The consequences of primary cytomegalovirus infection in pregnancy

Commentary: Development of Therapeutics for Congenital Cytomegalovirus Infection

In the mid 1980’s, I flew from Birmingham, Alabama to San Francisco, rented a car, and drove to Palo Alto so that I could meet with John Martin at Syntex. John, along with Julian Verheyden, synthesized ganciclovir, which had significant in vitro activity against cytomegalovirus (CMV) in vitro. This drug provided my colleagues and me an opportunity to evaluate it as a therapeutic agent for congenital CMV infection, knowing full well that it was mutagenic, teratogenic, and carcinogenic. John in his wisdom convinced the management of Syntex to provide ganciclovir for this disease, allowing me to study this drug in symptomatic congenitally infected children through the NIAID Collaborative Antiviral Study Group (CASG). Certainly, no other person or company would advocate for the use of such a medication in children, regardless of disease severity, because of its toxicity profile. Since these early days, ganciclovir, and subsequently its prodrug valganciclovir, have become the standard of care for the treatment of congenital cytomegalovirus infection. The following commentary defines the need and progress in the development of therapy

The Placental Response to Guinea Pig Cytomegalovirus Depends Upon the Timing of Maternal Infection

Human cytomegalovirus (HCMV) infects the placenta, and these placental infections can cause fetal injury and/or demise. The timing of maternal HCMV infection during pregnancy is a determinant of fetal outcomes, but how development affects the placenta's susceptibility to infection, the likelihood of placental injury post-infection, and the frequency of transplacental HCMV transmission remains unclear. In this study, guinea pig cytomegalovirus (GPCMV) was used to model primary maternal infection and compare the effects of infection at two different times on the placenta. When guinea pigs were infected with GPCMV at either 21- or 35-days gestation (dGA), maternal and placental viral loads, as determined by droplet digital PCR, were not significantly affected by the timing of maternal infection. However, when the transcriptomes of gestational age-matched GPCMV-infected and control placentas were compared, significant infection-associated changes in gene expression were only observed after maternal infection at 35 dGA. Notably, transcripts associated with immune activation (e.g. Cxcl10, Ido1, Tgtp1, and Tlr8) were upregulated in the infected placenta. A GPCMV-specific in situ hybridization assay detected rare infected cells in the main placenta after maternal infection at either time, and maternal infection at 35 dGA also caused large areas of GPCMV-infected cells in the junctional zone. As GPCMV infection after mid-gestation is known to cause high rates of stillbirth and/or fetal growth restriction, our results suggest that the placenta becomes sensitized to infection-associated injury late in gestation, conferring an increased risk of adverse pregnancy outcomes after cytomegalovirus infection.

Viral Manipulation of the Host Epigenome as a Driver of Virus-Induced Oncogenesis

Tumorigenesis due to viral infection accounts for a high fraction of the total global cancer burden (15–20%) of all human cancers. A comprehensive understanding of the mechanisms by which viral infection leads to tumor development is extremely important. One of the main mechanisms by which viruses induce host cell proliferation programs is through controlling the host’s epigenetic machinery. In this review, we dissect the epigenetic pathways through which oncogenic viruses can integrate their genome into host cell chromosomes and lead to tumor progression. In addition, we highlight the potential use of drugs based on histone modifiers in reducing the global impact of cancer development due to viral infection.

Vertical transmission of Zika virus and its outcomes: a Bayesian synthesis of prospective studies

BACKGROUND

Prospective studies of Zika virus in pregnancy have reported rates of congenital Zika syndrome and other adverse outcomes by trimester. However, Zika virus can infect and damage the fetus early in utero, but clear before delivery. The true vertical transmission rate is therefore unknown. We aimed to provide the first estimates of underlying vertical transmission rates and adverse outcomes due to congenital infection with Zika virus by trimester of exposure.

