁶ donations (95% CI, 8.4‐14.2), which could be reduced to 4.2 per 10⁶ donations (95% CI, 3.2‐5.2) by use of individual‐donation nucleic acid testing (NAT). CONCLUSION: The incidence and residual transfusion risk of HIV infection are relatively high in Brazil. Implementation of NAT will not be sufficient to decrease transmission rates to levels seen in the United States or Europe; therefore, other measures focused on decreasing donations by at‐risk individuals are also necessary.     

Prevalence of hepatitis B virus and hepatitis C virus among blood donors at a tertiary care hospital in India: a five‐year study

BACKGROUND: Hepatitis B virus (HBV) and hepatitis C virus (HCV) are important transfusion‐transmissible infections. This study was performed to assess the prevalence of HBV and HCV seropositivity among blood donors at a tertiary care hospital–based blood bank in India. STUDY DESIGN AND METHODS: The blood donation records over 5 years (2005‐2009) were reviewed, retrospectively, for the prevalence and yearly trends of HBV and HCV seropositivity. RESULTS: A total of 94,716 donations were received. The overall number of HBV‐seropositive donations was 1353 and that for HCV was 537, with the prevalence rates of 1.43% for hepatitis B surface antigen (HBsAg) and 0.57% for HCV. The seropositivity rate was higher in the replacement donors compared to the voluntary donors. The annual rates showed decreasing trends in case of HBsAg, but in case of HCV, there was a linear increase. CONCLUSIONS: Our study raises serious concerns regarding the HBV and HCV prevalence in our country. Although HBV showed decreasing trends, it cannot be relied upon because the donors were screened only for HBsAg. HCV is clearly on the rise. Stringent measures need to be taken on urgent basis including dissemination of information, strict screening of blood, inclusion of antibody to hepatitis B core antigen and other sensitive markers to the screening protocol, and better donor recruitment.     

Serologic and molecular typing of human T‐lymphotropic virus among blood donors in Maputo City,Mozambique

BACKGROUND: Screening for human T‐lymphotropic virus‐1/2 (HTLV‐1/2) infection is not performed in blood banks in Mozambique. The aim was to determine the prevalence of HTLV‐1/2 among blood donors of the Maputo Central Hospital Blood Bank and measure the coinfection rate of HTLV‐1/2 with human immunodeficiency virus (HIV), hepatitis B virus (HBV), and syphilis. STUDY DESIGN AND METHODS: A total of 2019 consecutive blood donors were screened for HTLV‐1/2 antibodies, HIV‐1/2 antibodies, hepatitis B surface antigen (HBsAg), and rapid plasma reagin (RPR) for syphilis. Specimens reactive on a first HTLV‐1/2 enzyme immunoassay (EIA) were retested using a second EIA. Specimens that were dually reactive on both EIAs were further tested using Western blot (WB) and real‐time polymerase chain reaction (PCR). RESULTS: All 18 dually reactive specimens (0.89%; 95% confidence interval, 0.48%‐1.30%) were positive for the presence of HTLV‐1 by WB and real‐time PCR. HTLV‐2 was not detected. The prevalences of anti‐HIV, HBsAg, and reactivity in the RPR test were 5.72, 6.01, and 0.98 percent, respectively. There was no significant association between HTLV‐1 infection and demographic variables (age and sex) or serologic markers (HIV, HBsAg, and RPR). For the 17 HTLV‐1–positive donors for whom serologic data for HIV, HBsAg, and syphilis RPR were available, 2 showed coinfection with HIV and 1 with HBV. CONCLUSION: Compared to other infectious agents, HTLV‐1 is present at relatively low levels among blood donors in Mozambique. Cost and logistics will present as major challenges for introducing HTLV‐1/2 screening in blood banks. In blood banks in Southern Africa where EIA testing is possible, a sequential algorithm of two EIAs may be a cost‐efficient option for HTLV‐1/2 screening.     

互助献血与无偿献血血清学标志物对比分析

目的：对互助献血和无偿献血的血清学指标进行分析对比,研究探讨互助献血的风险。方法2006年1月至2012年12月,对符合献血条件的1834例互助献血者以及217323例无偿献血者进行了血液采集和留取 ETDA 抗凝样本,进行 ALT、HBsAg、Anti-HCV、Anti-HIV、梅毒共5个项目的初复检。结果互助献血（8.67％）的总阳性率要高于无偿献血组（6.31％）,但两组的ALT 阳性率差异无统计学意义,互助献血组的HBsAg、Anti-HCV、梅毒均高于无偿献血组。结论无偿献血群体的血清学安全指标优于互助献血组,是血源性传播疾病较低的低危人群,应该是血液供应的主要来源群体;对互助献血采取合理的干预措施后,能确保其安全指数与无偿献血等同,可作为无偿献血的有益补充。     

Infectious disease markers in autologous and directed donations

SUMMARY. Autologous collections are strongly advocated by the New South Wales Red Cross Blood Transfusion Service (BTS) and have increased more than sevenfold since 1988. Directed donations, although not promoted, have also increased during this time. The prevalence of infectious disease markers (HIV, hepatitis C, hepatitis B and syphilis) in donations collected by the BTS from different donor groups including overall volunteer homologous, first-time volunteer homologous, autologous and directed were evaluated over a 42-month period. Donations from first-time volunteer homologous donors had the highest prevalence of hepatitis B and C. Autologous donations had a significantly higher prevalence of hepatitis B, hepatitis C and syphilis compared with overall volunteer homologous donations. The percentage of directed donations testing positive for either hepatitis B or C was higher than overall volunteer homologous donations, but not statistically significant. This study demonstrates that donations from first-time donors are the least safe, that the crossover of autologous blood into the volunteer homologous pool decreases the safety of that pool and suggests that directed donations may not be as safe as volunteer homologous donations and cannot be generally advocated at this time.