[Significance of diagnostics and treatment in preventing congenital infections with Toxoplasma gondii (Tg), cytomegalovirus (CMV) and parvowirus B19 (PVB19)]

Common use of available techniques detecting perinatal infections needs to be accompanied with knowledge of proper interpretation of the tests and indications for treatment as well as communication with patients. The aim of this paper is to summarize current standards of diagnosis and treatment of infections in pregnant women and neonates. The detection of specific IgG antibodies in pre-conceptive period excludes the risk of transplacental Tg and PVB19 infection, while the risk of CMV infection is diminished and probable symptoms alleviated. Confirmed diagnosis of primary infection during pregnancy: 1. Toxoplasmosis (seroconversion, presence of IgA and IgM, low avidity IgG, PCR in amniotic fluid) is an indication for antimicrobial therapy; 2. Symptomatic CMV infection [seroconversion, virus detected in blood and urine (PCR, pp65 antigen)] for prophylactic IgG administration in mother; 3. PVB19 (seroconversion, IgM, PCR in blood and amniotic fluid) for frequent ultrasonographic evaluation of possible symptoms of fetal hydrops, and fetal transfusin if hydrops occurs. Diagnosis and treatment of the neonates should be managed in specialized c enters. Further monitoring of the infection is handicapped by the presence of maternal antibodies as well as the suppression of neonatal production of specific IgA and IgM. Toxoplasmosis requires from 6 (in asymptomatic infestation) to 12 months (in symptomatic infestation) treatment with pyrimethamine and sulfadiazine with supplementation of folinic acid. In symptomatic CMV infection 6 weeks treatment with ganciclovir is legitimate (decreases viruria and the risk of hearing impairment); while in asymptomatic infection with massive viral replication it can be considered as supposedly beneficial. The impact of prolonged treatment (over 6 weeks) as well as oral antiviral (valganciclovir) is currently under clinical investigation. The educational efforts should include: methods of preventing infections (Tg, CMV), necessity of repeated testing and treatment in pregnancy (Tg, PVB19), treatment of the neonate (Tg, CMV) and breastfeeding (CMV).

Parvovirus B19 infection in pregnancy

Parvovirus B19 is a small single-stranded DNA virus and a potent inhibitor of erythropoiesis, due to its cytotoxicity to erythroid progenitor cells. Infection with parvovirus B19 during pregnancy can cause several serious complications in the fetus, such as fetal anemia, neurological anomalies, hydrops fetalis, and fetal death. Early diagnosis and treatment of intrauterine parvovirus B19 infection is essential in preventing these fetal complications. Testing maternal serum for IgM antibodies against parvovirus B19 and DNA detection by PCR can confirm maternal infection. If maternal infection has occurred, ultrasound investigation of the fetus and measurement of the peak systolic flow velocity of the middle cerebral artery are sensitive non-invasive procedures to diagnose fetal anemia and hydrops. Intrauterine transfusion is currently the only effective treatment to alleviate fetal anemia, but if the fetus is (near) term, induction of delivery should be considered. Most maternal infections with parvovirus B19 occur through contact with infected children at home. Individual counseling of susceptible pregnant women will reduce unnecessary fetal deaths.

Premature labor and leukoerythroblastosis in a newborn with parvovirus B19 infection

