High levels of IgM antibodies specific for Toxoplasma gondii in pregnancy 12 years after primary toxoplasma infection. Case report

A case of high levels of specific IgM antibodies registered by the immunosorbent agglutination assay (ISAgA) in a pregnant woman with a history of toxoplasmosis is reported. The patient had acute lymphoglandular toxoplasmosis diagnosed serologically by increases in the specific antibody titer detected by the Sabin-Feldman test (SFT) and pathohistologically 12 years before pregnancy. In pregnancy, she had stable titers of specific antibodies registered by the SFT, enzyme-linked immunosorbent assay (ELISA), indirect fluorescent antibody test (IFAT), indirect hemagglutination test (IHAT) and direct agglutination test. Specific IgM antibodies were detected by the ISAgA but not by the IgM-IFAT, IgM-ELISA and IgM-IHAT. She had a normal pregnancy and gave birth to a clinically healthy baby who had a negative ISAgA finding at 7 days of age. This case indicates that ISAgA is not necessarily a marker of recent infection and is therefore not reliable for the diagnosis of toxoplasmosis in pregnancy.     

Application of staphylococcal protein A for immunodiagnosis of early toxoplasma infection]

RH strain Toxoplasma gondii was used to inoculate mice and rats. Sera collected at intervals were assayed by the indirect fluorescent antibody test (IFAT) and the latex agglutination test (LAT) to monitor the time-course change in titers of anti-toxoplasma IgM and IgG antibodies. In addition, the above sera and some anti-toxoplasma seropositive human sera (with IFAT antibody titers greater than or equal to 1:16) were adsorbed with staphylococcal protein A (SpA) and assayed for changes in IgM and IgG antibody titers so as to evaluate the usefulness of SpA adsorption in detecting anti-toxoplasma IgM which shows up early in toxoplasma infections. Samples assayed included 262 sera from mice, 65 sera from 5 rats and 85 human sera. The results revealed that parasite specific IgM-IFAT antibodies were detectable in 40% of the sera from mice 3 days after infection. After SpA adsorption, however, the IgM-IFAT antibody could be detected in a few specimens as early as 2 days post infection. IgG-IFAT and LAT antibodies first appeared in the sera on the 5th day of infection. In mice inoculated with freeze-killed tachyzoites (immunized mice), IgG-IFAT and LAT antibodies remained high from 16-35 days after inoculation, whereas IgM-IFAT antibodies were undetectable. Even after SpA treatment, only about half of the 16-day samples showed IgM antibody titers and the other specimens still remained negative. In general, IgM antibody titers increased 2-6 fold after SpA adsorption while IgG antibodies were almost completely removed after the treatment with a residual IgG-IFAT titer of less than or equal to 1:4.(ABSTRACT TRUNCATED AT 250 WORDS)     

Pregnancy as a risk factor for acute toxoplasmosis seroconversion

OBJECTIVE: To test the hypothesis that pregnancy is a risk factor for toxoplasmosis seroconversion. MATERIALS AND METHODS: A prospective observational study of women at child-bearing age vulnerable to Toxoplasma gondii. Serological reactions with indirect immunofluorescent antibody and immunoenzyme tests were used. The risk estimate used limits of reliability at 95%, and the results were validated by chi(2) and RR tests. RESULTS: Acute infection among pregnant women was 8.6% (45/522), and pregnancy was confirmed to be a risk factor for seroconversion (P=0.001). Living in close contact with host animals and vehicles of oocyst transmission proved to be a statistical risk for pregnant women to seroconvert, which was aggravated in adolescents. CONCLUSION: Gestation, potentiating susceptibility to this infection, points to the need of primary and secondary prevention for all pregnant women at risk.     

