Cytomegalovirus Infection in Ireland: Seroprevalence, HLA Class I Alleles, and Implications

Cytomegalovirus (CMV) infections occur worldwide and primary infection usually occurs in early childhood and is often asymptomatic whereas primary infection in adults may result in symptomatic illness. CMV establishes a chronic latent infection with intermittent periods of reactivation. Primary infection or reactivation associate with increased mortality and morbidity in those who are immunocompromised. Transplacental transmission may result in significant birth defects or long-term sensorineural hearing loss.We performed a study to determine the CMV seroprevalence and the association between HLA Class I alleles and frequency of CMV infection in Ireland. The presence of CMV IgG, a marker of previous CMV infection, was determined for a cohort of 1849 HLA typed solid organ transplant donors between 1990 and 2013. The presence of CMV IgG was correlated with HLA type.The CMV seroprevalence in solid organ transplant donors was 33.4% (range 22-48% per annum) over the time period 1990 to 2013. Multivariate logistic regression analysis showed that both age and HLA alleles were associated with CMV seropositivity. A significant and positive relationship between age and CMV seropositivity was observed (OR = 1.013, P < 0.001, CI [1.007, 1.019]). Chi-square analysis revealed that the female gender was independently associated with CMV seropositivity (P < 0.01). Seroprevalence in women of reproductive age (20-39 years) was significantly higher than men of the same age (37% vs 26%, P < 0.01). The frequencies of HLA-A1, HLA-A2, and HLA-A3 in our cohort were 40.8%, 48.8%, and 25.9%, respectively. Logistic regression analysis showed that the presence of HLA-A1 but not HLA-A2 or HLA-A3 was independently associated with CMV seronegativity (P < 0.01). Interestingly, individuals who co-expressed HLA-A2 and HLA-A3 alleles were significantly more likely to be CMV seropositive (P < 0.02). The frequencies of HLA-B5, HLA-B7, and HLA-B8 in our cohort were 6.1%, 31.2%, and 30.8%, respectively. The presence of the most common inherited haplotype in the Irish population, HLA-A1, B8 was significantly associated with CMV seronegativity (OR = 1.278, P < 0.001, CI [1.049, 1.556]).CMV seroprevalence is lower in Ireland compared with other countries. The high frequency of HLA-A1 in the Irish population may, in part, have a role in the reduced susceptibility to CMV infection.

Mumps outbreaks in a highly vaccinated population: Investigation of a neutralization titre against the current circulating wildtype genotype G5 mumps virus

BACKGROUND

Mumps outbreaks continue to occur globally, despite high levels of uptake of the mumps vaccine.

OBJECTIVES

In order to address immunity to the current circulating wildtype virus, we sought to determine a mumps G5 specific IgG quantitative value which correlates with genotype G5 specific neutralization ability in vitro.

STUDY DESIGN

Sera from 199 individuals including controls and acute mumps cases were assessed for mumps specific IgG titres using five different enzyme immunoassays coated with antigen from different mumps virus strains. A subset of 66 sera was also assessed for in vitro neutralizing antibody against a contemporary circulating genotype G5 mumps virus.

RESULTS

For all the different antigenic targets, mumps specific IgG titres were higher in patients following acute mumps infection compared to controls. In acute mumps infected patients, females showed significantly higher serum titres of anti-G5 IgG compared to males (p<0.05). Furthermore, control males did not show any change in G5 specific IgG with increasing age whereas females show a progressive rise in titre. Linear regression analysis revealed a significant association between the mumps G5 specific IgG levels in the EIA and the in vitro neutralization titres (r(2)=0.59).

CONCLUSIONS

Specific IgG to the current circulating genotype G5 mumps strain showed significantly lower titres in males which supports our previous observation that there is a male gender bias in cases of acute mumps infection. Furthermore, in this preliminary study, the data indicate that genotype G5 specific IgG levels of >40 RU/ml are required for neutralization capability to be observed in vitro.

