Prospective study of cytomegalovirus infection in pregnancy

Congenital Cytomegalovirus Infection Burden and Epidemiologic Risk Factors in Countries With Universal Screening: A Systematic Review and Meta-analysis

IMPORTANCE

Congenital cytomegalovirus (cCMV) infection is the most common congenital infection and the leading acquired cause of developmental disabilities and sensorineural deafness, yet a reliable assessment of the infection burden is lacking.

OBJECTIVES

To estimate the birth prevalence of cCMV in low- and middle-income countries (LMICs) and high-income countries (HICs), characterize the rate by screening methods, and delineate associated risk factors of the infection.

DATA SOURCES

MEDLINE/PubMed, Scopus, and Cochrane Database of Systematic Reviews databases were searched from January 1, 1960, to March 1, 2021, and a total of 1322 studies were identified.

STUDY SELECTION

Studies that provided data on the prevalence of cCMV derived from universal screening of infants younger than 3 weeks were included. Targeted screening studies were excluded.

DATA EXTRACTION AND SYNTHESIS

Preferred Reporting Items for Systematic Reviews and Meta-analyses guideline was followed. Extraction was performed independently by 3 reviewers. Quality was assessed using the Newcastle-Ottawa Scale for cohort studies. Random-effects meta-analysis was undertaken. Metaregression was conducted to evaluate the association of sociodemographic characteristics, maternal seroprevalence, population-level HIV prevalence, and screening methods with the prevalence of cCMV.

MAIN OUTCOMES AND MEASURES

Birth prevalence of cCMV ascertained through universal screening of infants younger than 3 weeks for CMV from urine, saliva, or blood samples.

RESULTS

Seventy-seven studies comprising 515 646 infants met the inclusion criteria from countries representative of each World Bank income level. The estimated pooled overall prevalence of cCMV was 0.67% (95% CI, 0.54%-0.83%). The pooled birth prevalence of cCMV was 3-fold greater in LMICs (1.42%; 95% CI, 0.97%-2.08%; n = 23 studies) than in HICs (0.48%; 95% CI, 0.40%-0.59%, n = 54 studies). Screening methods with blood samples demonstrated lower rates of cCMV than urine or saliva samples (odds ratio [OR], 0.38; 95% CI, 0.23-0.66). Higher maternal CMV seroprevalence (OR, 1.19; 95% CI, 1.11-1.28), higher population-level HIV prevalence (OR, 1.22; 95% CI, 1.05-1.40), lower socioeconomic status (OR, 3.03; 95% CI, 2.05-4.47), and younger mean maternal age (OR, 0.85; 95% CI, 0.78-0.92, older age was associated with lower rates) were associated with higher rates of cCMV.

CONCLUSIONS AND RELEVANCE

In this meta-analysis, LMICs appeared to incur the most significant infection burden. Lower rates of cCMV were reported by studies using only blood or serum as a screening method.

Infections in Pregnancy

Infections during pregnancy may affect a developing fetus. If left untreated, these infections can lead to the death of the mother, fetus, or neonate and other adverse sequelae. There are many factors that impact infection during pregnancy, such as the immune system changes during pregnancy, hormonal flux, stress, and the microbiome. We review some of the outcomes of infection during pregnancy, such as preterm birth, chorioamnionitis, meningitis, hydrocephaly, developmental delays, microcephaly, and sepsis. Transmission routes are discussed regarding how a pregnant woman may pass her infection to her fetus. This is followed by examples of infection during pregnancy: bacterial, viral, parasitic, and fungal infections. There are many known organisms that are capable of producing similar congenital defects during pregnancy; however, whether these infections share common mechanisms of action is yet to be determined. To protect the health of pregnant women and their offspring, additional research is needed to understand how these intrauterine infections adversely affect pregnancies and/or neonates in order to develop prevention strategies and treatments.

High seropositivity of IgG and IgM antibodies against cytomegalovirus (CMV) among HIV-1 seropositive patients in Ilorin, Nigeria

BACKGROUND

Human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) is a major public health problem in sub-saharan Africa. Cytomegalovirus (CMV) has been reported to enhance HIV replication and accelerate the progression of HIV infection to AIDS.

OBJECTIVE

This study reports on the high seropositivity of immunoglobulin (Ig) G and M antibodies against CMV and the risk factors for CMV infection among HIV/AIDS patients in Ilorin, Nigeria.

METHOD

A total of 180 consented HIV-1 seropositive patients (age-range 16-56 years; 108 females and 72 males) were consecutively recruited. Socio-demographic/behavioral data and 5 ml blood samples were collected from each patient. Plasma of each sample was assayed for anti-CMV IgG/IgM using a CMV IgG and IgM Enzyme Linked ImmunoSorbent Assay (ELISA) kit.