Survey of obstetrician-gynecologists in the United States about toxoplasmosis

BACKGROUND: Although the incidence of toxoplasmosis is low in the United States, up to 6000 congenital cases occur annually. In September 1998, the Centers for Disease Control and Prevention held a conference about toxoplasmosis; participants recommended a survey of the toxoplasmosis-related knowledge and practices of obstetrician-gynecologists and the development of professional educational materials for them. METHODS: In the fall of 1999, surveys were mailed to a 2% random sample of American College of Obstetricians and Gynecologists (ACOG) members and to a demographically representative group of ACOG members known as the Collaborative Ambulatory Research Network (CARN). Responses were not significantly different for the random and CARN groups for most questions (p value shown when different). RESULTS: Among 768 US practicing ACOG members surveyed, 364 (47%) responded. Seven per cent (CARN 10%, random 5%) had diagnosed one or more case(s) of acute toxoplasmosis in the past year. Respondents were well-informed about how to prevent toxoplasmosis. However, only 12% (CARN 11%, random 12%) indicated that a positive Toxoplasma IgM test might be a false-positive result, and only 11% (CARN 14%, random 9%) were aware that the Food and Drug Administration sent an advisory to all ACOG members in 1997 stating that some Toxoplasma IgM test kits have high false-positive rates. Most of those surveyed (CARN 70%, random 59%; chi2 p < 0.05) were opposed to universal screening of pregnant women. CONCLUSIONS: Many US obstetrician-gynecologists will encounter acute toxoplasmosis during their careers, but they are frequently uncertain about interpretation of the laboratory tests for the disease. Most would not recommend universal screening of pregnant women.     

The indirect mixed antiglobulin reaction test using a commercially available kit for the detection of antisperm antibodies in serum

A simple procedure is described for the detection of antisperm antibodies of the IgG class in human serum using the indirect mixed antiglobulin reaction (MAR) test. The test uses only one dilution of serum (1/16) and no washing procedures. The test was performed in 361 sera. Comparative studies were conducted with the tray agglutination test (TAT) in 164 sera and with the direct MAR test on semen in 110 cases. In 24 sera with borderline test results, and in 13 sera with discordant findings, evidence of antisperm antibody activity was investigated by means of additional testing, namely, the adenosine triphosphate release cytotoxicity test (ARCT) and the indirect immunobead tests (IB) for IgA and IgM. Using the value of 40% reaction between motile spermatozoa and coated latex particles as the lower limit of significant activity, the indirect SpermMAR test has a sensitivity of 96% and specificity of 87%. The two false-negative indirect MAR results occurred in cases with IgM, the clinical significance of which is doubtful. Hence, the indirect MAR test appears to be an ideal screening procedure for sperm antibodies in serum since it is easy to perform and sensitive. Considering the false-positive rate of 13%, additional tests should, however, be performed on sera with a reaction of 40% or more in order to assess the relevance of the antibodies as a cause of infertility.     

Attitude towards serological tests for infection during pregnancy

Summary In anticipation of systematic prenatal screening at the antenatal clinic of Gasthuisberg University Hospital, Leuven, Belgium, the attitude of 500 successive pregnant women towards testing for rubella, toxoplasmosis, hepatitis B virus, HIV and syphilis was studied by means of written questionnaires. All tests were well accepted, toxoplasmosis and rubella being most (92 and 91%), syphilis and HIV being least (79 and 82%) favoured. Refusal was generally associated with lower education, but refusal for syphilis and HIV was associated with high education. Ninety-four percent wanted to be informed of the results of the tests. Only one woman (0.2%) of those who agreed with testing did not want to know her HIV test result. Pregnant doctors were more reluctant about screening, in particular for sexually transmitted diseases, whereas nurses were in favour of it. Written information failed to increase the acceptance rate, but lowered the number of women without an opinion.     

Neonatal screening for congenital toxoplasmosis in a cohort of 165 women infected during pregnancy and influence of in utero treatment on the results of neonatal tests

The aim of this study was to determine the performances of methods used for the neonatal diagnosis of congenital toxoplasmosis. We included 165 pregnant women infected during pregnancy over a 10-year period. Fifty-seven cases of congenital toxoplasmosis were demonstrated (34.5%). Neonatal diagnosis gave positive results in 50 cases (88%). Parasites were isolated from placenta or cord blood in 61% of the infected newborns, more frequently from placenta (60%) than from cord blood (43%). This method was the only criterion of infection in 18% of these infected infants. The detection of specific IgM and IgA antibodies performed on 42 sera of infected infants allowed the diagnosis of congenital infection in 34 cases (81%). IgA antibodies were more frequently detected (60%) than specific IgM (50%). Neonatal and prenatal screening were carried out for 143 pregnant women. This combination diagnosed 39 of 40 infected infants (98%). Prenatal diagnosis identified 30 of 40 cases (75%). Nine cases were diagnosed through neonatal screening and one case with the postnatal follow-up. When prenatal diagnosis was positive, pyrimethamine and sulfadoxine were administered to the mothers (25 cases) in addition to spiramycin. Toxoplasma gondii was less frequently isolated in the placenta and the cord blood of these women (32% and 19%, respectively) than in women treated by spiramycin alone (83% and 63%) proving the antiparasitic action of these drugs. In conclusion, neonatal screening combining parasite detection in placenta and immunological methods on cord blood is essential particularly when prenatal diagnosis is negative. Therefore, when this diagnosis is positive, a treatment with pyrimethamine and sulfamide can be started in the first month of life.     