The role of computed tomography in the assessment of dental disease in 66 guinea pigs

Sixty-six guinea pigs with dental disease were presented to the University of Veterinary Medicine, Vienna, Austria, from 2006 to 2010. Almost all patients had a history of eating difficulties (95 per cent) and underwent clinical and oral examination as well as CT of the head. Findings on extra- and intraoral examination were asymmetric elongation (n=28) and symmetric bridging (n=24) of cheek teeth, obliquely worn incisors (n=17), palpable lower jaw swellings (n=13), exophthalmos (n=10) and incisor macrodontia (n=6). Eighty per cent of guinea pigs with exophthalmos showed ipsilateral periapical disease of the maxillary cheek teeth on CT. Ninety-two per cent of patients with palpable lower jaw swellings showed corresponding dental pathologies on CT. Periapical disease of incisors (n=11) and cheek teeth (n=32) were the most common findings on CT. All abnormally large incisors were found on oral examination and CT, but macrodontia of cheek teeth could only be visualised by CT. Deviation of the lower jaw evaluated in awake animals by visual inspection appeared to correlate with cheek teeth abnormalities. Results emphasise the importance of diagnostic imaging, in particular CT, in guinea pigs with dental disease in order to localise lesions and underlying aetiologies.

Seroepidemiology and phylogenetic characterisation of measles virus in Ireland, 2004-2013

BACKGROUND

Ireland is classified as an area of high measles incidence. A World Health Organisation-European Region strategic plan exists for measles elimination by 2015.

OBJECTIVES

To retrospectively investigate measles outbreaks using all patient samples (sera and oral fluid) received for measles laboratory diagnosis and characterise the genetic diversity of circulating measles genotypes in Ireland.

STUDY DESIGN

704 cases of acute measles infection as determined by the presence of measles specific IgM in sera and oral fluids were confirmed at the National Virus Reference Laboratory. Measles positive samples (n=116) were examined by genotyping, sequence analysis and phylogenetic characterisation.

RESULTS

Three measles outbreaks occurred over the study period: 2004, 2009/2010 and 2011. Measles IgM positivity ranged from 22-29% in outbreak years to 5-10% in the intervening years. Age profile analysis revealed that whereas individuals >10 years accounted for only 8% of cases in the 2004 outbreak, this increased to 33% and 29% in the 2009/2010 and 2011 outbreaks, respectively. The <1 year cohort accounted for 18-20% of cases in all outbreaks. Phylogenetic analysis demonstrated both indigenous transmission and also importation events. Clade D viruses were exclusively found circulating in Ireland, with autochthonous transmission of diverse genotype D4 strains associated with large outbreaks across Europe. More recently, genotype D8 was identified and these were associated with importation events.

CONCLUSIONS

This study provides a comprehensive genetic analysis of circulating measles genotypes in Ireland and discriminated between indigenous and imported viral strains. Notably, an increase in laboratory-confirmed measles cases in the greater than 10 years of age group was seen over the study period. This information is valuable to inform vaccination strategies with a focus on those populations who remain susceptible to measles infection.

Increased levels of PD-1 expression on CD8 T cells in patients post-renal transplant irrespective of chronic high EBV viral load

Studies have identified solid organ transplant recipients who remain asymptomatic despite maintaining CHL. Factors which determine the CHL state remain poorly understood but are likely to involve immunological control of the viral infection. We monitored expression of PD-1, a marker of T-cell exhaustion and viral persistence, on CD8 T cells in patients who resolved EBV infection as determined by undetectable EBV DNA (REI) and CHL patients. PD-1 expression on CD8 T cells was increased in the first year post-transplant irrespective of EBV outcome, and most CD8 T cells continued to express PD-1 for up to three yr post-transplant. Although all patient groups showed similar frequencies of EBV-specific CD8+ T cells, PD-1 expression on these cells increased in the post-transplant groups compared with the pretransplant patients. Functional studies of EBV-specific CD8+ T cells stimulated with BZLF or LMP2 peptide pools revealed monofunctional IFN-γ responses. Our results indicate that PD-1 expression on CD8 T cells post-transplant may result from factors other than antigenic stimulation.

Is there diagnostic value in detection of immunoglobulin g antibodies to the epstein-barr virus early antigen?

