Cytomegalovirus infection in the north west of England. A report on a two-year study

Assignment of cytomegalovirus infection status in infants awaiting solid organ transplant: Viral detection methods as adjuncts to serology

Assignment of CMV infection status in infants awaiting SOT is challenging as passive maternal antibody can lead to false-positive serology. Since 2000, our protocol has recommended sending throat and urine samples for CMV viral detection, culture, or NAAT, for CMV-seropositive infants <18 months awaiting SOT. We reviewed pretransplant CMV serology for 152 infants and, for CMV seropositives, examined relationships between CMV IgG OD values, age, and CMV viral detection to explore time to clearance of maternal CMV IgG and evaluate viral detection in assignment of pretransplant CMV infection status. The proportion of CMV-seropositive infants decreased from 52% in infants 0-6 months of age to 28% in those 12-18 months. Among CMV-seropositive infants, median OD was significantly higher in the 6- to 12- and 12- to 18-month groups compared to the 0- to 6-month group. Distribution of OD by age group suggested that maternal antibody cleared before 12 months. Of 59 eligible CMV-seropositive infants, 49 (83%) had CMV viral detection studies and 18 of 49 (36.7%) had detectable CMV: 9 of 30 (30.0%) infants 0-6 months, 7 of 15 (46.7%) infants 6-12 months, and 2 of 4 (50.0%) infants 12-18 months. CMV viral detection studies are useful to confirm positive CMV infection status in CMV-seropositive infants awaiting SOT. Maternal CMV IgG likely clears before 12 months.

Review of cytomegalovirus shedding in bodily fluids and relevance to congenital cytomegalovirus infection

Congenital cytomegalovirus (CMV) infections are a leading cause of sensorineural hearing loss (SNHL) and neurological impairment. Congenital transmission of CMV can occur with maternal primary infection, reactivation, or reinfection during pregnancy. We reviewed studies of CMV shedding in bodily fluids (defined as CMV detected by culture or CMV DNA detected by polymerase chain reaction). Following diagnosis at birth, children with congenital CMV infection exhibited the highest prevalences of CMV shedding (median = 80%, number of sample population prevalences [N] = 6) and duration of shedding, with a steep decline by age five. Healthy children attending day care shed more frequently (median = 23%, N = 24) than healthy children not attending day care (median = 12%, N = 11). Peak shedding prevalences in children occurred at 1-2 years of age, confirming that young children are the key transmission risk for pregnant women. CMV shedding among children was more prevalent in urine specimens than in oral secretions (median prevalence difference = 11.5%, N = 12). Adults with risk factors such as STD clinic attendance had higher shedding prevalences (median = 22%, N = 20) than adults without risk factors (median = 7%, N = 44). In adults with risk factors, CMV was shed more frequently in urine; in adults without risk factors genital shedding was most common. The prevalence of CMV shedding in nine sample populations of pregnant women increased with advancing gestation. In seven sample populations of children with congenital CMV infection, higher viral load at birth was consistently associated with an elevated risk of SNHL. Higher CMV viral load at birth also consistently correlated with the presence of symptoms of congenital CMV at birth. Published 2011. This article is a US Government work and is in the public domain in the USA.

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.

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.

Cytomegalovirus infections in Toronto child-care centers: a prospective study of viral excretion in children and seroconversion among day-care providers

OBJECTIVES

To prospectively determine the rate of cytomegalovirus shedding in children and the rate of seroconversion to cytomegalovirus in providers at 38 infant-toddler day care centers in Toronto, Canada.

METHODS

Urine was collected for shell vial assay in 471 children between the ages of 3 and 42 months. Providers (n = 206) were tested for the presence of cytomegalovirus antibody by latex agglutination. Of the 68 providers who were seronegative, 56 were retested approximately 1 year later.

RESULTS

Viruria was documented in 79 (17%) children and antibody in 67% of providers. Seropositivity was significantly related to country of birth outside Canada, presence of children at home < 5 years of age and increased household size. Seroconversion was documented in 12.5% (n = 7). Of these providers 71% worked at centers where workers never wore gloves for diaper changing vs. 33% of those who did not seroconvert (P = 0.06), and all were younger than 30 years vs. 59% of those who did not seroconvert (P = 0.04). In centers with viruria the association of seroconversion with lack of glove use was enhanced (P = 0.04). Seroconversion was marginally more likely in providers working with infants only than with infants and toddlers or with toddlers alone. Logistic regression confirmed that seroprevalence was more likely in providers who were born outside Canada, had children younger than age 5 years in the household and with an increased number of people in the household. Seroconversion was more likely if the provider worked at centers not using gloves for diaper changes, worked with infants only rather than with toddlers and infants and was < 30 years old, with each factor contributing independently to the model.