Leukoerythroblastosis is a rarely observed disease characterized by the presence of leukocytosis, erythroid and myeloid blast cells in peripheral blood. To our knowledge, it had not been diagnosed in a premature newborn before the case we report have.A female baby weighing 1164 grams, who was born prematurely at the 29th week of gestation by Cesarean section was referred to our newborn intensive care unit due to prematurity and respiratory distress with no prenatal pathological findings. Physical examination revealed tachypnea and hepatosplenomegaly. Routine laboratory measurements showed significant leukocytosis (85,000/mm3) and anemia (Hb: 9.6 g/dL and Hct: 27.6%). The platelet count was normal. The peripheral blood smear suggested leukoerythroblastosis with the presence of nucleated erythrocytes, monocytosis, and 4% blasts. Bone marrow cytogenetic examination was normal. Parvovirus B19 Ig G and M serology were detected to be positive. The etiological factors observed in leukoerythroblastosis occurring during neonatal and early childhood period are congenital-postnatal viral infections, juvenile myelomonocytic leukemia and osteopetrosis. To our knowledge, no case of leukoerythroblastosis in such an early phase has been reported in the in literature. As a result, premature delivery and leukoerythroblastosis were thought to have developed secondary to intrauterine parvovirus B19 infection. Leukoerythroblastosis is a rarely observed disease characterized by the presence of leukocytosis, erythroid and myeloid blast cells in peripheral blood. It is reported that it can be observed following hematologic malignancies especially juvenile myelomonocytic leukemia, acute infections, hemolytic anemia, osteopetrosis, myelofibrosis, neuroblastoma and taking certain medicines. To our knowledge, it has not been diagnosed in a premature newborn before. Here we the case of a newborn who was referred to our intensive care unit due to being born prematurely at the 29th week of gestation and diagnosed with leukoerythroblastosis.

[Prenatal parvovirus B19 infection in fetus]

OBJECTIVE

To analyse 3 cases of parvovirus B19 infection in a pregnant woman followed by transplacental transmission to the fetus.

DESIGN

A reprospective study.

SETTING

Department of Obstetrics and Gynecology, University Hospital, Olomouc.

METHOD

Parvovirus B19 vertical transmission from a pregnant woman to the fetus was diagnosed in 3 cases. Serologic testing of IgG and IgM antibodies against parvovirus B19, cytological bone marrow examination and parvovirus B19 DNA analysis by PCR methods were performed. The fetal anemia was predicted by measurements of peak systolic velocities in the middle cerebral artery (MCA-PSV).

RESULTS

There were three pregnancies in all (1st - single, 2nd and 3rd - dizygotic twins). In the 1st and 2nd pregnancy the diagnosis of parvovirus B19 infection was set on the basis of erythroblastopenia diagnosed in the neonatal period or early infancy. In the 2nd pregnancy (dizygotic twins) intrauterine death of one twin occured. In the 3rd case (dizygotic twins) the diagnosis was already set in the 20th week of pregnancy. Subsequently the fetal anemia was predicted by doppler examination. The fetuses did not require invasive intrauterine intervention and mild anemia was diagnosed after delivery. Progressive intrauterine growth retardation of one twin was observed. Neither cardiomegaly nor fetal hydrops did not occur. All mothers were asymptomatic during the whole pregnancy.

CONCLUSION

Parvovirus B19 infection should be excluded in all cases of nonimmune fetal hydrops, severe fetal anemia, cardiomegaly, intrauterine growth retardation (IUGR) and chronic erythroblastopenia diagnosed in the neonatal period or early infancy. The presence of IgM and IgG antibodies against parvovirus B19 is highly specific but their negativity is insufficient for the exclusion of a parvovirus B19 infection. Viral DNA testing by PCR method is the only reliable method available.

Fetal middle cerebral artery peak systolic velocity in the investigation of non-immune hydrops

OBJECTIVE

In some cases of non-immune hydrops there is congenital or acquired fetal anemia. The aim of this study was to investigate the potential value of fetal middle cerebral artery peak systolic velocity (MCA-PSV) in the assessment and management of non-immune hydrops due to anemia.

METHODS

Fetal MCA-PSV and fetal hemoglobin concentration, in blood obtained by cordocentesis, were measured in 16 singleton pregnancies referred to our unit for further investigations because of a diagnosis of non-immune hydrops fetalis. In all cases a detailed ultrasound examination demonstrated moderate or severe ascites, with or without skin edema, and pericardial or pleural effusions. Furthermore, there were no obvious malformations to account for the hydrops. In each fetus the measured MCA-PSV and hemoglobin concentration were expressed as delta values (the difference in SD from the normal mean for gestation). Regression analysis was used to determine the significance of the association between delta MCA-PSV and delta fetal hemoglobin concentration. In addition, we searched our database to identify the sonographic features and hemoglobin concentration of fetuses with congenital infection.

