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Prevalence of anti-Toxoplasma gondii antibodies in the population of the area of Parma (Italy).

Between 1987 and 1991, the prevalence of IgG antibodies to Toxoplasma gondii was determined by ELISA in 28,247 serum samples belonging to 19,432 subjects of the area of Parma (Italy). The overall prevalence was 48.5%. The correlation of infection with age, performed on 420 sera, showed a significant increase of positivity until 30-40 approximately years. In consecutive sera obtained from 172 subjects, the IgG and IgM production was analyzed for about 8 months, and four different patterns were delineated which were comprehensive of the wide range of immunological responses to Toxoplasma gondii exposure observed. Among pregnant females the prevalence of anti-Toxoplasma gondii antibodies was 48.7%, and 5 cases of seroconversion during the pregnancy were observed (0.27%) from which two cases of congenital toxoplasmosis originated.

Animals↗

[Contribution of post mortem skull scanning for the study of sudden infant death].

BACKGROUND: Despite post-mortem examination and autopsy, many cases of sudden infant death (SID) remain unexplained. The aim of this study was to assess usefulness of CT-scan in the Sudden Infant Death Syndrome (SIDS). POPULATION: Twenty-three cases of SIDS had a post-mortem CT-scan evaluation of skull and brain. The pictures were retrospectively reviewed by several independent radiologists who were unaware of the circumstances of death and results of autopsy. RESULTS: Aspects of pneumatocele, probably due to lumbar puncture were found in 6 cases. The subarachnoid spaces appeared inexplically hyperdense, as they were not correlated to the results of lumbar puncture and autopsy. The ventricles were normal in size or density. Density of the dural sinuses (superfical and deep) was often increased, an aspect possibly artefactual, due to post-mortem thrombosis. The cerebral parenchyma was often slighty hypodense; microcalcifications due to congenital toxoplasmosis were found in one case. CONCLUSION: There was no correlation between the CT-scan imaging and the delay of death and lumbar puncture. Infants with or without subarachnoid hemorrage had the same CT scan findings. The CT-scan has a poor value when autopsy is performed; in its absence, it could be useful for diagnosing post-traumatic intracerebral hematoma.

Autopsy↗

Detection of Toxoplasma gondii from amniotic fluid, a comparison of four different molecular biological methods.

BACKGROUND: The infection caused by the parasite Toxoplasma gondii (T. gondii) is often asymptomatic or has mild symptoms. The infection can cause serious problems in pregnant women who acquire the infection during gestation and their fetuses are congenitally infected. METHODS: We tested 64 amniotic fluid samples for the presence of T. gondii by using fluorescent PCR and DNA fragment analysis. Later we compared four different molecular biological methods for the detection of the presence of T. gondii on same frozen DNA samples. These methods are the conventional PCR, fluorescent PCR with DNA fragment analysis, quantitative real-time PCR with SYBRGreen I and with fluorescence energy transfer hybridization probe detection. We determined the detection limit of these methods. RESULTS: The conventional PCR and quantitative real-time PCR with SYBRGreen I detection have the detection limit of 1000 parasites, followed by fluorescent PCR with the detection limit of 10-100 parasites. The real-time PCR using fluorescence energy transfer hybridization probes can detect one parasite. This is the most sensitive and the fastest method. We detected 5 T. gondii positive samples with all methods from the studied 64 amniotic fluids. CONCLUSIONS: All studied molecular biological methods are suitable for the detection of congenital toxoplasmosis. The quantitative real-time PCR based methods are more sensitive, simple and easy to perform these are opening the avenue to find out the effect of the number of parasites on fetal abnormalities.

Amniotic Fluid↗

A pregnant woman with a high level of naturally occurring immunoglobulin M antibodies to Toxoplasma gondii.

A pregnant woman diagnosed as positive for immunoglobulin M antibodies to Toxoplasma gondii did not have a subsequent rise of specific immunoglobulin G antibodies until delivery. The antibodies were therefore considered as naturally occurring immunoglobulin M antibodies. The baby was completely normal without any clinical and serologic signs suggestive of congenital toxoplasmosis.

Adult↗

Congenital infections and the nervous system.

Despite vaccines, new antimicrobials, and improved hygienic practices, congenital infections remain an important cause of death and long-term neurologic morbidity among infants world-wide. Important agents include Toxoplasma gondii, cytomegalovirus, Treponema pallidum, herpes simplex virus types 1 and 2, and rubella virus. In addition, several other agents, such as the varicella zoster virus, human parvovirus B19, and Borrelia burgdorferi, can potentially infect the fetus and cause adverse fetal outcomes. This article provides an overview of these infectious disorders and outlines current strategies for acute treatment and long-term management.

Cytomegalovirus Infections↗

Timely diagnosis of congenital infections.

