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.     

Prevalence,incidence, and residual risk of human immunodeficiency virus and hepatitis C virus infections among United States blood donors since the introduction of nucleic acid testing

BACKGROUND: Nucleic acid testing (NAT) for human immunodeficiency virus (HIV) and hepatitis C virus (HCV) was introduced for blood donation screening in the United States in 1999. This study analyzes temporal trends of these two infections since NAT introduction. STUDY DESIGN AND METHODS: Donation data from 1999 to 2008 were analyzed; each donation was tested for antibodies and viral RNA for HIV and HCV. Incidence for first‐time (FT) donors was derived by multiplying that among repeat (RP) donors by the ratio of NAT yield rates between FT and RP donors. Incidence for all donors was the weighted mean based on percentage of FT and RP donors. Residual risk (RR) was determined using the window‐period model. RESULTS: During the 10‐year period approximately 66 million donations were screened with 32 HIV (1:2 million) and 244 HCV (1:270,000) NAT yield donations identified. HCV prevalence among FT donors decreased by 53% for 2008 compared to 1999. HIV and HCV incidence among RP donors increased in 2007 through 2008 compared to 2005 through 2006. During 2007 through 2008, HIV incidence was 3.1 per 10⁵ person‐years (py), with an RR estimate of 0.68 per 10⁶ (1:1,467,000) donations; HCV incidence was 5.1 per 10⁵ py, with an RR estimate of 0.87 per 10⁶ (1:1,149,000). The increase in HIV incidence was primarily among 16‐ to 19‐year‐old, male African American donors and that in HCV was primarily among Caucasian donors of 50 or more years. Donors from the Southern United States had higher incidence rates. CONCLUSION: HCV prevalence decreased significantly since NAT introduction. The increase in HIV and HCV incidence in 2007 through 2008 warrants continued monitoring and investigation.     

Prevalence of and risk factors for hepatitis B and C infection among Mongolian blood donors

BACKGROUND: Mongolia has one of the highest rates of viral hepatitis infections worldwide yet risk factors have been largely unstudied. This sentinel study of hepatitis infection in Mongolia determined the prevalence of hepatitis B virus surface antigen (HBsAg) and hepatitis C virus antibody (anti-HCV) among a sample of blood donors and identified demographic and behavioral factors associated with hepatitis infection.
STUDY DESIGN AND METHODS: Data were collected by interview from 923 Ministry of Health Blood Center donors between August 2004 and February 2005. The exposure variables collected included donor demographics and health and behavioral risk factors. Bivariate and multivariate analyses assessed the prevalence ratio of hepatitis infection for each exposure.
RESULTS: Of 923 donors, 72 tested positive for HBsAg (7.8%; 95% confidence interval [CI], 6.1%-9.7%), 89 donors tested positive for anti-HCV (9.6%; 95% CI, 7.8%-11.5%), and six (0.6%) tested positive for both HBsAg and anti-HCV. Prevalence of HBsAg was highest among donors 18 to 19 years and anti-HCV tended to be most prevalent among those more than 40 years of age. Both pregnancy and alcohol use were associated with seroprevalent anti-HCV.
CONCLUSION: This sentinel study of hepatitis prevalence among Mongolian blood donors sheds considerable light on the epidemiology of hepatitis virus infection as well as the sociodemographic and behavioral risk factors associated with infection. Young age (HBsAg) and pregnancy (anti-HCV) were significant risk factors for hepatitis virus infection, indicating that improvements in education, vaccination rates, and general infection control procedures in health care institutions may reduce behavioral and nosocomial transmission.     

