Source and Relevance of the BK Polyomavirus Genotype for Infection After Kidney Transplantation.

BACKGROUND: BK polyomavirus (BKPyV)-associated nephropathy (BKPyVAN) is a major threat for kidney transplant recipients (KTRs). The role of specific BKPyV genotypes/serotypes in development of BKPyVAN is poorly understood. Pretransplantation serotyping of kidney donors and recipients and posttransplantation genotyping of viremic recipients, could reveal the clinical relevance of specific BKPyV variants. METHODS: A retrospective cohort of 386 living kidney donor-recipient pairs was serotyped before transplantation against BKPyV genotype I-IV viral capsid protein 1 antigen, using a novel BKPyV serotyping assay. Replicating BKPyV isolates in viremic KTRs after transplantation were genotyped using real-time polymerase chain reaction and confirmed by means of sequencing. BKPyV serotype and genotype data were used to determine the source of infection and analyze the risk of viremia and BKPyVAN. RESULTS: Donor and recipient BKPyV genotype and serotype distribution was dominated by genotype I (>80%), especially Ib, over II, III and IV. Donor serotype was significantly correlated with the replicating genotype in viremic KTRs (P < .001). Individual donor and recipient serotype, serotype (mis)matching and the recipient replicating BKPyV genotype were not associated with development of viremia or BKPyVAN after transplantation. CONCLUSIONS: BKPyV donor and recipient serotyping and genotyping indicates the donor origin of replicating BKPyV in viremic KTRs but provides no evidence for BKPyV genotype-specific virulence.

Pretransplantation Donor-Recipient Pair Seroreactivity Against BK Polyomavirus Predicts Viremia and Nephropathy After Kidney Transplantation.

Kidney transplant donors are not currently implicated in predicting BK polyomavirus (BKPyV) infection in kidney transplant recipients. It has been postulated, however, that BKPyV infection originates from the kidney allograft. Because BKPyV seroreactivity correlates with BKPyV replication and thus might mirror the infectious load, we investigated whether BKPyV seroreactivity of the donor predicts viremia and BKPyV-associated nephropathy (BKPyVAN) in the recipient. In a retrospective cohort of 407 living kidney donor-recipient pairs, pretransplantation donor and recipient sera were tested for BKPyV IgG levels and correlated with the occurrence of recipient BKPyV viremia and BKPyVAN within 1 year after transplantation. Donor BKPyV IgG level was strongly associated with BKPyV viremia and BKPyVAN (p < 0.001), whereas recipient BKPyV seroreactivity showed a nonsignificant inverse trend. Pairing of high-BKPyV-seroreactive donors with low-seroreactive recipients resulted in a 10-fold increased risk of BKPyV viremia (hazard ratio 10.1, 95% CI 3.5-29.0, p < 0.001). In multivariate analysis, donor BKPyV seroreactivity was the strongest pretransplantation factor associated with viremia (p < 0.001) and BKPyVAN (p = 0.007). The proportional relationship between donor BKPyV seroreactivity and recipient infection suggests that donor BKPyV seroreactivity reflects the infectious load of the kidney allograft and calls for the use of pretransplantation BKPyV serological testing of (potential) donors and recipients.

Detection of parvovirus B19 DNA in blood: Viruses or DNA remnants?

BACKGROUND: Parvovirus B19 (B19V) DNA can be detected in blood over a long period after acute infection. Several reports associate the presence of B19V DNA with disease, irrespective of timing of the initial B19V infection. OBJECTIVES: This study aims to analyze the properties of B19V DNA in blood, differentiating between bare, non-infectious strands of DNA and B19V DNA in viable virions. STUDY DESIGN: Ten blood donors with asymptomatic acute B19V infection were followed and sampled up to 22 months after infection. The samples were treated with and without an endonuclease and tested for B19V DNA, to distinguish between DNA in virions and naked DNA. RESULTS: In the acute phase of infection, high levels of B19V DNA were detected, concurrent with B19V IgM antibodies. B19V DNA apparently was encapsidated, as indicated by resistance to endonuclease degradation. Subsequently, B19V DNA remained detectable for more than one year in all donors at low levels (<105 IU/mL). Approximately 150days after infection B19V DNA became degradable by an endonuclease, indicating that this concerned naked DNA. In some donors a second endonuclease-resistant peak occurred. DISCUSSION: Detection of B19V DNA in blood by PCR does not necessarily imply that B19V replication takes place and that infectious B19V virions are present. We propose that remnant B19V DNA strands can be released from tissues without active replication. This finding urges to reconsider an assumed role of B19V infection mainly based on B19V DNA detection in blood, a much debated subject in clinical syndromes such as myocarditis and arthritis.