CONCLUSIONS

Cytomegalovirus infection is common in children and providers in Toronto day-care centers.

Lissencephaly-pachygyria associated with congenital cytomegalovirus infection

We report the presence of major cerebral migrational defects in five severely, multiply handicapped children with congenital cytomegalovirus (CMV) infection. These patients had both computed tomographic (CT) scan and magnetic resonance imaging (MRI) evidence of marked migrational central nervous system defects consistent anatomically with the spectrum of lissencephaly-pachygyria, a disorder commonly idiopathic or associated with chromosomal abnormalities or with unknown early gestational insults. Neuroradiologic features included broad, flat gyri, shallow sulci, incomplete opercularization, ventriculomegaly, periventricular calcifications, and white-matter hypodensity on CT scans or increased signal intensity on long-TR MRI scans. Evidence for congenital CMV infection included prenatal onset of microcephaly, periventricular calcifications, neonatal jaundice, hepatomegaly, elevated CMV-specific immunoglobulin M, or viral isolation from urine. Previous reports of the neurologic sequelae of CMV have emphasized varying degrees of psychomotor retardation, cerebral palsy and epilepsy due to polymicrogyria, periventricular calcification, microcephaly, or rarely, hydrocephalus. Our patients appear to represent extremely severe examples of the effects of CMV on neurologic growth, maturation, and development. Recognition of these severe migrational abnormalities was improved by use of MRI, a technique that affords superior definition of the nature and extent of gyral and white-matter abnormalities. We suggest that these abnormalities may be more common than has previously been recognized.

Liver findings in infantile cytomegalovirus infection: similarity to extrahepatic biliary obstruction

The histological findings in the liver in four fatal cases of infantile cytomegalovirus (CMV) infection are presented, three occurred in premature infants, and all died at the ages of 2-4 months. Most previously reported cases showed various degrees of hepatitis with giant cell transformation. In three of our four cases, however, the main feature was cholestasis, portal fibrosis and bile duct proliferation, not unlike the findings seen in extrahepatic biliary obstruction. In one case, massive hepatic necrosis was found, a finding not previously reported in this disease. The diversity of liver findings in infantile CMV infection is stressed.

Early clinical manifestations and intellectual outcome in children with symptomatic congenital cytomegalovirus infection

The Developmental Profile was completed on 32 prospectively followed children with symptomatic congenital cytomegalovirus infection (mean age 6 7/12 years; 78% white, 59% male). The distribution of intelligence and general developmental scores was bimodal; one group had severe deficits (mean IQ 28.8), the other had relatively less severe intellectual sequelae (mean IQ 91.6). Correlation analysis (Pearson r) showed that three variables--microcephaly, neurologic abnormalities, and chorioretinitis--when apparent during the first year of life, were all significantly associated with low intelligence. No correlation was found between IQ and severity of neonatal reticuloendothelial disease or hearing loss. Multiple regression analysis showed that age at testing, chorioretinitis, and neurologic sequelae accounted for 63% of the IQ variance in our sample. We conclude that children with symptomatic congenital cytomegalovirus infection have a greater range of intellectual outcomes than has been previously reported, and that certain early clinical manifestations may be useful in anticipating special needs.

Guillain-Barré syndrome and other neurologic syndromes in hepatitis A, B, and non-A, non-B

Guillain-Barré syndrome and other neurologic syndromes occur rarely as complications of viral hepatitis, although a causal association has not been established. Seven cases of serologically documented hepatitis A have been reported with Guillain-Barré syndrome; all recovered, with mild neurologic residua in four. Eight cases of serologically documented acute hepatitis B have been reported with Guillain-Barré syndrome; all recovered, with mild neurologic residua in two. In one case, immune complexes of hepatitis B surface antigen and its antibody were present in the cerebrospinal fluid. Other neurologic syndromes have also been reported in patients with serologically defined viral hepatitis, including mononeuritis, auditory neuritis, and seizures. Chronic hepatitis B and mononeuritis multiplex are found together in 31-54% of patients with periarteritis nodosa. The mechanisms for these associations are unknown, but may include direct cytotoxicity of the virus or immune-mediated damage. Vasculitis of the vasa nervorum plays an intermediate role in at least some cases.