献血者感染HBV相关危险行为因素的调查研究

目的研究献血者感染乙肝病毒(HBV)的相关危险因素。方法对203名单纯HBsAg阳性的献血者及406名所有血液检测项目均阴性的献血者进行对照研究,应用多因素条件Logistic回归模型分析与HBV感染有关的因素,并对危险因素的人群归因危险度(PAR)进行估计。结果筛选出5项与感染HBV有关的因素,研究发现使用共用剃刀、乙肝家族史、内窥镜检查史、牙科治疗史、未注射乙肝疫苗可以增加乙肝感染的危险性,其危险度(OR)分别是:4.010 2、2.808 2、5.815 7、1.758 3、4.044 4,人群归因危险度分别是:43.39%,5.50%,1.75%,13.46%,29.91%。5项危险因素总的人群归因危险度为66.78%。结论使用共用剃刀、乙肝家族史、内窥镜检查史、牙科治疗史、未注射乙肝疫苗是HBV感染的危险因素。     

Serological characterization of occult hepatitis B virus infection among blood donors in India

IntroductionDiscovery of hepatitis B infections characterized by the presence of viral genome without detectable HBsAg (Occult Hepatitis; OBI) has initiated a considerable amount of research in this regard. Our study is a serological and molecular characterization of OBI among the donors who donated at our blood bank during the study period.Material and MethodDuring the study period HBsAg ELISA non reactive ID-NAT reactive donors samples were screened for presence of antibody against HBc, HBs and HBe. Molecular analysis of these NAT yield samples was undertaken for detection of the viral load and genotyping.ResultWe studied 28,134 HBsAg ELISA non reactive donor samples. On testing them with ID-NAT, HBV DNA was detected in 25 samples. Eighteen samples out of these 25 NAT yield were further worked up. The 66.6% of the NAT yield samples (12 out of 18) were reactive for antibody against HBc. The 25% (3 out of 12) of these NAT yield samples having antibody against core antigen also had antibody against HBs. The 27.7% (5 out of 18) of NAT yield detected by ID-NAT did not have any detectable serological marker in blood. Four out of 12 core antibody positive NAT yield samples had genotype A HBV infection.ConclusionAs per our study molecular detection of HBV DNA by ID-NAT, we were able to analyze 18 HBV NAT yield cases among 28,134 HBsAg ELISA non reactive donors. Out of 18, 12 donors were OBI whereas the rest (6) were in window period (WP yield) of HBV infection. One out of every 3.6 NAT yield detected by ID-NAT was non reactive for all serological markers.     

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.     

Occult hepatitis B virus infection in Thai blood donors

BACKGROUND: An evaluation by the National Blood Center, the Thai Red Cross Society, of two commercial multiplex nucleic acid tests (NATs; the Chiron PROCLEIX ULTRIO test and the Roche Cobas TaqScreen MPX test) for screening Thai blood donors for hepatitis B virus (HBV), hepatitis C virus, and human immunodeficiency virus Type 1 identified 175 HBV NAT–reactive/hepatitis B surface antigen (HBsAg)‐negative donors. The classification of the HBV infection of these donors was confirmed by follow‐up testing. STUDY DESIGN AND METHODS: Index samples were tested for HBV serologic markers and HBV viral loads were determined. Donors were followed for up to 13 months and samples were tested with both NAT assays and for all HBV serological markers. RESULTS: Of 175 HBV NAT–yield donors, 72 (41%) were followed. Based on the follow‐up results, the majority of donors who were followed had an occult HBV infection (66.7%), followed by donors with a primary, acute infection (26.4%). The majority of donors in this latter group (20.8%) were in the window period. Three donors (4.2%), who were anti‐HBs positive, had a reinfection or breakthrough infection. CONCLUSION: The majority of donors detected during routine screening, who were HBsAg negative and NAT reactive, had an occult HBV infection, thus validating the decision to introduce NAT for blood donations in Thailand.     

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.     

