Annelie Plentz

Phylogenetic and case-control study on hepatitis E virus infection in Germany.

BACKGROUND Hepatitis E is a classic water-borne disease in developing countries. In Germany, hepatitis E virus (HEV) infections are notifiable. The number of non-travel-associated infections has increased in recent years, but the route of transmission in most is unknown. Our objective was to determine risk factors for autochthonous HEV infections in Germany. METHODS Cases of HEV met clinical definitions and were confirmed by laboratory analysis (defined as detection of HEV by polymerase chain reaction [PCR] or immunoglobulin M by serologic testing). PCR products from blood or stool samples were genotyped for phylogenetic analysis. A case-control study included case subjects with autochthonous HEV infection and matched control subjects who were randomly recruited from a population-based telephone list. RESULTS From May 2006 through August 2007, 76 of 96 persons for whom HEV infection had been reported to the routine surveillance system were interviewed. Sixty-six persons had disease that fulfilled the inclusion criteria: 45 (68%) had autochthonous infection, and 21 (32%) had travel-associated disease. Genotypes 3 or 4 were present in 15 of 15 persons with autochthonous infection, and genotype 1 was present in 8 of 9 persons with travel-associated infection. In conditional logistic regression involving 45 case subjects and 135 control subjects, consumption of offal (41% vs. 19%; odds ratio [OR], 2.7; 95% confidence interval [CI], 1.2-6.2) and wild-boar meat (20% vs. 7%; OR, 4.3; 95% CI, 1.2-15.9) were independently associated with autochthonous HEV infection. CONCLUSION Hepatitis E is endemic in Germany and likely exists as a food-borne zoonosis. Implicated meat products should be investigated to provide recommendations for preventive measures.

Detection of hepatitis E virus (HEV) from porcine livers in Southeastern Germany and high sequence homology to human HEV isolates

BACKGROUND Hepatitis E virus (HEV) has been identified as an emerging cause of infectious hepatitis over the last years in developed countries. In contrast to travel associated hepatitis E, zoonotic sources of infection are suspected for autochthonous cases in Europe. OBJECTIVE Since pigs are known reservoirs of HEV, we tested porcine livers sold as food in Southeastern Germany for the presence of hepatitis E virus RNA. STUDY DESIGN We purchased 200 porcine liver samples in 81 butcher shops and grocery stores in Regensburg, Germany. Nucleic acid preparations were tested for the presence of HEV RNA by quantitative real-time PCR (RT-qPCR). HEV isolates from positive samples were characterized by partial sequencing of ORF1 and ORF2 regions in the HEV genome and by phylogenetic analysis. RESULTS Specimens from eight (4%) of 200 purchased pig livers had detectable HEV RNA amounts. Sequence determination and phylogenetic analysis allowed two novel isolates to be classified as HEV genotype 3, subgenotype 3a (swR437) and 3c (swR269), respectively. Both novel swine HEV isolates showed high sequence homology to isolates obtained from patients with acute HEV infection from the same geographic region. CONCLUSIONS These results support the suggested role of undercooked pig products in food as a source of zoonotic HEV infection for humans. It remains to be clarified if this mechanism of transmission is responsible for the surprisingly high anti-HEV IgG prevalence recently observed in some European countries and the USA.

Humoral Immune Response Against Human Bocavirus VP2 Virus-Like Particles

Human bocavirus (HBoV) was recently detected in samples from children and infants with infections of the respiratory tract. Here we analyze the prevalence of IgG and IgM antibodies against HBoV virus-like VP2 particles in healthy adult blood donors and children using a newly established standardized enzyme-linked immunosorbent assay. Virus-specific IgG antibodies were frequently detected in infants with active viremia and respiratory illness (10/24, 42%) and in young children without detectable HBoV genomes in their blood (27/52, 52%). In sera obtained from healthy adults, ubiquitous VP2-specific antibodies were found in 280/299 (94%) cases. HBoV-specific IgM antibodies were detected in 10/24 (42%) of sera samples obtained from HBoV DNA-positive children, and in 6/24 (25%) the sera displayed equivocal responses. In contrast, VP2-specific IgM was not detectable in samples obtained from 52 children without detectable amounts of HBoV genomes in their blood. Only 2/299 sera samples from healthy adult blood donors were found to be IgM-positive (1%), and equivocal IgM responses were observed in 9/299 (3%) individuals. In conclusion, a high IgG seroprevalence of HBoV in the adult population was observed, whereas the presence of virus-specific IgM was associated with viremia. These data show that ELISA test systems for the detection of HBoV-specific antibodies are a valuable tool for serological diagnosis of this new emerging pathogen.