RESULTS

In the 16 cases of non-immune hydrops there were seven with parvovirus B19 infection, one each of alpha-thalassemia and primary cardiomyopathy and seven with no obvious explanation for the hydrops. There was a significant association between delta MCA-PSV and delta hemoglobin concentration (delta hemoglobin = (delta MCA-PSV + 0.1437)/-0.4154; R(2) = 0.7202; P < 0.0001). In 10 of the cases the fetal hemoglobin concentration was more than 4 SD below the normal mean for gestation and in all these cases the MCA-PSV was more than 2 SD above the normal mean for gestation. Our computer search identified an additional nine fetuses with parvovirus B19 infection and in all cases the predominant sonographic finding was ascites and the hemoglobin concentration was more than 4 SD below the normal mean. In contrast, only 3/14 fetuses with cytomegalovirus, toxoplasmosis, coxsackie B or Treponema infection had ascites and only 2/14 had a hemoglobin deficit of 4-6 SD.

CONCLUSION

In the management of non-immune hydrops, measurement of fetal MCA-PSV can help identify the subgroup with fetal anemia.

[Diagnostic and therapy of a severe fetal parvovirus-B19-infection with persistence of viral DNA in the mothers blood but inconspicuous serological tests. Case report]

In the 24th week of gestation we diagnosed a severe hydrops fetalis in a 25 year old VI gravid III para, who had contact to parvovirus B19 in the 14th week of gestation. Because of the severe anaemia of the fetus and the massively increased bilirubinoides in the amniotic fluid we decided at the same day to apply the first of four intrauterine transfusions. The serological patterns of maternal blood with highly positive parvovirus-B19-IgG and negative IgM suggested that an infection had occurred. Parvoviral DNA was found in maternal and fetal blood confirming the diagnosis of an acute intrauterine parvovirus-B19 infection. No viral DNA was detected in fetal ascites. IgM in fetal blood was negative. By means of four transfusions, the pregnancy could be prolonged until the 32 + 5th week of gestation while the ascites was declining. When rupture of membranes occurred, a cesarean section had to be performed due to contractions and presentation of the feet. The newborn's blood count exhibited a thrombocytopenia with normal haemoglobin and haematocrit. Five days after delivery, a blood exchange had to be done because of a hyperbilirubinaemia. After seven weeks, the child could be dismissed from hospital in good general status, with decreasing ascites, normal liver function and normal neurological status. The blood of the newborn was tested to be positive for IgG, while IgM-antibodies and parvovirus-B19-DNA were negative. The diagnosis of a parvovirus-B19 infection of a fetus with severe hydrops and anaemia could be verified by a positive proof for DNA in maternal blood, with negative IgM and highly positive parvovirus-B19-IgG and on the other hand highly positive viral DNA in fetal blood and in the amniotic fluid. 10 weeks after contact to parvovirus B19, i. e. in the 24th week of gestation, positive IgG- and negative IgM-antibodies were found in the mother's blood, whereas fetal complications were noticed. These data demonstrate that following an acute parvovirus-B19-infection of the mother IgM-antibodies can be proofed for 6 - 8 (- 10) weeks. On the other side parvovirus-B19-DNA in the mothers blood is detectable by means of PCR for 8 - 10 weeks and in some cases even more than 15 weeks.

Parvovirus B19 in pregnancy

Parvovirus B19 is a common, self-limiting, usually benign childhood virus that causes erythema infectiosum, also known as fifth disease. Acute infection in pregnancy can cause B19 infection in the fetus, leading to nonimmune fetal hydrops or fetal loss, depending on gestational age at the time of infection. Susceptibility to parvovirus B19 infection should be determined in selected pregnant women at high risk for exposure, and counseling should be provided regarding prevention, testing, and treatment options if exposed.