The acronym TORCH has served to increase awareness of congenital infections; however, this collective term suggests that the clinical manifestations of congenital infections are not distinguishable by pathogen. Although some clinical features may be common to several of these infections, a congenital infection caused by one pathogen generally can be distinguished from infection caused by another pathogen on a clinical basis. Pediatricians need to be aware of the prominent features of each congenital infection rather than to consider them collectively. This article focuses on the prominent features of the more common congenital infections, suggests a specific diagnostic approach, and reviews the available therapeutic strategies.

Cytomegalovirus Infections↗

In vitro-model for Toxoplasma gondii invasion into neuroepithelial cells.

In order to study the interactions of Toxoplasma gondii and neuroepithelial cells morphologically and biochemically we established an easy in vitro model, which simulates cellular contacts in congenital toxoplasmosis. Monolayer cultures of neuroepithelial cells from 13-14-day-old mouse embryos were prepared containing the typical ventricular cell types found in an embryonic brain, such as young neurons, macroglial and microglial cells. Ultrastructural investigations on cultures incubated for 1, 5 and 30 min or 1, 6, 12, 24 and 48 h with T. gondii indicated that all three cell types had been invaded by the parasites, multiplying in parasite vacuoles by means of endodyogeny. Microglial cells had already been penetrated by trophozoites within one minute and showed up to 3 or 5 parasite vacuoles per cell. Neurons and glial cells were invaded within 5 min and contained only one vacuole per host cell. All the parasite vacuoles were bounded by a membrane and bordered by the rough endoplasmic reticulum and mitochondria of the host cell after a few minutes. The vacuoles also contained some membranic tubuli. After 30 min some neuronal neurites were destroyed while the perikarya seemed to be unchanged. After 6 h the cytoplasm of the microglia lost more and more ribosomes and organelles. Neurons and glial cells showed no alterations. After 12h large areas of the vacuole membrane were folded up and lay curled up in the vacuoles. After 24 h incubation T. gondii had destroyed nearly all the microglial cells. The ultrastructure of neurons and glial cells now began to change in the same way as shown for microglial cells. The organelles and cellular membranes disintegrated and after 48 h incubation nearly all the cells in the neuroepithelial cell culture had fallen to pieces. For an identification of T. gondii in vitro by light microscopy or for the characterization of the cell surface we tried to label the parasites with 11 different FITC-stained lectins. None of the tested lectins bound to the parasites. We conclude that our in vitro-model for invasion of T. gondii in neuroepithelial cells opens an opportunity for studying the interaction of these cells or the pharmacological effects on this interaction under defined conditions.

Animals↗

Infection of the fetus and the newborn: prevention, treatment and related handicap.

Congenital infection is uncommon and the cause of only a small proportion of handicap seen in children but some infections may be preventable or even treatable. As an example, the congenital rubella syndrome first described in the 1940s is preventable by use of the vaccine but cases still occur. It is hoped that with the introduction of the measles, mumps, rubella immunization for young children, rubella will become as rare in the UK as it is in the USA. Cytomegalovirus is now a more common cause of handicap than rubella but no vaccine has been developed. Although antiviral drugs are available for herpes simplex virus and vaccinia, infection mortality in the newborn is high, even following the use of these agents; many HSV infections in the newborn arise following primary and asymptomatic maternal infections so that treatment may start late in the course of the illness. The obstetrician needs to understand the natural history as well as possible investigations available for congenital infections. There may be warning signs which require action, such as herpetic lesions in the genital tract of the mother. Less specific abnormalities during pregnancy, such as intra-uterine growth retardation and spontaneous onset of preterm labour, may point to congenital infection. This chapter describes both antenatal and postnatal management of the major congenital infections. We have included recent research data that should influence clinical practice; studies on HSV which suggest that, for women with a history of recurrent infection, routine viral culture of the genital tract at the end of pregnancy is unnecessary; reports from both the USA and the UK that rubella immunization performed inadvertently during early pregnancy has not resulted in the congenital rubella syndrome. The chapter would not have been complete without a discussion of human immunodeficiency virus, of concern to the obstetrician and midwife. There is still much to be learned about the natural history of this infection in both the mother and infant.

Chickenpox↗

Risk factors for Toxoplasma infection in a reproductive age female population in the area of Belgrade, Yugoslavia.

The contribution to Toxoplasma infection of known transmission risk factors such as consumption of undercooked meat, contact with soil, and contact with cats, as well as that of age, degree of education, residence in central vs. suburban city communities, and year of entry into the study, has been investigated in a group of 1157 female residents (age range 15 to 45 years) of a defined geographic area (Belgrade) during a 4-years period (1988-1991). The rate of infection increased with age, ranging from 57% to 93%, with an overall mean of 77%. However, it decreased significantly over the study period (p < 0.01). Of the potential risk factors examined, regression analysis showed that the following: age (relative risk (RR): 1.18, 95% confidence interval (CI): 1.02-1.37, p = 0.022), undercooked meat consumption (RR: 2.22, 95% CI: 1.2-2.86, p = 0.001), and the year of entry into the study (RR: 0.69, 95% CI: 0.6-0.8, p = 0.000) were significantly associated with infection. However, while the consumption of undercooked meat contributed to the frequency of infection in the whole group, its significance increased with the degree of education but decreased with age, and was greater in women residing in the suburbs. In addition, in women below age 20, exposure to soil (farming, gardening) was significantly associated with infection (RR: 1.38, 95% CI: 1.12-1.97, p = 0.037). Since cats are the single source of toxoplasma oocysts, the above finding indicates that cats are an epidemiologically significant source of environmental contamination in Belgrade. However, cat ownership itself as a criterion of contact with cats was not associated with infection (p = 0.326). In the absence of a general screening in pregnancy program in Yugoslavia, these data point out the groups of pregnant women at the highest risk of infection and provide a basis for a region-appropriate educational program to prevent congenital toxoplasmosis.