METHODS

This was a Bayesian latent class analysis of data from seven prospective studies of Zika virus in pregnancy. We estimated vertical transmission rates, rates of Zika-virus-related and non-Zika-virus-related adverse outcomes, and the diagnostic sensitivity of markers of congenital infection. We allowed for variation between studies in these parameters and used information from women in comparison groups with no PCR-confirmed infection, where available.

FINDINGS

The estimated mean risk of vertical transmission was 47% (95% credible interval 26 to 76) following maternal infection in the first trimester, 28% (15 to 46) in the second, and 25% (13 to 47) in the third. 9% (4 to 17) of deliveries following infections in the first trimester had symptoms consistent with congenital Zika syndrome, 3% (1 to 7) in the second, and 1% (0 to 3) in the third. We estimated that in infections during the first, second, and third trimester, respectively, 13% (2 to 27), 3% (-5 to 14), and 0% (-7 to 11) of pregnancies had adverse outcomes attributable to Zika virus infection. Diagnostic sensitivity of markers of congenital infection was lowest in the first trimester (42% [18 to 72]), but increased to 85% (51 to 99) in trimester two, and 80% (42 to 99) in trimester three. There was substantial between-study variation in the risks of vertical transmission and congenital Zika syndrome.

INTERPRETATION

This preliminary analysis recovers the causal effects of Zika virus from disparate study designs. Higher transmission in the first trimester is unusual with congenital infections but accords with laboratory evidence of decreasing susceptibility of placental cells to infection during pregnancy.

FUNDING

European Union Horizon 2020 programme.

Zika virus infection in pregnancy: a protocol for the joint analysis of the prospective cohort studies of the ZIKAlliance, ZikaPLAN and ZIKAction consortia

INTRODUCTION

Zika virus (ZIKV) infection in pregnancy has been associated with microcephaly and severe neurological damage to the fetus. Our aim is to document the risks of adverse pregnancy and birth outcomes and the prevalence of laboratory markers of congenital infection in deliveries to women experiencing ZIKV infection during pregnancy, using data from European Commission-funded prospective cohort studies in 20 centres in 11 countries across Latin America and the Caribbean.

METHODS AND ANALYSIS

We will carry out a centre-by-centre analysis of the risks of adverse pregnancy and birth outcomes, comparing women with confirmed and suspected ZIKV infection in pregnancy to those with no evidence of infection in pregnancy. We will document the proportion of deliveries in which laboratory markers of congenital infection were present. Finally, we will investigate the associations of trimester of maternal infection in pregnancy, presence or absence of maternal symptoms of acute ZIKV infection and previous flavivirus infections with adverse outcomes and with markers of congenital infection. Centre-specific estimates will be pooled using a two-stage approach.

ETHICS AND DISSEMINATION

Ethical approval was obtained at each centre. Findings will be presented at international conferences and published in peer-reviewed open access journals and discussed with local public health officials and representatives of the national Ministries of Health, Pan American Health Organization and WHO involved with ZIKV prevention and control activities.

Timing of primary maternal cytomegalovirus infection and rates of vertical transmission and fetal consequences

OBJECTIVE

Cytomegalovirus infection is the most frequent congenital infection and a major cause of long-term neurologic morbidity. The aim of this meta-analysis was to calculate the pooled rates of vertical transmission and fetal impairments according to the timing of primary maternal infection.

DATA SOURCES

From inception to January 2020, MEDLINE, Scopus, Cochrane Library, and gray literature sources were used to search for related studies.

STUDY ELIGIBILITY CRITERIA

Cohort and observational studies reporting the timing of maternal cytomegalovirus infections and rate of vertical transmission or fetal impairments were included. The primary outcomes were vertical transmission and fetal insult, defined as either prenatal findings from the central nervous system leading to termination of pregnancy or the presence of neurologic symptoms at birth. The secondary outcomes included sensorineural hearing loss or neurodevelopmental delay at follow-up and prenatal central nervous system ultrasonography findings.

STUDY APPRAISAL AND SYNTHESIS METHODS

The pooled rates of the outcomes of interest with their 95% confidence intervals (CI) were calculated for primary maternal infection at the preconception period, periconception period, first trimester, second trimester, and third trimester.