Disease burden of congenital cytomegalovirus infection at school entry age: study design, participation rate and birth prevalence.

Congenital cytomegalovirus infection (cCMV) may lead to symptoms at birth and long-term consequences. We present a nationwide, retrospective cohort study on the outcome of cCMV up to age 6 years. For this study we identified cCMV, using polymerase chain reaction, by analysing dried blood spots, which are taken shortly after birth for neonatal screening. The group of children with cCMV were compared to a group of children who were cCMV negative at birth. Data were collected about their health and development up to age 6 years. Parents of 73 693 children were invited to participate, and 32 486 (44·1%) gave informed consent for testing of their child's dried blood spot for CMV. Of the 31 484 dried blood spots tested, 156 (0·5%) were positive for cCMV. Of these, four (2·6%) children had been diagnosed with cCMV prior to this study. This unique retrospective nationwide study permits the estimation of long-term sequelae of cCMV up to the age of 6 years. The birth prevalence of cCMV in this study was 0·5%, which is in line with prior estimates. Most (97·4%) children with cCMV had not been diagnosed earlier, indicating under-diagnosis of cCMV.

Cytomegalovirus infection in the Netherlands: seroprevalence, risk factors, and implications.

BACKGROUND: Cytomegalovirus (CMV) infections occur worldwide and are usually asymptomatic in healthy individuals. In fetuses and immunocompromised persons, they can cause severe disease and disabilities. OBJECTIVE: To determine the CMV seroprevalence and risk factors for CMV infection in the Netherlands. STUDY DESIGN: In a cross-sectional population-based study (PIENTER-2, 2006-2007), sera and questionnaire data were collected from 6386 individuals. Sera were tested for CMV-specific IgG antibodies using enzyme-linked immunosorbent assay (ELISA). RESULTS: The CMV seroprevalence in the general population (6 months-79 years) was 45.6%. Age and country of origin were the most prominent independent risk factors. The seroprevalence was significantly lower in native Dutch and Western individuals (41.5%) than in non-Western individuals (76.7%). Multivariable logistic regression analysis showed that age, lower educational level, first-generation migrancy, and among native Dutch/Western individuals, female gender and having contact with young children, were independently associated with CMV seropositivity. The geometric mean concentrations of antibodies increased with age and were higher in women than in men. CONCLUSION: CMV seroprevalence in the Netherlands is relatively low compared to other countries. This is in line with our finding of a higher seroprevalence among migrants compared to the native population. The higher seroprevalence in women and individuals who have contact with young children is especially important for women of reproductive age. Preventing CMV infection in these women, through counseling on hygiene or possible future vaccination, may lead to a decrease of congenital CMV infections.

Viral loads and antiviral resistance of herpesviruses and oral ulcerations in hematopoietic stem cell transplant recipients.