RESULTS

Twenty (11.1%) of the 180 HIV-1 seropositive subjects were positive for anti-CMV IgM antibody while 169(93.9%) were positive for anti-CMV IgG antibody. Age, marital status, number of sexual partners, CD4 cells counts and previous history of blood transfusion were the main correlates of CMV seropositivity among these patients. However, occupation, sex, highly active antiretroviral therapy (HAART) were not statistically associated with CMV seropositivity in this study.

CONCLUSION

This study has shown that greater percentages of HIV-1 seropositive patients had active CMV infection. It has further shown that CMV is hyperendemic in HIV-1 seropositive patients in Ilorin, Nigeria.

Autism spectrum disorder in children born preterm-role of exposure to perinatal inflammation

Autism Spectrum Disorder (ASD) is the collective term for neurodevelopmental disorders characterized by qualitative impairments in social interaction, communication, and a restricted range of activities and interests. Many countries, including Australia, have reported a dramatic increase in the number of diagnoses over the past three decades, with current prevalence of ASD at 1 in every 110 individuals (~1%). The potential role for an immune-mediated mechanism in ASD has been implicated by several studies, and some evidence suggests a potential link between prenatal infection-driven inflammation and subsequent development of ASD. Furthermore, a modest number of contemporary studies have reported a markedly increased prevalence of ASD in children born preterm, who are at highest risk of exposure to perinatal inflammation. However, the mechanisms that underpin the susceptibility to infection-driven inflammation during pregnancy and risk of preterm birth, and how these intersect with the subsequent development of ASD in the offspring, is not understood. This review aims to summarize and discuss the potential mechanisms and evidence for the role of prenatal infection on the central nervous system, and how it may increase the susceptibility for ASD pathogenesis in children born preterm.

The "silent" global burden of congenital cytomegalovirus

Human cytomegalovirus (CMV) is a leading cause of congenital infections worldwide. In the developed world, following the virtual elimination of circulating rubella, it is the commonest nongenetic cause of childhood hearing loss and an important cause of neurodevelopmental delay. The seroprevalence of CMV in adults and the incidence of congenital CMV infection are highest in developing countries (1 to 5% of births) and are most likely driven by nonprimary maternal infections. However, reliable estimates of prevalence and outcome from developing countries are not available. This is largely due to the dogma that maternal preexisting seroimmunity virtually eliminates the risk for sequelae. However, recent data demonstrating similar rates of sequelae, especially hearing loss, following primary and nonprimary maternal infection have underscored the importance of congenital CMV infection in resource-poor settings. Although a significant proportion of congenital CMV infections are attributable to maternal primary infection in well-resourced settings, the absence of specific interventions for seronegative mothers and uncertainty about fetal prognosis have discouraged routine maternal antibody screening. Despite these challenges, encouraging results from prototype vaccines have been reported, and the first randomized phase III trials of prenatal interventions and prolonged postnatal antiviral therapy are under way. Successful implementation of strategies to prevent or reduce the burden of congenital CMV infection will require heightened global awareness among clinicians and the general population. In this review, we highlight the global epidemiology of congenital CMV and the implications of growing knowledge in areas of prevention, diagnosis, prognosis, and management for both low (50 to 70%)- and high (>70%)-seroprevalence settings.

Review of cytomegalovirus seroprevalence and demographic characteristics associated with infection

Cytomegalovirus establishes a lifelong latent infection following primary infection that can periodically reactivate with shedding of infectious virus. Primary infection, reactivation and reinfection during pregnancy can all lead to in utero transmission to the developing fetus. Congenital CMV infections are a major cause of permanent hearing loss and neurological impairment. In this literature review, we found that CMV infection was relatively common among women of reproductive age, with seroprevalence ranging from 45 to 100%. CMV seroprevalence tended to be highest in South America, Africa and Asia and lowest in Western Europe and United States. Within the United States, CMV seroprevalence showed substantial geographic variation as well, differing by as much as 30 percentage points between states, though differences might be explained by variation in the types of populations sampled. Worldwide, seroprevalence among non-whites tended to be 20-30 percentage points higher than that of whites (summary prevalence ratio (PR) = 1.59, 95% confidence interval (CI) = 1.57-1.61). Females generally had higher seroprevalences than males, although in most studies the differences were small (summary PR = 1.13, 95% CI = 1.11-1.14). Persons of lower socioeconomic status were more likely to be CMV seropositive (summary PR = 1.33, 95% CI = 1.32-1.35). Despite high seroprevalences in some populations, a substantial percentage of women of reproductive age are CMV seronegative and thus at risk of primary CMV infection during pregnancy. Future vaccine or educational campaigns to prevent primary infection in pregnant women may need to be tailored to suit the needs of different populations.

Virological and immunological correlates of mother-to-child transmission of cytomegalovirus in The Gambia

BACKGROUND

Cytomegalovirus (CMV) is the most common congenital infection and can follow primary and recurrent maternal infection. We studied correlates of vertical transmission of CMV in The Gambia, where most children acquire CMV during the first year of life.