Prenatal diagnosis of congenital toxoplasmosis

Ninety-three pregnant women with Toxoplasma gondii seroconversion during pregnancy underwent prenatal diagnosis of fetal toxoplasmosis. The following tests were used: (1). amniocentesis for mouse inoculation (93 subjects), (2). amplification of T. gondii DNA by polymerase chain reaction (PCR) (79 subjects), and (3). cordocentesis for the detection of T. gondii-specific IgM antibodies (13 subjects). All patients had serial ultrasonographic scans to detect those fetuses with abnormalities that could be associated with congenital toxoplasmosis. Eighteen pregnancies (19.4%) had evidence of vertical transmission. A total of 11/18 (61.1%) had positive amniotic mouse inoculation test, while 10/12 (83.3%) had positive PCR results. The combination of both tests allowed the prenatal diagnosis in 17/18 infected fetuses (94.4%). All patients who underwent cordocentesis for the detection of T. gondii-specific IgM antibodies had negative results. However, in two of the above cases fetal toxoplasmosis was detected by amniotic fluid studies. In five of the infected fetuses there were abnormal ultrasonographic findings. All pregnancies with evidence of vertical transmission were terminated, whereas the remaining pregnancies proceeded normally to term. The present data showed that amniotic fluid studies, preferably PCR amplification of T. gondii DNA, are the best diagnostic tools for the detection of vertical transmission in pregnancies with seroconversion during pregnancy.     

Sperm-agglutinating antibodies in infertile women

This paper explored the experience with sperm-agglutininating antibodies in 168 infertile couples. 2 of the 46 subjects with organic causes for infertility had positive sperm agglutination tests, and neither became pregnant in the 6-18 month followup period. Of the remaining 122 subjects with no organic cause for infertility, 24 (20%) had positive tests (including 13 women with primary infertility and 11 with secondary infertility). 9 of the 24 women (38%) with positive tests became pregnant following condom therapy. There was no correlation between the sperm antibody test and postcoital test, nor between sperm agglutinins and ABO incompatibility. These results suggest that a small number of women have specific reactions against sperm or seminal fluid that inhibit fertility. It is concluded that screening of serum for sperm agglutinins should be continued to provide an estimate of immunologic reactions against semen in cases of infertility.     

Is One Question Enough to Detect Female Sexual Dysfunctions? A Diagnostic Accuracy Study in 6,194 Women

IntroductionLiterature shows that recognition of sexual dysfunctions in women is insufficient and existing instruments to aid detection are mostly too extensive to be used in routine practice.AimTo develop a brief and accurate screening instrument to detect female sexual dysfunctions in routine care.MethodsThe initial item pool for the index test consisted of 15 items. In a 4-year period, a total of 12,957 persons filled out the test on a specifically designed web-site. Six thousand one hundred ninety-four complete data sets could be used for statistical analysis. The validated German version of the Female Sexual Function Index (FSFI-d) served as reference standard to estimate the accuracy of the screening test. In order to test several possible ways of combining items a multi-step procedure employing univariate analyses, multiple logistic regression, and classification and regression tree analysis was applied to a learning sample and cross-validated in a test sample.Main Outcome MeasuresDiagnostic performance (sensitivity, specificity, positive and negative predictive value, accuracy, diagnostic odds ratio as well as adjusted odds ratio) of the items and resulting models to discriminate women with sexual dysfunction from those without were calculated.ResultsOne dichotomous question for overall satisfaction proved to show high accuracy as a stand-alone instrument and played also a central role in multivariate models. It may be recommended as a one-question screening test (76.4% sensitivity and 76.5% specificity in the test sample). A hierarchical two-question test yielded higher sensitivity (93.5%) and lower specificity (60.1%). A slightly more extensive version consists of five questions (83.1% sensitivity and 81.2% specificity).ConclusionsDespite some methodological limitations of our study all developed tests showed acceptable to good diagnostic performance, all are very short and could therefore be easily implemented into routine care. Further tests of psychometric properties in other settings are needed. Kriston L, Günzler C, Rohde A, and Berner MM. Is one question enough to detect female sexual dysfunctions? A diagnostic accuracy study in 6,194 women.     

