The prevalence of human parvovirus B19 DNA and antibodies in blood donors from four Chinese blood centers

BACKGROUND: Human parvovirus B19 is a common human pathogen that causes a variety of diseases with outcomes ranging from asymptomatic to severe, especially in immunocompromised patients. The B19 virus can be transmitted via blood and/or blood products and its resistance to common viral inactivation and/or removal methods raises the importance of B19‐related blood safety. However, the existence, variation, and loading of B19 in Chinese blood donors have not been determined. STUDY DESIGN AND METHODS: Quantitative polymerase chain reaction (PCR) was developed to detect all three genotypes of the human erythrovirus DNA in plasma samples. In total, 3957 donations from four Chinese blood centers were screened for B19 by real‐time minipool nucleic acid amplification technology (NAT). The positive samples were then confirmed by nested PCR and subjected to sequence analysis and alignment for phylogenetic studies. An enzyme‐linked immunosorbent assay–based experiment was also performed to identify the prevalence of immunoglobulin (Ig)G and/or IgM antibodies specific to the B19 structural proteins in acquired samples. RESULTS: Of 3957 blood donors, 23 (0.58%) specimens were found positive for B19 DNA. The quantitative DNA levels ranged from 2.48 × 10² to 6.38 × 10⁴ copies/mL. The phylogenic analyses showed that the prevalent genotypes in Chinese blood donors belong to B19 Genotype 1. A total of 448 samples from Chinese blood donors were investigated for the seroprevalence of B19 antibodies, among which 24.6 and 6.9% of specimens were seropositive for B19 IgG and IgM antibodies, respectively. A total of 2.5% of these samples were positive for both antibody isotypes. CONCLUSIONS: Whether B19 NAT screening of blood and blood products should be launched in China, larger studies are needed to facilitate an informed decision.     

Prevalence and quantitation of parvovirus B19 DNA levels in blood donors with a sensitive polymerase chain reaction screening assay

BACKGROUND: Blood donor parvovirus B19 DNA prevalence with sensitive nucleic acid test assays has recently been demonstrated to be higher than that found with assays designed to detect high viral titers in the plasma manufacturing sector. STUDY DESIGN AND METHODS: Stored plasma aliquots from 5020 donations collected between 2000 and 2003 at seven US blood centers were tested. Testing was performed with a real-time B19 DNA polymerase chain reaction (PCR; TaqMan, Applied Biosystems) assay with a 50 percent limit of detection (LOD) of 1.6 IU per mL (95% confidence interval [CI], 1.2-2.1 IU/mL) and a 95 percent LOD of 16.5 IU per mL (95% CI, 10.6-33.9 IU/mL). Confirmation and quantitation of B19 DNA was accomplished by retesting of two additional subaliquots. Confirmed-positive specimens were tested for the presence of anti-B19 immunoglobulin M (IgM) and IgG with FDA-licensed assays. RESULTS: B19 DNA prevalence was 0.88 percent (95% CI, 0.64%-1.2%). Among the 23 donations with B19 DNA titers of at least 20 IU per mL, the median DNA concentration was 105 IU per mL with an interquartile range of 42 to 481 IU per mL; the highest value was 1869 IU per mL. All B19 DNA-positive donations were positive for the presence of IgG and 10 (23%) were also positive for the presence of IgM; IgM seropositivity was associated with increasing DNA levels (p = 0.0013). CONCLUSION: Low-level B19 DNA was detected in nearly 1 percent of donations. The 23 percent of DNA-positive donations with both IgM and IgG B19 antibody most likely represent acute resolving infection, whereas those with IgG but no IgM are most consistent with a more chronic and possibly persistent phase of B19 infection.     

