A population-based epidemiological survey of human parvovirus B19 infection: a project of the Kyushu and Okinawa Population Study (KOPS)

Human parvovirus B19 infection occurs by droplet nuclei through the respiratory tract and causes a wide range of diseases. It can be transmitted through blood transfusion from asymptomatic blood donors. This study was done to investigate the parvovirus B19 infection rate of a group of healthy Japanese residents. Of 2,081 blood samples tested, 15 (0.72 %) were positive for parvovirus B19 IgM, 1,412 (67.9 %) for B19 virus IgG, and 4 (0.2 %) for parvovirus B19 DNA. About half of all women of childbearing age were susceptible to parvovirus B19 infection. No relationship was found between the frequency of symptoms and the prevalence of parvovirus B19 IgG and IgM, suggesting that there are asymptomatic carriers in the healthy Japanese population. There is a risk of parvovirus B19 infection by blood transfusion from asymptomatic donors and that pregnant women are at high risk for parvovirus B19 infection.     

Seroprevalence of parvovirus B19 antibodies and evidence of viremia among Nigerian patients with sickle cell anemia

Clinical, biochemical and molecular evidence for the sickle cell anemia (SCA) crisis in Nigerian patients arising from parvovirus b19 infection remains inadequate. This study determined the prevalence and correlates of anti-parvovirus b19 antibodies in a population of SCA patients and non-SCA healthy controls in Lagos, Nigeria. In this prospective cross-sectional study, we enrolled 73 confirmed SCA patients from 5 district hospitals in Lagos and 81 sex and age-matched non-SCA healthy controls. Serum sample from each study participant was screened for anti-parvovirus b19 by ELISA and PCR techniques. Standard biomedical assays were also done. Anti-parvovirus b19 IgM and IgG antibodies were detected in 22 (14.3%) and 97 (62.9%) of the 154 sera screened, 13 (17.8%) and 45 (61.6%) in SCA patients; 9 (11.1%) and 52 (64.2%) in non-SCA controls. The overall seronegativity rate was 19.5%. Parvovirus B19 DNA was found in 2 (11.1%) of the 18 IgM seropositive SCA serum samples screened. On the whole, parvovirus b19 infection was more commonly asymptomatic in non-SCA controls but caused significant elevation in liver enzymes in infected SCA patients (P < 0.05). The risk of acute parvovirus b19 infection increased 65 times during unsteady state among the SCA patients. Although no deaths of infected patients were recorded during the study, age below 12 years, hospitalization and overcrowded environment were risk factors for infection. We conclude that parvovirus b19 is common in SCA patients, incurring greater susceptibility to infections.     

Detection of IgE anti-parvovirus B19 and increased CD23+ B cells in parvovirus B19 infection: relation to Th2 cytokines

The immune profile of a parvovirus B19-infected patient (male, 8 years old) was studied on day 0 (initial presentation) and on days 14 and 210 post symptom presentation (psp). Before infection, the patient was skin test positive to various allergens, including ragweed and tree and grass pollens, and had a serum IgE level of 150 IU/mL. On day 0, the patient was diagnosed as parvovirus B19 infected, as judged by the presence of IgG anti-parvovirus Abs in serum (EIA) and presentation of "slap cheek" rash. The patient's serum IgE level increased from 150 IU/mL before infection to 256 IU/mL on day 0, was 233 IU/mL on day 14, and returned to preinfection levels on day 210. In contrast, there was little change in the levels of serum IgM, IgG, or IgA (nephelometry). IgE anti-parvovirus B19 protein (VP-N) was detected in serum (Western blot) on days 0, 14, and 210, despite the decrease in total IgE on day 210. Although there was no increase in total numbers of blood CD23+ B cells on day 0, by day 14 the numbers of these cells increased dramatically (93%), remaining high on day 210. In contrast, there were virtually no changes in total numbers of CD4+ and CD8+ T cells or CD16/56+ NK precursor cells on days 0-210. On day 0, when IgG and IgE anti-parvovirus were detected in serum, patient's peripheral blood mononuclear cells (PBMC) expressed mRNA for the Th2 cytokines IL-4 and IL-10, but not for the Th1 cytokines IFN-gamma or IL-2. However, by day 14 psp, PBMC expressed mRNA for the Th1 cytokines IFN-gamma and IL-2, as well as for IL-4 and IL-10. This is the first demonstration of the existence of IgE anti-parvovirus B19 Ab. The presence of IgE anti-parvovirus B19 Ab in serum on day 0 and its persistence in serum 7 months psp suggests that IgE anti-parvovirus may be useful in prognosis of parvovirus B19 infection. Our results reinforce the idea that IgE, in general, may play a major role in anti-viral immunity, perhaps in conjunction with CD23+ cells. The results further suggest that clearance of this infection is accompanied by a switch to Th1 cytokines.     