Diagnosis of perinatal TORCH infections

Collectively, TORCH infections create more neonatal morbidity than early-onset group B streptococcal sepsis. Fortunately, the incidence of maternal infection by CMV or toxoplasmosis is low (2-10 per 1,000 births). There have been tremendous advances in direct antigen testing and in the sensitivity and specificity of IgG and IgM testing. Consistently, research laboratories show more accurate results than in the past. Unfortunately, commercial laboratories are using older, single-kit testing. The relatively poor degree of reliability can lead to unnecessary obstetric intervention or elective termination. Any positive pathogen-specific IgM on maternal serum should have additional confirmatory testing in a reputable research laboratory before any intervention. Direct antigen testing or multiple testing would seem to be appropriate for confirmation. This may include amniocentesis of fetal blood sampling. The research on the newer tests is based of the evaluation of blood from seriously immunocompromised subjects. Extrapolations of test accuracy to similar tests on healthy, pregnant women and their fetuses are likely to be in error. The application of these accurate tests to the obstetric population is a critical research need.     

Analysis of complications during pregnancy in women with serological features of acute toxoplasmosis or acute parvovirosis

OBJECTIVES: Toxoplasma gondii and parvovirus B19 (PVB19) infections in a healthy adult are usually asymptomatic. Congenital toxoplasmosis is the cause of hydrocephalus, chorioretinitis and intracranial calcifications. Hydrops remains the most common complication during the fetal PVB infection. The aim of the study was to analyze the complications during pregnancy in women with serological features of acute toxoplasmosis or acute parvovirosis. MATERIAL AND METHODS: In our study, we have included 1800 pregnant women, hospitalized in Department of Fetal-Maternal Medicine and Gynecology Research Institute, Polish Mother's Memorial Hospital (RIPMMH) in Lodz, (Poland) between 2000-2007. Anti-T.gondii antibodies were tested by ELISA Vidas Toxo IgG, ELISA Vidas IgM (BioMerieux) and Platelia Toxo-A Anti-PVB19 antibodies were detected by NovaLisa Parvovirus B19 Recombinant IgG-ELISA and IgM-ELISA (NOVATEC). RESULTS: Prevalence of IgG anti-PVB19 among pregnant women was 35% (n=633). IgG anti-T.gondii was noticed in 55.5% (n=910) of women. Serological features of acute parvovirosis were demonstrated in 13.5% (n=243) of the patients and 74.2% (n=256) of women suffered from acute toxoplasmosis. Fetal hydrocephalus or ventriculomegaly was diagnosed in 19.5% (n=64) of the pregnancies with IgM anti-PVB19 and in 7.3% (n=79) women with serological features of acute toxoplasmosis. In 8.5% (n=28) of the patients with IgM anti-PVB19 and 9% (n=5) of the pregnant women with IgM and/or IgA anti-T.gondii, fetal hydrops was detected. Intrauterine death was diagnosed in 4.5% (n=15) of the cases with acute PVB19 infection and in 2.3% (n=6) of the patients with acute toxoplasmosis. Amniotic fluid disorders were noticed more often in women with acute parvovirosis (polihydramnion 15.5%, n=51; oligohydramnion 8.5%, n=28; ahydramnion 6.3%, n=21) than in those with active toxoplasmosis (polihydramnion 3.4%, n=9; oligohydramnion 3.4%, n=9; ahydramnion 0%). We have examined also the influence of T.gondii and PVB19 infections on an intrauterine growth restriction, preterm delivery and spontaneous abortions. CONCLUSIONS: In conclusion, infections of T.gondii and PVB19 are a very common cause of complications in pregnancy. Due to high prevalence rate of IgG antibodies in Poland, it is necessary to consider routine serological testing in pregnancy.     