RESULTS

A total of 17 studies were included. The pooled rates of vertical transmission (10 studies, 2942 fetuses) at the preconception period, periconception period, first trimester, second trimester, and third trimester were 5.5% (95% CI, 0.1-10.8), 21.0% (95% CI, 8.4-33.6), 36.8% (95% CI, 31.9-41.6), 40.3% (95% CI, 35.5-45.1), and 66.2% (95% CI, 58.2-74.1), respectively. The pooled rates of fetal insult in case of transmission (10 studies, 796 fetuses) were 28.8% (95% CI, 2.4-55.1), 19.3% (95% CI, 12.2-26.4), 0.9% (95% CI, 0-2.4%), and 0.4% (95% CI, 0-1.5), for maternal infection at the periconception period, first trimester, second trimester, and third trimester, respectively. The pooled rates of sensorineural hearing loss for maternal infection at the first, second, and third trimester were 22.8% (95% CI, 15.4-30.2), 0.1% (95% CI, 0-0.8), and 0% (95% CI, 0-0.1), respectively.

CONCLUSION

Vertical transmission after maternal primary cytomegalovirus infection increases with advancing pregnancy, starting from the preconception period. However, severe fetal impairments are rare after infection in the first trimester of pregnancy.

Researching Zika in pregnancy: lessons for global preparedness

Our understanding of congenital infections is based on prospective studies of women infected during pregnancy. The EU has funded three consortia to study Zika virus, each including a prospective study of pregnant women. Another multi-centre study has been funded by the US National Institutes of Health. This Personal View describes the study designs required to research Zika virus, and questions whether funding academics in the EU and USA to work with collaborators in outbreak areas is an effective strategy. 3 years after the 2015-16 Zika virus outbreaks, these collaborations have taught us little about vertical transmission of the virus. In the time taken to approve funding, agree contracts, secure ethics approval, and equip laboratories, Zika virus had largely disappeared. By contrast, prospective studies based on local surveillance and standard-of-care protocols have already provided valuable data. Threats to fetal and child health pose new challenges for global preparedness requiring support for the design and implementation of locally appropriate protocols. These protocols can answer the key questions earlier than externally designed studies and at lower cost. Local protocols can also provide a framework for recruitment of unexposed controls that are required to study less specific outcomes. Other priorities include accelerated development of non-invasive tests, and longer-term storage of neonatal and antenatal samples to facilitate retrospective reconstruction of cohort studies.

Growth Patterns in Children With Congenital Cytomegalovirus Infection

BACKGROUND

Congenital cytomegalovirus infection (CMVc) affects 0.7%-6% of recent births. Among its clinical manifestations are low weight and length at birth.

OBJECTIVE

Describe the growth patterns of children with CMVc in their early years.

METHODS

Observational, multicenter study of patients with CMVc. Anthropometric data were collected during the first 2 years of life and compared with World Health Organization standards.

RESULTS

Anthropometric characteristics of 383 children with CMVc were studied, of which 198 (51%) were symptomatic at birth. At birth, 9% were small for gestational age (SGA) in terms of their weight and length and 17% had microcephaly. At 24 ± 3 months, 10% had a weight and length ≤2 SD, and 13% a head circumference ≤2 SD. Of those who were SGA at birth, at 24 ± 3 months >20% remained at ≤2 SD of their weight and length. Conversely, 75% of children with low weight or length at 24 ± 3 had not been SGA at birth. 20% of infants with microcephaly at birth remained with microcephaly, and 10% of those without microcephaly developed it at 24 ± 3 months. The average growth rate in length and weight was normal. Patients who were symptomatic at birth, premature and with motor and neurocognitive impairment had a significantly higher risk of low weight and length at 24 ± 3 months.

