Zika virus vertical transmission in interferon receptor1-antagonized Rag1-/- mice results in postnatal brain abnormalities and clinical disease

The mechanisms by which vertically transmitted Zika virus (ZIKV) causes postnatal brain development abnormalities and congenital disease remain poorly understood. Here, we optimized the established anti-IFNAR1 treated, Rag1^-/- (AIR) mouse model of ZIKV infection to examine the consequence of vertical transmission on neonate survival and postnatal brain development. We found that modulating the infectious dose and the frequency of anti-IFNAR1 treatment of pregnant mice (termed AIR^low mice) prolonged neonatal survival allowing for pathogenesis studies of brain tissues at critical postnatal time points. Postnatal AIR^low mice all had chronic ZIKV infection in the brain that was associated with decreased cortical thickness and cerebellar volume, increased gliosis, and higher levels of cell death in many brain areas including cortex, hippocampus and cerebellum when compared to controls. Interestingly, despite active infection and brain abnormalities, the neurodevelopmental program remained active in AIR^low mice as indicated by elevated mRNA expression of critical neurodevelopmental genes in the brain and enlargement of neural-progenitor rich regions of the cerebellum at a developmental time point analogous to birth in humans. Nevertheless, around the developmental time point when the brain is fully populated by neurons, AIR^low mice developed neurologic disease associated with persistent ZIKV infection in the brain, gliosis, and increased cell death. Together, these data show that vertically transmitted ZIKV infection in the brain of postnatal AIR^low mice strongly influences brain development resulting in structural abnormalities and cell death in multiple regions of the brain.

Women's perspectives on caesarean section recovery, infection and the PREPS trial: a qualitative pilot study

Background

In England, 27.8% of all pregnant women undergo caesarean sections (CS) to deliver their babies. Women undergoing CS are at risk of developing sepsis and post-natal infections, which not only contribute significantly to maternal mortality and morbidity, but also negatively impact upon post-natal recovery and wellbeing. This study explores patients’ priorities in relation to CS recovery, focusing on their knowledge and experiences of infection prevention. The study formed part of the PREPS (Vaginal Preparation at caesarean section to Reduce Endometritis and Prevent Sepsis – a feasibility study of chlorhexidine) Trial; patients’ views on the PREPS Trial were also sought.

Methods

Using qualitative methodology, two focus groups and six telephone interviews were carried out between September and October 2017 with a total of 21 women who had undergone a CS within the preceding six months. Focus groups and individual telephone interviews were audio-recorded and transcribed verbatim; a thematic analysis was conducted using NVivo 11.

Results

Women’s priorities around CS recovery centred on pain (or the lack thereof), mobility and the ability to resume everyday activities, including caregiving. Those undergoing a CS for the first time reported not feeling confident in their ability to identify signs of infection and sought visiting health professionals’ expertise and reassurance. Women were unable to recall whether they had received information regarding infection prevention and felt that they had not received sufficient advice. Some reported receiving general information regarding CS recovery, which ranged in quality. Prevention of womb infection is a major goal of the PREPS trial, however, the majority of women were not aware that womb (as opposed to wound) infection was a post CS risk.

Conclusions

Women undergoing a CS want more information on what constitutes a ‘normal’ post-operative recovery and specifically would welcome written information and infection prevention advice. This should be a key element of improving post-CS maternal experiences and potentially reducing sepsis and infection rates. CS stigma negatively impacts women’s recovery experiences and possibly information provision.

The PREPS team incorporated findings regarding consent pathways for recruiting women into intrapartum research and developed two patient reported outcomes to collect in the main trial.

Trial registration

The PREPS trial has been registered with ISRCTN on the 10th July 2017 (ISRCTN33435996).