Low prevalence of active parvovirus B19 infection in HIV-infected patients

In a prospective study to determine the prevalence of parvovirus B19 in adult patients positive for the human immunodeficiency virus, a series of 55 consecutively presenting patients was tested for antibodies to parvovirus B19 and parvovirus B19 DNA. Specific IgG antibodies were detected in 96% of cases; specific IgM antibodies were present in 10%. Viral DNA was not detected in any of the sera analysed by polymerase chain reaction. Anemia could not be correlated with the presence of either IgG or IgM antibodies to parvovirus B19. Thus, no evidence of acute or chronic parvovirus B19 infection was found in the 55 patients. These findings suggest that active parvovirus B19 infection is uncommon in HIV-infected patients.     

Evidence for persistence of human parvovirus B19 DNA in bone marrow

A nested polymerase chain reaction assay (nPCR) was used to investigate the potential of human parvovirus B19 DNA to persist in blood or bone marrow samples obtained either from blood donors or cadaveric bone donors or from patients presenting with clinical signs of parvovirus B19 infection. The presence of parvovirus B19 specific antibody in blood was tested by enzyme immunoassay (EIA). B19 virus genome was not detected in any blood sample of 115 blood donors, of whom 92 (80%) had anti-B19 IgG antibody only as an indication of past infection. In contrast, B19 virus DNA was detected in the bone marrow of 4 out of 45 bone donors. Each one of the serum samples available for 3 of these 4 individuals contained anti-B19 IgG antibody. Among 84 patients with clinical manifestations of parvovirus B19 infection, 17 (20%) had B19 virus DNA in bone marrow. Eight of the latter patients had anti-B19 IgG antibody in their blood but neither anti-B19 IgM nor B19 virus DNA. These data document the ability of parvovirus B19 DNA to persist in the bone marrow of asymptomatic individuals and patients with parvovirus B19 infection suspected on clinical grounds. J. Med. Virol. 53:229–232, 1997. © 1997 Wiley-Liss, Inc.     

Presence and significance of human parvovirus B19 DNA in synovial membranes and bone marrow from patients with arthritis of unknown origin

Acute rheumatologic symptoms are frequently associated with human parvovirus B19 (B19) infections. A nested PCR (nPCR) assay was used to test for the presence of parvovirus B19 DNA in synovial fluid and/or synovial membrane specimens obtained from a total of 90 patients with arthritis of unknown origin. Whereas only one out of 73 synovial fluid samples were found positive, 15 (16.7%) out of 90 patients had parvovirus B19 DNA in the synovium. B19 virus DNA was detected in nine bone marrow aspirates subsequently obtained from these 15 patients (60%). Whereas each one of the 15 corresponding blood samples contained anti-B19 IgG antibody, none contained anti-B19 IgM antibody and only one was positive for B19 virus DNA. The blood and synovial fluid samples that contained B19 virus DNA were obtained from the same patient, who also had B19 DNA in synovium and bone marrow. For one patient, two distinct synovial membrane specimens collected 10 months apart tested positive for B19 virus DNA. Parvovirus B19 DNA was also detected in synovial tissue of one out of nine nonarthritic patients serving as control group, who also had anti-B19 IgG circulating antibody. These data illustrate that human parvovirus B19 may persist in bone marrow and synovial tissues of patients with arthritis of unknown origin. In contrast, persistence of B19 virus DNA in synovial fluid is rare. The significance of parvovirus B19 DNA in synovium of healthy patients has to be established. J. Med. Virol. 56:199–204, 1998. © 1998 Wiley-Liss, Inc.     