Toxoplasmosis-antibody seroprevalence in Mecklenburg-Western Pomerania]

OBJECTIVE: The aim of this study was to get a general idea of the antibody prevalence of toxoplasmosis within the different agegroups of the population of Mecklenburg-Western Pomerania. 4854 serums (collected between 1994 and 1996) from different institutions of the federal state were investigated with the "Toxo-Competitions Test LTXC)" at the Mini-Vidas divice (bio Merieux). MATERIAL AND METHODS: An antibody prevalence rate of 59% was found. As expected, with rising age a continuing increase was recognisable. The antibody prevalence rate with the male test persons amounted to 58.5%, with the female test persons to 59.3%, and within the pregnant women 63.2%. RESULTS: Therefore 36.8% of pregnant women have got no toxoplasmosis antibodies, i.e. they are exposed to the danger of a primary infection. Within pregnant women aged between 20 and 40 an increase of antibody prevalence of 1% per year of age was recognisable. There was only a small share of pregnant women (10.5%), but they confirm the facts known from literature. CONCLUSIONS: More than 1/3 of our test persons hadn't had toxoplasmosis antibodies. Therefore in order to reduce the danger of a primary infection in pregnant women a screening before pregnancy in recommendable.     

Studies on the management of pregnant women having high hemagglutination inhibition (HI) antibody titer of rubella virus in the first trimester examination of rubella virus antibody in the pregnant women having high HI titer by different methods and prognosis of their infants after birth

Several serological studies of rubella virus (RV) infection were carried out on sera of 45 pregnant women having RV hemagglutination inhibition (HI) antibody titer more than 1:512 in the first trimester, including a follow-up study of these women's pregnancies. In order to detect RV-specific IgM antibody, various procedures were employed as follows: Complement fixation test (CF), HI test after treatment of the sera with Protein-A (ProA-HI), enzyme linked immunosorbent assay (ELISA) by indirect or sandwich procedures and several tests using fractionated sera by sucrose density gradient ultracentrifugation (SDG). Positive ratios found with the CF test and ProA-HI were 26.7% and 20.0%, respectively. In indirect ELISA, 4 cases were positive for RV-specific IgM, but all sera were negative in sandwich ELISA and SDG tests. Both RV isolation from urine of some infants and detection of high RV-specific IgM antibody in cord sera failed to be positive. Of 44 pregnancies, 4 cases resulted in spontaneous abortion and all others in normal delivery. These forty normal infants had no sign of congenital rubella syndrome, but one case among them showed polysyndactyly . The results obtained here seemed to indicate that sandwich ELISA is the most valuable and convenient method among the tested procedures for clinically determined diagnosis of recent RV infection in pregnant women having a high HI antibody titer.     

Feasibility of human T-lymphotropic virus type I screening using pooled sera.

BACKGROUND AND PURPOSE: The human T-cell lymphotropic virus type I (HTLV-I) seroprevalence rate among volunteer blood donors in Taiwan is low. To study the feasibility of HTLV-I enzyme immunoassay (EIA) screening using pooled sera, we prospectively compared its sensitivity to that of the routine test for each donor. METHODS: HTLV-I EIA tests for each serum sample and a pooled-sera test with 50 samples from voluntary donated blood samples were performed concurrently to assess the effectiveness and cost savings of this screening method. RESULTS: Of 135,606 blood samples from volunteer donors tested for HTLV-I infection, 60 samples (0.044%) were HTLV-I EIA-positive using the routine method. Among these, the positive results were confirmed by Western blot in 22 samples (36.7%). In the pooled-sera test, 17 of 2,713 pooled samples were EIA-positive and these results were all confirmed by Western blot. Five of the 22 (22.7%) EIA-positive samples had a false-negative result in the pooled-sera test. Serial dilution in these five cases revealed that the maximum dilution before loss of sensitivity was 8-fold for two specimens and 16-fold for three specimens. CONCLUSION: In this study, the 50-pooled sera test had higher specificity (100%), but lower sensitivity (77.3%), than the routine HTLV-I screening. Our results suggest that use of a pooling method with five samples would leave a reasonable safety margin and be feasible for HTLV-I mass screening in areas with low seroprevalence for HTLV-I infection.     