The Epstein-Barr virus early antigen (EBV EA) complex consists of multiple proteins with potential significance for diagnosis of EBV-related diseases. In many individuals, detection of antibody to the early antigen (EA) is a sign of active infection, but 20% of healthy people may have this antibody for years. We studied the role of EA immunoglobulin G (IgG) in individuals with atypical antibody responses in the diagnosis of infectious mononucleosis (IM) and in EBV-infected transplant patients. EA IgG was present in 72% of confirmed IM patients. A trend was observed between high viral loads and the presence of EA IgG and between low viral loads and the absence of EA IgG in EBV-associated disease negative liver transplant recipients. Three assays that measure serum EA IgG were compared; enzyme-linked immunosorbent assay (ELISA), chemiluminescent immunoassay (CLIA), and immunoblot assay. The automated CLIA was found to be more accurate than the ELISA when using the immunoblot assay as a "gold standard" assay in the detection of EA IgG. There may be a potential role for EA IgG testing, together with EBV viral load, in the prediction of transplant recipients at risk of EBV-associated disease; however, EA IgG does not play a significant role in the differential diagnosis of EBV infection in immunocompetent individuals.

Use of a geographic information system to map cases of measles in real-time during an outbreak in Dublin, Ireland, 2011

In 2011, there was a large measles outbreak in Dublin. Nationally 285 cases were notified to the end of December 2011, and 250 (88%) were located in the Dublin region. After the first case was notified in week 6, numbers gradually increased, with 25 notified in June and a peak of 53 cases in August. Following public health intervention including a measles-mumps-rubella (MMR) vaccination campaign, no cases were reported in the Dublin region in December 2011. Most cases (82%) were children aged between 6 months and 14 years, and 46 cases (18%) were under 12 months-old. This is the first outbreak in Dublin to utilise a geographic information system for plotting measles cases on a digital map in real time. This approach, in combination with the analysis of case notifications, assisted the department of public health in demonstrating the extent of the outbreak. The digital mapping documented the evolution of two distinct clusters of 87 (35%) cases. These measles cases were infected with genotype D4-Manchester recently associated with large outbreaks across Europe. The two clusters occurred in socio-economically disadvantaged areas and were attributable to inadequate measles vaccination coverage due in part to the interruption of a school-based MMR2 vaccination programme.

ISOLATION AND CHARACTERIZATION OF INFECTIOUS LARYNGOTRACHEITIS VIRUS IN LAYER CHICKENS

The present research work was conducted for the isolation and characterization of infectious laryngotracheitis (ILT) virus in layer chickens from commercial farms of Gazipur District. A total of 25 field samples were collected from suspected layer chickens of five commercial farms and were cultivated into 10-12 days old embryonated chicken eggs through chorioallantoic membrane (CAM) route for isolation of field virus. The field viruses were characterized by physico-chemical properties against pH, heat, ether and chloroform, serological test such as virus neutralization test (VNT) and passive haemagglutination (PHA) test and pathogenicity testing. In the embryonated chicken eggs, virus produced discrete pock lesions as early as 2 days of post inoculation and embryo death was recorded within 4-6 days of inoculation. The viruses could be inactivated by pH 4 within 2 hours. Inactivation of viruses was observed at 600C for 6 minutes, 550C for 15 minutes and 380C for 2 days. Ether-chloroform treatment also inactivated the viruses. Virus neutralization test revealed that all the virus isolates were neutralized by antiserum to ILT vaccine. Passive haemagglutination test showed that the tanned sheep RBC sensitized with the virus isolates were agglutinated in presence of the antiserum to ILT vaccine. The pathogenicity test recorded 100% mortality in experimental chickens. Data of this study suggest that the field isolates might be infectious laryngotracheitis virus.DOI = http://dx.doi.org/10.3329/bjvm.v8i2.11194 Bangl. J. Vet. Med. (2010). 8 (2) : 123-130 

Multi-Lorentzian representation of deuterium spectrum to study water spin magnetization exchange in MCM-41

Water behavior on the pore surface of nano-silica MCM-41, at a hydration level corresponding to one water molecule per OH group, is studied using (2)H NMR spectra in the temperature range 213 to 313 K. In an earlier study [J. Hassan, E. Reardon, H. Peemoeller, Microporous Mesoporous Materials, 122 (2009) 121-127] it was shown that at this hydration level, deuterons of water at single OH sites exhibit a Lorentzian line shape and deuterons of water at hydrogen-bonded OH sites exhibit a powder pattern. Here it is shown that magnetization exchange occurs between these two deuteron spin groups. This exchange cannot be described using the common, two-site exchange model, involving two Lorentzians. We successfully apply a multi-Lorentzian exchange model, prompted by Woessner's work [D. E. Woessner, Mol. Phys. 34, 4, (1977) 899-920] on the effects of motion on the shape of water spin resonance lines exhibiting doublet splitting. For this low hydration sample the rate of magnetization exchange out of the hydration site, where the water deuterons exhibit a Lorentzian line in the (2)H spectra, is 1.3 ms(-1) and the activation energy for the exchange is found to be 3.4±0.1 kcal/mole.