CONCLUSION

Around 10% of children with CMVc are at ≤2 SD in weight, length and head circumference at 24 ± 3 months. The lack of adequate growth is associated with symptoms at birth, prematurity and motor and neurocognitive impairment. Growth impairment could be incorporated into the symptomatic spectrum of CMVc.

Congenital Cytomegalovirus Infection and Tetralogy of Fallot: An Unusual Association in a Three-month-old Baby

Congenital cytomegalovirus (cCMV) infection is the leading cause of infant morbidity and mortality worldwide. Despite being associated with significant neurological sequelae in infected infants, it remains an under-recognized public health entity. Symptomatic newborns most frequently display hepatosplenomegaly, petechiae, jaundice, microcephaly, intrauterine growth restriction, chorioretinitis, purpura, and seizures. Progressive sensorineural hearing loss is the most prominent adverse outcome of both symptomatic and asymptomatic CMV infections in infants. We report the case of a three-month-old baby who presented with complaints of progressive jaundice for three months and a two days history of fever associated with one episode of fits. The baby was diagnosed with congenital CMV infection on the basis of positive CMV IgM and IgG and positive maternal serum CMV IgG. Finding a murmur on physical examination prompted echocardiography which revealed Tetralogy of Fallot (TOF). The child was managed with a 6-week course of ganciclovir after which his symptoms improved and he was referred to cardiology for the evaluation of his heart defect. Follow-ups at the clinic have shown normal growth and development. This is the first reported association of cCMV infection with TOF. This case highlights the need to consider the possibility of the presence of heart defects in all infants with cCMV infection in addition to neurodevelopmental abnormalities. Clinicians should maintain a high degree of suspicion for cCMV infection in all neonates to ensure timely intervention and to prevent long-term neurological sequelae.

Congenital Cytomegalovirus and Neonatal Herpes Simplex Virus Infections: To Treat or Not to Treat?

Congenital cytomegalovirus infections are among the most common of the newborn in the developed world. These infections are the most common cause of sensorineural hearing loss. Studies utilizing ganciclovir and valganciclovir demonstrate improved hearing and Bailey Developmental scores. Because of the ease of administration, valganciclovir is the recommended treatment of choice for 6 months. Therapy should be reserved for those babies with symptomatic disease; no data are available regarding the impact of treatment on those babies with asymptomatic disease.

Pathogenesis of Non-Zika Congenital Viral Infections

A widespread epidemic of Zika virus (ZIKV) infection was reported in 2015 from South and Central America and the Caribbean. Although the full spectrum of ZIKV infection of the newborn has yet to be determined, other maternal viral infections resulting in transmission to the fetus provide instructive lessons that can be applied to the prospective evaluation of individuals with ZIKV infection. This review focuses on those other congenital infections, including rubella, congenital cytomegalovirus, human immunodeficiency virus, hepatitis B virus, and neonatal herpes simplex virus, from which lessons for the evaluation of ZIKV in the newborn can be applied.

Maternal and fetal cytomegalovirus infection: diagnosis, management, and prevention

Congenital cytomegalovirus infection is a major cause of central nervous system and sensory impairments that affect cognition, motor function, hearing, language development, vestibular function, and vision. Although the importance of congenital cytomegalovirus infection is readily evident, the vast majority of maternal and fetal infections are not identified, even in developed countries. Multiple studies of prenatal cytomegalovirus infections have produced a body of knowledge that can inform the clinical approach to suspected or proven maternal and fetal infection. Reliable diagnosis of cytomegalovirus infection during pregnancy and accurate diagnosis of fetal infection are a reality. Approaches to preventing the transmission of cytomegalovirus from mother to fetus and to the treatment of fetal infection are being studied. There is evidence that public health approaches based on hygiene can dramatically reduce the rate of primary maternal cytomegalovirus infections during pregnancy. This review will consider the epidemiology of congenital cytomegalovirus infection, the diagnosis and management of primary infection during pregnancy, and approaches to preventing maternal infection.