[Congenital aplastic anemia caused by parvovirus B19 infection]

Human parvovirus B19 causes the fifth disease (erythema infectiosum) in childhood. Intrauterine infection by parvovirus in immunocompromised fetus can lead to the severe congenital aplastic anemia. Here we report the case of 2.5-year-old girl with congenital infection with parvovirus B19. The girl was born as a pre-term baby with hydrops, congenital aplastic anemia, and low level of immunoglobulins IgG and IgM. She depended on the repeated blood transfusions and she did not respond to erythropoietin therapy. The parvovirus B19 infection in bone marrow was detected by polymerase chain reaction and its therapy started with intravenous administration of immunoglobulins. Hemoglobin reached normal level one year later, but low levels of parvovirus B19 were detectable for another 6 months. Immunoglobulin treatment was finished when the virus could not be detected in the circulation. However, one-month later parvovirus B19 DNA was detected again. The two months course of immunoglobulin treatment was repeated, and the DNA analysis of blood cells for parvovirus B19 has been negative since then. Five months after the final withdrawal of the immunoglobulin therapy the girl is in a good shape and all lab tests, except for the decreased levels of IgM, are within the normal range. The PCR monitoring of the presence of parvovirus B19 DNA in blood and bone marrow cells during and after the treatment of congenital aplastic anemia caused by parvovirus B19 chronic infection becomes the necessity for the rational therapy.

Angio-oedema in a neonate with IgG antibodies to parvovirus B19 following intrauterine parvovirus B19 infection

We report a neonate with angio-oedema following fetal hydrops caused by maternal parvovirus B19 infection. Levels of complement components, including total haemolytic complement activity and C1 inhibitor concentration, were within normal ranges in cord blood. Neonatal angio-oedema might be included in the clinical spectrum of parvovirus B19 infection in pregnancy.

Prenatal diagnosis of congenital parvovirus B19 infection: value of serological and PCR techniques in maternal and fetal serum

Intrauterine infection with parvovirus B19 (B19) is associated with non-immune hydrops fetalis, miscarriage and stillbirth. Accurate laboratory tests for diagnosis of B19 infection are required to exclude other diagnoses. We analysed the diagnostic value of B19 IgM antibody testing and polymerase chain reaction (PCR) in the sera from 57 patients and their fetuses with abnormal ultrasonography. Viral DNA was found in 16 of the 58 fetuses (one twin pregnancy) whereas only 7 of these were tested positive for B19 IgM antibodies. The sera of all 16 mothers were also positive for B19 DNA. False-positive B19 IgM results were obtained from two fetuses. The study highlights the limitations of B19 IgM serology and shows for the first time that, if a sensitive PCR assay is used, DNA measurement is the best indicator of infection not only in the fetal blood but also in the maternal blood. This improves the diagnostic value of the laboratory results considerably. DNA assays are essential in cases of doubtful serological results.

Congenital infection by human parvovirus B19 ascites-anaemia

A case of intrauterine infection by human parvovirus B19 (HPV B19) manifested as ascites during pregnancy is presented. Ascites was diagnosed by ultrasound at 27 weeks' gestation. A caesarean section was performed at 37 weeks'. owing to affected mobility of the fetus. A pale, female infant with low haemoglobin and bradycardia was delivered. Polymerace Chain Reaction (PCR) lab tests revealed that the mother and the fetus were infected by HPV B19. The neonate was born with low haemoglobin (Hb = 10 g/dl) and with ascites; it was discharged in good general condition 50 days after delivery.

Immediate and long term outcome of human parvovirus B19 infection in pregnancy

OBJECTIVE

To estimate more precisely the risk of fetal loss and congenital abnormalities after maternal parvovirus B19 infection, and to assess the long term outcome for surviving infants.

