Search

Objective: Toxoplasmosis acquired in early pregnancy is a potentially severe complication for the fetus. Evaluating the risk of transplacental infection in pregnant women accessing the Tuscany Reference Center for Infectious Diseases in Pregnancy during the last 20 years with suspected or confirmed toxoplasmosis acquired in early pregnancy was the aim of the study.Study Design: We retrospectively enrolled all pregnant women undergoing amniocentesis for toxoplasmosis acquired in the first 16 gestational weeks in the period 1999-2019, comparing patients with certain acute infection (seroconversion occurred in pregnancy, CAIP) with those with suspected acute infection (IgG positive with low/intermediate IgG avidity index, SAIP).Results: 237 patients were enrolled, 187 (78.9%) with SAIP and 50 (21.1%) with CAIP. Specific IgM was detected in 47.5% and 76.7% (p-value 0.001), and the mean IgG avidity index was 22.7% and 7.1% (p-value < 0.001) in the SAIP and in the CAIP group, respectively. The mean delay from diagnosis to antibiotic initiation was 14.6 in SAIP and 11 days in CAIP group. Toxoplasma DNA was detected in the amniotic fluid in one case in a patient with CAIP. Excluding 24 newborns with not available data, prevalence of congenital infection was 0.47% [1/213 (95% CI 0.08%-2.61%)], 0% [0/178 (95% CI 0%-2.11%)] in SAIP and 2.8% [1/35 (95% CI 0.51%-14.53%)] in CAIP group.Conclusions: Toxoplasmosis acquired in early pregnancy has a low risk of fetal infection. Actively discussing case-by-case amniocentesis indication with patients, especially when a recent toxoplasmosis is not properly confirmed, is desirable. [ABSTRACT FROM AUTHOR]

Toxoplasmosis is one of the common chronic infections caused by the parasite Toxoplasma gondii. Even though its infection in healthy non-pregnant women is self-limited and largely asymptomatic, the main concern is the risk to the fetus by vertical transmission in pregnancy. Congenital toxoplasmosis can result in permanent neurological damage and even serious morbidity such as blindness. Screening programs are implemented in various countries depending on the prevalence and virulence of the parasite in the respective regions. Upon diagnosis of infection, appropriate antibiotic therapy should be initiated as it has been proven to reduce the risk of fetal transmission. Primary prevention remains the key intervention to avoid the infection and hence patient education is an important aspect of the management. [ABSTRACT FROM AUTHOR]

Introduction and Aim: Toxoplasma gondii is an intracellular protozoan parasite infecting approximately 30% of the global human population. It has often been suggested that chronic infection with T. gondii is related to personality changes and various mental disorders including depression. It is not known whether this includes post-partum blues or depression. In this study, we test the hypothesis that there is a relationship between T. gondii infection and post-partum blues by measuring the association between infection and postpartum blues.Methods: A total of 475 Chinese women who have just given birth were detected serology for Toxoplasma IgG and IgM antibodies, and evaluated the degree of depression by Hamilton Depression Scale (HAMD) score. Data were analyzed by Chi-square or Fisher's Exact tests using SPSS software.Results: We found an overall Toxoplasma seroprevalence of 5.68% (27/475; 95% CI: 3.59-7.77) which was broken down into a prevalence of 6.60% (7/106; 95% CI: 1.80-11.41) in mothers with post-partum blues and 5.42% (20/369; 95% CI: 3.10-7.74) in non-affected mothers. There was no significant association between infection and post-partum blues (p = 0.64).Conclusion: The results suggest that there is no relationship between T. gondii infection and postpartum blues, at least in this sample of patients from China. [ABSTRACT FROM AUTHOR]

The immunochromatographic test (ICT) is a convenient and low-cost method that can rapidly obtain results (10 min) under normal conditions. In this study, we established an ICT assay with two monoclonal antibodies: TgSAG3-3A7 and TgSAG3-4D5 based on the conserved protein of TgSAG3 that can be expressed in all the infective stages of T. gondii. 20 nm gold particles were prepared and conjugated with TgSAG3-3A7 MAb at the concentration of 12.5 μg/mL. TgSAG3-4D5 MAb were used as the capture antibody because of its higher affinity tested by ELISA. The detection limit of the ICT assay was 100 ng with visual detection under optimal conditions of analysis. Positive porcine serum of Cryptosporidium suis , Mycoplasma suis , Streptococcus suis , Salmonella choleraesuis , Cysticercus cellulosae , Isospora suis , and Trichinella spiralis were used to evaluate the specificity of this ICT and no cross-reactivity was observed. 310 porcine serum samples obtained from pig farms in Zhejiang Province, China were detected by this ICT and ELISA kit, 23 positive samples were found by the developed strip with the rate of 7.42% comparing with 22 positive samples detected by the commercially ELISA kit which the positive rate was 7.1%, the relative sensitivity and specificity of this ICT are 100% and 99.65%. Therefore, the ICT established in this study is proved effective, simple, specific and sensitive of T. gondii detection. [ABSTRACT FROM AUTHOR]

