Seroprevalence of parvovirus B19 in the German population.

Acute parvovirus B19 infection is a risk for pregnant women. After vertical transmission the infected fetus may develop hydrops fetalis. Since B19 infection occurs mainly during childhood, children represent a main source for virus transmission. In order to determine whether certain groups in the German population show increased risks for B19 infection we analysed the seroprevalence using 6583 sera collected from adults in former Eastern and Western Germany during the German National Health Survey and 649 sera from healthy Thuringian children and adolescents. In adults the overall seroprevalence was 72.1%, rising from 20.4% in children (1-3 years) and 66.9% in adolescents (18-19 years) to 79.1% in the elderly (65-69 years). Significant differences were observed between females (73.3%) and males (70.9%) and between inhabitants of small (74.8%) and big cities (69.0%) but not between people of the former Eastern (72.8%) and Western states (72.0%) of Germany. For women during childbearing age (18-49 years) highest values were observed in those living together with two or more children (81.6%) and in women with occupational contact with children aged <6 years (88.9%). In contrast seroprevalence was significantly lower in age-matched female singles (64.8%) and in women with occupational contact with children aged >6 years and adolescents (63.8%).

Prevalence of markers of hepatitis B in the adult German population.

The prevalence of hepatitis B virus markers was investigated in 5305 individuals considered to be representative for the adult German population. After adjustment of the data according to the age and sex distribution in the whole German population an anti-HBc prevalence of 8.71% (95% confidence interval, 7.94-9.48%) and an HBsAg carrier rate of 0.62% (95% confidence interval, 0.40-0.84%) were calculated. Anti-HBc prevalence increased with age from 4.12% in the youngest group to 15.66% in the 61-70-year-old. The percentage of HBsAg carriers showed a maximum of 1.12% in the 41-50-year-old individuals and decreased significantly in the older age groups. 1.40% (95% confidence interval, 1.08-1.72%) of individuals had anti-HBc only. There was a trend to higher rates of this pattern in males than in females; a significantly higher percentage of persons with anti-HBc only was found in anti-HBc-positive individuals below 31 years than in older individuals. Five participants with anti-HBc only (7.7%, or about 0.1% of the whole population) showed HBV-DNA despite the absence of HBsAg. 3.1% of anti-HBc positive individuals where also positive for anti-HCV, that was significantly higher than the percentage of anti-HCV-positives among persons without any HBV marker (0.46%). This study provides a comprehensive picture of the current hepatitis B situation in Germany, showing new data especially on the distribution of HBsAg in the general population and on the subgroup of individuals with anti-HBc only.

Immunogenicity of a combined hepatitis A and B vaccine in healthy young adults.

Combining several vaccines in a single formulation can change the potency of the vaccine antigens. Previous studies suggested a higher immunogenicity of a new combined hepatitis A and B vaccine compared with the monovalent hepatitis B vaccine. We investigated the immune response to hepatitis B surface antigen 1 month after the third vaccine dose in 282 healthy adults who had received either a monovalent hepatitis B vaccine (n=148) or the combined hepatitis A/B vaccine (n=134). A slight trend towards higher geometric mean titres of anti HBs was found at this point in time in the group immunised with the combined vaccine, especially in the few vaccinees with preexisting antibodies against hepatitis A virus. However none of these differences was statistically significant, arguing against an advantage of the combined vaccine regarding hepatitis B immunisation.

Prevalence of antibodies against hepatitis C virus in the adult German population.

OBJECTIVE: The prevalence of anti-HCV in Germany has been determined for blood donors and certain risk groups, but the burden of disease in the general population remains unknown. The aim of this study was to determine the prevalence of anti-HCV in a study group representing the normal adult German population. DESIGN: A total of 5312 individuals aged 18-70 years were randomly selected from small, middle-sized and big cities in five different German states. Sera were tested for anti-HCV by enzyme immunoassay and immuno dot assay, as well as for anti-HBc and, in the case of a positive result, for anti-HBs and HBsAg. Serological typing was performed in anti-HCV-positive persons. RESULTS: Thirty-nine individuals were anti-HCV positive; indeterminate results (with antibodies against the viral core protein only) were obtained in 20. There was a tendency to higher prevalence rates with increasing age as well as to a higher prevalence in women. Serological typing revealed the presence of genotype 1 in the vast majority of participants (82%); only a minority showed genotype 3 (7.2%) or other genotypes (7.2%). Markers of HBV were seen in 43.6% of the anti-HCV positive individuals, with nearly one third (29.4%) of the double-infected showing anti-HBc as the only marker for HBV. CONCLUSIONS: According to our data, an anti-HCV prevalence of 0.63% (95% confidence interval, CI, 0.42-0.84%) can be assumed in the general adult German population, with higher values in older people and women. Nearly half of the anti-HCV positive individuals also show markers of hepatitis B virus.

Heat stability of parvovirus B19: kinetics of inactivation.