Cytomegalovirus alpha-chemokine genotypes are associated with clinical manifestations in children with congenital or postnatal infections

Human cytomegalovirus (HCMV) is the leading cause of congenital infections. The aim of our study was to determine the prevalence of genotypes based on the highly polymorphic UL146 and UL147 HCMV genes and the relationship between the genotype and symptoms or viral load. We analyzed samples from 121 infants with symptomatic HCMV infection, including 32 congenitally infected newborns. The G7 and G5 genotypes were predominant in postnatal infection, whereas the G1 genotype was prevalent in congenital infection. Central nervous system (CNS) damage and hepatomegaly were detected more frequently among children infected with the G1 genotype than in those infected by other genotypes. An association between the viral genotype and viruria level was found. There was a strong correlation between HCMV genotypes determined through the UL146 and UL147 sequences (ĸ=0.794). In conclusion, we found that certain vCXCL genotypes are associated with clinical sequelae following HCMV infection.

Urine is superior to saliva when screening for postnatal CMV infections in preterm infants

BACKGROUND

Cytomegalovirus (CMV) is the most frequently contracted virus in preterm infants. Postnatal infection is mostly asymptomatic but is sometimes associated with severe disease. To diagnose an infection, urine or saliva samples can be tested for CMV-DNA by real-time polymerase chain reaction (rtPCR). Although the diagnostic accuracy of testing saliva samples has not been determined in preterm infants, saliva is widely used because it is easier to obtain than urine.

OBJECTIVES

To determine whether screening of saliva is equivalent to urine to detect a postnatal CMV infection in preterm infants.

STUDY DESIGN

Between 2010 and 2013 saliva and urine samples were collected from infants admitted to the Neonatal Intensive Care Unit of the University Medical Center Utrecht and born with a gestational age (GA) below 32 weeks. Urine samples were obtained within three weeks after birth and urine and saliva samples at term equivalent age (40 weeks GA) and tested for CMV-DNA by rtPCR. Infants with a congenital CMV infection were excluded.

RESULTS

Of 261 preterm infants included in the study, CMV-DNA was detected in urine of 47 and in saliva of 43 children. Of 47 infants with postnatal CMV infection, CMV was detected in 42 saliva samples (sensitivity 89.4%; CI 76.9-96.5). Of 214 children without postnatal CMV infection, one saliva sample tested positive for CMV (specificity 99.5%; CI 97.4-99.9).

CONCLUSIONS

Screening saliva for CMV-DNA by rtPCR is inferior to urine to diagnose postnatal CMV infections in preterm infants.

[Usefulness of a real-time quantitative polymerase-chain reaction (PCR) assay for the diagnosis of congenital and postnatal cytomegalovirus infection]

INTRODUCTION

Cytomegalovirus (CMV) is the main virus causing congenital and postnatal infections in the pediatric population. The aim of this study is to evaluate the usefulness of a quantitative real-time PCR in the diagnosis of these infections using urine as a single sample.

PATIENTS AND METHODS

We studied all the urine samples of newborns (< 7 days) with suspected congenital infection, and urine of patients with suspected postnatal infection (urine negative at birth). Urines were simultaneously studied by cell culture, qualitative PCR (PCRc), and quantitative real-time PCR (PCRq).

RESULTS

We analyzed 332 urine samples (270 to rule out congenital infection and 62 postnatal infections). Of the first, 22 were positive in the PCRq, 19 in the PCRc, and 17 in the culture. PCRq had a sensitivity of 100%, on comparing the culture with the rest of the techniques. Using the PCRq as a reference method, culture had a sensitivity of 77.2%, and PCRc 86.3%. In cases of postnatal infection, PCRq detected 16 positive urines, the PCRq 12, and the cell culture 10. The urines showed viral loads ranging from 2,178 to 116,641 copies/ml.

CONCLUSIONS

The genomic amplification technique PCRq in real time was more sensitive than the other techniques evaluated. This technique should be considered as a reference (gold standard), leaving the cell culture as a second diagnostic level. The low cost and the automation of PCRq would enable the screening for CMV infection in large neonatal and postnatal populations.