The winding road to understanding the neonatal origins of inflammatory gastrointestinal disorders

Beginning with the observation that birth weight correlates with increased risk of cardiovascular disease, the concept of neonatal programming, that the environmental influence on fetal and neonatal development results in modification of the risk profile for adult disease, has begun to emerge as an important component to understanding the origin of chronic diseases of many different organ systems. Until recently, the gastrointestinal system has not been considered. Our understanding of the pathogenesis of many intestinal inflammatory disorders is still incomplete; however, a brief review of what is known reveals several opportunities for the early intraluminal environment to affect the development of the intestinal immune system. Early clinical observations such as the increased risk of celiac disease observed in those born by cesarean section and the protective effect of breast-feeding against inflammatory bowel disease and celiac disease support the role of neonatal programming in the development of chronic inflammatory gastrointestinal disease. Additional, more robust clinical studies are needed to confirm this role. Furthermore, examination of the possible mechanisms of immune phenotype modification is necessary.

Viruses - from pathogens to vaccine carriers

Vaccination is mankind's greatest public health success story. By now vaccines to many of the viruses that once caused fatal childhood diseases are routinely used throughout the world. Traditional methods of vaccine development through inactivation or attenuation of viruses have failed for some of the most deadly human pathogens, necessitating new approaches. Genetic modification of viruses not only allows for their attenuation but also for incorporation of sequences from other viruses, turning one pathogen into a vaccine carrier for another. Recombinant viruses have pros and cons as vaccine carriers, as discussed below using vectors based on adenovirus, herpesvirus, flavivirus, and rhabdovirus as examples.

Guidelines on CMV congenital infection

Congenital cytomegalovirus (CMV) infection occurs in 0.6-0.7% of all newborns and is the most prevalent infection-related cause of congenital neurological handicap. Vertical transmission occurs in around 30% of cases, but the fetus is not always affected. Symptomatic newborns at birth have a much higher risk of suffering severe neurological sequelae. Detection of specific IgG and IgM and IgG avidity seem to be the most reliable tests to identify a primary infection but interpretation in a clinical context may be difficult. If a seroconversion is documented or a fetal infection is suspected by ultrasound markers, an amniocentesis should be performed to confirm a vertical transmission. In the absence of a confirmed fetal infection with fetal structural anomalies, a pregnancy termination should be discouraged. Fetal prognosis is mainly correlated to the presence of brain damage. Despite promising results with the use of antiviral drugs and CMV hyperimmune globulin (HIG), results have to be interpreted with caution. Pregnant women should not be systematically tested for CMV during pregnancy. Managing CMV screening should be restricted to pregnancies where a primary infection is suspected or among women at high risk. The magnitude of congenital CMV disease and the value of interventions to prevent its transmission or to decrease the sequelae need to be established before implementing public health interventions. In this paper, aspects of CMV infection in the pregnant woman and her infant are reviewed.

Washing our hands of the congenital cytomegalovirus disease epidemic

Background

Each year in the United States, an estimated 40,000 children are born with congenital cytomegalovirus (CMV) infection, causing an estimated 400 deaths and leaving approximately 8000 children with permanent disabilities such as hearing or vision loss, or mental retardation. More children are affected by serious CMV-related disabilities than by several better-known childhood maladies, including Down syndrome, fetal alcohol syndrome, and spina bifida.

Discussion

Congenital CMV is a prime target for prevention not only because of its substantial disease burden but also because the biology and epidemiology of CMV suggest that there are ways to reduce viral transmission. Because exposure to the saliva or urine of young children is a major cause of CMV infection among pregnant women, it is likely that good personal hygiene, especially hand-washing, can reduce the risk of CMV acquisition. Experts agree that such measures are likely to be efficacious (i.e., they will work if consistently followed) and the American College of Obstetricians and Gynecologists recommends that physicians counsel pregnant women about preventing CMV acquisition through careful attention to hygiene. However, because of concerns about effectiveness (i.e., Will women consistently follow hygienic practices as the result of interventions?), the medical and public health communities appear reluctant to embrace primary CMV prevention via improved hygienic practices, and educational interventions are rare. Current data on the effectiveness of such measures in preventing CMV infection are promising, but limited. There is strong evidence, however, that educational interventions can prevent other infectious diseases with similar transmission modes, suggesting that effective interventions can also be found for CMV. Until a CMV vaccine becomes available, effective educational interventions are needed to inform women about congenital CMV prevention.