Discovery and analysis of a novel parvovirus B19 Genotype 3 isolate in the United States

BACKGROUND: Parvovirus B19 (B19V) is a pathogen frequently identified in human plasma donations through the detection of nucleic acids. Three B19V genotypes have been defined based on isolates having greater than 10% divergence in overall DNA sequence. B19V Genotype 3 is a rarely occurring genotype that has been detected primarily in Ghana with sporadic reports in Brazil and France but has not been previously reported in North America.
STUDY DESIGN AND METHODS: A polymerase chain reaction assay was developed with broad specificity for B19V detection. The performance of this assay was assessed by testing approximately 440,000 clinical samples representing more than 81,000 individual donors. Determinations of B19V titer, DNA sequence, and antibody concentrations were performed on samples of interest.
RESULTS: This assessment identified a series of eight plasma donations spanning 28 days from a single donor in the United States infected with B19V Genotype 3 as confirmed by DNA sequence analysis. The B19V titer of this series of donations showed virus titers that peaked at greater than 10¹¹ IU/mL. The virus titer decreased significantly over the next several donations coinciding with an increase in immunoglobulin M (IgM) levels. The immunoglobulin G levels also increased but lagged approximately 7 days behind the IgM levels.
CONCLUSION: This is the first report of a B19V Genotype 3 detected from a plasma donor located in the United States. Although our data are consistent with recent reports suggesting low incidence for this genotype, they indicate its increasing relevance among blood and plasma donors.     

广州地区献血人群人类细小病毒B19感染情况及病毒载量分析

目的了解广州地区献血者HPVB19感染状况。方法采用EIA对献血者血进行HPVB19 IgG、IgM筛查,并用PCR法对HPV B19抗体阳性血样进行HPV B19 DNA检测。结果HPV B19 IgG阳性率为38.6%(679/1760),HPVB19 IgM阳性率为1.9%(33/1760),两者有显著差异(P<0.001)。33例HPVB19 IgM阳性样本,HPVB19 DNA阳性检出率为63.6%(21/33);56例HPVB19 IgG阳性样本,HPVB19 DNA阳性检出率为1.8%(1/56),两者有显著差异(P<0.001)。21例HPV B19 DNA阳性样本中,病毒载量≥1×104Copies/ml占51.9%(13/21)。结论广州地区献血者HPV B19病毒既往感染率较高,但HPV B19病毒急慢性感染率较低。     

Parvovirus B19 transmission by a high-purity factor VIII concentrate

BACKGROUND: Parvovirus B19 (B19) is known to cause a variety of human diseases in susceptible individuals by close contact via the respiratory route or by transfusion of contaminated blood or blood products. In this study, whether a case of B19 transmission was causally related to the infusion of implicated lots of a solvent/detergent (S/D)-treated, immunoaffinity-purified factor VIII concentrate (antihemophilic factor [human][AHF]) was investigated. STUDY DESIGN AND METHODS: Anti-B19 (both immunoglobulin M [IgM] and immunoglobulin G [IgG]) and B19 DNA (by a nucleic acid testing [NAT] procedure) were assayed in two implicated product lots, a plasma pool, and a recipient's serum sample. Analysis of the partial B19 sequences obtained from sequencing clones or direct sequencing of the samples was performed. RESULTS: Only one of the two implicated lots was B19 DNA-positive. It contained 1.3 x 10(3) genome equivalents (geq or international units [IU]) per mL. The negative lot was derived from plasma screened for B19 DNA by NAT in a minipool format to exclude high-titer donations, whereas the positive lot was mostly from unscreened plasma. This high-purity AHF product had no detectable anti-B19 IgG. A 4-week postinfusion serum sample from a recipient, who received both lots and became ill, was positive for the presence of B19 antibodies (both IgM and IgG) as well as B19 DNA. The B19 sequences from the positive lot, its plasma pool, and the recipient's serum sample were closely related. CONCLUSION: These findings and the recipient's clinical history support a causal relationship between the implicated AHF product and B19 infection in this recipient. The seronegative patient became infected after receiving 2x10(4) IU (or geq) of B19 DNA, which was present in this S/D-treated, high-purity AHF product.     