METHODS

A cohort of 281 mothers and infants was recruited at birth. Infants were prospectively followed up for CMV infection during the first year of life. Excretion of CMV and antiviral immune response were studied at birth in mothers of children infected in utero, early during infancy, or late during infancy or not infected at 1 year of age.

RESULTS

Congenital infection was diagnosed in 3.9% of newborns, and 85% of children were infected by 1 year. Excretion of CMV in colostrum or in the genital tract was more common in mothers of congenitally (100%) or early infected children (48%) than in mothers of late-infected (20%) or uninfected children (27%). Higher rates of viral excretion were associated with significantly higher levels of serum anti-CMV immunoglobulin G and higher frequencies of CMV-specific CD4+ T cells.

CONCLUSION

In the context of recurrent maternal infection, transmission of CMV in utero and during early postnatal life is associated with excretion of the virus in colostrum and the genital tract.

Natural history of perinatal cytomegaloviral infection

Epidemiological data presented here indicate that cytomegaloviral (CMV) infection is one of the most common perinatal infections found in human beings. Transmission to the offspring occurs in utero at birth and postnatally. Intrauterine infection results from primary or recurrent maternal involvement, the latter being more common in populations where infection is initially acquired during childhood or adolescence, such as in low socioeconomic settings. Congenital infection is usually subclinical with either type of maternal involvement but primary infection has a greater tendency to produce disease in the fetus. About 20% of the offspring infected in utero are damaged, infrequently with generalized disease, but more often with auditory involvement. The latter can develop in utero or postnatally and can be progressive. The major cause of recurrent maternal infection according to restriction enzyme analysis is reactivation of latent virus, which occurs in the face of substantial maternal humoral immunity, even with intrauterine transmission of virus. Reinfection by exogenous virus remains a lesser possibility for maternal recurrences. Even more commonly, CMV can be transmitted at birth from the infected maternal genital tract and postnatally through infected breast milk, especially in highly immune populations. With the possible exception of early pneumonia, these infections appear to be innocuous.

Review and meta-analysis of the epidemiology of congenital cytomegalovirus (CMV) infection

We reviewed studies that reported results of systematic cytomegalovirus (CMV) screening on fetuses and/or live-born infants. The overall birth prevalence of congenital CMV infection was 0.64%, but varied considerably among different study populations. About 11% of live-born infants with congenital CMV infection were symptomatic, but the inter-study differences in definitions of symptomatic cases limit the interpretation of these data. Non-white race, low socioeconomic status (SES), premature birth, and neonatal intensive care unit admittance were risk factors for congenital CMV infection. Birth prevalence increased with maternal CMV seroprevalence. Maternal seroprevalence accounted for 29% of the variance in birth prevalence between study populations. Maternal seroprevalence and birth prevalence were both higher in study populations that were ascertained at birth rather than in the prenatal period. Thus, timing of ascertainment should be considered when interpreting birth prevalence estimates. Birth prevalence was inversely correlated with mean maternal age, but this relationship was not significant when controlling for maternal seroprevalence. The rate of transmission to infants born to mothers who had a primary infection or a recurrent infection during pregnancy was 32% and 1.4%, respectively. Possible maternal primary infections (i.e. seropositive mother with CMV IgM) resulted in congenital infections about 20% of the time, but are likely to represent a mixture of primary and recurrent infections. In summary, CMV is a common congenital infection worldwide that can lead to permanent disabilities. There is an urgent need for interventions that can reduce the substantial burden of this often overlooked disease.

Brief report: autistic disorder in three children with cytomegalovirus infection

Previous research has identified a relationship between autistic disorder (autism) and specific congenital infections. Three cases of congenital or perinatal cytomegalovirus (CMV) infection occurring in association with autism are described. Hypothetical mechanisms relating congenital infection, such as CMV, to the development of autism are discussed. A better understanding of the immunologic response to certain congenital infections may provide important information pertaining to the pathophysiology and etiology of autism in vulnerable individuals.

Use of serial maternal urine cytomegalovirus PCR to detect primary CMV infection in seronegative pregnant women

The aim of the study was to determine if serial maternal urine polymerase chain reaction (PCR) tests can detect primary CMV infection during pregnancy. This was a prospective study conducted from 1 January 1999 to 31 December 1999 in an antenatal clinic setting of a teaching hospital. The study group included women who were CMV IgG negative and aged <30 years or had a pre-school child. They were invited to self-collect urine samples monthly and send them to the laboratory by post. Cord bloods were tested for CMV IgG to detect seroconversion. An anxiety questionnaire was sent to all study participants. At first attendance, 1549 (42%) women were CMV IgG negative. Of the 696 eligible women, 609 (88%) participated in the urine PCR study. PCR was performed on 2263 urine samples (median of 4/pregnancy). Primary CMV infection was identified in one woman by urine PCR at 36 weeks (baby CMV negative). Cord blood samples were available from 152/609 infants (25%). Seroconversion was noted in only one woman. Replies to the questionnaire were received from 264/609 women (43%): 214 (81%) had little or no anxiety, and 220 (83%) felt reassured by their study participation. Serial urine PCR is a feasible method of detecting primary maternal CMV infection during pregnancy which has potential for evaluation in further studies.