Congenital toxoplasmosis: a review

Toxoplasmosis is caused by infection with the protozoan parasite Toxoplasma gondii. In the United States, approximately 85% of women of childbearing age are susceptible to acute infection with T. gondii. Acute infections in pregnant women may cause serious health problems when the organism is transmitted to the fetus (congenital toxoplasmosis), including mental retardation, seizures, blindness, and death. An estimated 400 to 4000 cases of congenital toxoplasmosis occur in the U.S. each year. Manifestations of congenital toxoplasmosis may not become apparent until the second or third decade of life. Serologic tests are used to diagnose acute infection in pregnant women, but false-positive tests occur frequently, therefore, serologic diagnosis must be confirmed at a reference laboratory before treatment with potentially toxic drugs should be considered. Much of congenital toxoplasmosis can be prevented by educating women of childbearing age and pregnant women to avoid eating raw or undercooked meat, to avoid cross-contamination of other foods with raw or undercooked meat, and to use proper cat-litter and soil-related hygiene.     

Early detection of pregnancy by new beta-hCG monoclonal urine test

1,066 urine samples were assayed by beta-human chorionic gonadotrophin (beta-hCG) monoclonal pregnancy test with a sensitivity of 150 IU hCG/l. Tests were performed in 5 independent laboratories and results were compared with those of pregnancy tests which were used routinely. Urine samples which showed discordant results under evaluation were reassayed for beta-hCG using radioimmunoassay. 569 urine samples were from nonpregnant women, and a consistent result with comparison pregnancy tests was achieved in 97.19% of urine samples. The trial test from 389 urine samples of pregnant women was 99.49% in accordance with routine pregnancy tests. Results from 108 urine samples of women over 40 years of age indicate the high specificity of the new beta-hCG monoclonal pregnancy test. Titration experiments showed 63% positive tests at 150 IU beta-hCG/l. Data presented combine to suggest that this new monoclonal pregnancy test is a valuable aid in diagnosing early pregnancy. It may also be used in the diagnosis of tubal pregnancy and in other ectopic processes.     

Toxoplasmosis and pregnancy: current trends in serological follow-up

Prevention of congenital toxoplasmosis is based on serological follow-up of pregnant patients. Routine serology includes search and titration of specific IgG and IgM. In presence of specific IgM, complementary tests should be carried out for a better dating of the contamination. Among them, the avidity test is the most currently used. It allows to exclude a recent infection in the majority of the cases. For difficult cases, it is useful to contact a specialized laboratory.     

Commercial laboratory IgM testing for Toxoplasma gondii in pregnancy: a 20-year experience

OBJECTIVE: This study was performed to review the clinical utility of commercial laboratory Toxoplasmosis-specific IgM testing during pregnancy and outcomes of the gestation at our institution. METHODS: A retrospective review of all women referred for suspected acute Toxoplasma gondii infection during pregnancy from 1984 through 2004 was performed. Women were diagnosed with suspected acute toxoplasmosis based on commercial laboratory serologic antibody testing. All women had blood sent to a recognized reference laboratory for antibody testing within 2 weeks of the commercial laboratory results. The study protocol was approved by the Institutional Review Board. Chi-square analysis were used with a significance of P < .05. RESULTS: A total of 130 women were evaluated during the study period with 116 IgM positive results from the commercial laboratories. The commercial laboratory antibodies were as follows: IgM positive with IgG negative (n = 20), IgM positive with IgG positive (n = 96), and IgM negative with IgG positive (n = 14). There was a significant reduction in the IgM positive results when comparing commercial laboratory (n = 116) with the reference laboratory results (n = 28; p < .001). Acute toxoplasmosis infection was diagnosed in 7 (5%) of the women. All cases of acute toxoplasmosis infection had a positive commercial laboratory IgM result. The false positive rate for the commercial laboratory IgM was 88.6% and the diagnostic indices were sensitivity 100%, specificity 11.4%, positive predictive value 6% and negative predictive value 100%. CONCLUSION: Commercial laboratory Toxoplasmosis-specific IgM is associated with a high false positive rate. The commercial and reference laboratory IgM results identified all cases of acute toxoplasmosis infection. Commercial laboratories reflexively obtaining reference laboratory confirmation of positive results could reduce costs associated with testing, referrals, retesting, and invasive procedures.