DESIGN

Prospective cohort study of pregnant women with confirmed B19 infection with follow up of the surviving infants. The rate of fetal loss in the study cohort was compared with that in pregnant women with varicella.

SETTING

Cases reported by laboratories in England and Wales between 1985-1988 and 1992-1995.

SAMPLE

Four hundred and twenty-seven pregnant women with B19 infection and 367 surviving infants of whom 129 were followed up at 7-10 years of age.

METHODS

Questionnaires to obstetricians and general practitioners on outcome of pregnancy and health of surviving infants. Maternal infection confirmed by B19-specific IgM assay and/or IgG seroconversion.

RESULTS

The excess rate of fetal loss in women with B19 infection was confined to the first 20 weeks of gestation and averaged 9%. Seven cases of fetal hydrops followed maternal infections between 9 and 20 weeks of gestation (observed risk 2.9%, 95% CI 1.2-5.9). No abnormalities attributable to B19 infection were found at birth in surviving infants (observed risk 0%, upper 95% CI 0.86%). No late effects were found at 7-10 years.

CONCLUSIONS

Around 1 in 10 women infected before 20 weeks of gestation will suffer a fetal loss due to B19. The risk of an adverse outcome of pregnancy after this stage is remote. Infected women can be reassured that the maximum possible risk of a congenital abnormality due to B19 is under 1% and that long term development will be normal.

Congenital parvovirus infection

Congenital parvovirus infection was diagnosed in two liveborn premature infants born at 24 and 35 weeks of gestational age. The illnesses were associated with placentomegaly, petechial rash, edema, hepatomegaly, anemia and thrombocytopenia, respiratory insufficiency, and death at 5 and 6 days of age. The syndromes exhibited by these cases shared common but nonspecific features with other life-threatening congenital infections. Serological studies in one case supported the diagnosis of parvoviral infection. Postmortem examination of both revealed nuclear inclusions in erythroid precursor cells characteristic of parvovirus infection. Use of the polymerase chain reaction confirmed the presence of parvovirus DNA in one of the cases. Intrauterine parvovirus B19 infection is most commonly associated with hydrops fetalis, "transient" hydrops, or a favorable outcome in infants found to be viremic after birth. These and previously reported examples of congenital B19 disease exemplify an exceptional form of human parvovirus infection.

In utero diagnosis of congenital infections by direct fetal sampling

Counseling for infections during pregnancy has traditionally focused on the clinical and laboratory findings of infection in the mother and the estimated risk of fetal damage associated with possible transmission of infection to the child. Now, with the use of techniques for fetal sampling, it is possible to diagnose infections of the fetus in utero and to correlate that information with the occurrence of fetal damage. The techniques that are available for sampling include amniocentesis, cordocentesis and chorionic villus sampling. The laboratory tests include: a) isolation of the organism in appropriate laboratory systems; b) detection of the DNA or RNA of the organism directly or with amplification with techniques such as PCR; c) detection of the organism by fluorescence or in situ hybridization; and d) identification of IgM or IgA fetal antibody to the organism by ELISA or similar methods. In utero infections can be documented for agents such as rubella, cytomegalovirus, parvovirus, Toxoplasma gondii and human immunodeficiency virus type 1. Further information is needed concerning the sensitivities and specificities of these methods for identifying fetal infection and predicting fetal damage.

Fetal damage caused by parvoviral infections

The single-stranded DNA parvoviruses occur in humans and many species of animals. In general, they are species-specific and capable of producing disease at any stage of life. Parvoviruses have a requirement to replicate in cells in a permissive S-phase of DNA mitosis. The infections may be cytolytic to select cell groups resulting in specific developmental defects or may produce more generalized effects such as anemia, pancytopenia, or hemorrhage. The fetus is at particular risk for damage because of the vast number of cells in active mitosis. The teratogenic effects may be severe, often resulting in fetal death. Infections in childhood and adulthood are more frequently mild to subclinical. Some of the teratogenic effects recognized in animal species have been identified in humans. With increased knowledge of parvovirus effects in animals, more pathogenic effects may be related to human parvoviral disease. The need for vaccination, currently used annually in many domestic animal species, continues to be evaluated for humans.