Prevalence and association of human parvovirus B19V with hepatitis B and C viruses in Nigeria

Co-infection of parvovirus B19 with hepatitis B virus has been found in patients with acute and chronic hepatitis. The clinical significance of parvovirus B19 in hepatitis B co-infected patients is still controversial. In this study parvovirus B19 antibodies and DNA were investigated in serum samples from 76 patients with HBV infection, 17 with HBV/HCV co-infection and 44 healthy controls. In the sera from patients with HBV infection, anti-B19V IgM and IgG antibodies were detected in 24/76 (32%) and 25/76 (33%), in 6/17 (35%) and 8/17 (47%) of HBV/HCV co-infected patients, and in 14/44 (32%) and 12/44 (12%) of a non-hepatitis healthy controls, respectively. B19V DNA was detected in 8/76 (11%) of patients with HBV infection and in 3/17 (18%) of patients with a HBV/HCV co-infection, and in 4/44 (9%) healthy controls. The occurrence of parvovirus B19 DNA was significantly higher in patients with symptomatic HBV 4/20 (20%) compared to asymptomatic HBV carrier 4/56 (7%) (P<0.05). Ten of the positive B19V DNA sequences belonged to B19V genotype 1 while two belonged to genotype 3. The results of this study showed a significant difference in the prevalence of parvovirus B19 DNA in symptomatic HBsAg positive as compared to asymptomatic HBsAg positive individuals; however, the conclusion that parvovirus B19 infection increased the frequency of liver disease was not supported. Long-term longitudinal studies are, however, required to determine the synergistic effect of parvovirus B19 infection in HBV or HBV and HCV co-infected persons.     

Persistence of parvovirus B19 DNA in synovium of patients with haemophilic arthritis

A progressive arthropathy develops commonly in haemophiliacs and its pathogenesis is not fully understood. Human parvovirus B19 has been associated with several diseases including acute and chronic arthropathy and some studies suggest its implication in chronic inflammatory diseases of the joints such as rheumatoid arthritis. In haemophiliacs parvovirus B19 infection occurs very frequently because of its transmission with plasma derivatives. In order to assess a role of B19 virus in haemophilic arthritis, synovial tissue samples from patients with haemophilia with arthritis and from patients, nonhaemophiliacs, with arthrosis or with joint trauma were examined for B19 DNA by nested PCR. In addition, the prevalence of antibody to parvovirus B19 NS1 protein as a possible serological marker of persistent B19 infection was tested and the association of the outcome of parvovirus infection with genetic diversity of B19 P6 promoter sequences was investigated. B19 DNA was detected in the synovial tissue of 31% of haemophiliacs with progressive arthropathy and of 5% of control patients. Fourteen out of 17 patients (82%) with haemophilic arthritis and with B19 DNA in their synovial membranes had IgG antibodies against the nonstructural protein NS1 of parvovirus B19. On the other hand, 19% of patients with haemophilia with B19 PCR negative synovial tissue and 21% of controls showed anti-NS1 antibodies. The P6 promoter presented specific sites of point mutations shared frequently by isolates from patients with haemophilia and arthritis. These results indicate that B19 DNA can persist in the synovial membranes of patients with haemophilic arthritis significantly more frequently in comparison to control individuals with arthrosis or joint trauma and show a correlation between anti- NS1 antibody presence and B19 DNA persistence in the synovial tissue.     