瑶族无偿献血者人细小病毒B19与TTV重叠感染分析简

目的 了解广东瑶族无偿献血者人细小病毒B19及TTV重叠感染现状,探讨HPV B19与TTV感染相关性.方法 采用ELISA法检测HPV B19 IgG和抗-TTV IgG,并采用PCR法对部分血样进行HPV B19 DNA及TTV DNA检测.结果 376例无偿献血者血液标本中,检出HPV B19 IgG阳性110例,阳性率29.26％,检出抗-TTV IgG阳性176例,阳性率46.81％.147例血样检出HPV B19 DNA 10例,阳性率6.80％,检出TTV DNA 12例,阳性率8.16％.两者阳性检出率差异有统计学意义（x2=21.279,P＜0.05）. 67例抗-TTV IgG阳性中HPV B19的检出率为35.82％,43例HPV B19 IgG阳性中TTV的检出率为53.49％,两者检出率差异无统计学意义（x2=3.341,P＞0.05）.在阴性血液中,HPV B19总阳性检出率为36.25％,TTV总阳性检出率为53.85％,两者阳性率比较差异有统计学意义（x2＝5.633,P＜0.05）.结论 广东瑶族无偿献血者存在较高的HPV B19与TTV重叠感染,目前尚未在献血人群中开展HPV B19及TTV筛查,存在输血传播的风险.     

Laboratory diagnosis of cytomegaloviral infection in patients with anemia and hemoblastosis in the Omsk region

Research was carried out in 335 blood specimens of patients in the age of 3-35 y.o. in order to optimize diagnosis and treatment of such patients with aplastic anemia and hemoblastosis who got hemotransfunction to eliminate cytomegaloviral infection (CMVI). IgM were found out in 37.9% cases (2.8 times higher than in donors), low-avide IgG--in 44.8%. "early" proteins CMV--29.9% and DNA--in 36.8% cases. Concerning the DNA presence, preference was given to research of leucocytic suspension compared with blood serum. Of 28 children of 3-13 y.o. with anemia being seropositive in CMV, IgG antibodies were detected in 13 children while IgM antibodies to Parvovirus B19 were found in 10 children. 7 children with a grave form of disease showed combined infection of Parvovirus B19 and CMV with activation signs. It is not excluded that parallel influence of Parvovirus B19 on erythrocytic hemopoiesis growth and that of CMV on lymphocytic-monocytis cells aggravates immunodeficiency and promotes development of infection complications.     

Blood donor screening for parvovirus B19 in Germany and Austria

BACKGROUND: Although the main transmission pathway of parvovirus B19 (B19) is typically via the respiratory route, several transfusion-transmitted infections have been reported. To increase blood safety, all blood donations to our blood donor service have been screened by a B19 minipool real-time nucleic acid testing (NAT) since April 2000. Additional customers have been screened since the summer of 2003. STUDY DESIGN AND METHODS: In total, 2.8 million donations from Germany and Austria were screened for B19 by real-time minipool NAT. A subgroup of 50 B19 DNA-positive donors was screened for B19 immunoglobulin G (IgG) and IgM antibodies and B19 DNA over a 6-month period. Results were compared to those of 100 B19 DNA-negative donors. RESULTS: Data accumulated over the past 6 years indicate a high incidence period from May 2004 to January 2006. In total, the incidence was 12.7 and 261.5 per 100,000 donations with high virus loads equal to or above 10(5) and below 10(5) IU per mL, respectively. Median virus concentration in the case group was 4.85 x 10(7) IU per mL at Time Point T0 and was reduced to 4 x 10(2) IU per mL at the time of the next donation (3 months later). Neutralizing antibodies (VP2) were detected in all donations if virus load was reduced to less than 10(5) IU per mL. CONCLUSION: The release of B19 DNA-positive blood products with a concentration of less than 105 IU per mL is thought to be safe due to the high level of neutralizing VP2 antibodies and is currently examined in a donor recipient infectivity study. In contrast, blood products with a high B19 DNA concentration (> or =10(5) IU/mL), some of which did not contain neutralizing antibodies, were discarded to protect at risk individuals.     