Heat inactivation of parvovirus B19 (B19) was studied in a culture of hematopoietic progenitor cells generated in vitro from peripheral human blood. After inoculating cell cultures with identical volumes of plasma (MII) containing B19 (B19-MII) heat-treated (60 degrees C) for various periods of time, a time-dependent inactivation of the input virus was determined by a decrease of viral DNA replication. No B19 DNA was detected after infection with B19-MII heat-treated for 20 min or more by Southern blot. Viral B19 protein production decreased time-dependently and was not detected after infection with samples treated for 12 min at 60 degrees C or more determined by the enzyme immunoassay. This study indicates that infectivity of B19 virus in plasma can be reduced in vitro by heat-treatment (60 degrees C). However, this does not mean that the heat treatment completely inactivated B19 virus.

Replication of parvovirus B19 in hematopoietic progenitor cells generated in vitro from normal human peripheral blood.

Erythroid progenitor cells generated in vitro from peripheral human blood in the presence of interleukin-3 and erythropoietin were infected with human parvovirus B19. B19 virus DNA replication was highest 48 to 72 h after infection, and maximum levels of B19 virus proteins were detected in culture supernatants at 72 to 96 h after infection. B19 virus propagated in vitro was infectious. This cell culture system with peripheral blood cells facilitates studies in vitro of B19 virus replication.

Prevalence of antibodies to parvovirus B19 in selected groups of patients and healthy individuals.

The prevalence of antibodies to parvovirus B19 in sera (n = 745) of various groups of patients and healthy individuals was determined by the enzyme immunoassay, using viral particles as antigen. Among healthy individuals, anti-B19 IgG prevalence was highest in nurses (65.4% (17/26)); in medical students it was 34.1% (47/138) and in pregnant females, 24.4% (48/197). 37.0% (44/119) of HIV-negative haemophiliac patients and 91.7% (33/36) of haemophilic patients with HIV infection were anti-B19 IgG-positive. 45.8% (55/120) of dialysis patients and 27.5% (30/109) of patients with asymptomatic HIV infection were positive for anti-B19 IgG. With the exception of HIV-infected haemophiliac patients, no specific "risk group" for B19 infection could be identified.

[Blood picture findings in children with Parvovirus B19 infections (fifth disease/erythema infectiosum)]. / Blutbildbefunde bei Kindern mit Parvovirus B19-Infektion (Ringelröteln/Erythema infectiosum).

The human parvovirus B19 provokes erythema infectiosum ("e.i."); moreover there is a wide range of diseases due to parvovirus B19 without exanthema/rash. The erythropoietic blast cells of the bone marrow seems to be the main target cells for this virus. Therefore in cases of prenatal infection the consequences are extremely similar to fetal erythroblastosis ("non-immunological" fetal hydrops). In postnatal life the parvovirus B19 infection causes hyporegenerative phases of the erythropoiesis with anaemia after 3-4 weeks. We studied the white blood cell count (WBC), erythrocytes and thrombocytes in children suffering from (serologically well documented) parvovirus B19 infection with exanthem/"e.i." (group 1; n = 23), without exanthem (group 2; n = 46) and with unknown febrile exanthematous rashes (group 3; n = 76). We did not find any characteristic data in the WBC for a diagnosis of parvovirus B19 infection. However we have for the first time documented a significant thrombocytopenia in "e.i." (group 1) not found in group 2. The thrombocytopenia appears earlier than the anaemia, because the lifespan of thrombocytes is considerably shorter than that of erythrocytes. These data suggest that parvovirus B19 attacks not only "erythropoietic" blast cells but also immature bone marrow cells, which are later responsible for the thrombocytopoiesis.

[Obstructive respiratory tract diseases in children and Parvovirus B19 infections]. / Obstruktive Respirationstrakterkrankungen bei Kindern und Parvovirus B19-Infektion.

Acute respiratory diseases (ARD) due to parvovirus B 19 infection can be observed relative frequently in children. In 21 children (infants, toddlers and school children) we have seen acute or prolonged obstructive bronchitis/bronchiolitis (15 infants), acute subglottic laryngitis (3 toddlers) and acute asthmatic attacks (3 children of school age) in connection with parvovirus B 19 infection. Other respiratory viruses (adeno-, influenza, parainfluenza and RS-virus) could be excluded as agents causing the ARD. We suggest that parvovirus B 19 can provoke ARD with obstructive ventilatory disturbances of the upper or lower airways in children with a specific endogenous predisposition (small or unstable bronchial walls, or bronchial or tracheal mucosal hyperreactivity).

Removal of parvovirus B19 from contaminated factor VIII during fractionation.

A solution of pooled cryo-precipitate for preparing factor VIII (F VIII) by the solvent/detergent method was contaminated experimentally with parvovirus B19-positive plasma to evaluate virus reduction achieved by the final steps of the F VIII production process. Virus reduction was at least 2 logs of the total amount of B19 virus added to the pooled cryo-precipitate. The major amount of B19 virus was detected in the solution used to regenerate the F VIII-selective anion exchange chromatography column. A few viral particles were detected in the final F VIII concentrate before filtration but these were aggregates and were removed by filtration, and in the solution used to regenerate the anion exchange resin. It is not known whether the residual viral DNA present in the final product represents infectious or inactivated particles.