Ulcerative oral mucositis and infection are frequent complications in hematopoietic stem cell transplant (HSCT) recipients. The aim of this study was to investigate the relationship between oral ulcerations and HSV-1, EBV and CMV excretion and the presence of aciclovir-resistant HSV-1 strains in HSCT recipients. This prospective observational study included 49 adult patients who underwent allogeneic HSCT. In total, 26 patients received myeloablative and 23 received non-myeloablative conditioning. Ulcerations on non-keratinized and keratinized oral mucosa were scored and oral rinsing samples were taken twice weekly. Viral loads were determined by real-time PCR. Samples from patients remaining HSV-1 positive despite antiviral treatment were studied for resistance to antivirals. Having an HSV-1 or EBV DNA-positive sample was a significant predictor for ulceration of keratinized mucosa. HSV-1 was a significant predictor for ulcerations on non-keratinized mucosa as well. Persistent HSV-1 infection occurred in 12 of 28 patients treated with antiviral medication and aciclovir-resistant HSV-1 was found in 5 persistent infections. In conclusion, HSV-1 is a predictor of ulcerations on non-keratinized as well as keratinized oral mucosa following HSCT. The role of EBV deserves further study. Persistent HSV-1 replication despite antiviral treatment is common and is due to resistance in 18% of treated patients.

The association of recombination events in the founding and emergence of subgenogroup evolutionary lineages of human enterovirus 71.

Enterovirus 71 (EV71) is responsible for frequent large-scale outbreaks of hand, foot, and mouth disease worldwide and represent a major etiological agent of severe, sometimes fatal neurological disease. EV71 variants have been classified into three genogroups (GgA, GgB, and GgC), and the latter two are further subdivided into subgenogroups B1 to B5 and C1 to C5. To investigate the dual roles of recombination and evolution in the epidemiology and transmission of EV71 worldwide, we performed a large-scale genetic analysis of isolates (n = 308) collected from 19 countries worldwide over a 40-year period. A series of recombination events occurred over this period, which have been identified through incongruities in sequence grouping between the VP1 and 3Dpol regions. Eleven 3Dpol clades were identified, each specific to EV71 and associated with specific subgenogroups but interspersed phylogenetically with clades of coxsackievirus A16 and other EV species A serotypes. The likelihood of recombination increased with VP1 sequence divergence; mean half-lives for EV71 recombinant forms (RFs) of 6 and 9 years for GgB and GgC overlapped with those observed for the EV-B serotypes, echovirus 9 (E9), E30, and E11, respectively (1.3 to 9.8 years). Furthermore, within genogroups, sporadic recombination events occurred, such as the linkage of two B4 variants to RF-W instead of RF-A and of two C4 variants to RF-H. Intriguingly, recombination events occurred as a founding event of most subgenogroups immediately preceding their lineage expansion and global emergence. The possibility that recombination contributed to their subsequent spread through improved fitness requires further biological and immunological characterization.

Evaluation of the antiviral response to zanamivir administered intravenously for treatment of critically ill patients with pandemic influenza A (H1N1) infection.

A retrospective nationwide study on the use of intravenous (IV) zanamivir in patients receiving intensive care who were pretreated with oseltamivir in the Netherlands was performed. In 6 of 13 patients with a sustained reduction of the viral load, the median time to start IV zanamivir was 9 days (range, 4-11 days) compared with 14 days (range, 6-21 days) in 7 patients without viral load reduction (P = .052). Viral load response did not influence mortality. We conclude that IV zanamivir as late add-on therapy has limited effectiveness. The effect of an immediate start with IV zanamivir monotherapy or in combination with other drugs need to be evaluated.

High sensitivity and specificity of the C6-peptide ELISA on cerebrospinal fluid in Lyme neuroborreliosis patients.

Lyme neuroborreliosis (LNB) is a serious but treatable disease. The diagnosis of LNB poses a challenge to clinicians, and improved tests are needed. The C6-peptide ELISA is frequently used on serum but not on cerebrospinal fluid (CSF). Data on the sensitivity of the C6-peptide ELISA in CSF in patients suffering from LNB have been conflicting. Serum-CSF pairs from 59 LNB patients, 36 Lyme non-neuroborreliosis cases, 69 infectious meningitis/encephalitis controls and 74 neurological controls were tested in a C6-peptide ELISA. With the optimal cut-off of 1.1, the sensitivity of the C6-peptide ELISA for LNB patients in CSF was 95%, and the specificity was 83% in the Lyme non-neuroborreliosis patients, 96% in the infectious controls, and 97% in the neurological controls. These results suggest that the C6-peptide ELISA has a high sensitivity and good specificity for the diagnosis of LNB patients in CSF. The C6-peptide ELISA can be used on CSF in a clinical setting to screen for LNB.