佛山地区无偿献血人群人细小病毒B19感染情况分析

目的了解佛山地区无偿献血人群人细小病毒(HPV)B19感染现状。方法采用ELISA检测血液中的HPV B19IgG和IgM抗体,并用PCR检测抗体阳性标本HPV B19DNA。结果 368例无偿献血者标本中检出HPV B19IgG阳性92例,阳性率为25.00%;检出HPV B19IgM阳性2例,阳性率为0.54%,两者比较差异有统计学意义(P0.01)。94例抗体阳性标本中,检测HPV B19DNA阳性4例,阳性率为4.26%。结论佛山地区无偿献血人群存在较高的HPV B19既往感染率,急、慢性感染率较低,慢性感染者HPV B19病毒载量较低。     

Prevalence of Parvovirus B19 and Hepatitis A virus in Portuguese blood donors.

INTRODUCTION: In recent years, concern about the safety of blood in regard to the transmission of blood-borne viruses has been decreased. Safety has been achieved with a combination of different strategies, such as careful selection of donors, screening for relevant virological markers and viral inactivation/removal methods. More recently, the implementation of the nucleic acid amplification technologies for the detection of HIV-1, HCV and HBV, has increased safety by reducing the "window period" of the infections. Other viruses, such as Parvovirus B19 (PB19) and Hepatitis A virus (HAV), can cause problems for blood safety. These infections could provoke serious complications in some risk groups, such as pregnant women, patients with hematological problems, children and patients with immunodeficiencies. MATERIALS AND METHODS: An observational study was performed to determine the prevalence of PB19 and HAV in Portuguese blood donors. We gathered, during four months, 5025 plasma donations and made them into 505 pools with no more than 10 donations each. The nucleic acids were isolated using MagNA Pure LC (Roche, Mannheim, Germany). A "Real Time PCR" (LightCycler, Roche) was used to perform the nucleic acid amplification and detection, using kits from the manufacturer. RESULTS: We found a prevalence of 0.12% for PB19 and 0% for HAV. Viraemia levels found in the positive donations range from 7.1x10(4) to 2.1x10(12)IU/ml. DISCUSSION: This study demonstrates the possibility of performing these tests in routine blood banks. We found a similar prevalence of PB19 when compared with other European and USA countries. In the case of HAV, we predict a maximum risk of 0.06% for a donor to be infected. It is necessary to perform other studies, including cost/benefit analysis to evaluate the risks and profits of implementing these methodologies in Transfusion Medicine.     

柳州地区合格献血者戊型肝炎感染情况调查

目的 调查柳州地区无偿献血者戊型肝炎病毒感染情况.方法 对2019年10～11月柳州地区合格献血者血液标本进行ELISA法戊肝病毒抗原(HEV-Ag)、抗体(HEV-IgG和HEV-IgM)检测;对HEV-Ag阳性和(或)HEV-IgM阳性者进行HEV RNA检测;对各检测结果 进行统计分析.结果 本次检测5 751人...     

Seroprevalence of SARS-CoV-2 antibodies among healthy blood donors in Karachi,Pakistan

BackgroundCovid-19 spread through blood transfusion has not yet been reported. Despite the prevailing pandemic, there are no recommendations available as yet for testing SARS-CoV-2 antibodies as part of blood screening.ObjectiveTo determine the seroprevalence of SAR-CoV-2 antibodies, its clinical significance and to identify if total antibodies(IgA, IgM, IgG) should be tested or just the specific IgG antibodies only.MethodConsecutive blood donors donated were screened for standard serological panel of HbsAg, Anti-HCV, Anti-HIV and Syphilis using Cobas-411 analyser and Malaria. All seronegative donors were then screened for COVID serology using the same instrument. These results were compared with the blood donors’ seroprevalence checked in a cohort in the first week of June 2020. Pre-COVID-19 period (October 2019) blood donors’ archived samples were also compared. Donors who were positive on ECLIA were then tested for specific antibodies (IgM or IgG) by ELISA.ResultsA total of 380 healthy blood donors were included. All were males with the mean age being 30.6 ± 6.3 years. Ten pre-pandemic samples did not show COVID-19 antibodies, whereas out of 70 samples in the 3rd week of June, only 15 (21.4 %) were positive. However, in July out of the 300 blood donors, 113 (37.7 %) were found to be reactive. To reconfirm our findings, these 113 donors were then tested on ELISA for presence of IgG specifically. Out of these 128 samples, 81 were IgG positive, 23 were borderline positive and 24 were negative.ConclusionAlmost 40 % of blood donors are now seroconverted for COVID-19. This is a reflection of widespread seroprevalence in the adult male population.     