Cytomegalovirus infections: occupational risk for health professionals

Health care personnel are becoming increasingly aware of potential hazards associated with caring for patients with contagious diseases. The cytomegalovirus is of special concern, because infection with this virus in a pregnant female employee could be associated with significant neurologic injury in her fetus. Nosocomial transmission from patient to health care worker has not been documented. A review of cytomegalovirus excretion in hospitalized patients and prospective evaluations of primary infection in hospital personnel do not support frequent occurrence of cytomegalovirus infection despite ample opportunity for exposure. Adherence to proper isolation techniques should be adequate to prevent nosocomial transmission of the cytomegalovirus.

Electron microscopic examination of congenital cytomegalovirus hepatitis

The electron microscopic features of cytomegalovirus hepatitis in the liver biopsy of a three-week-old infant were studied. The liver cells did not contain virus, but severe alterations similar to virus hepatitis were observed. In the bile duct cells, nuclear and cytoplasmic virus inclusions were demonstrated. In the nuclear inclusions virus particles of various degrees of maturity were embedded in dense granular material. The cytoplasm of the infected cells contained vacuoles with mature viruses. The Golgi zone seemed to play an important role in vacuole formation. In another type of infected cell, viruses were lying free in the cytoplasm and passed into the lumen of the bile ducts. It is concluded that viruses are eliminimated by the bile. Based on this electron microscopical observations, the examination of duodenal fluid is recommended as a new diagnostic procedure for demonstrating viruses.

Antibody to cytomegalovirus in Malta

Antibody to cytomegalovirus (CMV) was sought in sera from Malta using immunofluorescence. Seven per cent of the infants, 36% of the school children, increasing to 100% of the adults aged over 40 years were found to have antibody. Most infection occurred in pre-school children and adults over 25 years of age. This pattern of antibody acquisition appears different from that described for other countries.

A comparison of cervical cytomegalovirus (CMV) excretion in gynaecological patients and post-partum women

CMV was isolated from the cervix of 4.2 per cent of 191 gynaecological patients and from 9.8 per cent of 51 women post-partum; all patients were attending the same general practice clinic. The CMV excretion rate was particularly high in the early post-partum period decreasing to nearly normal levels as menstruation returned. Three of 14 (21.4 per cent) post-partum patients excreted CMV before menses had restarted whereas virus was isolated from only two of 36 (5.6 per cent) women who had returned to a normal menstrual cycle. Although this difference was not statistically significant, the excretion rate early post-partum was significantly higher than in the gynaecological group (p less than 0.05). Five of seven excretors in the gynaecological group were in the first half of a menstrual cycle at the time of virus isolation thus suggesting that hormonal changes may lead to CMV reactivation in the genital tract. Other factors which may influence the presence of CMV in the genital tract of non-pregnant women are discussed. Three of four infant born to women excreting virus on the cervix post-partum became infected with CMV.

Risk of cytomegalovirus infection in nurses and congenital infection in their offspring

The risk of contracting cytomegalovirus (CMV) infection in nursing of infants and of congenital CMV infection in infants born to such nursing personnel were investigated. The investigation comprised 292 women working in paediatric clinics or day nurseries and a control group of 163 women who had no professional contact with infants. Among the women younger than 25, those who had tended infants for more than six months were significantly (p less than 0.001) more often seropositive for CMV than were those--mainly student nurses--with less than six months' infant nursing service, but ot more often than control women. At ages above 25 there was no demonstrable difference between the groups. In a separate study the occupation of 36 mothers of infants with congenital CMV infection was investigated. Compared to a control group no overrepresentation of nurses was found. All six congenitally infected infants born to nurses developed normally.

A prospective study of primary cytomegalovirus infection in pregnant women

During a four year study, sera were obtained from 5575 women attending for antenatal care and 3188 (57.2 per cent) were shown to possess complement fixing antibodies to cytomegalovirus (CMV). A total of 1608 seronegative women were followed to term and 14 (0.87 per cent) primary CMV infections occurred in either the second or third trimester. Transplacental spread of CMV occurred in 3 out of 12 (25 per cent) of the 14 babies born to infected mothers. All 14 babies were apparently normal at birth but short term clinical follow-up has already revealed that one child has impaired hearing whilst another is microcephalic. The women were also monitored serologically throughout pregnancy for evidence of rubella infections. Only 12 infections were detected and 7 of these occurred during the large rubella epidemic of 1978. Of the 10 pregnancies which were allowed to proceed to term, transplacental spread of rubella virus occurred in 1 out of 7 (14 per cent). During this study period, CMV infections occurred as frequently as did rubella infections. We therefore conclude that, apart from those years when extensive epidemics occur, many more pregnant women are infected with CMV than with rubella virus.

