Detection of herpesvirus EBV DNA in the lower respiratory tract of ICU patients: a marker of infection of the lower respiratory tract?

Epstein-Barr virus (EBV) is a lymphotropic herpesvirus causing clinically self-limiting but lifelong persisting infections. Although several severe diseases (e.g., Hodgkin's disease) are associated with EBV, its role in lower respiratory tract infections is still elusive. The prevalence of EBV, herpes simplex virus (HSV) and cytomegalovirus (CMV) in bronchoalveolar fluid (BAL) samples was evaluated in a retrospective study. BAL samples from 135 patients in the intensive or coronary care unit (ICU/ICC) at University Hospital Frankfurt/Main (Germany) were investigated using an in-house real-time PCR to detect EBV-, HSV- and CMV-specific DNA. Overall, herpesvirus DNA was detected in n = 82/135 BAL samples (60.7 %). Besides mono-infections with either EBV or HSV, concomitant infection with EBV and HSV DNA was most frequent, whereby the relative HSV viral load was typically higher. Patients with HSV-positive BAL required mechanical ventilation on average 5 days longer than patients with HSV-negative BAL (p = 0.006). Additionally, the proinflammatory cytokine IL-6 was significantly elevated in sera of patients positive for EBV in comparison with patients with EBV-negative BAL (p = 0.01). This study demonstrates a high prevalence of herpesviruses in BAL samples of ICU/ICC patients. The detection of one or more herpesvirus in BAL is strongly associated with the duration of ventilation and patient's age. The association between IL-6 levels and EBV detection should be evaluated in further studies.

Hepatitis delta: on soft paws across Germany.

INTRODUCTION: Globally, more than 350 million people are considered to be chronic carriers of the hepatitis B virus (HBV) infection; thereof, 15-20 million of these individuals are thought to be coinfected with hepatitis delta virus (HDV). The clinical course depends on the mode of transmission; whereas coinfection commonly resolves, superinfection aggravates the disease and progresses to chronicity in over 90 % of the cases, which, again, results in cirrhosis. OBJECTIVE: Although many tests are performed in HBV carriers, data on the prevalence of anti-HDV-IgG in Germany are only rarely available and outdated. Therefore, we retrospectively evaluated the seroprevalence of anti-HDV-IgG from the results of our routine service. MATERIALS AND METHODS: Between January 2000 and October 2011, serum samples from 2,844 patients (carrying hepatitis B surface antigen) admitted to University Hospital Frankfurt am Main, Frankfurt, Germany, were tested for anti-HDV-IgG by enzyme-linked immunosorbent assay (ELISA). RESULTS: The overall seroprevalence of anti-HDV-IgG in the collective of Frankfurt (n = 2,844) is 7.4 % [95 % confidence interval (CI): 6.4-8.4]. The amount of seropositive men (8.3 %, 95 % CI: 6.9-10) significantly exceeds the female proportion (5.7 %, 95 % CI: 4.3-7.5). The rate of seropositivity to anti-HDV-IgG in this collective of Frankfurt reached a maximum in the year 2003 (10.1 %, 95 % CI: 8.9-11.1). The lowest rate was observable in 2004, where 5.4 % were positive to anti-HDV-IgG. CONCLUSION: Of the HBV carriers in Germany, 5-8 % reveal serologic evidence of coinfection with HDV. The vaccination against HBV is the key to prevent HDV infection; therefore, vaccination must strongly be propagated further on.

H1N1v at a seroepidemiological glance: is the nightmare over?

When the second wave of pandemic influenza A H1N1v 2009 (H1N1v) emerged in the winter of 2010/2011, public health authorities were afraid of dangerous implications and severe clinical courses again. As further H1N1v waves might appear, achievement of sufficient herd immunity is a matter of urgency. The objective of this study was to determine the seroprevalence of antibodies against H1N1v by hemagglutination-inhibition test (HI) after the second wave. We compared our recent findings with our data obtained after the first pandemic in 2009/2010. Between March and May 2011 we collected serum samples from 600 persons aged 1 to 84 years admitted to University Hospital Frankfurt/Main and analysed the titres of anti-H1N1v by HI. The overall seroprevalence of anti-H1N1v has risen from 36.9% (95% confidence interval (95%CI), 33-41) in unvaccinated persons after the first wave to 57.3% (95%CI, 53.1-61.2) in vaccinated and unvaccinated. The highest rate of seropositivity was detected in the age group of 10-19 years (66%; 95%CI, 55.8-75.2), whereas the lowest was found in the age group 40-59 years (51%; 95%CI, 40.8-61.1). Although seroprevalence has significantly increased, sufficient herd immunity is still not achieved. Therefore, general vaccination programs have to be propagated continuously by public health authorities.

[Diagnostic of neurotropic enteroviruses in children with CSF and/or stool: virus isolation by cell culture or PCR?]. / Enterovirusdiagnostik bei aseptischer Meningitis im Kindesalter mit Liquor und/oder Stuhl: Zellkulturgestützte Virusisolierung oder PCR?