Discriminating Lyme neuroborreliosis from other neuroinflammatory diseases by levels of CXCL13 in cerebrospinal fluid.

CXCL13 in cerebrospinal fluid (CSF) could be an important component for diagnosing Lyme neuroborreliosis (LNB). Levels of intrathecal CXCL13 were determined for 58 LNB patients and 210 controls; sensitivity was 88% and specificity was 89% (cutoff, 250 pg of CXCL13/ml of CSF). Elevated levels of CXCL13 can aid in the diagnosis of LNB, but levels should be interpreted with care.

Parvovirus B19 infection in pregnancy: new insights and management.

In this article, we review the virology, pathology, epidemiology and clinical spectrum of intrauterine human parvovirus B19 (B19V) infection, including intrauterine fetal death, non-immune hydrops fetalis, thrombocytopenia and neurological manifestations such as pediatric stroke and perivascular calcifications. In addition, we discuss the new insights into the neurodevelopmental outcome of intrauterine B19V infection. Current diagnosis and management of B19V infection is summarized, including a diagnostic and follow-up flowchart for practical clinical use.

Evolutionary dynamics and temporal/geographical correlates of recombination in the human enterovirus echovirus types 9, 11, and 30.

The relationship between virus evolution and recombination in species B human enteroviruses was investigated through large-scale genetic analysis of echovirus type 9 (E9) and E11 isolates (n = 85 and 116) from 16 European, African, and Asian countries between 1995 and 2008. Cluster 1 E9 isolates and genotype D5 and A E11 isolates showed evidence of frequent recombination between the VP1 and 3Dpol regions, the latter falling into 23 (E9) and 43 (E11) clades interspersed phylogenetically with 46 3Dpol clades of E30 and with those of other species B serotypes. Remarkably, only 2 of the 112 3Dpol clades were shared by more than one serotype (E11 and E30), demonstrating an extremely large and genetically heterogeneous recombination pool of species B nonstructural-region variants. The likelihood of recombination increased with geographical separation and time, and both were correlated with VP1 divergence, whose substitution rates allowed recombination half-lives of 1.3, 9.8, and 3.1 years, respectively, for E9, E11, and E30 to be calculated. These marked differences in recombination dynamics matched epidemiological patterns of periodic epidemic cycles of 2 to 3 (E9) and 5 to 6 (E30) years and the longer-term endemic pattern of E11 infections. Phylotemporal analysis using a Bayesian Markov chain Monte Carlo method, which placed recombination events within the evolutionary reconstruction of VP1, showed a close relationship with VP1 lineage expansion, with defined recombination events that correlated with their epidemiological periodicity. Whether recombination events contribute directly to changes in transmissibility that drive epidemic behavior or occur stochastically during periodic population bottlenecks is an unresolved issue vital to future understanding of enterovirus molecular epidemiology and pathogenesis.

Is routine TORCH screening warranted in neonates with lenticulostriate vasculopathy?

BACKGROUND: Congenital infections are associated with a wide spectrum of clinical symptoms, including lenticulostriate vasculopathy (LSV). OBJECTIVE: To determine the relationship between LSV and congenital infections, as diagnosed by TORCH serology and viral culture for cytomegalovirus (CMV). METHODS: All neonates with LSV admitted to our neonatal intensive-care unit from 2004 to 2008 were included in the study. Results of maternal and neonatal TORCH testing were evaluated. RESULTS: During the study period, cranial ultrasound scans were performed in 2,088 neonates. LSV was detected in 80 (4%) neonates. Maternal and/or neonatal serological TORCH tests were performed in 73% (58/80) of cases. None of the mothers or infants (0 of 58) had positive IgM titres for Toxoplasma, rubella, CMV or herpes simplex virus. Additional urine culture for CMV was performed in 38 neonates. None of the infants (0 of 38) had a positive CMV urine culture test. CONCLUSIONS: Routinely applied efforts to diagnose congenital infections in cases presenting with LSV have a poor yield. Routine TORCH screening in neonates with LSV cases should only be regarded as mandatory once well-designed studies demonstrate a clear diagnostic benefit.