Hepatitis B and residual risk of infection in English and Welsh blood donors, 1996 through 2008

BACKGROUND: Globally, of all infections that donations are tested for, hepatitis B has the highest residual risk of transfusion transmission, despite donor selection criteria and advances in testing. Every blood donation in England and Wales is tested for hepatitis B surface antigen. Knowledge of infections being detected can inform donor selection and testing strategies. STUDY DESIGN AND METHODS: Data on donation testing and infections detected are collated by the NHS Blood and Transplant and Health Protection Agency Epidemiology Unit. Infected donors are classified as having acute or chronic hepatitis B virus (HBV) by a clinician; their demographic characteristics were described. The prevalence (by acute or chronic HBV status, ethnicity, and geography) and incidence of infection were calculated between 1996 and 2008. The residual risk was calculated for four periods using a modification of the incidence and window period model; the effects of modifying variables were investigated. RESULTS: Most infections (1047/1155) detected were chronic and seen in new donors. People with acute infections were more likely to be white and/or born in Western Europe. Prevalence was highest in donors from minority ethnic communities and in London. Incidence in repeat donors has halved in recent years. The estimated frequency of an infectious donation being missed was 1.37 per million donations (2006‐2008), the lowest since surveillance began or three per year. CONCLUSION: Many HBV infections in England and Wales were detected among new donors, who had chronic infection and were born overseas. The residual risk of infection declined over the 13 study years, but is still higher for HBV than other viral infections for which testing is undertaken.     

不同核酸检测方法对献血者隐匿性乙肝病毒感染的研究

目的了解无偿献血者中隐匿性乙肝病毒感染情况,并比较不同核酸检测方法对隐匿性乙肝病毒感染检测能力的差异。方法分别采用nested-PCR和Procleix Ultrio全自动核酸检测系统对无偿献血者血浆标本进行HBV核酸检测,对核酸阳性标本进行HBV DNA序列分析。结果在总计9 209例次标本的检测中,共有9 159例为HBsAg(-);HBsAg(-)标本中nested-PCR方法检出18例HBV DNA阳性(0.19%,18/9 159),而Procleix Ultrio检出7例(0.076%,7/9 159),两者间差异有统计学意义(P<0.05);测序结果显示隐匿性HBV感染者中C基因型所占的比例(64.7%,11/17)明显高于HBsAg阳性的HBV感染者(23.1%,6/23,P<0.01)。结论闽南地区无偿献血者中存在较高比例的隐匿性乙肝病毒感染;不同核酸检测方法对献血者隐匿性乙肝病毒感染的检测能力存在差异。     

Risk factors for chronic hepatitis B virus infection among blood donors in Bangalore,India

Objectives and Aim: We performed a study of hepatitis B virus (HBV) risk factors among blood donors in Bangalore, India. Background: HBV infection is prevalent in India and poses a potential risk of transmission by blood transfusion, but studies of risk factors for hepatitis B surface antigen (HBsAg) carriage among Indian blood donors are lacking. Methods/Materials: Using a case‐cohort design, we enrolled 71 cases with repeatedly reactive HBsAg results and a cohort of 212 contemporaneous blood donors with unknown HBsAg status. Questionnaire data were analysed using multivariable logistic regression. Results: In our multivariate analysis controlling for age, HBsAg positivity was associated with repeat donor status (OR = 0·34, 95% CI 0·17–0·71 vs first‐time donor status), residence outside Bangalore and Hosur (rural areas) (OR = 15·66, 95% CI 3·60–68·07vs Bangalore residence), having been a customer at a local barber shop (OR = 4·07, 95% CI 2·06–8·03), close contact with a person who had jaundice (OR = 13·64, 95% CI 3·71–50·24) and cigarette smoking (OR = 3·25, 95% CI 1·39–7·60). Conclusion: In addition to recognised demographic risk factors, associations with patronage of local barbers and contact with jaundiced individuals suggest behavioural risk factors that could be adopted as exclusionary criteria for blood donation in India.     