Congenital parvovirus infection

A case of congenital parvovirus (B19) viraemia with associated thrombocytopenic purpura and platelet antigen incompatibility in an infant is reported. Results of laboratory investigations indicated that the baby was infected in utero.

Evaluation of severe growth retardation using cordocentesis--hematologic and metabolic alterations by etiology

Hematologic and respiratory blood gas parameters were studied in 21 fetuses with severe or early-onset (at or before 34 weeks) growth retardation and in 44 age-matched control fetuses. Diagnostic categories included uteroplacental insufficiency (N = 7) and uteroplacental insufficiency with associated fetal structural abnormality (N = 7), aneuploidy (N = 5), and congenital infection (N = 2). The mean (+/- 1 SEM) gestational age was 29.3 +/- 1 week. Compared with the control group matched for gestational age, the growth-retarded fetuses had higher hematocrits regardless of etiology. The platelet count was reduced in growth-retarded fetuses with aneuploidy (P less than .05). Leukopenia was observed in a fetus with congenital infection and in the group of fetuses with uteroplacental insufficiency unassociated with a structural abnormality (P less than .05). Leukocytosis was seen in growth-retarded aneuploid fetuses (P less than .01). The pH, pO2, and percent oxygen saturation were each lower in growth-retarded fetuses with either uteroplacental insufficiency or aneuploidy, and the pCO2 and bicarbonate were higher compared with controls (each P less than or equal to .05). Appropriately grown aneuploid fetuses had normal hematologic and respiratory blood gas measurements but were significantly more likely not to be trisomic (P = .04). Fetuses with uteroplacental insufficiency unassociated with a structural anomaly had significantly higher umbilical artery systolic/diastolic ratios than both the control group (P = .0002) and the group with uteroplacental insufficiency and a structural anomaly (P less than .008). This investigation confirms previous studies of fetuses suffering uteroplacental insufficiency and extends the observations to other etiologies.(ABSTRACT TRUNCATED AT 250 WORDS)

Should we expand the TORCH complex? A description of clinical and diagnostic aspects of selected old and new agents

Physicians faced with a newborn infant with signs and symptoms of perinatal infection must consider a multitude of diseases, and may need to embark on a complex differential diagnosis. As stated by Alford in 1967, "neonatal diagnoses of infections acquired in utero, natally and postnatally, are inherently difficult." Twenty years later, this statement is still true. In this review, the diagnostic problems encountered in the evaluation of a suspected perinatal infection have been discussed, as have the complexities of the evaluation process for the original four TORCH agents, as well as for three additional agents. From our point of view, the usefulness of the TORCH acronym has been to focus attention on perinatal infections. Its main drawback has been the resultant overuse of TORCH titers ignoring the complexity of the diagnostic process. Ideally, the TORCH concept serves two functions. It continues to remind us of the multiplicity of pathogens that can cause perinatal infection, and it underscores the need for thorough diagnostic evaluation for these challenging infections. We believe that this is an appropriate expansion of the TORCH complex, and we anticipate that this expanded TORCH complex will continue to grow.

[Association of non-immunologically-induced hydrops fetalis with Parvovirus B19 infection]

Five weeks after the onset of clinical symptoms of erythema infectiosum, a 24 year old pregnant woman, gravida I, para 0, suffered a hydrops fetalis which resulted in fetal loss. The maternal infection with the human parvovirus B19 could be confirmed serologically with ELISA and immunoblot by detecting specific IgM antibodies against B19. In an amniotic sample of the fetus Parvovirus B19 DNA could be detected by hybridisation. Fetal loss was obviously due to a parvovirus B19 infection of the mother and the fetus.