Cytomegalovirus hepatitis in late pregnancy

A case of pregnancy complicated by cytomegalovirus hepatitis is represented. The mother had a fulminant disease, but she delivered spontaneously at 31 weeks of gestation. The baby was unaffected.

Recurrent cytomegalovirus infection during pregnancy: ultrasonographic diagnosis and fetal outcome

Fetal infection as a consequence of recurrent disease is uncommon. We present a case of recurrent cytomegalovirus infection in the second trimester of pregnancy. Fetal infection was detected through severely abnormal findings on ultrasound examination and verified by detecting cytomegalovirus DNA in the amniotic fluid and cytomegalovirus-specific immunoglobulin M antibodies in the fetal blood and associated pancytopenia. Because of the severity of the infection, a fatal outcome was predicted. A Cesarean section was performed at 33+5 weeks of gestation; the child died shortly after birth.

Congenital cytomegalovirus infection: review of the epidemiology and outcome

Cytomegalovirus (CMV) is one of the most common viral causes of congenital infection. A future decision to lower its incidence by vaccination will depend on epidemiological conditions within a country and on the safety of the vaccine to be used, because a life vaccine may cause latency and subsequent reactivation that still may harm the fetus. The aim was to review the epidemiological studies published so far, with respect to factors that affect the incidence of congenital CMV infection, and factors that may influence its outcome, such as preexisting maternal immunity. The study included the data of 19 studies that were retrieved from a MEDLINE search during the period 1977 to 1997. The incidence of congenital CMV infection varied between 0.15% and 2.0% and seemed to correlate with the level of preexisting immunity in the population. Although preexisting maternal immunity was reported to strongly reduce transmission, the severity of congenital CMV infection (symptoms at birth and or sequelae later in life) was not significantly greater after virus transmission due to a primary infection of the mother as compared with recurrence or reinfection. The data indicate that preexisting immunity of the mother does not significantly mitigate the outcome of congenital infection. Moreover, life vaccines may bear a serious risk when transmittable to the fetus.

TARGET AUDIENCE

Obstetricians and Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this article, the reader will be able to describe the natural course of a CMV infection, to list the potential sequelae of a congenital CMV infection, to outline potential strategies to prevent transmission of CMV, and to summarize the diagnostic work up of a patient with a potential CMV infection.

Screening and diagnosis of congenital cytomegalovirus infection: a 5-y study

Although cytomegalovirus infection is the most common infection transmitted via the placenta, there are no guidelines for routine screening to detect children congenitally infected with cytomegalovirus. From 1993 to 1997, maternal serum and cord vein blood of newborns was screened for HCMV-IgM (n = 21,183). Urine was examined for HCMV-excretion during the first postnatal week to prove HCMV infection in children who expressed HCMV-IgM in cord vein blood (n = 13) or who were born to mothers positive for HCMV-IgM in the serum (n = 234), or when both cord vein blood and maternal serum were positive for HCMV-IgM (n = 6). Congenital HCMV infection was detected in 17 newborns. To determine the incidence of congenital HCMV infection, only those mother/child pairs were selected in whom serum and cord vein blood were investigated (n = 5967 mother/child pairs). In this group 13 newborns were infected. The observed incidence for congenital HCMV infection is 0.21%. It is concluded that that this screening programme will detect those children at risk for congenital HCMV infection. These children have to be examined for virus excretion in the urine. Although the observed incidence is only 0.21%, congenital HCMV infection is a problem that can no longer be neglected because of its long-term sequelae.

Pathogenesis of HSV and CMV Infections in Pregnancy

Human herpesvirus (HHSV) and human cytomegalovirus (HCMV) infections during pregnancy are a major concern of public health because of the risk for severe sequelae for the fetuses and the neonates and because primary infections, reinfections and reactivations can be asymptomatic. The risk for neonatal herpes is mostly congenital, while the risk for HCMV infection is either prenatal or congenital. Screening exposed women has not brought definite solutions but is currently being evaluated. Among pregnant women with active infection, evaluation of the fetus for contamination and thus for the risk for severe immediate or long-term sequelae for neonates is the major goal. Diagnostic tools are available, cell culture still being the gold standard, and polymerase chain reaction (PCR) being currently evaluated for its contribution to diagnosis of active infection. Consensus for screening pregnant women as well as achievement of antiviral vaccines are the most urgent intervention strategies to develop in the near future.