Investigation on the Maternal-Infantile Infection with Human Parvovirus B19

With the investigations on pregnant women and newbornsinfected withToxoplasma, rubella virus, cytomegalovirus,herpes simplex virus (TORCH), it was found that humanparvovirus B19 (B19 virus), which belongs to the familyParvoviridae and the genus Erythrovir…     

吉林省供血者人类细小病毒B19 IgG抗体的调查

目的 了解吉林省供血者人类细小病毒感染的流行病学情况,为评估我国B19病毒的感染状况提供基础数据.方法 用间接ELISA方法检测血清中的抗B19 IgG抗体.结果 在184份血清中,抗B19 IgG抗体总检出率为55.43%.女性抗体阳性率高于男性,差异有统计学意义（P＜0.05）,年龄段在35～45岁之间的献血人员抗体阳性率最高.结论 本研究数据提示吉林省地区献血人员B19病毒感染率较高,有必要进行进一步B19 DNA的调查研究,为输血安全和血液制品安全提供保障.     

Parvovirus B19 seroprevalence,viral load,and genotype characterization in volunteer blood donors from southern Brazil

Usually transmitted via respiratory droplets, parvovirus B19 (B19V) can also be acquired by blood transfusion especially because of viral persistence, resistance to blood treatment procedures, and high viral load during the early infection phase. This is particularly problematic in immunocompromised or anemic patients where the infection can have a severe outcome. As B19V DNA was detected in blood donations from South Brazil during a viral metagenomic survey performed by Next-Generation Sequencing, the objective of this retrospective study was to evaluate the seroprevalence, B19V DNA presence and circulating genotypes in a Hospital Blood Transfusion Service in Santa Maria city in South Brazil (Rio Grande do Sul state). Among 480 volunteer blood donors, 53.9% (n = 258 of 479) were anti-B19V IgG-positive, and 9 (1.9%) plasma samples presented B19V DNA. In almost all cases (n = 7 of 9, 77.8%), B19V DNA load was accompanied by the presence of anti-B19V IgG suggesting a persistent infection. The sequencing of the strains demonstrated that all belong to genotype 1 which is the most prevalent worldwide. The analysis of the recipient information of the positive for B19V DNA units revealed no related posttransfusion adverse effects. Our results demonstrate for the first time, B19V seroprevalence, viral load, and genotypes among blood donors from South Brazil and give a light for the circulation and impact of this B19V in this part of the country.     

Increased risk of parvovirus B19 infection in young adult cancer patients receiving multiple courses of chemotherapy

An increased human parvovirus B19 infection rate has been observed in immunocompromised hosts. In this study, we sought to determine the prevalence of parvovirus B19 infection in adult cancer patients receiving multiple courses of systemic chemotherapy. From March 1999 through April 2000, 59 men and 68 women, with a median age of 49 (18 to 79) years, were enrolled in this study. They had received an average of 7.1 (4 to 32) courses of systemic chemotherapy. The median duration from the date of starting chemotherapy to the date of blood sampling was 11 (4 to 88) months. Serum B19 immunoglobulin G (IgG) and IgM levels were examined by an enzyme-linked immunosorbent assay, and B19 DNA was examined by a nested PCR. A group of 400 healthy blood donors served as the control group. The overall prevalences of anti-B19 IgG in adult cancer patients and healthy blood donors were 61.4 and 25.0%, respectively (P < 0.01). Anti-B19 IgM and B19 DNA were not detectable in these anti-B19 IgG-seropositive individuals. A further age-stratified comparison revealed that only patients younger than 40 years had a significantly higher anti-B19 IgG seropositivity rate than the controls (19 of 39 versus 53 of 310; P < 0.001). The increased prevalence of B19 infection in these 39 adult patients younger than 40 years might be clinically significant, since unexplained anemia, a common sequela of B19 infection, was detected in 3 of 20 seronegative patients (15.0%) and in 12 of 19 seropositive patients (63.2%) (P < 0.005). The results of this study suggest that adult patients younger than 40 years and receiving multiple courses of systemic chemotherapy may have a significantly increased risk of B19 infection. Prospective studies to define the time course and clinical consequence of B19 infection in this group of patients are needed.     