Distribution of parvovirus B19 DNA in blood compartments and persistence of virus in blood donors

BACKGROUND: Because the receptor for parvovirus B19 (B19V) is on red blood cells (RBCs), we investigated B19V distribution in blood by in vitro spiking experiments and evaluated viral compartmentalization and persistence in natural infection. STUDY DESIGN AND METHODS: Two whole blood (WB) protocols (ultracentrifugation and a rapid RBC lysis and removal protocol) were evaluated using quantitative real‐time polymerase chain reaction. WB was spiked with known concentrations of B19V and recovery in various blood fractions was determined. The rapid RBC lysis and removal protocol was then used to compare B19V concentrations in 104 paired WB and plasma samples collected longitudinally from 43 B19V‐infected donors with frozen specimens in the REDS Allogeneic Donor and Recipient Repository (RADAR). RESULTS: In B19V spiking experiments, approximately one‐third of viral DNA was recovered in plasma and two‐thirds was loosely bound to RBCs. In the immunoglobulin (Ig)M‐positive stage of infection in blood donors when plasma B19V DNA concentrations were greater than 100 IU/mL, median DNA concentrations were approximately 30‐fold higher in WB than in plasma. In contrast, when IgM was absent and when the B19V DNA concentration was lower, the median WB‐to‐plasma ratio was approximately 1. Analysis of longitudinal samples demonstrated persistent detection of B19V in WB but declining ratios of WB to plasma B19V with declining plasma viral load levels and loss of IgM reactivity. CONCLUSIONS: The WB‐to‐plasma B19V DNA ratio varies by stage of infection, with 30‐fold higher concentrations of B19V DNA in WB relative to plasma during the IgM‐positive stage of infection followed by comparable levels during persistent infection when only IgG is present. Further study is required to determine if this is related to the presence of circulating DNA‐positive RBCs derived from B19V‐infected erythroblasts, B19V‐specific IgM‐mediated binding of virus to cells, or other factors.     

2016-2017年武汉地区儿童细小病毒B19感染及流行情况分析

摘要：目的 了解武汉地区儿童细小病毒B19感染状况及流行病学特征。 方法 采集自2016年1月1日至2017年12月31日在我院门、急诊和住院部就诊或住院治疗的疑似细小病毒B19感染儿童静脉血,通过ELISA法检测血清细小病毒B19-IgM,并对抗体活性值在10 ~20 U/mL之间的标本进行细小病毒B19 DNA定量检测,综合分析武汉地区儿童细小病毒B19感染状况及流行病学特征。结果 武汉地区2017年儿童细小病毒B19感染率为2.83%,较2016年6.31%的感染率显著下降,两年平均总体感染率为4.34%;儿童细小病毒B19感染状况具有明显的年龄（2岁以上）及性别（女性高于男性）差异; ELISA法检测HPV-B19抗体活性值处于10~13 U/mL之间的标本与PCR检测结果一致性较好,阴性符合率为93.54%;抗体活性值处于13~17 U/mL之间的标本结果一致性较差,阳性符合率为43.21%。抗体活性值17~20 U/mL的标本,阳性符合率为74.81%。结论 武汉地区儿童细小病毒B19感染具有年龄、性别差异,同时对于经ELISA法检测抗体活性值处于13~20 U/mL之间的标本,有必要进行PCR检测确诊。     

Frequent detection of the parvoviruses, PARV4 and PARV5, in plasma from blood donors and symptomatic individuals