Congenital cytomegalovirus infection

OBJECTIVE

Congenital cytomegalovirus is the most common viral infection affecting approximately 1% of newborns. The virus can be transmitted to the fetus during both primary and recurrent infection. Although most of the infants are asymptomatic at birth, up to 15% develop late complications. The annual cost of treating cytomegalovirus infection complications in the USA is two billion US dollars. Many issues regarding cytomegalovirus infection such as routine screening, antenatal diagnosis and vaccination during pregnancy are unsettled and disputed. The aim of this article is to review the current literature on the subject and to draw some conclusions.

DESIGN

Review of the current literature.

CONCLUSIONS

At present, it appears that there is no indication for routine prenatal screening, while other issues, such as the most accurate method for antenatal diagnosis and the indications for pregnancy termination are, as yet, unsettled.

Serological evaluation of the role of cytomegalovirus in the pathogenesis of IDDM: a prospective study. The Childhood Diabetes in Finland Study Group

To study the possible temporal association between primary cytomegalovirus infection and the appearance of islet cell autoantibodies or the development of insulin-dependent diabetes mellitus (IDDM) cytomegalovirus antibodies were analysed from follow-up sera of 46 initially non-diabetic siblings of diabetic children who either manifested clinical IDDM (22 siblings) or turned islet cell antibody positive (24 siblings) during the prospective observation (mean follow-up time 2.9 years). Secondly, cytomegalovirus antibodies were analysed during pregnancy in 96 mothers whose child presented with IDDM before the age of 7 years and in 96 control mothers who gave birth to a non-diabetic child. Thirdly, a case-control series including 90 newly-diagnosed young children with IDDM and their 90 control subjects was analysed. No seroconversions were found in cytomegalovirus antibodies during the follow-up of the 46 siblings indicating no temporal association with islet cell antibody seroconversion or manifestation of clinical diabetes. During the follow-up 17 (37%) siblings were constantly seronegative and 29 (63%) seropositive for cytomegalovirus IgG and there was no difference between islet cell antibody positive and negative siblings. Cytomegalovirus IgG and IgM were not different in pregnant mothers who gave birth to a subsequently diabetic child compared to control mothers, or in newly-diagnosed diabetic children compared to control children. Cytomegalovirus IgA was higher in newly-diagnosed diabetic children than in control children (p < 0.005). This difference disappeared when only cytomegalovirus IgG positive individuals were analysed. No correlation was found between islet cell antibodies and cytomegalovirus antibodies in newly-diagnosed diabetic patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Fetal and neonatal thrombocytopenia

Thrombocytopenia is defined as platelet count less than 150,000 plat/mm3. Etiologic factors involved include immunological (NAIT and ITP), fetal infectious disease, chromosomal and nonchromosomal, and miscellaneous causes. While the understanding of fetal thrombocytopenia is driven by reason to do fetal blood sampling, discovery of neonatal thrombocytopenia is driven by blood counts performed because of the risk of infections. The most serious consequence of thrombocytopenia in the fetus/neonate is intracranial hemorrhage which can occur in utero as early as 18 weeks gestation. The key factor in perinatal prevention of intracranial hemorrhage is early diagnosis and treatment, possibly in utero. Cordocentesis under direct ultrasound guidance and platelet transfusions have played a major role in the management of fetal/neonatal thrombocytopenia. Ongoing studies and high resolution ultrasound will continue to explore and hopefully clarify fetal and neonatal thrombocytopenia and facilitate recognition of primary and secondary thrombocytopenias.

Role of breast milk in acquisition of cytomegalovirus infection

The prevalence of IgG antibody against cytomegalovirus (CMV) was compared between the age-matched (0 month to 2 years of age) groups of 212 breast-fed children and 223 bottle-fed children to examine the role of breast milk for acquisition of CMV. Mothers of both groups of children were also examined for CMV IgG antibodies. Both the breast-fed and bottle-fed children groups showed high seropositivity for CMV at 0 to 2 months of age, which gradually decreased and bottomed at 6 to 8 months of age. Thereafter, in the breast-fed children group, the seropositivity rate increased up to 70% by 1 year of age. In contrast, in the bottle-fed children group, the seropositivity rate remained at the bottom level of lower than 30%, without showing any apparent increases. The serological data of the children whose mothers were confirmed to be seropositive, revealed that mother-to-child transmission of CMV occurred in 11 of 17 (64.7%) of the breast-fed children and in 24 of 87 (27.6%) of the bottle-fed children. All the bottle-fed children born to seronegative mothers remained seronegative for CMV up to 1 year of age. The bottle-fed children showed significantly lower seropositivity than the breast-fed children, although most of both groups of children were born to seropositive mothers. The results strongly suggested that about 40% of the breast-fed children acquire CMV via breast milk and breast-feeding has certain protective effects on congenital CMV disease in the offspring.

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.

Can cytomegalovirus cause brachydactyly? A case report and review of the literature

A child with the diagnosis of CMV infection associated with brachydactyly is presented. The case is interesting as, to our knowledge, no similar case has been reported up to the present. In our case, apart from CMV, no teratogenic factor which may cause brachydactyly could be detected.