闽南地区无偿献血者隐匿性乙型肝炎病毒感染研究

目的研究闽南地区无偿献血者中隐匿性乙型肝炎病毒感染(OBI)情况,探讨现有输血传播乙肝病毒(HBV)的检测方法的有效性。方法依据多种与HBV相关血清学指标的检测情况对献血者标本进行HBV携带风险评价分级,对较高携带风险的标本做单份多区段巢式-PCR检测其HBV DNA,对低携带风险的标本做10份混合的巢式-PCR检测。采用这一方案,对闽南地区19 360例HBsAg阴性的无偿献血者标本做检测分析。结果闽南地区HBsAg阴性献血者中的HBV DNA阳性检出率为0.21%(40/19 360,95%CI:0.15%—0.28%),属于OBI;其中抗-HBc阳性检出率85%(34/40),但阳性预测值仅为3.4%(34/995,95%CI:2.4%—4.7%);HBV NRAg阳性预测值30%(6/20),但灵敏度为15%(6/40)。结论现有筛查体系下无偿献血者中仍存在一定比例的OBI,需要寻求更为有效的检测方法。     

Trends in prevalence of hepatitis B virus infection among Iranian blood donors, 1998–2007

Assessment of the quality of donor selection and safety of the blood supply can be estimated by monitoring the prevalence of the serologic markers of infectious disease in screening tests. In the present study, changes in rates of hepatitis B virus (HBV) infection are studied in the period 1998–2007 in Iranian Blood Transfusion Organization (IBTO). Prevalence of serological marker of HBV infection [hepatitis B surface antigen (HBsAg)] was evaluated in blood donations in Iran as well as for Fars province representing a low prevalence, and Sistan-Baluchestan (S&B) province as a high prevalence region throughout 1998–2007. For assessing frequency of infection, the prevalence of HBsAg per 100 000 donations and 95% confidential intervals (95% CIs) is calculated. P value is estimated by χ² test. A total of 14 599 783 donations were collected during 10 years. The overall HBsAg prevalence rates declined from a 1.79% (1789/100 000 donations) in 1998 to 0.41% (409/100 000 donations) in 2007 in Iran. In Fars province, HBsAg prevalence decreased from 0.89% in 92 999 donations in 1998 to 0.34% in 148 014 donations in 2007 and in S&B province, the rate of HBsAg has gone down from 3.74% in 44 036 donations in 1998 to 1.15% in 56 057 donations in 2007. The frequency of HBV infection entering the blood supply has decreased over this period as a result of improvement in donor recruitment and selection, usage of software in transfusion services and possibly decreasing HBV infection prevalence in general population.     

Diversity and origin of hepatitis C virus infection among unpaid blood donors in the Netherlands

BACKGROUND: To improve transfusion policy and to increase understanding of the spread of hepatitis C virus (HCV) in the general population, HCV infections among voluntary Dutch blood donors were examined with molecular epidemiologic techniques. STUDY DESIGN AND METHODS: During 6 years, 1997 through 2002, confirmed anti-HCV-positive donors were interviewed on HCV-associated risk behavior with a standardized questionnaire. Additionally, HCV isolates were genotyped, partially sequenced, and compared to sequences obtained from Dutch injecting drug users (IDUs). RESULTS: HCV prevalence and incidence rates among Dutch donors were extremely low; the residual risk of transmitting HCV was calculated to be 1 in 30 million donations. Former IDUs (21%), transfusion recipients (30%), and immigrants (>12%) were identified as major HCV risk groups. Cryptogenic transmission caused 18 percent of infections among new donors and all infections among repeat donors. Compared to IDUs, genotype distribution among donors was highly diverse; major subtypes were 3a (27%), 1a (24%), 1b (24%), 2a/b (10%), and 4 (9%). Half of the donors were infected with IDU-related subtypes 1a and 3a, whereas subtype 1b mainly spread via blood transfusion and various other nosocomial modes of transmission in the past. HCV infections acquired in endemic countries could be clearly identified based on genotype. CONCLUSION: Different modes of transmission are linked to infections with certain HCV subtypes, suggesting separate HCV epidemics, but spillover between different risk groups underlines the value of molecular epidemiologic techniques to gain insight into the origin and dynamics of HCV infections on a population level.