Persistent parvovirus B19 infections in immunocompromised children

Immunocompromised patients have been shown to suffer from prolonged viral infections often without detectable immune response. Here chronic infections with low virus levels can be frequently observed. In these patients viral DNA can be detected over long periods by polymerase chain reaction (PCR). In this study parvovirus B19 presence was assessed by PCR, immunoblot and enzyme-linked immunosorbent assay in sera from children with mainly oncological and hematological diseases. In 45% of sera B19 DNA was observed. Of the children 25% had IgG antibodies to viral protein 1 and 2 (VP1/2) and 15% to nonstructural protein 1 (NS1). In 6% of children IgM antibodies to VP1/2 were detected. These results indicate that the number of children with immune response to B19 proteins is distinctly lower than the number of children with B19 DNA. Transfusions of blood products might have been a possible route for B19 infection. Establishment and maintenance of a persistent parvovirus B19 infection with or without immune response are enhanced in the analyzed immunocompromised children in comparison with immunocompetent children. A persistence of B19 DNA was demonstrated up to 10 months in patients sera. Received: 22 September 1997     

Seroepidemiology of human parvovirus B19 in Taiwan

In order to determine the prevalence and risk factors of human parvovirus B19 (B19) infection in Taiwan, a seroepidemiological study was carried out in 19 townships. Serum samples were collected from 862 healthy residents, who were selected by stratified random sampling from various study areas. They were chosen from four different ethnic groups including aborigines, Fukien Taiwanese, Hakka Taiwanese, and mainland Chinese. Serum samples were screened for B19 IgG antibody by indirect antibody capture enzyme-linked immunosorbent assay (ELISA) and B19 IgM by IgM antibody capture (MAC)-ELISA, respectively. The overall prevalence of anti-B19 IgG and anti-B19 IgM was 32.8% and 0.35%, respectively. The anti-B19 seropositive rate in females was significantly higher than that of males (36.4% vs. 29.4%, P < .001). The age-sex-adjusted seropositive rate in urban townships (39.9%) was higher than that in aboriginal townships (30.5%, P < .001). The seropositive rate increased significantly with age showing a dose–response relationship (P = 0.0001 based on a trend test). Blood transfusion was found to be associated with an increased seropositive rate showing a multivariate-adjusted odds ratios of 1.6. J. Med. Virol. 57:169–173, 1999. © 1999 Wiley-Liss, Inc.     

Molecular characterization of human erythrovirus B19 strains obtained from patients with several clinical presentations in the Amazon region of Brazil

BACKGROUND: Human erythrovirus B19, endemic in the Amazon region since 1990, is associated with a wide spectrum of clinical presentations. OBJECTIVES: To assess the prevalence of erythrovirus B19 infection and the relative frequency of erythrovirus B19 genotypes in patients in the Amazon region with various clinical presentations. STUDY DESIGN: A total of 487 clinical samples obtained from patients with symptoms suggestive of erythrovirus infection were tested using specific IgM and IgG antibody assays (ELISA) and PCR for viral DNA detection. Partial VP1 and VP2 regions were sequenced and genotyped by phylogenetic reconstruction. RESULTS: B19 DNA was detected in 117 (24%) of 487 samples. Of these, 106 (91%) isolates were genotype 1 and 11 (9%) were genotype 3. No genotype 2 was found. Genotype 1 had three clusters (A1, A2 and B) and all genotype 3 sequences were subtype 3b. All patients with hematological disorders within cluster B of genotype 1 were infected by the same B19 lineage, suggesting that this lineage of B19 may have been transmitted via transfusion of blood products. CONCLUSION: We reported two genotypes, 1 and 3b, with three genotype 1 clusters co-circulating in the Amazon region during the past 10 years.     