Summary

Perhaps no single cause of birth defects and developmental disabilities in the United States currently provides greater opportunity for improved outcomes in more children than congenital CMV. Given the present state of knowledge, women deserve to be informed about how they can reduce their risk of CMV infection during pregnancy, and trials are needed to identify effective educational interventions.

Equid herpesvirus 1 infection of endothelial cells requires activation of putative adhesion molecules: an in vitro model

Antisera to activated equine endothelial cells, which detected surface molecules of 116 kD, 97 kD, 42 kD and 38 kD, were made to investigate the role of endothelial adhesion molecules in equid herpes virus 1 infection. These putative adhesion molecules could be induced by 17-beta oestradiol, chorionic gonadotrophin, or IL-2, as well as by LPS and PWM. In an in vitro flow system, using equine veins or arteries, equid herpesvirus 1 in leucocytes was only transferred to infect endothelial cells if both leucocytes and endothelial cells expressed these surface molecules. Blocking of the membrane molecules with polyclonal antibodies prevented transfer of virus to the endothelial cells, indicating that the adhesion molecules had a key role in effecting transfer of virus. These in vitro observations give particular insight into the reports that in the natural course of infection in horses infection of endothelial cells is restricted to certain tissues, and in a wider context the results illustrate the complexity of factors that may direct tissue tropism.

Investigation of stillbirth

The pathologic investigation of stillbirth is often frustrating, and may be viewed as unrewarding, because the reason for death of the infant frequently is not identifiable. This outline attempts to identify an approach to the examination of the stillborn and accompanying placenta, with appropriate use of ancillary studies that may uncover the cause of death and/or identify factors that could prejudice future pregnancies.

Report on a long-term study of maternal and congenital cytomegalovirus infection in Sweden. Review of prospective studies available in the literature

This report summarizes knowledge accumulated in a long-term study of congenital and maternal cytomegalovirus (CMV) infection in Sweden. Some new findings are included. We considered diagnostic methods, sources of maternal infection (including occupational risks), roles of primary and secondary maternal infections, transmission to foetuses, incidence, symptoms and prognosis of established congenital infection and relative importance of such infection in infantile sensorineural deafness, microcephaly and type 1 diabetes mellitus. Virus isolation testing was done 1977-1985 on 16,474 newborns. 76 (0.5%) congenitally infected infants were found, 22/76 (29%) with transient neonatal symptoms and 11/60 (18%) with neurological symptoms by the age of 7 y. Type of maternal CMV infection was serologically determined in 62/76 cases (30 primary, 32 secondary). CNS disturbances in the infants occurred after both primary (all trimesters) and secondary maternal infections. The negative potential of secondary maternal infections might be an obstacle to preventive vaccination.

Permissive cytomegalovirus infection of primary villous term and first trimester trophoblasts

Forty percent of women with primary cytomegalovirus (CMV) infections during pregnancy infect their fetuses with complications for the baby varying from mild to severe. How CMV crosses the syncytiotrophoblast, the barrier between maternal blood and fetal tissue in the villous placenta, is unknown. Virus may cross by infection of maternal cells that pass through physical breaches in the syncytiotrophoblast or by direct infection of the syncytiotrophoblast, with subsequent transmission to underlying fetal placental cells. In this study, we show that pure (>99.99%), long-term and healthy (>3 weeks) cultures of syncytiotrophoblasts are permissively infected with CMV. Greater than 99% of infectious progeny virus remained cell associated throughout culture periods up to 3 weeks. Infection of term trophoblasts required a higher virus inoculum, was less efficient, and progressed more slowly than parallel infections of placental and human embryonic lung fibroblasts. Three laboratory strains (AD169, Towne, and Davis) and a clinical isolate from a congenitally infected infant all permissively infected trophoblasts, although infection efficiencies varied. The infection of first trimester syncytiotrophoblasts with strain AD169 occurred at higher frequency and progressed more rapidly than infection of term cells but less efficiently and rapidly than infection of fibroblasts. These results show that villous syncytiotrophoblasts can be permissively infected by CMV but that the infection requires high virus titers and proceeds slowly and that progeny virus remains predominantly cell associated.

