Jutte J.C. de Vries

The apparent paradox of maternal seropositivity as a risk factor for congenital cytomegalovirus infection: a population-based prediction model

Because maternal seropositivity for CMV is associated with substantial protection against congenital CMV infection, prevention measures have focused mainly on seronegative pregnant women for decades. However, population‐wide insight in the contribution of nonprimary infection (reactivation and/or re‐infection with a different strain) on the most common sequela, hearing loss, is missing.

Evaluation of DNA extraction methods for dried blood spots in the diagnosis of congenital cytomegalovirus infection

BACKGROUND Dried blood spots (DBS) may be valuable in the diagnosis of congenital cytomegalovirus (CMV) infection. However, the 2007 European Quality Control for Molecular Diagnostics (QCMD) proficiency testing programme showed that CMV DNA detection in DBS was lacking sensitivity in a considerable number of participating laboratories. OBJECTIVE To compare DNA extraction methods for DBS for detecting CMV. Sensitivity and applicability of the methods for high-throughput usage were assessed. STUDY DESIGN Guthrie cards were spotted with CMV DNA-positive whole blood (n=15). DNA was extracted from the DBS using different extraction methods, followed by CMV amplification by means of real-time PCR. RESULTS Significant differences between the extraction methods with respect to the sensitivity were found. Optimal sensitivity was achieved when samples were tested in triplicate, demonstrating that the methods in general operated around their detection limits. Triplicate testing using the protocol by Barbi et al. [Barbi M, et al. Cytomegalovirus DNA detection in Guthrie cards: a powerful tool for diagnosing congenital infection. J Clin Virol 2000;17:159-65], representing the most sensitive methods, resulted in sensitivities of 100%, 86%, and 50% for DBS with CMV DNA loads of 5-4, 4-3, and 3-2log(10)copies/ml, respectively. This indicates that sensitivity limitations apply in the clinically relevant concentration range. Few methods appeared suitable for 96-well format high-throughput testing. DISCUSSION When considering universal neonatal screening for congenital CMV infection, an assay which is both sensitive and applicable for high-throughput testing is required. The protocol by Barbi et al. and the BioRobot Universal System appear appropriate candidates currently available for 96-well format application in neonatal screening using DBS.

Implementing neonatal screening for congenital cytomegalovirus: addressing the deafness of policy makers.

Congenital cytomegalovirus (CMV) infection is an important public health problem with approximately 7 in 1,000 newborns infected and consequently at risk for hearing impairment. Newborn hearing screening will fail to detect this hearing impairment in approximately half of the cases because late onset hearing loss is frequent. Hearing impairment has profound impact on cognitive and social development of children and their families, determining most of the disease burden of congenital CMV infection. The potential value of newborn screening for congenital CMV is increasingly discussed. To date, many experts acknowledge the benefit of antiviral treatment in the prevention of hearing deterioration in newborns with neurological symptoms, and the benefit of early identification of late‐onset hearing impairment by means of extensive audiological follow up of infected infants. These opinions imply that the potential of newborn screening for CMV would lie in the identification of the large proportion of asymptomatic congenitally infected newborns at risk for developing late‐onset hearing loss. Experience with postnatal antiviral treatment of symptomatic newborns is encouraging, but has not been studied in asymptomatic congenitally infected newborns. A large‐scale study on the safety and effectiveness of combined screening and antiviral therapy for congenital CMV infection is the necessary next step to take and should not be delayed. Copyright

Real-time PCR versus viral culture on urine as a gold standard in the diagnosis of congenital cytomegalovirus infection.

BACKGROUND Cytomegalovirus (CMV) infection is the most common cause of congenital infection. Whereas CMV PCR has replaced viral culture and antigen detection in immunocompromised patients because of higher sensitivity, viral culture of neonatal urine is still referred to as the gold standard in the diagnosis of congenital CMV infection. OBJECTIVE To compare real-time CMV PCR with shell vial culture on urine in the diagnosis of congenital CMV, in a multicenter design. STUDY DESIGN A series of neonatal urines (n=340), received for congenital CMV diagnostics and routinely assessed with shell vial CMV culture, was retrospectively tested by real-time CMV PCR. RESULTS The proportion of newborns found to be congenitally infected by real-time CMV PCR was 8.2% (28/340, 95%CI 5.6-11.8%), and 7.4% (25/340, 95%CI 4.9-10.8%) by rapid culture. When considering rapid culture as reference, real-time PCR was highly sensitive (100%), whereas sensitivity of rapid culture was 89.3% when considering real-time PCR as reference. CONCLUSIONS Our results, supported by analytical and clinical data on CMV DNA detection in neonatal urine, suggest enhanced sensitivity of recent PCR techniques when compared to viral culture. There is considerable rationale to favor real-time CMV PCR as a gold standard in the diagnosis of congenital CMV infection. A large-scale study combining both laboratory and clinical data is required to determine the exact time frame for sampling of neonatal urine when using real-time PCR.