There are not any records on the detection of Toxoplasma gondii and Neospora caninum in tissues of wild birds in the African continent. The aim of the study was to investigate the occurrence of DNA from these protozoan parasites in brain tissue samples collected in years 2014–2015 from 110 wild and domestic birds of 15 orders. Birds came mainly from the province of Limpopo (n = 103); the other seven birds came from other five provinces of South Africa. Parasite DNAs were detected by PCR in animal brains. While all samples were negative for N. caninum , T. gondii DNA was detected in three (2.7%) birds: a Red-eyed Dove ( Streptopelia semitorquata ), a Laughing Dove ( S. senegalensis ) and a Southern-Yellow-billed Hornbill ( Tockus leucomelas ), all from Limpopo province. Positive samples were selected for genotyping by a 15 microsatellite markers method in a single multiplex PCR assay. Only the sample from the Red-eyed Dove was successfully genotyped and characterized as type II. This is the first detection of T. gondii in tissue of native African wild birds and the first study focusing on N. caninum in birds from South Africa. [ABSTRACT FROM AUTHOR]

Diagnosis of clinical toxoplasmosis remains a challenge, thus limiting the availability of human clinical samples. Though murine models are an approximation of human response, their definitive infection status and tissue availability make them critical to the diagnostic development process. Hydrogel mesh nanoparticles were used to concentrate antigen to detectable levels for mass spectrometry. Seven Toxoplasma gondii isolates were used to develop a panel of potential peptide sequences for detection by parallel reaction monitoring (PRM) mass spectrometry. Nanoparticles were incubated with decreasing concentrations of tachyzoite lysate to explore the limits of detection of PRM. Mice whose toxoplasmosis infection status was confirmed by quantitative real-time PCR had urine tested by PRM after hydrogel mesh concentration for known T. gondii peptides. Peptides from GRA1, GRA12, ROP4, ROP5, SAG1, and SAG2A proteins were detected by PRM after nanoparticle concentration of urine, confirming detection of T. gondii antigen in the urine of an infected mouse. [ABSTRACT FROM AUTHOR]

Nanotechnology is a promising arena for generating new applications in Medicine. To successfully functionalised nanoparticles for a given biomedical application, a wide range of chemical, physical and biological factors have to be taken into account. Silica-coated nanoparticles, (SiO2NP) exhibit substantial diagnostic activity owing to their large surface to volume ratios and crystallographic surface structure. This work aimed to evaluate the advantage of bioconjugation of SiO2NP with PAb against Toxoplasma lyzate antigen (TLA) as an innovative diagnostic method for human toxoplasmosis. This cross-sectional study included 120 individuals, divided into Group I: 70 patients suspected for Toxoplasma gondii based on the presence of clinical manifestation. Group II: 30 patients harboring other parasites than T. gondii Group III: 20 apparently healthy individuals free from toxoplasmosis and other parasitic infections served as negative control. Detection of circulating Toxoplasma antigen was performed by Sandwich ELISA and Nano-sandwich ELISA on sera and pooled urine of human samples. Using Sandwich ELISA, 10 out of 70 suspected Toxoplasma -infected human serum samples showed false negative and 8 out of 30 of other parasites groups were false positive giving 85.7% sensitivity and 84.0% specificity, while the sensitivity and specificity were 78.6% and 70% respectively in urine samples. Using Nano-Sandwich ELISA, 7 out of 70 suspected Toxoplasma -infected human samples showed false negative results and the sensitivity of the assay was 90.0%, while 4 out of 30 of other parasites groups were false positive giving 92.0% specificity, while the sensitivity and specificity were 82.6% and 80% respectively in urine samples. In conclusion, our data demonstrated that loading SiO2 nanoparticles with pAb increased the sensitivity and specificity of Nano-sandwich ELISA for detection of T.gondii antigens in serum and urine samples, thus active (early) and light infections could be easily detected. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the performance of conventional serology (Q-Preven™ and ELFAVIDAS™) and flow cytometry-based serologic tools for early serologic diagnosis of congenital toxoplasmosis. The study groups included prospectively confirmed cases of congenital toxoplasmosis (TOXO = 88) and age-matching non-infected controls (NI = 15).The results demonstrated that all samples tested positive/indeterminate for anti- T. gondii IgM screening at birth using air-dried whole blood samples. Serum samples collected at 30–45 days after birth tested positive for ELFAVIDAS™ IgG in both groups. While all NI tested negative for ELFAVIDAS™ IgM and IgA, only 78% and 36% of TOXO tested positive for IgM and IgA, respectively. Flow cytometry-based anti- T. gondii IgM, IgA and IgG reactivity displayed moderate performance with low sensitivity (47.6%, 72.6% and 75.0%, respectively). Regardless the remarkable specificity of IgG1, IgG2 and IgG3 subclasses for early diagnosis, weak or moderate specificity was observed (Se = 73.9%, 60.2% and 83.0%, respectively). The analysis of IgG avidity indices (AI) demonstrated the highest performance among the flow cytometry-based methods (Se = 96.6%; Sp = 93.3%), underscoring the low avidity index (AI < 60%) within TOXO (97.0%) in contrast with the high avidity index (AI > 60%) in NI (93%). Analysis of anti- T. gondii IgG and IgG3 reactivity for mother:infant paired samples may represent a relevant complementary tests for early diagnosis. In conclusion, a feasible high-standard algorithm (Accuracy = 97.1%) was proposed consisting of Q-Preven™ IgM screening at birth, followed by ELFAVIDAS™ IgM and flow cytometric IgG avidity analysis at 30–45 days after birth as a high performance tool for early serological diagnosis of congenital toxoplasmosis. [ABSTRACT FROM AUTHOR]

