Development of a qPCR platform for quantification of the five bacteriophages within bacteriophage cocktail 2 (BFC2)

To determine phage titers accurately, reproducibly and in a non-laborious and cost-effective manner, we describe the development of a qPCR platform for molecular quantification of five phages present in bacteriophage cocktail 2 (BFC2). We compared the performance of this molecular approach, with regard to quantification and reproducibility, with the standard culture-based double agar overlay method (DAO). We demonstrated that quantification of each of the five phages in BFC2 was possible by means of qPCR, without prior DNA extraction, but yields were significantly higher in comparison to DAO. Although DAO is assumed to provide an indication of the number of infective phage particles, whereas qPCR only provides information on the number of phage genomes, the difference in yield (qPCR/DAO ratio) was observed to be phage-dependent and appeared rather constant for all phages when analyzing different (freshly prepared) stocks of these phages. While DAO is necessary to determine sensitivity of clinical strains against phages in clinical applications, qPCR might be a valid alternative for rapid and reproducible quantification of freshly prepared stocks, after initial establishment of a correction factor towards DAO

Hearing loss and congenital CMV infection: a systematic review

BACKGROUND AND OBJECTIVE: Hearing loss caused by congenital cytomegalovirus (cCMV) infection was first observed in 1964. Today cCMV is the most common cause of nonhereditary sensorineural hearing loss in childhood. Our objective was to provide an overview of the prevalence of cCMV-related hearing loss, to better define the nature of cCMV-associated hearing loss, and to investigate the importance of cCMV infection in hearing-impaired children. METHODS: Two reviewers independently used Medline and manual searches of references from eligible studies and review articles to select cohort studies on children with cCMV infection with audiological follow-up and extracted data on population characteristics and hearing outcomes. RESULTS: Thirty-seven studies were included: 10 population-based natural history studies, 14 longitudinal cohort studies, and 13 retrospective studies. The prevalence of cCMV in developed countries is 0.58% (95% confidence interval, 0.41–0.79). Among these newborns 12.6% (95% confidence interval, 10.2–16.5) will experience hearing loss: 1 out of 3 symptomatic children and 1 out of 10 asymptomatic children. Among symptomatic children, the majority have bilateral loss; among asymp- tomatic children, unilateral loss predominates. In both groups the hear- ing loss is mainly severe to profound. Hearing loss can have a delayed onset, and it is unstable, with fluctuations and progression. Among hearing-impaired children, cCMV is the causative agent in 10% to 20%. Despite strict selection criteria, some heterogeneity was found between selected studies. CONCLUSIONS: This systematic review underscores the importance of cCMV as a cause of sensorineural hearing loss in childhood

Congenital cytomegalovirus infection registry in Flanders : opportunities and pitfalls

In 2007, a prospective multicentre registry was set up to collect data on incidence and outcome of children with congenital cytomegalovirus infection in Flanders. A consensus was reached about management and follow up of cytomegalovirus-infected children. With this registration, we aimed at gathering information on congenital cytomegalovirus infection in Flanders and evaluating the consensus on management and therapy. Children with proven congenital cytomegalovirus infection were eligible for registration in the database. Information on prenatal and neonatal management, therapy and follow up until 6 years was obtained. Between 2007 and 2017, 686 children were registered. Data on the prenatal and neonatal characteristics in children with congenital cytomegalovirus infection are reported. Conclusion: In this article, we report on our experience of conducting a registry for cCMV in Flanders. Eleven years of collecting data on CMV in a multicenter setting have shown us some pitfalls and opportunities. We address some of the problems and aim at improving our data gathering. We encourage other groups to share their data. Better knowledge of the burden of the disease will be important to guide future management strategies

Hearing in Children with Congenital Cytomegalovirus Infection: Results of a Longitudinal Study