Prevalence of parvovirus B19 and parvovirus V9 DNA and antibodies in paired bone marrow and serum samples from healthy individuals

Parvovirus B19 (hereafter referred to as B19) exhibits a marked tropism to human bone marrow (BM), and infection may lead to erythema infectiosum, arthropathy, hydrops fetalis, and various hematologic disorders. Recently, a distinct parvovirus isolate termed V9 with an unknown clinical spectrum was discovered. In contrast to the many studies of B19 serology and viremia, valid information on the frequency of B19 or V9 DNA in the BM of healthy individuals is limited. To develop a reference value, paired BM and serum samples from healthy subjects were tested for the presence of B19 and V9 DNA and specific antibodies. Immunoglobulin M (IgM) was not found in any of the serum samples. The prevalence of IgG showed a gradual and steady increase from 37% in children aged 1 to 5 years to 87% in people aged >50 years. When 190 well-characterized subjects were examined, B19 DNA was detected in the BM of 4 individuals (2.1%; 95% confidence interval, 0.58 to 5.3%) while none of the paired serum samples showed evidence of circulating viral DNA. V9 DNA was not found in any of the BM or serum samples. The finding of B19 DNA probably indicated a primary infection in one 7-year-old individual and reinfection or reactivation of persistent infection in the remaining three persons, aged 47 to 58 years. Serving as a benchmark for future studies, these findings are useful when interpreting epidemiologic data, performing BM transplantation, or considering clinical implications of parvovirus infection.     

Chronic parvovirus B19 infection induces the production of anti-virus antibodies with autoantigen binding properties

Human parvovirus B19 infection in adults shows some clinical features similar to those found in autoimmune connective tissue diseases. To better clarify the relationship between viral infection and autoimmunity, we have evaluated the ability of anti-parvovirus antibodies to specifically recognize autoantigens in ten patients with chronic symmetric arthritis resembling rheumatoid arthritis or with recurrent episodes of arthritis and cutaneous manifestations and persistence of specific IgM antibodies against B19 parvovirus. We synthetized a 24-amino acid immunodominant peptide corresponding to a part of the virus protein 1 and virus protein 2 overlapping region. The peptide has been used to test patients' sera at different time points with an enzyme-linked immunosorbent assay (ELISA) and to purify anti-virus antibodies by affinity chromatography on a peptide-Sepharose column. Eluted immunoglobulins recognized the B19 peptide in both direct and competitive ELISA. Affinity-purified anti-parvovirus antibodies were then tested on a panel of autoantigens including human keratin, collagen type II, thyreoglobulin, single-strand (ss)DNA, cardiolipin and ribonucleoprotein antigen Sm. Eluted antibodies specifically recognized keratin, collagen type II, ssDNA and cardiolipin. Autoantibody activity was not detected in the immunoglobulin fraction after complete removal of anti-peptide antibodies and in antibodies eluted from normal donors. Epstein-Barr virus-transformed cell clones obtained from two subjects produced antibodies which simultaneously recognize the viral peptide and several autoantigens. To further confirm the role of the virus in inducing an autoantibody response, eight BALB/c mice were immunized with the viral peptide coupled to a carrier protein. Autoantibody activity against keratin, collagen II, cardiolipin and ssDNA was detected in six of the eight mice which developed a strong anti-virus response. Together, these data indicate that B19 parvovirus may be linked to the induction of an autoimmune response.     

High Prevalence of Human Parvovirus B19 DNA in Myocardial Autopsy Samples from Subjects without Myocarditis or Dilative Cardiomyopathy

Human parvovirus B19 has been linked to a variety of cardiac diseases, as well as to erythema infectiosum, acute arthropathy, and fetal hydrops. A causal association between viral infection and cardiac disease was frequently postulated following the detection of B19 DNA by PCR in endomyocardial biopsy specimens. Since the lifelong persistence of B19 DNA in bone marrow, skin, synovia, tonsils, and liver was previously reported, the aim of our study was to investigate the possibility of asymptomatic B19 DNA persistence in heart tissue. Myocardial autopsy and postmortem blood samples were prospectively collected from 69 bodies sent to the Department of Forensic Medicine, Freiburg University Medical Center, for inquests. All study subjects were screened for B19-specific antibodies using a commercial enzyme immunoassay. Tissue samples were analyzed by real-time PCR for the presence of viral DNA. Since the presence of B19 genotype 2, known to have been circulating before 1960, would prove long-lasting persistence, the presence of the B19 genotype was retrospectively determined in seven of the study subjects by melting temperature analysis and sequencing of the PCR product. B19 DNA was found in myocardial samples from 46 of 48 seropositive and in none of 21 seronegative individuals. B19 genotype 1 was found in three patients born between 1950 and 1969. Genotype 2 was found in four patients born between 1927 and 1957. Our findings suggest lifelong persistence of B19 DNA in heart tissue. Thus, the detection of B19 DNA in myocardial biopsy specimens alone is not sufficient to postulate a relationship between B19 infection and cardiac disease.     