BACKGROUND: Plasma pools used in the manufacture of blood- and plasma-derived medicinal products are frequently contaminated with parvovirus B19. The presence of the novel human parvovirus PARV4 and a related variant PARV5 in manufacturing plasma pools was recently demonstrated. Another recently identified parvovirus, human bocavirus (HBoV), has been identified in respiratory samples from children with lower respiratory tract disease. STUDY DESIGN AND METHODS: Recent and archived manufacturing plasma pools, as well as plasma from healthy blood donors (individual donations; pools of 16 donations) and febrile patients, were examined for the presence of PARV4 and PARV5 with conventional and TaqMan polymerase chain reaction assays. In addition, highly sensitive assays were used to examine the presence of HBoV DNA in manufacturing pools. RESULTS: Of 351 recent manufacturing plasma pool samples, 14 (4%) tested positive for the presence of PARV4 and PARV5. This frequency was elevated in the archived pools. Viral loads ranged from less than 100 up to 4 million copies per mL plasma, with some pools containing a mixture of both viruses. In individual plasma samples from healthy blood donors and febrile patients, the frequencies of detection were 2 and 6 percent, respectively. No HBoV sequences were identified in manufacturing plasma pools (n = 167). CONCLUSION: PARV4 and PARV5 are readily detected in manufacturing plasma pools, test pools (constructed from 16 donations), and individual donations derived from healthy blood donors. The prevalence of these viruses was increased in plasma samples from febrile patients. Despite the use of highly sensitive assays for HBoV, it was not possible to identify manufacturing plasma pools containing HBoV sequences.     

上海地区无偿献血者乙肝病毒核酸检测分析

目的了解无偿献血者乙肝病毒核酸筛查(NAT)阳性人群特点,为血液安全策略提供参考。方法无偿献血者血液经Murex和科华HBsAg ELISA试剂检测,结果为阴性的血液使用cobas TaqScreen MPX试剂进行HBV DNA,HCV RNA,HIV RNA 3项联合核酸检测。对于MPX反应性标本,使用COBAS AmpliPrep/TaqMan进行核酸鉴别试验,同时使用罗氏ECL电化学发光检测系统进行乙肝补充血清学试验。结果 2011年11月1日～2012年1月31日3个月共有献血者86 375人(次),其中有63 351人(次)为初次献血者,HBsAg反应性为1.04%,23 024人(次)为重复献血者,HBsAg反应性为0.46%,两者差异有统计学意义(χ2=63.63,P0.05)。84 990份HBsAg、抗-HCV、抗-HIV1/2阴性血液进行MPX核酸检测,共发现52例(0.060%)HBV DNA阳性,均为低拷贝,含量为(20～200)IU/ml间,其中32例(0.051%)来自初次献血者,20例(0.087%)来自重复献血者,两者比例差异无统计学意义(χ2=3.65,P0.05),没有发现HCV RNA与HIV RNA阳性。结论重复献血者HBsAg反应性比率低于初次献血者;HBsAg阴性献血者HBV DNA阳性率为0.060%,重复献血者HBV DNA阳性率与初次献血者比较,两者差异无统计学意义;开展HBV核酸检测能够进一步保障血液安全。     

Parvovirus B19 infection transmitted by transfusion of red blood cells confirmed by molecular analysis of linked donor and recipient samples

BACKGROUND: Extremely high viremic levels of parvovirus B19 (B19V) can be found in acutely infected, but asymptomatic donors. However, reports of transmission by single‐donor blood components are rare. In this prospective study, paired donor‐recipient samples were used to investigate the transfusion risk. STUDY DESIGN AND METHODS: Posttransfusion plasma or blood samples from recipients were tested for B19V DNA by polymerase chain reaction, generally at 4 and 8 weeks, and for anti‐B19V immunoglobulin (Ig)G by enzyme immunoassay, at 12 and 24 weeks. To rule out infection unrelated to transfusion, pretransfusion samples and linked donor's samples for each B19V DNA–positive recipient were assayed for B19V DNA and anti‐B19V IgG and IgM. To confirm transmission, sequencing and phylogenetic analysis were performed. RESULTS: A total of 14 of 869 (1.6%) recipients were B19V DNA positive, but only 1 of 869 (0.12%; 95% confidence interval, 0.0029%‐0.6409%) was negative for B19V DNA and anti‐B19V IgG before transfusion and seroconverted posttransfusion. This newly infected patient received 5 × 10¹⁰ IU B19V DNA in one red blood cell (RBC) unit from an acutely infected anti‐B19V–negative donor in addition to RBCs from three other donors that cumulatively contained 1320 IU of anti‐B19V IgG. DNA sequencing and phylogenetic analysis showed that sequences from the linked donor and recipient were identical (Genotype 1), thus establishing transfusion transmission. CONCLUSIONS: The 0.12% transmission rate documented here, although low, could nonetheless result in hundreds or thousands of infections annually in the United States based on calculated confidence limits. Although most would be asymptomatic, some could have severe clinical outcomes, especially in neonates and those with immunocompromised or hemolytic states.     