Objectives: To evaluate hearing outcome, to characterize the nature of symptomatic and asymptomatic congenital cytomegalovirus (cCMV) infection and associated hearing loss, and to compare results with data from previous studies. Study design: A prospective multicenter registry was set up in 2007. Six centers participated in the development of a standardized protocol for diagnosis, treatment, and follow-up. Data were gathered in an online registry. Children (n = 379) with a documented cCMV infection and at least 2 separate audiologic evaluations were included. Audiometric results from a multicenter cohort study of children with cCMV infection with longitudinal observation were examined. Results: Results from 123 children with a symptomatic and 256 children with an asymptomatic cCMV infection were analyzed. In the group with symptomatic cCMV, 63% had hearing loss, compared with 8% in the group with asymptomatic cCMV. Delayed-onset hearing loss occurred in 10.6% of symptomatic cCMV and in 7.8% of asymptomatic cCMV. In the group with symptomatic cCMV, 29.3% of children used some kind of hearing amplification; 1.6% in the group with asymptomatic cCMV used hearing amplification. Conclusions: Symptomatic and asymptomatic cCMV infections are a major cause of hearing loss in childhood. Reliable estimates of the long-term outcome of cCMV infection are mandatory to increase vigilance, especially among pregnant women and to draw attention to preventive measures, vaccine development, and prenatal and postnatal therapy. Universal screening of newborns for cCMV infection should be initiated and combined with longitudinal audiometric follow-up

Hearing in children with congenital cytomegalovirus infection: results of a longitudinal study

Objectives: To evaluate hearing outcome, to characterize the nature of symptomatic and asymptomatic congenital cytomegalovirus (cCMV) infection and associated hearing loss, and to compare results with data from previous studies. Study design: A prospective multicenter registry was set up in 2007. Six centers participated in the development of a standardized protocol for diagnosis, treatment, and follow-up. Data were gathered in an online registry. Children (n = 379) with a documented cCMV infection and at least 2 separate audiologic evaluations were included. Audiometric results from a multicenter cohort study of children with cCMV infection with longitudinal observation were examined. Results: Results from 123 children with a symptomatic and 256 children with an asymptomatic cCMV infection were analyzed. In the group with symptomatic cCMV, 63% had hearing loss, compared with 8% in the group with asymptomatic cCMV. Delayed-onset hearing loss occurred in 10.6% of symptomatic cCMV and in 7.8% of asymptomatic cCMV. In the group with symptomatic cCMV, 29.3% of children used some kind of hearing amplification; 1.6% in the group with asymptomatic cCMV used hearing amplification. Conclusions: Symptomatic and asymptomatic cCMV infections are a major cause of hearing loss in childhood. Reliable estimates of the long-term outcome of cCMV infection are mandatory to increase vigilance, especially among pregnant women and to draw attention to preventive measures, vaccine development, and prenatal and postnatal therapy. Universal screening of newborns for cCMV infection should be initiated and combined with longitudinal audiometric follow-up

Congenital cytomegalovirus infection registry in flanders: opportunities and pitfalls

In 2007, a prospective multicentre registry was set up to collect data on incidence and outcome of children with congenital cytomegalovirus infection in Flanders. A consensus was reached about management and follow up of cytomegalovirus-infected children. With this registration, we aimed at gathering information on congenital cytomegalovirus infection in Flanders and evaluating the consensus on management and therapy. Children with proven congenital cytomegalovirus infection were eligible for registration in the database. Information on prenatal and neonatal management, therapy and follow up until 6 years was obtained. Between 2007 and 2017, 686 children were registered. Data on the prenatal and neonatal characteristics in children with congenital cytomegalovirus infection are reported. Conclusion: In this article, we report on our experience of conducting a registry for cCMV in Flanders. Eleven years of collecting data on CMV in a multicenter setting have shown us some pitfalls and opportunities. We address some of the problems and aim at improving our data gathering. We encourage other groups to share their data. Better knowledge of the burden of the disease will be important to guide future management strategies.status: publishe