Productive infection of in vitro generated haemopoietic progenitor cells from normal human adult peripheral blood with parvovirus B19: studies by morphology, immunocytochemistry, flow-cytometry and DNA-hybridization.

Parvovirus B19 exerts a highly selective cytopathic effect on erythroid progenitor cells. Studies so far on the pathogenesis of B19-infection have been performed using bone marrow samples providing large amounts of erythroid progenitor cells. Extensive study, however, has been hampered by the limited access to bone marrow samples. We have designed a liquid culture method allowing the generation of large numbers of erythroid progenitor cells, initiating cultures with CD3- and CD14-poor peripheral blood mononuclear cells. Following a 12 d preincubation in liquid cultures containing recombinant human interleukin 3 (rhIl-3) and recombinant human erythropoietin (rhEpo), cells harvested from the liquid cultures were exposed to B19-containing plasma, followed by a further cultivation in liquid culture for up to 96 h. Cells expressing the CD13 and the glycophorin A (GlyA) antigens, respectively, were monitored sequentially by flow-cytometry, demonstrating a selective inhibition of GlyA-positive cells following B19-inoculation. Typical morphological changes were observed on cytocentrifuge-spots, and typical giant-cells were identified as staining for GlyA. Productive infection by B19 was demonstrable, as B19-DNA increased by about x 100 after 72 h of culture. The liquid culture method generating erythroid target cells for effective infection by B19 virus promises to be a useful and easily accessible tool for further research on B19 infection of haemopoietic cells.

Parvovirus B19 infection of the fetus. Histology and in situ hybridization.

Fetal tissues from 16 spontaneous abortions, two terminations, and one perinatal death, 18 of which were associated with maternal human parvovirus B19 infection, were examined for B19 infection by histology and in situ hybridization using a digoxigenin-labeled B19-DNA probe. In 15 spontaneous abortions and one termination, erythroblasts with intranuclear inclusions (lantern cells) reacted with B19-DNA by in situ hybridization. No internal or external fetal malformations were observed. Because 13 (86.7%) spontaneous abortions with lantern cells occurred between the 20th and 28th weeks of gestation, it is postulated that B19 infection may be a particular threat to the fetus during this stage of gestation.

New oligopeptide immunoglobulin G test for human parvovirus B19 antibodies.

A new, highly sensitive and specific enzyme immunoassay using oligopeptides as antigen (enzyme-linked immunosorbent assay [ELISA] B19-OP) for detecting parvovirus B19-specific immunoglobulin G (IgG) was established. As antigens, B19-specific oligopeptides of 24 and 30 kDa derived from a 196-kDa fusion protein of beta-galactosidase and viral capsid protein (VPI) of B19 after CNBr cleavage and separation by high-pressure liquid chromatography were used. Of 139 serum specimens tested in parallel for anti-B19 IgG by standard ELISA using B19 particles as antigen and by ELISA B19-OP, 73 (52.5%) were positive and 63 (45.3%) were negative in both tests, and 3 (2.2%) were negative by standard ELISA but positive by ELISA B19-OP and by immunoblot. By using ELISA B19-OP, it was possible to detect anti-B19 IgG in an asymptomatic blood donor 4 weeks after acute infection, and anti-B19 IgG titers of 10(-5) could be measured in convalescent-phase sera.

[Seroprevalence of human parvovirus B 19 antibodies (Sticker's disease/erythema infectiosum) in the DRG population]. / Seroprävalenz von Antikörpern gegen das humane Parvovirus B 19 (Ringelröteln/Erythema infectiosum) in der DDR-Bevölkerung.

We tested 638 human sera of all age groups (patients and blood donors) from the northern area of the G.D.R. and found 216 cases (33.9%) of specific parvovirus B19 antibodies (IgG) by antibody capture ELISA. The seroprevalence rose to 36.7% when the 18 parvo B19-IgM- and/or parvo B19-DNA-positive results were included. The antibody prevalence was 24.9 (27.8% resp.) in the 0-10 years group and increased continuously in the following age groups up to 61.1% (69.4% resp.) in the 51-60 years group. 50% of the newborn infants showed parvo B19-IgG-antibodies in the cord blood (of maternal origin). No sex differences in seroprevalence were observed. Parvovirus B19 is obviously very prevalent in the G.D.R. population. The main immunization occurs in the first 30-40 years of life but infection with parvo B19 at a later age is also well documented. Hence it follows that 35-45% of all G.D.R. females of reproductive age are susceptible to a parvovirus B19 infection.

[Parvovirus B19 infections in Germany 1987-1988]. / Parvovirus B19-Infektionen in Deutschland 1987-1988.

3289 sera of patients were tested for Parvovirus B19 specific antibodies (IgM/IgG) by ELISA for routine virological diagnostics in 1987/1988. Acute B19 infection could be confirmed in 14.5%, while 24.4% were already immune and in 61.1% antibodies could not be detected. Only 0.12% of all sera were B19-DNA positive by nucleic acid hybridisation. The highest rate of acute B19 infections could be detected in the age-group of the 6-15 year old. Infections occurred above all in the period of January to July resp. August. The most frequent clinical manifestation of acute B19 infection was exanthema (54.4%) and arthritis/arthralgia (6.5%).