Infectious causes of hydrops fetalis

A variety of infectious agents have been associated with nonimmune hydrops fetalis, most notably parvovirus B19, cytomegalovirus, herpes simplex virus, Toxoplasma gondii, and Treponema pallidum. These agents produce hydrops through effects on fetal bone marrow, myocardium, or vascular endothelium. Knowledge of the epidemiology and clinical characteristics of maternal and fetal infection can be used to select a diagnostic approach. Etiologic diagnosis will guide prognosis and the selection of specific chemotherapy.

Lymphocyte responses and virus excretion as risk factors for intrauterine infection with cytomegalovirus

Serological screening of pregnant women in this and a previous study identified 28 cases of primary infection with cytomegalovirus, 7 (25%) of whom transmitted the infection to their fetuses. Risk factors for intrauterine infection were: 1) age less than 20 years, 2) Caucasian rather than non-Caucasian race, 3) a weak response to cytomegalovirus antigen in the lymphocyte transformation test, and 4) the excretion of cytomegalovirus in the urine. The greatest risk was when a weak lymphoproliferative response was detected in combination with a positive result for virus isolation, in which case the chance of fetal infection was 83%. Despite these associations, there was one important anomalous result of a woman who demonstrated a strong lymphocyte response during pregnancy and a negative result for virus isolation, but who gave birth to an infected baby who developed unilateral hearing loss.

Ganciclovir therapy of congenital cytomegalovirus disease

A newborn with cytomegalovirus disease with cerebral involvement was treated with ganciclovir for 21 days. The treatment resulted in only temporary cessation of virus shedding in the urine and probably had no ameliorating effect on the long-term clinical outcome.

Congenital cytomegalovirus infection in a twin pregnancy: a case report

A case of congenital cytomegalovirus infection in a twin pregnancy is described, causing neonatal death in one of the infants whereas the other survived without major complications. The possible mechanisms involved are discussed.

Porcine cytomegalovirus (PCMV) in early gestation

Following intranasal exposure to PCMV at or within 48 h of coitus transplacental infection occurred in two groups of gilts. Five out of 22 embryos were infected in the first group but only 2 out of 63 in the second. A more rapid immune response as measured by circulating antibody was probably instrumental in abrogating infection in the second group. In the infected embryos the virus localized in leptomeningeal cells, hepatic sinusoidal cells, peritoneal macrophages, periosteal cells and occasional alveolar cells, but the placenta did not appear to be a primary site of viral replication.

Young children as a probable source of maternal and congenital cytomegalovirus infection

To identify possible sources of cytomegalovirus infection in pregnant women, we studied seven families with a recent case of congenital or maternal cytomegalovirus infection and a history of maternal contact with a young child shedding the virus. We used restriction-endonuclease techniques to compare the DNA of viral isolates collected from family members. Five families contained an infant who had congenital or perinatal infection, a mother who had had evidence of primary infection during her most recent pregnancy, and a child less than three years of age who was excreting cytomegalovirus. All five of the young children attended day-care centers at least part-time. In each of these five families, strains from family members were identical, and it is most likely that the toddler-aged child was the source of the virus for both the mother and the fetus or infant. In two other families, acquisition of cytomegalovirus by children in a day-care center was followed by seroconversion in the mother along with excretion of a strain of the virus identical to that in her child, as demonstrated by restriction-endonuclease analysis. Five of the seven fathers were tested for antibody to cytomegalovirus; four were seronegative, ruling them out as a source of infection in the mothers. These results not only strengthen evidence for the transmission of cytomegalovirus from child to mother but also indicate that infections acquired by a mother from a child can be transmitted to her fetus.