BACKGROUND: Aseptic meningitis in children is most frequently caused by enteroviruses. In clinical setting there arises the question, whether stool samples or cerebrospinal fluid (CSF) are better suited for laboratory diagnosis. METHODS: Between 06/2006 and 03/2010 a total number of 613 specimens (376 CSF [61.4%] and 237 stool [38.6%]) of 613 children (270 female [44.1%] and 343 [55.9%] male) aged 22 days to 15 years were collected and investigated by enterovirus-PCR and by virus isolation in cell culture, respectively. RESULTS: Enterovirus was detected in 35.4% (217/613) of the samples by cell culture and/or PCR. In total, specimens of CSF were significantly (p<0.001) more often positive (59.4%, n=129) for enterovirus than stool (40.6%; n=88). Concerning stool, PCR gained no significant advantage when compared to cell culture (35.4% vs. 27.8%; p=0.08), However, virus isolation in cell culture using CSF samples succeeded significantly PCR (30.1% vs. 13.8%; p<0.001). DISCUSSION: Because of its not-invasive sampling, stool is the preferred specimen in suspicion of aseptic meningitis in pediatric clinic. If only stool is available, PCR as well as cell culture are valuable; on contrary, if CSF is available cell culture is significantly superior to PCR in attaining a positive result.

Limited prevalence of influenza A/H1N1v antibodies: footprints of the pandemic of 2010.

BACKGROUND: The intention of our investigation was to determine the seroprevalence of H1N1v antibodies after a pandemic by the haemagglutination inhibition (HI) test. We included the serum samples of adults who had not received vaccination against H1N1v. By means of serological footprints, the spread of infection can be investigated. MATERIALS AND METHODS: Between December 2009 and May 2010, we collected 233 serum samples from healthy people aged 1-72 years and analysed the titres of H1N1v antibodies by the use of the HI test. RESULTS: After the pandemic, a seroprevalence of 36.9% was observed. The highest rate of seropositivity was detected in the age group of 10-19 years (60%) and the lowest rate was found in the age group of 30-39 years (22%). The seroprevalence of H1N1v antibodies in females exceeded the rate of positive men (41.5 vs. 31.8%). Almost 70% of the influenza A/H1N1v infections were passed inapparently.

Seroepidemiology of parvovirus B19 in the Frankfurt am Main area, Germany: evaluation of risk factors.

BACKGROUND: Parvovirus B 19 is a virus that is distributed by respiratory droplets. It is known to be an initiator of erythema infectiosum (children's fifth disease), with erythroblasts being the target cells of infection. In case of vertically transmission, hydrops fetalis has been documented. OBJECTIVE: Parvovirus B19 seroprevalence was investigated in serum samples routinely collected from patients who had been admitted to the University Hospital in Frankfurt a. M., Germany. Patients were classified in different groups in order to analyze parovirus B19 seroprevalences in terms of risk factors. MATERIALS AND METHODS: Between June 2007 and March 2010, a total of 2,197 serum samples were analyzed for parvovirus B19-immunoglobulin G using an enzyme-linked immunosorbent assay. The study population included six groups of patients, namely, patients suffering from haemophilia, malignant disease, immunodeficiency diseases, common gynecological ailments, pregnant women and children with malignant diseases. RESULTS: Of the 2,197 serum samples, 1,383 contained antibodies to parvovirus B19 (62.9%). The overall seroprevalence in adults (20 to ≥60 years of age) was 71%. Gradually rising prevalences were recorded in children/adolescents with increasing age. We found a positive serostatus in 54.9% of adult patients with malignant disease, in 64.2% of patients with haemophilia (1 to ≥60 years), in 66.7% of patients under immunosuppression with various drugs (1 to ≥60 years) and in 41.7% of oncological patients aged 1-19 years. Of the pregnant women (aged 15-49 years), 71.1% were seropositive. CONCLUSION: The seroprevalence of parvovirus B19 in patients admitted to the University Hospital in Frankfurt a.M. was, on average, lower than that among the general population in Germany. Infection among patients in specific risk groups did not spread more than that in age-matched non-selected patients, with the exception of the group of immunocompromised patients.

Holographic subsonic flow visualization.

A pulsed ruby laser holographic interferometer was used to detect density gradients in the airflow around an airfoil at subsonic speeds in a low speed wind tunnel. These experiments proved that vibration of the optical components or object between exposures of the interferometric hologram does not destroy the detection of density gradients but actually can aid in the flow visualization. The density gradients determined from the fringe pattern analysis are consistent with the anticipated flow pattern.

An Intensity MTF Theory for Coherent Imaging.

The effect that any parameter of a holographic or coherent imaging system would have on the resultant image is normally described by an amplitude modulation transfer function. We show here that an intensity modulation transfer function (MTF) can be used to analyze the coherent systems if diffuse targets are employed and if the usable area image.