Adolescent↗

Parasite load in guinea pig foetus with real time PCR after maternofoetal transmission of Toxoplasma gondii.

Parasite loads of different tissues were assessed in guinea pig foetus after maternal infection. Twelve female guinea pigs were infected with 100 cysts of the 76 K strain of Toxoplasma gondii by the oral route. Inoculation was performed 20 +/- 5 days (G20) or 40 +/- 5 days (G40) after the beginning of gestation. Gestational age was determined by progesterone assay. Maternal and foetal organ samples were taken 60 days after the beginning of gestation. Parasite loads (from placenta, amniotic fluid (AF), cord blood (CB), foetal brain, liver, lung and spleen) were assessed by a real-time PCR quantification using fluorescence resonance energy transfer (FRET) hybridization probes on the Light Cycler. Congenital transmission was proven by the presence of parasites in blood or tissue samples of the foetus in 84.6% (11/13) and 100% (16/16) of cases after inoculation on G20 and G40, respectively. The quantitative analysis of our results after inoculation at G20 and G40 has allowed us to determinate the positive parasitic loads as a function of the origin of the sample and the period of inoculation. The parasite loads expressed as log (parasite/g) were low in AF and CB samples: 1.49 +/- 0.50 and 1.05 +/- 0.10 at G20 and 1.21 +/- 0.36 and 1.20 +/- 0.42 at G40 respectively. In contrast the placenta and the different foetal tissues had higher parasite burdens: 2.89 +/- 0.54 to 5.30 +/- 0.51 at G20 and 2.81 +/- 0.71 to 3.65 +/- 0.59 at G40. All the placentae were positive for parasites even in the two cases with no proven transmission. Real time quantitative PCR using the hybridization probe was a very sensitive and reproducible technique to study the kinetics of congenital toxoplasmosis in the guinea pig model wich is close to that of humans.

Amniotic Fluid↗

Herpes simplex virus infections in neonates and early childhood.

Of the commonly considered congenital infections, those caused by cytomegalovirus (CMV), syphilis, and herpes simplex virus (HSV) are frequently (CMV, HSV) or exclusively (syphilis) acquired sexually by the mother, with subsequent transmission to the developing fetus. Of the other commonly considered congenital infections, including rubella and toxoplasma infections, the mother is exposed to the infectious agent via interpersonal or environmental contacts. Unlike each of these other pathogens, which are transmitted transplacentally to the developing fetus following maternal infection though, HSV usually is transmitted perinatally as the neonate is exposed to the virus during passage through an infected birth canal. This difference in timing of acquisition of infection has had important consequence in the therapeutic advances achieved during the last 30 years in the management of neonatal HSV infections. Because the time period between the acquisition of infection and initiation of effective antiviral therapy is shorter in neonatal herpes than in congenital toxoplasmosis or CMV infections, the outcomes of therapy have the potential to be markedly different. This article will summarize the current state of neonatal HSV disease presentation, diagnosis, and management.

Adult↗

Incidence and clinical significance of echogenic vasculature in the basal ganglia of newborns.

Cranial sonography has become the main modality of the investigation and diagnosis of a wide variety of neonatal intracranial abnormalities. Occasionally, cranial sonograms reveal basal ganglia and thalami bright echoes. It is believed that these lesions are indicative of vasculitis due to intrauterine infections, in particular with cytomegalovirus (CMV). We hypothesized that the incidence of proven neonatal intrauterine TORCH infection is low and that screening of all asymptomatic infants with bright lenticulostriate echodensities would not be cost-effective. We reviewed brain sonograms of 3700 infants, performed over a period of 3 1/2 years. Echogenic basal ganglia vasculature were observed in 75 patients (2%). Chart review performed for clinical presentation and TORCH studies showed that only one infant had confirmed intrauterine congenital infection, which was by CMV. This infant had no signs or symptoms of CMV. In addition, there were 4 patients with chromosomal anomalies among the 75 patients (5%), of these one had trisomy 13 and another-trisomy 21. Our results indicate that echogenic basal ganglia blood vessels are not an exceptional finding on cranial sonograms, and are seldom associated with intrauterine infection. We conclude that it is not cost-effective to screen infants with echogenic basal ganglia blood vessels for intrauterine infection, unless clinical suspicion exists.

Basal Ganglia↗