Examination of products of conception terminated after prenatal investigation

A large number of district general hospitals have access to diagnostic ultrasonography and other methods of prenatal diagnosis, resulting in an increased supply of freshly terminated malformed fetuses to general histopathology departments, and there is now more open discussion of malformation and greater concern over fetal wastage. General pathologists are therefore under greater pressure to produce complete and detailed descriptions of a wide range of often complex anomalies. The dismissal of specimens as "multiple congenital anomalies" is becoming increasingly unacceptable to couples who wish to embark on further pregnancies and to their medical attendants. As in other fields an understanding of the methods and terminology in clinical use and a consistent diagnostic approach should help pathologists to extract sufficient information for accurate counselling.

A developmental approach to sensory disabilities in early childhood

Rehabilitation for young children with hearing and visual disabilities is considered from a developmental angle. The effect of these sensory disabilities on parents; the constraints on development imposed by each disability; and medical and surgical treatment and the use of aids in young children are discussed.

Congenital cytomegalovirus infection

Clinical details of 50 infants with congenital cytomegalovirus infection identified in a prospective study are reported. The mean birthweight, gestational age, and head circumference of children with congenital cytomegalovirus infection were not significantly different from those of controls. Three (6%) had symptoms at birth--two neurological and one pneumonitis. In the first four months of life transient hepatosplenomegaly occurred in two infected children and six suffered interstitial pneumonitis. Three congenitally infected children have major neurological handicaps including spastic quadriplegia, microcephaly, and psychomotor delay, and five (10%), including the one with quadriplegia, have sensorineural deafness which is bilateral in three (6%). Estimates based on these findings suggest that the impact of congenital cytomegalovirus infection is comparable to that of congenital rubella in the era before vaccination. Of the 42 children where the nature of maternal infection was classifiable, congenital infection followed primary maternal infection in 32 (76%) and recurrent infection in 10 (24%). Neurological defects followed exposure to primary maternal infection in all three trimesters of pregnancy and also recurrent maternal infection.

A prospective study of primary cytomegalovirus infection during pregnancy: final report

In a 7-year prospective study cytomegalovirus (CMV) was shown to infect approximately twice as many pregnant women as did rubella virus. Fetal loss occurred in 4/26 (15%) early CMV infections which was seven-fold higher than the rate found in controls (16/744; 2.2%). There was no evidence that fetal loss resulted from intrauterine transmission of virus. Fifty-eight women experienced primary CMV infection and congenital infection was found in nine (20%) of the 46 infants from whom clinical samples were obtained. Transmission of virus was found in 20%, 0% and 40% in the first, second and third trimesters respectively. All babies were normal at birth but two have so far developed definite intellectual impairment attributable to cytomegalovirus infection. The mothers of both of these cases were infected after the fetus had become legally viable. We conclude that the lessons learned from studying rubella infection during pregnancy cannot be applied to cytomegalovirus; in particular, we could find no evidence that termination of pregnancy should be offered to women with early CMV infections.

Intra-uterine transmission of cytomegalovirus in women known to be immune before conception

A prospective study identified 785 pregnant women who had been shown to possess complement fixing antibodies against cytomegalovirus (CMV) during a previous pregnancy. As these women were thus known to have been immune prior to their subsequent conception, their neonates were examined for evidence of congenital CMV infection. Specimens were obtained from 725 (92%) of the neonates and congenital infection was found in only one (0.14%). The elder sister of the infected child was also shown, by retrospective testing of her stored cord serum for specific IgM antibodies, to have been infected in utero. Thus, one woman was identified who had delivered consecutive siblings congenitally infected with CMV. We conclude that some women have a propensity for intra-uterine transmission of CMV, despite being immune prior to conception, and speculate that such women may have acquired their infections perinatally.