Congenital cytomegalovirus infection in the Netherlands: Birth prevalence and risk factors

Congenital cytomegalovirus (CMV) infection is the most common congenital viral infection worldwide. The sequela encountered most frequently is hearing impairment, affecting approximately one out of five infants congenitally infected. Data on the birth prevalence and risk factors of congenital CMV infection in the Netherlands are scarce. The aim of this study was to determine the birth prevalence of congenital CMV in the Netherlands. A sample of 6,500 dried blood spots (DBS) from infants born in the Netherlands was tested anonymously for CMV DNA. The sample was stratified by the number of live births in different regions of the Netherlands of the year 2007. Additionally, on a regional level, risk factors for congenital CMV were analyzed. The birth prevalence of congenital CMV in the Netherlands was 0.54% (35/6,433, 95%CI 0.36–0.72). Congenital CMV infection was significantly higher in regions with more than 15% young children (0–5 years) compared with regions with a lower proportion of young children (OR 5.9, 95%CI 1.4–25.2). Congenital CMV infection was significantly higher in regions with more than 30% immigrants compared with regions with a lower proportion of immigrants (OR 2.2, 95%CI 1.1–4.6). This association was strongest for regions with more than 30% non‐Western immigrants (OR 3.3, 95%CI 1.5–7.5). Based on the knowledge of the natural history of congenital CMV infection, approximately 1,000 children are born with congenital CMV infection in the Netherlands annually, of whom eventually approximately 180 children (0.1% of all newborns) will be affected by long term sequelae, with hearing loss being the symptom encountered most frequently. J. Med. Virol. 83:1777–1782, 2011.

Extraction of DNA from Dried Blood in the Diagnosis of Congenital CMV Infection

Viral DNA detection in dried blood spotted on filter paper, dried blood spots (DBS), is valuable in the diagnosis of viral infections, with at the moment congenital cytomegalovirus (CMV) being the most common application. CMV detection in clinical samples taken within the first 2-3 weeks after birth differentiates congenital CMV infection from the in general harmless postnatal acquired cytomegalovirus infection. DBS render the possibility to diagnose congenital CMV infection retrospectively, e.g., when late-onset hearing loss, the most frequently encountered symptom of congenital CMV infection, becomes manifest. Additionally, CMV DNA detection in DBS can be of usage in recently advocated newborn screening on congenital CMV infection. The procedure of CMV DNA detection in DBS consists of two separate steps: (1) DNA extraction from the DBS, followed by (2) CMV DNA amplification. Here, we describe two efficient methods for the extraction of DNA from DBS. Sensitivity, specificity, and applicability of the methods for high-throughput usage are discussed.

Cytomegalovirus DNA detection in dried blood spots and perilymphatic fluids from pediatric and adult cochlear implant recipients with prelingual deafness

BACKGROUND Congenital cytomegalovirus (CMV) infection is the leading cause of non-genetic congenital hearing loss. The contribution of congenital CMV to prelingual deafness and the pathophysiology is largely unknown. OBJECTIVE (1) To analyze the prevalence of congenital CMV among cochlear implant (CI) recipients with prelingual deafness. (2) To genotype CMV present in dried blood spots (DBS) and in the inner ear years after birth. STUDY DESIGN Children and adults with prelingual deafness who received a CI in 2010-2011 were included prospectively. Perilymphatic fluids were collected during CI surgery and, in the pediatric cases, DBS were retrieved for CMV DNA detection. Furthermore, a cohort of children with prelingual deafness who received a CI between 2003 and 2008 were included retrospectively. CMV detection in DBS and perilymph was followed by gB and gH genotyping. RESULTS Seventysix pediatric CI recipients were included. Seventy DBS were tested for CMV DNA, resulting in a prevalence of congenital CMV of 14% (10/70). Perilymphatic fluid was available from 29 pediatric CI recipients. One perilymph fluid, of a 21-month old girl with congenital CMV, asymptomatic at birth, was CMV DNA positive. The CMV strain in the perilymph was genotypically identical to the strain present in her DBS (gB1/gH2). Perilymph samples from 21 adult CI recipients were CMV DNA negative. CONCLUSIONS Our study stresses the important contribution of congenital CMV among pediatric CI recipients. Furthermore, our genotyping data support the hypothesis that CMV-related hearing loss is associated with ongoing viral replication in the inner ear up to years after birth.