Systemic viral infections and their retinal and choroidal manifestations

Viruses are one of the most common causes of infections involving the posterior segment of the eye. Such infections can occur either on a congenital or an acquired basis, and may affect primarily the retina or the choroid. Congenital cytomegalovirus (CMV) and rubella infections may result in retinitis. CMV retinitis is also the most common cause of acquired viral retinitis, primarily because of the acquired immunodeficiency syndrome (AIDS). Other types of viral retinitis, such as those caused by herpes simplex or herpes zoster, can occur in immunocompromised or immunocompetent individuals. Retinitis or choroiditis caused by viruses such as measles, influenza, Epstein-Barr virus, and Rift Valley fever virus, typically occurs subsequent to an acute viral systemic illness. The systemic and ocular manifestations, as well as the histopathology, laboratory tests, differential diagnoses, and treatment regimens for each of the individual viruses are discussed in detail.

Current management of cytomegalovirus disease

Cytomegalovirus (CMV) is an important pathogen for the fetus, for allograft recipients, and for acquired immunodeficiency syndrome (AIDS) patients; the clinical features in each of these groups of patients are described. CMV may also act as a cofactor to accelerate the rate at which the human immunodeficiency virus (HIV) causes AIDS. Active CMV infection in immunocompromised patients is best managed by routine laboratory screening of patients at risk using assays that provide prognostic information. Antiviral therapy can then be considered under one of four headings: For prophylaxis, the drug is given to all patients from a particular time point, e.g., time of transplantation. Successful trials have been reported for interferon (renal transplant), acyclovir (renal transplant and bone marrow transplant), and ganciclovir (heart transplant and bone marrow transplant). For suppression, the drug is given once CMV excretion has been detected in peripheral sites of particular patients. A successful trial of ganciclovir in bone marrow transplant patients has been reported. For pre-emptive therapy, the drug is given once CMV has been detected systemically. A successful trial of ganciclovir in bone marrow transplant patients has been reported. Regarding treatment, a controlled comparison of ganciclovir and foscarnet for CMV retinitis in AIDS patients has shown that both drugs are equally effective but that foscarnet has a survival benefit. Open studies suggest that the combination of immunoglobulin and ganciclovir is of benefit for treatment of established CMV pneumonitis. In open studies other treatments have been tried, with no clinical success, despite control of viral replication in some cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Prospective study on maternal, intrauterine, and perinatal infections with cytomegalovirus in Japan during 1976-1990

Since 1976, sera obtained serially from 10,218 pregnant women during the first, second, and third trimesters of gestation and cord sera were tested for CMV complement-fixing (CF) and immunofluorescent (IF) antibodies. CMV IgG-IF antibody was positive in 9,735/10,218 (95%) in the first trimester, and a significant rise of CF antibodies during pregnancy was found in 70/9,206 (0.76%) of the seropositive group and in 5/438 (1.14%) of the seronegative group. IgM antibody was found in 6/9,206 (0.06%) of seropositive women during the first trimester and in 7/70 (10.0%) of seropositive mothers with CF antibody rise and in 4/5 of seroconverted mothers of the seronegative group, suggesting that the incidence of primary infection with CMV during pregnancy was approximately 1% of susceptible women. All the mothers with immune response had infants with neither viruria nor IgM antibody in the cord blood, whereas seropositive mothers without an immune response had infants with viruria (7/1,826; 0.4%) or with IgM antibody in the cord blood (6/9,136; 0.06%). None of these 13 babies, shedding CMV or with IgM IF antibody, had physical or mental retardation. CMV IgG-IF antibody was present in almost 80% of infants between 7 and 12 months of age in 1988, suggesting that perinatal or postnatal CMV infection may occur in infants born to seropositive mothers in 70-80% of pregnancies.

Prevalence of cytomegalovirus infection in Italy

Between 1987 and 1989, the prevalence of antibody to cytomegalovirus (CMV) was determined, by the ELISA method, in serum samples from 1494 apparently healthy subjects, 3-18 years old. Subjects were selected by a systematic cluster sampling from five geographical areas in Italy. The overall prevalence of antibody was 64.2%, increasing from 54.4% in 4-6-year-olds to 73.3% in subjects 17-18 years old (P less than 0.01). Prevalence of antibody was significantly higher in females (P less than 0.05) and in subjects residing in the South of Italy (P less than 0.01). A significant association was found with sociodemographic factors. Subjects belonging to a household with six or more persons had a 1.5-fold risk (C.I. 95% = 1.11-2.04) and subjects whose fathers had less than 6 years of schooling had a 1.4-fold risk (C.I. 95% = 1.1-1.87) of previous exposure to CMV infection. The high prevalence (74.4%) of young women who are naturally immune when entering childbearing years does not guarantee that there will be a low risk of fetal infection.

Intrauterine diagnosis of cytomegalovirus and rubella infections by amniocentesis

OBJECTIVE

To establish a correlation between the presence of cytomegalovirus (CMV) or rubella virus in amniotic fluid obtained through amniocentesis and fetal infection.