Parvovirus B19 infection in thoracic organ transplant recipients.

BACKGROUND: Clinical manifestations of parvovirus B19 infection in immunocompromised patients are mostly reported as acute or chronic hematologic disorders. More recently, respiratory or renal involvement has been described. OBJECTIVE: We started in 1994 a prospective study of parvovirus B19 infection in a group of lung (LTP) and heart-lung (HLTP) transplanted patients, including occasionally heart transplanted (HTP) patients. STUDY DESIGN: 62 patients (49 LTP, 11 HLTP, 2 HTP) were included in a serological survey and DNA detection by PCR was performed on each serum sample of the first 29 patients; later we performed it only when serology could suggest an acute episode, or when parvovirus infection could be suspected on clinical or biological observations. A total of 1655 sera were examined by serological tests and DNA detection was done in 500 samples. Specific IgM, seroconversion, significant increase of specific IgG levels, and/or parvovirus B19 DNA detection, were considered as markers of viral infection. RESULTS: We observed the presence of both markers of infection in 24 patients (39%), with an individual combination of positive antibody and PCR results. Acute or chronic anaemia, neutropenia were associated to these laboratory findings in 19 patients, but in five cases, an asymptomatic clinical infection suggested viral persistence. CONCLUSIONS: We report parvovirus associated acute or chronic anaemia and pancytopenia in a group of LTP, HLTP and HTP patients, as well as asymptomatic cases of infection. In the hypothesis of a parvoviral persistent or latent infection, current diagnosis methods may be unreliable to identify any other clinical manifestations.     

Le risque infectieux viral chez le polytransfusé : séroprévalence de sept agents viraux dans le centre tunisien

The aim of this study is to evaluate the prevalence of seven transfusion-transmitted viruses in polytransfused adults and children comparatively with a group of healthy control subjects. We studied 107 polytransfused patients (59 adults and 48 children) and 160 control subjects (100 blood donors and 60 children). Immunoenzymatic tests were used for detection of HBs antigen (HBs Ag), antibodies against hepatitis C Virus (anti-HCV), and human immunodeficiency virus (anti-HIV), and IgG antibodies against human cytomegalovirus (IgG anti-CMV), human parvovirus B19 (IgG anti-PB19), and hepatitis E virus (IgG anti-HEV). An immunofluorescent assay was performed for the detection of human herpesvirus 8 antibodies (anti-HHV8). Prevalence of HBs Ag, anti-HCV, anti-HIV, IgG anti-CMV, IgG anti-PB19, IgG anti-HEV, and anti-HHV8 in polytransfused group was 8.4, 4.7, 0, 86.9, 60.7, 28.9, and 47.6%, respectively, and 1.8, 0.6, 0, 86.2, 53.1, 10, and 12.5%, respectively, in the control group. The difference in prevalence between the two groups was statistically significant for HBs Ag (P = 0.01), anti-HCV (P = 0.03), IgG anti-HEV (P < 10(-4)), and IgG anti-HHV8 (P < 10(-4)). Categorization according to age showed that hepatitis B and C risk was limited in adult polytransfused group. HHV8 infection was higher in polytransfused subjects born before the use of leucocyte-depleted blood components. Our results corroborate literature data on the risk of HEV and HHV8 infection by blood transfusion. Hepatitis B vaccination and improvement in screening tests have an important role in reduction of hepatitis B and C risk in transfusion, especially in young polytransfused persons. However, a residual risk of transmitting viral infections persists, and efforts are needed to improve transfusion safety.