Association of parvovirus B19 infection and Hashimoto's thyroiditis in children.

Hashimotos thyroiditis is a common autoimmune disorder of the thyroid gland. It has been linked to infections with hepatitis C, EBV, HTLV-1, and Yersinia enterocolitica. As parvovirus B19 has been associated with a wide spectrum of autoimmune diseases, we investigated the potential role of B19 infection in inducing Hashimotos thyroiditis. Serum samples derived from 73 children and adolescents with Hashimotos thyroiditis and from 73 age-matched controls were included in the study. The mean age of disease manifestation was 10 y 7 mo. All samples were analyzed for the presence of viral DNA and for antibodies against VP1, VP2, and NS1 proteins. VP1- and VP2-specific antibodies were present in 38 patients (52%) and 43 controls (59%; N.S.). NS1-specific antibodies were detectable in 23 patients (32%) and 19 controls (26%; N.S.). Parvovirus B19 DNA was detectable in 9 patients (12%) and 2 controls (3%; p < 0.03), indicating recent B19-infection. A negative correlation between disease duration and the detection of viral DNA was seen. The mean disease duration in B19-DNA-positive patients was 6 mo, compared to 29 mo in the remainder (p < 0.01). There is strong evidence that acute parvovirus B19 infections are involved in the pathogenesis of some cases of Hashimotos thyroiditis.

Exposure of hematologic patients to parvovirus B19 as a contaminant of blood cell preparations and blood products

BACKGROUND: Patients with hematologic malignancies often require blood products, and parvovirus B19 is known to be transmitted by this route. Primary infection with parvovirus B19 shows a wide variety of disease manifestation. In immunocompromised patients, symptoms are severe and viral clearance is delayed or missing.

Long-term persistence of tick-borne encephalitis antibodies in adults 5 years after booster vaccination with Encepur® Adults

Tick-borne encephalitis (TBE) is a potentially serious disease, especially in adults. There is no treatment available for TBE; supportive therapy may help to ease symptoms of the disease. Vaccination is the most effective method of preventing TBE disease and is recommended for those who live, work, or travel in TBE-endemic areas. Regular booster vaccinations are recommended every 3-5 years to maintain protection. Evidence from recent clinical studies suggests that TBE antibodies persist at high levels for longer than the current recommended intervals for TBE booster vaccination. The aim of this study was to evaluate the long-term persistence of TBE antibodies in adults after primary vaccination using a rapid schedule and a first booster dose of Encepur Adults, an inactivated TBE vaccine. A total of 222 adults 19-51 years of age were invited for serological follow-up investigations 3 and 5 years following their first booster dose. High antibody titres were recorded throughout the follow-up period. Neutralization test (NT) titres > or =10 were noted in 99% of subjects 3 and 5 years after the first booster vaccination and 97% tested positive by enzyme-linked immunosorbent assay (ELISA). These results indicate that initially high levels of TBE antibodies following the first booster dose of the vaccine may lead to long-term persistence of TBE antibodies, confirming previous findings and suggesting it may be appropriate to extend the interval between booster doses from 3 to 5 years.

Detection of Herpesvirus DNA in Cerebrospinal Fluid and Correlation with Clinical Symptoms

Background:Novel PCR techniques can detect minute quantities of herpesvirus DNA in cerebrospinal fluid (CSF). The clinical significance of such findings is not always clear.Patients and Methods:(a) Investigation of clinical characteristics of 76 patients with herpesvirus DNA detection in CSF. (b) Screening for herpesvirus DNA in CSF samples of 208 patients without clinical signs of herpesvirus infection.Results:(a) Eleven of 76 herpesvirus-DNA-positive patients did not show symptoms usually associated with the detected virus (HSV-1/2, n = 5; EBV, n = 6). (b) Two of 208 patients without hint for herpesvirus infection had HHV-6 DNA of low concentration in CSF.Conclusions:The detection of low-level herpesvirus replication in CSF by highly sensitive PCR assays requires critical evaluation.

False-negative serology in patients with acute parvovirus B19 infection.