DESIGN

Case series.

SETTING

Five hospitals in the Montreal region. Virology testing was done at the Virology Research Centre, Institut Armand-Frappier, Laval, Que.

PATIENTS

Thirteen pregnant women infected with CMV, 3 with rubella, their 15 babies and 2 fetuses. Twelve of the women with CMV infection were recruited from a prospective study of CMV infection in pregnancy. Infection in the other women was detected through routine laboratory diagnostic testing.

INTERVENTION

Amniotic fluid samples were cultured for CMV and rubella virus. Congenital infection of the neonates was established through isolation of either virus from pharyngeal mucus and urine specimens collected during the first 3 days of life or from fetal tissue if the pregnancy was terminated.

MAIN RESULTS

CMV was cultured from the amniotic fluid of three of the CMV-infected women and from the pharyngeal mucus and urine specimens of their infants. Of the three women with rubella the amniotic fluid of one (who had a twin pregnancy) was positive for rubella virus. After the in-utero death of one fetus she underwent a therapeutic abortion of both. Examination of fetal tissue indicated that both fetuses had been infected with rubella virus. Each of the two other women with rubella gave birth to an uninfected, healthy infant.

CONCLUSIONS

We found a strong correlation between the isolation of CMV or rubella virus from the amniotic fluid and the presence of congenital infection. This suggests that amniocentesis used to detect the presence of a virus is a useful method for the diagnosis of fetal infection.

Progressive hearing loss in children with congenital cytomegalovirus

Case studies of five children with congenital cytomegalovirus (CMV) who were referred for audiological evaluation are presented. Significant deterioration of hearing was noted in all cases within the first 4 years of life. It is essential that neonates with congenital CMV be referred for hearing assessment and that the child's hearing be monitored on a long-term basis. Early intervention is vital for the speech and language development of the hearing-impaired child.

Immune response to guinea pig cytomegalovirus polypeptides and cross reactivity with human cytomegalovirus

The immune response to guinea pig cytomegalovirus (gpCMV) was evaluated by immunoblotting. Preinoculation guinea pig plasma did not react with gpCMV antigen, whereas convalescent plasma reacted to at least 18 gpCMV-specific polypeptides. The initial immune response was primarily directed at polypeptides with MWs of 100, 75, and 56 kDa. Over 80% of plasma collected more than 29 days after viral inoculation reacted to these polypeptides and also to those with MW of 54, 52, and 38 kDa. In this report, we also demonstrate cross reactivity between gpCMV and human CMV (HCMV). Human immunoglobulin (IVIG) reacted to at least 20 HCMV polypeptides and cross reacted with six gpCMV polypeptides. GpCMV convalescent plasma also reacted with HCMV polypeptides.

Relation of maternal CMV viremia and antibody response to the rate of congenital infection and intrauterine growth retardation

Pregnancy outcome after maternal primary CMV infection initiated at different times during gestation was investigated by using the inbred Strain-2 guinea pig model of congenital CMV infection. The highest vertical transmission rates occurred in pups from dams that were initially viremic in late gestation presumably because delivery occurred prior to detectable maternal CMV-specific immune response. In contrast, conceptus loss was highest with maternal CMV infection initiated at conception. Intrauterine resorptions, intrauterine growth retardation, and disseminated neonatal CMV infection with CNS involvement were more frequent in pups born to mothers that were initially viremic prior to rather than after midgestation. Maternal viremia was prolonged and antibody responses were delayed after CMV inoculation in early gestation compared to late gestation. Prolonged maternal viremia plus early gestational virus exposure/infection of the fetus appeared to be associated with the most severe outcome. These findings suggest that the timing of initial maternal viremia and immune responses, the stage of fetal development, and the length of in utero exposure to CMV are important factors in subsequent disease expression and rates of congenital infection.

Fetal cytomegalovirus infection: a case report

Congenital cytomegalovirus infection is the most common perinatal infection. We describe a case of primary maternal cytomegalovirus infection during pregnancy and the prenatal diagnosis of fetal cytomegalovirus infection. Diagnosis was accomplished with percutaneous umbilical blood sampling. The fetal blood was evaluated with viral cultures, cytomegalovirus serologic testing, and nonspecific indicators of infection. Amniotic fluid was also cultured. All cultures were positive, which confirmed fetal infection. The pregnancy was terminated. Autopsy findings were consistent with fetal infection. The significance and utility of prenatal diagnosis are discussed.

Antibody response to recombinant lambda gt11 fusion proteins in cytomegalovirus infection

Significant epitopes of two of the major cytomegalovirus antigens, a nonstructural DNA-binding protein of 52 kilodaltons (kDa) and a structural phosphoprotein of 150 kDa, expressed as fusion proteins with the beta-galactosidase, were induced in Escherichia coli after infection with recombinant lambda gt11 clones. The epitopes were then used in immunoblotting to assay specific immunoglobulin G (IgG) and IgM in several groups of sera from long-term seropositive subjects and from patients undergoing primary or secondary virus infection. The data obtained showed that IgM reacting with the 52-kDa nonstructural antigen are linked to primary virus infection and can therefore be considered a serological marker of this infection.