Excess drug prescriptions during influenza and RSV seasons in the Netherlands: potential implications for extended influenza vaccination.

Influenza and respiratory syncytial virus (RSV) infections are responsible for considerable morbidity, mortality and health-care resource use. For the Netherlands, we estimated age and risk-group specific numbers of antibiotics, otologicals and cardiovascular prescriptions per 10,000 person-years during periods with elevated activity of influenza or RSV, and compared these with peri-season rates. Data were taken from the University of Groningen in-house prescription database (www.iadb.nl) and virological surveillance for the period 1998-2006. During influenza and RSV periods excess antibiotic prescriptions were estimated for all age groups. In the age groups 0-1 and 2-4 years, excess antibiotic prescriptions during periods with elevated RSV activity (65% and 59% of peri-seasonal rates) exceeded the surpluses estimated during the influenza-activity periods (24% and 34% of peri-seasonal rates) while for otologicals excess prescriptions were higher for influenza (22% and 27%) than for RSV (14% and 17%). Among persons of 50 years and older, notably those without medical high-risk conditions, excess prescriptions for cardiovascular medications were estimated during the influenza periods at approximately 10% (this was also already seen in persons aged 45-49). Our results may have implications for influenza vaccination policies. In particular, extension of influenza vaccination to groups of non-elderly adults and young children may lower excess prescriptions during these influenza periods for all three types of drug prescriptions investigated.

Significance of isolated antibody to hepatitis B core antigen in Dutch national vaccination campaign of behavioural high-risk groups.

In the Dutch national vaccination campaign for behavioural risk groups, anti-HBcore is used as the primary HBV screening test. Samples with positive results undergo testing for active infection (HBsAg) but are otherwise accepted as indicating past infection, thereby assuming immunity. This study evaluated evidence for immunity in the target population screened on the basis of this algorithm, by re-analysing 1000 anti-HBcore-positive blood samples equally divided among risk groups: 14.7% of confirmed anti-HBcore lacked anti-HBs ('isolated' anti-HBcore). Independent risk factors for isolated anti-HBcore were risk group, HCV infection in hard-drug users (DU) and origin from Sub-Saharan Africa. After extrapolation, the proportion of participants who were said to be immune but lacked any additional evidence of immunity amounted to 9.6% (ranging from 12.5% in DU to 6.5% in men who have sex with men). It is recommended that as a minimum anti-HBs screening is included in testing algorithms used to determine vaccination programmes for risk groups, in particular in DU.

Transmission networks and population turnover of echovirus 30.

Globally, echovirus 30 (E30) is one of the most frequently identified enteroviruses and a major cause of meningitis. Despite its wide distribution, little is known about its transmission networks or the dynamics of its recombination and geographical spread. To address this, we have conducted an extensive molecular epidemiology and evolutionary study of E30 isolates collected over 8 years from a geographically wide sample base (11 European countries, Asia, and Australia). 3Dpol sequences fell into several distinct phylogenetic groups, interspersed with other species B serotypes, enabling E30 isolates to be classified into 38 recombinant forms (RFs). Substitutions in VP1 and 3Dpol regions occurred predominantly at synonymous sites (ratio of nonsynonymous to synonymous substitutions, 0.05) with VP1 showing a rapid substitution rate of 8.3 x 10(-3) substitutions per site per year. Recombination frequency was tightly correlated with VP1 divergence; viruses differing by evolutionary distances of >0.1 (or 6 years divergent evolution) almost invariably (>97%) had different 3Dpol groups. Frequencies of shared 3Dpol groups additionally correlated with geographical distances, with Europe and South Asia showing turnover of entirely distinct virus populations. Population turnover of E30 was characterized by repeated cycles of emergence, dominance, and disappearance of individual RFs over periods of 3 to 5 years, although the existence and nature of evolutionary selection underlying these population replacements remain unclear. The occurrence of frequent "sporadic" recombinants embedded within VP1 groupings of other RFs and the much greater number of 3Dpol groups than separately identifiable VP1 lineages suggest frequent recombination with an external diverse reservoir of non-E30 viruses.