Surveillance of Epstein-Barr virus loads in adult liver transplantation: associations with age, sex, posttransplant times, and transplant indications

Epstein-Barr virus (EBV)-associated posttransplant lymphoproliferative disorder (PTLD) is a life-threatening complication after adult orthotopic liver transplantation (AOLT). Besides EBV and immunosuppression, relatively little is known about the pretransplant clinical parameters associated with the risk of PTLD, and the benefit of using EBV surveillance to predict EBV-associated disease in AOLT patients is uncertain. The aims of this single-center study were to monitor EBV viral loads (VLs) in AOLT patients and to investigate any associations with age, sex, cytomegalovirus (CMV) serostatus, posttransplant times, and indications for transplantation. 1275 blood samples that were collected from 197 AOLT patients 1 day to more than 15 years after transplantation were investigated with quantitative polymerase chain reaction for EBV and CMV DNA. Seventy-two percent of the patients had EBV DNAemia less than 100 days after transplantation without clinical manifestations. No association was observed between the EBV copy numbers and the time since transplantation. EBV DNAemia was weakly associated with male sex but was not associated with age, CMV serostatus, or indications for AOLT. The highest EBV VL levels were observed in patients who presented with congenital liver diseases, whereas patients with viral hepatitis maintained high EBV VLs after transplantation. None of the patients developed PTLD during the study period; however, 3 patients presented with EBV-associated diseases. In conclusion, EBV DNAemia is common in AOLT patients, and routine EBV surveillance has limited value for predicting EBV-associated morbidity or mortality.

Kinetics of host immune responses and cytomegalovirus resistance in a liver transplant patient

Among solid organ transplant (SOT) recipients, donor-seropositive/recipient-seronegative (D+/R-) cytomegalovirus (CMV) status is associated with the highest risk of ganciclovir-resistant CMV disease, which has been reported for patients receiving oral ganciclovir but not valganciclovir prophylaxis. We report a case of CMV breakthrough infection in a D+/R- liver transplant patient while he was receiving oral valganciclovir. Forty samples collected over 6 months were analyzed for the CMV viral load, lymphocyte counts, cytokine levels, and lymphocyte differentiation status. Genotypic resistance testing of the viral UL97 gene was performed when the patient failed to respond. CMV viremia occurred on day 50 post-transplant, and 5 samples taken between days 50 and 85 showed the wild-type UL97 genotype. The appearance of deletion 594-595 was observed from day 114 post-transplant. Viral loads declined when foscarnet was commenced and remained below 10,000 copies/mL when the lymphocyte count was greater than 1000/microL (P = 0.02). T cell responses revealed significant expansion of CD8+ terminal effector memory cells. CD4+ cells were largely populations of naïve and central memory cells. Circulating interleukin 10 (IL-10) levels correlated with the viral load (P < 0.0001). Seroconversion occurred on day 230. The CMV viral load in combination with lymphocyte counts and IL-10 may be a predictive marker for the risk of development of resistant CMV disease in D+/R- SOT patients.

Transvaginal sonography of cervical length and Bishop score as predictors of successful induction of term labor: the effect of parity

OBJECTIVE

To evaluate the predictive value for successful labor induction of transvaginal ultrasound (TVS) of cervical length according to parity.

METHOD

TVS of the cervix was performed before term labor induction. Induction was considered successful if vaginal delivery was achieved within 24 hours; 231 women were available for final analysis.

RESULTS

Analysis of the receiver operator characteristics curve showed an optimal cut-off for cervical length of < or = 20 mm for successful induction. Following multivariate logistic regression analysis, a sonographic short cervix (AOR 5.6; p < 0.001) was an independent predictor of successful induction but not a favorable Bishop score (p = 0.47). Among multiparas with a short cervix, positive and negative predictive values for successful induction were 98% (95% CI 90-100%) and 21% (95% CI 13%-32%) and among nulliparas, predictive values were 69% (95% CI 53%-82%) and 77% (95% CI 64%-87%) respectively.

CONCLUSION

In nulliparas, cervical length can usefully predict labor induction outcome.