Seroprevalence of human parvovirus B19 amongst North Indian blood donors - do current donor testing guidelines need a relook?

Objectives

The present study was aimed to find out the prevalence of parvovirus B19? amongst healthy blood donors and blood transfusion recipients so as to determine the feasibility of providing seronegative blood components to vulnerable recipients.

Parvovirus B19 infection in patients with hemophilia

BACKGROUND: The long-term consequences of parvovirus B19 infection in transfusion recipients are not known, and thus the value of B19 screening of blood donors remains unresolved. Hemophiliacs, at risk for B19 through their chronic exposure to clotting factor concentrates, have frequent, close medical follow-up and thereby constitute an ideal group in which to study the hematologic sequelae of B19 infection. STUDY DESIGN AND METHODS: An enzyme-linked immunosorbent assay was used to detect B19 IgG and IgM and the polymerase chain reaction was used to detect B19 DNA in frozen, stored plasma samples, obtained between 1987 and 1994, from 136 subjects with hemophilia, including 71 who were human immunodeficiency virus (HIV)-positive and 65 who were HIV- negative. Then the results of the tests were compared with clinical hematological data and blood product usage data. RESULTS: B19 seroprevalence in the hemophilic cohort was 81.6 percent (111/136), including 74.6 percent (53/71) of HIV-positive and 89.2 percent (58/65) of HIV-negative hemophiliacs. It was not affected by age, type or severity of hemophilia, HIV status, CD4 number, or yearly blood product usage. Only 1 (0.7%) of the 136 samples was positive for B19 IgM and none was positive in polymerase chain reaction for B19 DNA. After adjusting for HIV status, there were no differences between B19- positive and B19-negative hemophiliacs in hematologic values, CD4 counts, or blood product use. CONCLUSION: Although B19 IgG seroprevalence in this hemophilic cohort is high and indicative of past B19 infection, there is no detectable B19 viral activity or any associated long-term clinical or hematologic sequelae.     

Recipients potentially infected with parvovirus B19 by red blood cell products

BACKGROUND: Since 2000, blood donor screening for parvovirus B19 (B19) by nucleic acid testing (NAT) at the Ulm Institute has been conducted 6 to 8 weeks postdonation, that is, after transfusion of cellular blood products, whereas at the Frankfurt Institute all donations are screened before releasing any blood product. In this study, we evaluated the infectivity of B19‐positive blood products in relation to the virus concentration in the transfused blood component. STUDY DESIGN AND METHODS: Recipients were classified into two groups (A, transfused with blood products with B19 virus load less than 10⁵ IU/mL; and B, transfused with blood products with B19 virus load greater than 10⁵ IU/mL). Phylogenetic analyses were done for B19 DNA–positive donor and recipient pairs in the variant VP‐1u genome region. All samples were investigated for immunoglobulin (Ig)M and IgG B19 antibodies. RESULTS: B19 DNA was detected in 9 of 18 recipients of red blood cells (RBCs) from Group B, whereas none of the 16 recipients of RBCs from Group A were positive for B19 DNA (p = 0.016). Phylogenetic analysis demonstrated identical genomic sequences between the donors and recipients. Because recipient B19 DNA and antibody results were not available before transfusion, we interpret our overall data to indicate equivocal evidence of B19 transmission by RBC transfusion. CONCLUSION: B19 transmission by cellular blood products correlates with the virus concentration and the concentration of neutralizing antibodies. Thus, blood donor screening for B19 by minipool NAT should be done to supply at‐risk patients (e.g., immunosuppressed patients) with B19‐negative blood components.