[Infection with human parvovirus B19 ('fifth disease') during pregnancy: potential life-threatening implications for the foetus]. / Infectie met het Humaan parvovirus B19 ('vijfde ziekte') in de zwangerschap: voor de foetus soms levensbedreigend.

Four pregnant women, aged 29, 32, 36 and 36 years, respectively, were diagnosed with Human parvovirus B19 (B19V) infection. Only the first woman had exanthema and fever. In the first three cases, the source of infection appeared to be another child; two of these children were infected during a school outbreak. All four foetuses were infected, but the first foetus was asymptomatic and healthy at birth. The second foetus had anaemia and increased blood flow in the middle cerebral artery; it received an intrauterine transfusion and was healthy at birth. The third foetus was almost immobile and had cardiomegaly and hydrops fetalis; it was dead upon induced birth. In the fourth case, pregnancy was uneventful until two days before parturition, when the mother reported a decrease in foetal movement. The infant was born and developed respiratory insufficiency after 8 hours. Imaging revealed multiple bilateral lesions in frontal, occipital and parietal white matter consistent with infarction. The infant died after 5 days. Infection with B19V is associated with a wide range of clinical presentations and outcomes. Effects may range from an uncomplicated pregnancy to severe hydrops fetalis or intrauterine foetal death. Maternal symptoms may be aspecific, which complicates early diagnosis. When maternal B19V infection is suspected, immediate investigation for recent B19V infection should be performed. Quantitative B19 viral load measurements may provide insight into the stage of infection and may guide foetal monitoring. Referral to a foetal therapy unit is essential for hydrops fetalis or severe foetal anaemia. Intrauterine transfusion with erythrocytes significantly improves foetal outcome. Despite a successful transfusion procedure, long-term neurodevelopment may be affected, and developmental follow up is advised.

Thrombocytopenia in hydropic fetuses with parvovirus B19 infection: incidence, treatment and correlation with fetal B19 viral load.

OBJECTIVE: To examine (1) the incidence of fetal thrombocytopenia in hydropic fetuses with congenital B19 virus infection, (2) the effect of intrauterine platelet transfusions and (3) the correlation between fetal B19 viral load and severity of thrombocytopenia. DESIGN: Retrospective analysis of data from prospectively collected fetal blood samples. SETTING: Leiden University Medical Centre, the national centre for management of intrauterine fetal disease in the Netherlands. POPULATION: Thirty hydropic fetuses treated with intrauterine red blood cell and platelet transfusions for human B19 virus-induced severe fetal anaemia and thrombocytopenia over a 10-year period. METHODS: Fetal blood samples (n= 30) taken before and after intrauterine transfusion were investigated. No cases were excluded, and there was no loss to follow up. MAIN OUTCOME MEASURES: Parameters recorded were gestational age, experienced fetal movements, gravidity and parity, severity of fetal hydrops, severity of fetal anaemia and thrombocytopenia and megakaryocyte and reticulocyte counts. Survival and procedure-associated complications were documented. Quantitative B19 viral load measurements were performed on all fetal samples. RESULTS: Forty-six percent of all hydropic fetuses showed severe thrombocytopenia. No antenatal intracerebral haemorrhage or procedure-associated bleeding occurred. Overall, survival was 77%. Platelet counts increased following platelet transfusion and decreased significantly following red blood cell transfusion alone. No correlation was found between fetal viral loads and platelet counts. CONCLUSION: Thrombocytopenia was frequently encountered in fetal B19V infection, but fetal bleeding complications were not noted. Absence of a direct relationship between fetal B19 viral load and platelet counts suggests a temporal dissociation between these findings. Dilutional thrombocytopenia is frequently seen in the fetus following red blood cell transfusion alone. The clinical significance of this phenomenon is unclear. The risk of fluid overload by fetal platelet transfusion in a severely hydropic fetus should be weighed against the low incidence of fetal bleeding complications.