BACKGROUND Acute parvovirus B19 (B19V) infection is characterized by high-level viremia. Antibodies against the capsid proteins VP1 and VP2 may complex with B19V-particles thereby becoming undetectable in diagnostic tests. OBJECTIVES We intended to obtain data on the frequency of false-negative serology in acute B19V-infection. STUDY DESIGN 129 plasma or serum samples of healthy blood donors and of patients with suspected B19V-infection were analyzed for B19V-DNA by qPCR and VP1/VP2-specific IgG and IgM by ELISA. Eleven of these samples were derived from four pregnant women with previous contact to B19V-infected individuals. Using acidic conditions virus/antibody-complexes were disrupted and detected by WesternLine and ELISA. RESULTS 83/118 samples were derived from acutely infected individuals displaying viremia (10(3)-10(12)geq/mL). In 24/83 viremic samples (28.9%) VP1/VP2-specific IgM and IgG were undetectable in ELISA, but could be demonstrated to be complexed with B19V-particles. Each 7/83 (8.4%) was IgM-positive/IgG-negative and IgM-negative/IgG-positive, in 45/83 samples (54.2%) IgG and IgM could be detected. 35 samples did not contain B19V-DNA; five of these were from seronegative persons. Analyzing consecutive sera derived from four pregnant women, B19V-DNA was demonstrated in 10/11 samples, B19V-specific IgG- and IgM-antibodies were detectable in 10/11 and 4/11 samples, respectively. In 2/4 women seroconversion was observed, but IgM was not detected in 50% of the samples. B19V-specific IgG but not IgM was detectable in 2/4 women. CONCLUSION Acute B19V-infection cannot be diagnosed by exclusive analysis of B19V-specific antibodies. Only the combination of assays for detection of B19V-DNA and antibodies enables correct serodiagnosis.

TBE booster immunization in adults--first experience with a new tick-borne encephalitis (TBE) vaccine, free of protein-derived stabilizer.

A total of 222 adult subjects, all of whom received primary immunization according to the rapid immunization schedule in a preceding clinical trial with either a new (i.e. polygeline free) or formerly licensed (i.e. polygeline containing) TBE vaccine were invited for extension studies. The subjects received the first booster immunization with the new TBE vaccine at 12 to 18 months after primary immunization. Subsequently, a total of 191 of the 222 subjects could be enrolled in a serological follow-up one year after the booster immunization. Neutralizing TBE antibody titers were determined prior to, 21 days after and approximately 12 months after booster immunization. Prior to first booster immunization, TBE antibodies (GMTs) had remained on a high level and were far above the detection limit of the neutralization test used. All subjects of the per protocol population who were primarily immunized with the new TBE vaccine formulation and all but one subject of the control group were still seropositive prior to the booster. All subjects showed a sharp increase of TBE antibodies following the booster immunization. Within the 12 months follow-up period, neutralizing TBE antibody titers remained on a high level. The booster vaccination was well tolerated by the subjects. Only very few febrile reactions (< 1%) none higher than 38.5 degrees C were reported. No serious or unexpected adverse events related to vaccination were reported. These successful results in terms of both immunogenicity and safety indicate that TBE vaccination with this new TBE vaccine can be used safely in adults. A long lasting immunity can be concluded from the strong immune response following the booster immunization.

Low Risk of Clostridium difficile Infections in Hospitalized Patients with Inflammatory Bowel Disease in a German Tertiary Referral Center

Introduction: Many reports, mainly from the US and Canada but also a recent report from a center in Europe, have documented the increasing impact of Clostridium difficile infections in patients with inflammatory bowel disease (IBD) during the last years. To determine the prevalence of C. difficile infections in hospitalized IBD patients in a tertiary referral center in Germany, we conducted this retrospective analysis. Methods: Data of all IBD in-patients treated due to an acute flare of their IBD at the Department of Internal Medicine I of the University of Regensburg between January 1, 2001, and June 30, 2008, were analyzed. In patients with a concomitant diagnosis of C. difficile infection, further variables such as IBD-related treatment at the time of infection or outcome were examined. Results: In total, 995 in-patients with IBD were treated in this hospital [638 patients with Crohn’s disease (CD), 357 with ulcerative colitis (UC)] during the study period. Of these, 279 patients with CD and 242 patients with UC were admitted with an acute flare and suffering from diarrhea and abdominal pain. Only 10 of those were diagnosed as having a concomitant infection with C. difficile. Six patients were female and the median age was 49 years (range: 15–80). Six patients with C. difficile infections suffered from UC and 4 patients from CD, all with previous colonic involvement. Eight patients used immunosuppressive therapies; only 2 patients were treated with antibiotics before infection. Conclusion: In contrast to recent reports from other countries, only a low percentage of hospitalized patients with acute flares of their IBD were identified as having an underlying C. difficile infection in this German tertiary referral center. However, in IBD patients with an acute flare, a concomitant C. difficile infection should be excluded, especially in patients with immunosuppressive treatment and colonic involvement of their disease. Further research is needed to evaluate if regions with different risks of C. difficile infections exist and to find out more about potential reasons for this observation.