Six-minute walk test in children with chronic conditions

OBJECTIVES

The 6-minute walk test (6MWT) is a frequently used indicator of functional exercise capacity. The goals of this study were to compare the 6-minute walk performance of three paediatric patient groups with that of healthy peers, to assess differences between published reference values and to investigate which anthropometric characteristics best predict 6-minute walk performance.

METHODS

47 children with haemophilia (mean (SD) age 12.5 (2.9) years), 44 with juvenile idiopathic arthritis (JIA) (mean age 9.3 (2.2) years) and 22 with spina bifida (SB) (mean age 10.3 (3.1) years) were included. Subjects performed a 6MWT, and the distance walked (6MWD) was compared with published reference values.

RESULTS

The haemophilia, JIA and SB patients achieved 90%-92%, 72%-75% and 60%-62% of predicted walking distances, respectively. There were significant associations between 6MWD and age, height and weight in the haemophilia group and 6MWD and height in the JIA group. None of the anthropometric variables was significantly related to 6MWD in the SB group. All anthropometric variables were strongly correlated with walking distance-body weight product (6Mwork) in all groups. Height explained 24% (haemophilia) and 11% (JIA) of the variance in 6MWD and 84% (haemophilia), 78% (JIA) and 73% (SB) of the variance in 6Mwork.

CONCLUSIONS

Walking distances of children with haemophilia, JIA and SB are significantly reduced compared with healthy references. Walking distance-body weight product seems to be a better outcome measure of the 6MWT compared with distance walked alone. Height is the best predictor of 6MWD and 6Mwork.

Epidemiologic and diagnostic evaluation of a recent mumps outbreak using oral fluid samples

OBJECTIVE

To determine the optimal strategy to investigate mumps virus infection in a partially vaccinated cohort.

STUDY DESIGN

122 oral fluid and serum samples were collected in a recent outbreak in Ireland. The largest age cohort, students aged 18-21 years old attending third level institutions, were investigated using virus isolation, detection of mumps specific IgM, IgG, RT-PCR and molecular genotyping.

RESULTS

97% of patients had both detectable serum IgM and IgG. Mumps virus RNA was detected in 17 oral fluid samples and 14 of these originated from a single geographic location. Only 6 of the IgM positive samples had detectable mumps virus RNA whereas this could be detected in 11 IgM negative samples. Genotyping studies revealed that genotypes G and J were co-circulating during this outbreak.

CONCLUSIONS

The use of an oral fluid sample to detect mumps virus RNA and IgM offers a major improvement over serological diagnosis in acute infection in both non-vaccinated or partially vaccinated individuals, and has the advantage that specimens are collected non-invasively.

Predictors of newborn admission after labour induction at term: Bishop score, pre-induction ultrasonography and clinical risk factors

INTRODUCTION

Following labour induction at term, 12 percent of neonates can expected to be admitted to the neonatal intensive care unit. We aimed to evaluate the Bishop score, pre-induction ultrasonography (US) assessment of amniotic fluid, foetal weight and cervical length, and pre-induction and intrapartum risk factors as predictors of neonatal admission.

METHODS

152 women at term, scheduled for labour induction, consented to participate in this prospective study. Transabdominal US was performed to obtain foetal biometry and amniotic fluid index, followed by transvaginal US to measure cervical length. US findings were concealed. The Bishop score was obtained at initiation of labour induction. Pre-induction and intrapartum risk factors were also considered in the multivariate logistic regression analysis. All study women received standard care.

RESULTS

On univariate analysis, factors associated with neonatal admission were: gestational age at less than or equal to 40 weeks, labour induction for diabetes mellitus, Bishop score of less than 5 at initiation of labour induction, estimated foetal weight of less than 2.5 kg by US, induction to delivery interval of more than 24 hours, caesarean delivery and umbilical cord blood pH of less than 7.1. Cervical length of greater than 20 mm on transvaginal US (p-value is 0.10) was not significant. After multivariate logistic regression analysis, controlling for the significant variables, only the unfavourable Bishop score (adjusted OR 4.2; 95% CI 1.2-13.8; p-value is 0.02) and caesarean delivery (adjusted OR 3.9; 95% CI 1.1-13.7; p-value is 0.035) were independent predictors of neonatal admission.

CONCLUSION

The identification of an unfavourable Bishop score as an independent predictor of neonatal admission is useful in the counselling of women who are considering labour induction.