Immune status of health care workers to measles virus: evaluation of protective titers in four measles IgG EIAs

BACKGROUND Following the recognition of a measles case in a hospital in The Netherlands, health care workers (HCW) from the premises were screened by a commercial enzyme immunoassay (EIA) for measles IgG to identify persons at risk for measles. At least 10% of the HCW were tested measles IgG-negative. As this was considered an unusually high proportion, we hypothesized suboptimal sensitivity of EIAs, especially in medical personnel that had vaccine-induced immunity rather than antibodies resulting from natural infection. OBJECTIVES To determine (vaccine-induced) measles immunity in HCW, using different EIAs compared to the plaque reduction neutralization (PRN) test, the best surrogate marker for vaccine efficacy and immune protection. STUDY DESIGN Sera from HCW were tested for measles IgG antibodies in three commercial EIAs, in a bead-based multiplex immunoassay (MIA) and in the PRN test, and evaluated against age and vaccination history of the HCW. RESULTS Of the 154 HCW, born between 1960 and 1995, 153 (99.4%) had protective levels of measles antibodies (PRN> 120mIU/ml). The three EIAs failed to detect any measles IgG antibodies in approximately 10% of the HCW, while this percentage was approximately 3% for the MIA. Negative IgG results rose to 19% for individuals born between 1975 and 1985, pointing to an age group largely representing vaccinated persons from the first measles vaccination period in The Netherlands. CONCLUSION The results show limitations in the usefulness of current EIA assays for determining protective measles antibodies in persons with a vaccination history.

Rhinovirus viremia in adult patients with high viral load in bronchoalveolar lavages

BACKGROUND In children, rhinovirus viremia has been associated with higher nasopharyngeal loads and increase in severity of clinical signs and symptoms. OBJECTIVES This study aims to detect rhinovirus viremia in adult patients and to establish potential correlations with the clinical course. STUDY DESIGN Adult patients with rhinovirus strongly positive bronchoalveolar lavages (BAL, quantitation cycle, Cq values <25) detected between 2008 and 2014 were studied retrospectively. Blood sampled between two weeks before and two weeks after BAL sampling was tested for rhinovirus RNA. Underlying conditions, symptoms, radiography, microbiological data, and disease outcome were analysed. RESULTS Twenty-seven of 43 patients with rhinovirus positive BAL at Cq values <25 had blood samples available within the prespecified time-frame (mean blood 3-4 samples per patient). Four of these 27 patients (15%) tested rhinovirus RNA positive in their blood (of whom one patient twice). Genotyping demonstrated rhinovirus A01, A24, B52 and B92 in these four immunocompromised patients. Viremic patients were not significantly different with regard to underlying conditions, respiratory symptoms, radiological findings, co-pathogens nor the number of blood samples tested for RV. However, patients with rhinovirus viremia had significant higher mortality rates compared to patients without viremia, as all four died as a consequence of respiratory problems (100%) versus 22% (5/23), p=0.007 (Fishers exact). CONCLUSIONS Rhinovirus viremia can occur in adult patients with a high viral load in BAL fluid. Rhinovirus viremia may be considered a negative prognostic factor, although a causative role with regard to the adverse outcome has yet to be demonstrated.

False-negative detection of respiratory syncytial virus as an example that regular update of RT-PCR is required for reliable molecular detection of respiratory viruses

no: 78 Presentation at ESCV 2016: Poster 221 Rapid diagnosis of respiratory viral infections in primary health care A.H.L. Bruning 1,∗, W.B. de Kruijf 1, H.C.P.M. van Weert 2, W.L.M. Willems 3, M.D. de Jong 4, D. Pajkrt 1, K.C. Wolthers 4 1 Department of Pediatric Infectious Diseases and Immunology, Emma Children’s Hospital, AMC, Amsterdam, The Netherlands 2 Department of General Practice, AMC, Amsterdam, The Netherlands 3 Health Center Gein, GAZO, Amsterdam, The Netherlands 4 Laboratory of Clinical Virology, Department of Medical Microbiology, AMC, Amsterdam, The