A prospective study on the incidence and significance of congenital cytomegalovirus infection

Screening of 3060 neonates for congenital cytomegalovirus (CMV) infection by virus excretion in the urine showed an overall incidence of 0.4%. The incidence was about 1% for mothers between 16 and 25 years and only 0.2% for mothers between 25 and 35. No mothers over 35 years of age gave birth to congenitally infected infants. The percentage of women in the child-bearing age susceptible to CMV infection was estimated by the absence of CMV complement-fixing antibodies in cord sera and ranged from 48% to 33% with increasing age. None of the infected infants showed obvious signs of congenital CMV infection at birth. At follow-up, two infants showed slight, but transient symptoms compatible with a foetal infection; a pair of premature twins exhibited retarded physical and psychomotor development, but this could just as well be ascribed to the prematurity itself. None of the infants had detectable CMV--IgM antibodies in cord sera, but a trend towards elevated total IgM concentration in cord sera and elevated virus excretion titres appeared in the infants with symptoms. With the very low incidence and no signs of sensomotor sequelae the preliminary conclusion is that foetal CMV infection in our population by no means has a significance to deserve screening or a vaccination programme.

Identification of pregnancies at risk from cytomegalovirus infection

The fluorescent antibody technique was used for the identification of specific cytomegalovirus IgM in the sera of twenty-four of 1065 unmarried pregnant women. Seventeen of them were followed to term and five infected infants were identified. Two other infants had CMV IgM in neonatal serum samples but virus excretion was not demonstrated. The congenital infection rate in this study was 5.3 per 1000 births by virus excretion and 7.9 per 1000 if cases with specific IgM are included; from previous studies a rate of 8.8 per 1000 was expected. The reasons for the lack of relationship between specific IgM in the mothers' serum and infected babies is discussed.

Evaluation of a walking-donor blood transfusion program in an intensive care nursery

A prospective study was carried out to identify the immediate and long-range advantages and disadvantages of a walking-donor transfusion program for an intensive care newborn nursery. The effect of heparin on coagulation of blood was evaluated and found to be minimal. There was no evidence of transmission of HBSAg. The prevalence of CMV infection at the time of follow-up was higher in infants who had received blood from donors seropositive for CMV than in infants who had been transfused from seronegative donors. In our experience, a walking-donor program has been a safe and effective method for the provision of small transfusions of blood to sick neonates.

Cytomegalovirus in female patients attending a VD clinic

A study of 531 female patients attending a venereal disease clinic was undertaken to assess the incidence of cytomegalovirus (CMV) in the cervix. The findings were as follows: (1) 35 of 531 patients had positive cervical cultures for CMV (6-6 per cent.). (2) 28 of 531 patients were positive for Herpes virus hominis (5-3 per cent.). (3) Excluding those who were pregnant, 20 of 28 with CMV were taking oral contraceptives (71 per cent.). (4) Seven babies born to infected mothers showed no signs of cytomegalic inclusion disease. (5) 28 of 35 with CMV had associated genital infections (80 per cent.). (6) Positive cultures were obtained in twenty cases for periods up to 10 months. (7) The CMV complement-fixation test was positive in all 23 patients with positive CMV cultures who were tested. (8) Seven male consorts were examined but CMV was not isolated from any of them. (9) A case of CMV mononucleosis was detected. It is suggested that the higher incidence in patients attending a VD clinic is due to the presence of CMV in the cervix predisposing to other genital infections rather than to its being sexually transmitted.

Prospective study of cytomegalovirus infection in pregnancy

In a prospective study of cytomegalovirus infection in 1,040 pregnant women in London 319 (42%) of the white Englishwomen but only 28 (10%) of the immigrant Asian women were without antibodies at the onset of pregnancy. Out of 254 susceptible white women and 16 susceptible Asian women 8 (3%) and 3 (16%) respectively experienced primary infection during the course of pregnancy. The overall incidence of fetal infection after primary infection in the mother was almost 50%, and was higher in early pregnancy. One out of the five infected infants was found to be mentally retarded.Reactivation of latent infection was recognized in 0.7-2.9% of pregnant women; this occurred without involving the fetus.