Search

Introduction: In most cases of stillbirth, the cause is still unknown. Aim: The impact of parvovirus B19/erythrovirus infection and chromosomal abnormalities in stillborns and neonatal deaths. Material and Methods: 57 consecutive cases, 23 second-trimester abortions (from gestational weeks 16 to 22), 27 intrauterine fetal deaths (from gestational week 22 onwards) and 7 early neonatal deaths were examined for intrauterine parvovirus B19 infection with PCR, dot blot, Southern blot, in situ hybridization, specific IgM and IgG antibodies in maternal serum, fetal serum, placenta and fetal liver tissue. Chromosomal analysis and extensive histopathology were performed on all fetuses. Results: A sensitive PCR was developed and enabled detection of 9 (15.8%) parvovirus B19-infected fetuses. Parvovirus B19 IgM and IgG antibody tests were in good concordance with PCR findings. 5 of 9 infected fetuses had a concurrent abnormality that could have contributed to fetal death, 4 of which (44%) were trisomy karyotypes, compared to 0/48 in the non-B19-infected group (p = 0.0004). Conclusion: Combination of PCR and specific parvovirus B19 IgG/IgM tests enabled high detection rates of parvovirus B19 infection in this series of 57 consecutive pregnancies with adverse outcomes. The high mortality rate in the B19-infected fetuses was partly explained by a high occurrence of fetal trisomy, compared to non-B19-infected fetuses, suggesting a higher vulnerability of the former. After correction for this concomitant karyotype abnormality, the percentage of presumably lethal infection due to parvovirus B19 was 8.8%. Copyright © 2010 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: Foot-and-Mouth Disease (FMD) causes significant economic losses in Turkish livestock. We have analysed the genetic diversity of the 1D sequences, encoding the hypervariable surface protein VP1, of Turkish isolates of serotype A and O collected from 1998 to 2004 in order to obtain epidemiological and immunological information. Results: The 1D coding region of 33 serotype O and 20 serotype A isolates, obtained from outbreaks of FMD between 1998 and 2004, was sequenced. For serotype A, we confirmed the occurrence of the two subtypes IRN99 and IRN96. These subtypes are most divergent within the region encoding the immuno-dominant GH-loop. Also a close relationship to Foot-and-Mouth Disease virus (FMDV) serotype A isolates obtained from outbreaks in Iraq and Iran were detected and a clustering of isolates collected during the same period of time were found. The analysis of the deduced amino-acid sequences of these subtypes revealed evidence of positive selection in one site and one deletion, both within the GH-loop region. By inferring the ancestral history of the positively selected codon, two potential precursors were found. Furthermore, the structural alignment of IRN99 and IRN96 revealed differences between the tertiary structures of these subtypes. The similarity plot of the serotype O isolates suggested a more homogeneous group than the serotype A isolates. However, phylogenetic analysis revealed two major groups, each further divided in subgroups, of which some only consisted of Turkish isolates. Positively selected sites and structural differences of the Turkish isolates analysed, were not found. Conclusion: The sequence and structural analysis of the IRN99 strains is indicative of positive selection suggesting an immunological advantage compared to IRN96. However, results of antigenic comparison reported elsewhere do not substantiate such a conclusion. There is evidence that IRN99 was introduced to Turkey, in all probability from Iran. Since, a member of the IRN96 lineage was included as a component of the FMDV vaccine produced since 2000, the outbreaks caused by IRN96 strains in 2004 could be due to incomplete vaccine coverage. The Turkish type O strains, all with a VP1 structure similar to the O1/Manisa/69 vaccine, appear in several sublineages. Whether these sublineages reflect multiple samplings from a limited number of outbreaks, or if they reflect cross-boundary introductions is not clear. [ABSTRACT FROM AUTHOR]

Objectives: To determine the prevalence of TT virus (TTV) in a population of Danish hemodialysis patients and evaluate possible relations between TTV infection and elevated levels of C-reactive protein (CRP) and hypo-response to treatment with erythropoietin (EPa). Material and Methods: Patients on maintenance hemodialysis at a single center were invited to participate. Demographic and clinical data were registered. Blood samples for virological and routine biochemical tests were drawn simultaneously. TTV DNA was detected using polymerase chain reaction (PCR). TTV viral load was estimated by means of semi-quantitative PCR. All patients were tested for hepatitis B, hepatitis C and GB virus C. Results: Of 252 patients, 204 (80.9%) gave their written informed consent to participate in the study. The prevalence of TTV was 68% and 50% of TTV-positive patients had a high TTV viral load. TTV-positive patients were significantly older than TTV-negative patients (p = 0.011). No relations were found between TTV infection and elevated levels of alanine aminotransferase (ALT) or CRP or hypo-response to EPa treatment. The mean hemoglobin concentration was 11.24 ± 1.48 g/dl. Patients with a high TTV viral load had a lower level of hemoglobin (10.86 ± 1.47 g/dl) than the others (p = 0.01). This trend suggested a positive relation between TTV infection and the number of blood transfusions. A restriction fragment length polymorphism assay suggested that patients were infected with different TTV strains. Conclusions: TTV is common in patients on maintenance hemodialysis. The presence of TTV is associated with increasing age. Patients with a high TTV viral load had lower levels of hemoglobin than the others. TTV infection is not related to elevated levels of ALT or CRP or to hypo-response to EPa treatment. [ABSTRACT FROM AUTHOR]