Epidemiologic patterns in childhood hearing loss: a review

In an attempt to clarify international epidemiologic trends, a review of the published literature pertaining to childhood hearing loss is presented. Inconsistencies of methodology and classification, which complicate the interpretation of data and make difficult the quantification of the influence of genuine population differences, are discussed. Selective review of the literature allows certain crude statements to be made regarding childhood hearing loss. In developed countries, serous otitis media is the most common cause of hearing loss in children, affecting up to two thirds of preschool children. In addition, 1.0-2.0/1000 children have bilateral SNHL of at least 50 dB. In underdeveloped countries, suppurative middle ear disease is common and is still frequently associated with either an intratemporal or intracranial complication. SNHL appears to occur almost twice as often as in developed countries, with a greater proportion being of infectious etiology. In specific populations, the Inuits, Amerindians and Aboriginals, acute and chronic suppurative otitis media are almost endemic, yet both cholesteatoma and serous otitis media are uncommon.

Antibodies to human cytomegalovirus structural polypeptides during primary infection

This study aimed at broadening the understanding of the immunogenic potential of cytomegalovirus (CMV) structural polypeptides during natural infection and to ascertain their possible use in serological diagnosis. Immunoblotting was used to analyse the appearance and development of serum IgG and IgM against human CMV structural polypeptides in sequential sera from renal transplant recipients during the first 1-3 months of primary CMV infection. The results showed that the first IgG to appear is specific for a polypeptide of 66 kDa and these antibodies appear either alone or together with others against another polypeptide of 82 kDa. IgG to the 150 kDa protein appears at least one week later. The first IgM to appear reacts preferentially with a 38 and 66 kDa polypeptide. The early detection of antibody against the major viral antigenic proteins in the diagnosis of CMV primary infection is discussed.

Epidemiologic characteristics of cytomegalovirus infection in mothers and their infants

In this longitudinal study of cytomegalovirus in 4578 pregnant women of middle/upper socioeconomic status in Houston, 52% had cytomegalovirus antibody when enrolled, and 48% were serologically susceptible. Studies were completed on 3899 mothers and their infants; 2.2% of these women experienced primary cytomegalovirus during pregnancy and 24% of those with primary infection transmitted cytomegalovirus to their infants. Of 22 cytomegalovirus-infected infants, 2 had disease at birth and 20 were asymptomatic. One symptomatic infant (primary maternal infection) has developmental delay. The other (immunocompromised mother with cytomegalovirus antibody before pregnancy) had hepatitis but has no symptoms at 1 year of age. On follow-up, 4 of 16 infants asymptomatic at birth have sequelae (hearing loss in 3, developmental delay in 1). All four were born to mothers with primary cytomegalovirus infection. Infant outcome was not related to trimester of maternal infection.

Cytomegalovirus infection in pediatric house officers: susceptibility to and rate of primary infection

Hospital personnel, especially women in their child-bearing years, continue to express concern about the risk of acquiring cytomegalovirus (CMV) infection as a result of their occupation. Previous investigations of occupational risk of CMV infection have focused primarily on pediatric nursing personnel. However, assessment of the rate of CMV infection by other hospital personnel who have different clinical responsibilities and levels of patient contact cannot rely solely on the rates obtained for nursing personnel.

Rapid detection of cytomegalovirus by tissue culture, centrifugation, and immunofluorescence with a monoclonal antibody to an early nuclear antigen

A rapid, sensitive and specific assay for the detection of cytomegalovirus (CMV) was developed utilizing MRC-5 cells in 24-well plates containing round coverslips. Centrifugation expedited the detection of CMV early antigen with monoclonal antibody. Immunofluorescent staining 16 h after inoculation with a stock CMV preparation (AD-169), demonstrated an 11-fold increase in the number of nuclear inclusions when the specimens were centrifuged (18 +/- 2.2) as compared to the non-centrifuged specimen (1.6 +/- 0.9). However, the number of nuclear inclusions depended on the age of the MRC-5 cells. They were more sensitive to CMV infection between 4 and 11 days after the cells were seeded into plates. Among 159 patient samples cultured for CMV, 23 (14%) were positive by the rapid method (mean of 32 h) and 18 (11%) by routine tissue culture (mean of 12 days). Cytomegalovirus in urine was detected within 1.3 days, whereas buffy coats (2.3 days) and bronchial washings (2.5 days) took longer. Staining for CMV inclusions at more than one time point was necessary for the optimal detection of CMV by the rapid method. We recommend using this assay system as it is rapid, specific, sensitive and versatile for the detection of CMV in many biological specimens.