Serological tests available for the diagnosis of acute Toxoplasma gondii infection have limitations in establishing the temporal diagnosis of acute toxoplasmosis. The present analytical-descriptive investigation comprises of a prospective longitudinal cohort study to search for accurate biomarkers to distinguish acute, early and late convalescent T. gondii infection. Classic methods (immunofluorescence-IFA along with Enzyme-linked immunosorbent-ELISA and fluorescent-ELFA assays) for IgM, IgA, IgG and IgG avidity were employed in parallel with flow cytometry-based anti-fixed T. gondii tachyzoites serology (FC-AFTA-IgM, IgG, IgG avidity and IgG subclasses). The results reemphasized the limitations of IgM & IgG IFA, IgG ELFA, IgG & IgG subclasses FC as well as IgA ELISA biomarkers for the temporal diagnosis of acute toxoplasmosis. Receiver Operating-characteristics features (ROC-curves) were employed to adjust conventional cut-offs aiming at establishing a novel protocol to discriminate more accurately the different phases of toxoplasmosis. Conversely, IgM presented high diagnostic co-positivity for acute toxoplasmosis (97% for ELISA, 96% for ELFA and 95% for FC-AFTA) along with moderate co-negativity for detection of late convalescent toxoplasmosis (82%, 76% and 79%, respectively). IgG avidity (ELFA and FC-AFTA) outstand with the highest performance indices with 91% and 96% co-negativity for assessing acute toxoplasmosis and 91% and 98% co-positivity for late convalescent toxoplasmosis, respectively. Multivariate analysis generated a three-step algorithm comprising IgM ELFA screening followed by ELFA and FC-AFTA IgG avidity with high accuracy in discriminating acute from late convalescent infection. Together, these findings demonstrate the applicability of the proposed panel of diagnostic tools for accurate temporal classification of T. gondii infection. [ABSTRACT FROM AUTHOR]

Toxoplasmosis is caused by the protozoan parasite Toxoplasma gondii , which belongs to the phylum Apicomplexa. Since this parasite causes severe clinical symptoms in immunocompromised patients, early diagnosis of toxoplasmosis is essential. PCR is currently used for early diagnosis, but there is no consensus regarding the most effective method for amplifying Toxoplasma DNA. In this study, we considered the utility of the cytochrome c subunit I ( cox1 ) gene, which is encoded in the mitochondrial DNA of this parasite, as a novel target of PCR for the diagnosis of toxoplasmosis. To do this, we compared its copy number per haploid nuclear genome and the detection sensitivity of cox1 -PCR with the previously reported target genes B1 and 18S rRNA and the AF146527 repeat element. We found that the copy number of cox1 was high and that the PCR using cox1 primers was more efficient at amplifying Toxoplasma DNA than the other PCR targets examined. In addition, PCR using clinical samples indicated that the cox1 gene would be useful for the diagnosis of toxoplasmosis. These findings suggest that use of cox1 -PCR would facilitate the diagnosis of toxoplasmosis in clinical laboratories. [ABSTRACT FROM AUTHOR]

Background Quantitative immunoassays to detect IgG antibodies are the most commonly used tests for diagnosing toxoplasmosis. We investigated the current state of standardization of quantitative immunoassays used to measure anti-Toxoplasma IgG levels. Methods Four fully automated immunoassays (Architect i4000ISR, Immulite 2000 Xpi, Siemens; Liaison, DiaSorin; Cobas e601, Roche) and one manual immunoassay (ELISA classic Toxo IgG, Virion Serion) were performed on the following: individual patient serum samples, the WHO international standards, control samples, and calibrators provided by 5 immunoassay manufacturers. Statistical analysis was used to illustrate the results. Results No perfect correlation (slope = 1.0) was found between any 2 assays. Large differences in anti-Toxoplasma IgG titers were observed among the 5 immunoassays using serum samples from individual patients. Using IS 01/600 as a calibrator minimized the inter-assay variability of anti-Toxoplasma IgG values Conclusions There is still significant effort needed towards standardization of anti-Toxoplasma IgG quantitative immunoassays. [ABSTRACT FROM AUTHOR]

Background The diagnosis of Toxoplasmosis in pregnant women during the early first trimester of pregnancy is very important for preventing congenital infection of the fetus; it will not only prevent the risk of transmitting the infection to the fetus but it will also enable to give these women a preventive treatment. In this study, the avidity test was performed on pregnant women during their first prenatal visit at the National Institute of Hygiene in Rabat, Morocco. Findings One hundred and twenty-eight sera samples were collected from 128 pregnant women between August 2015 and June 2016; these women were chosen retrospectively and were in their first four months of pregnancy. The samples were screened using the specific anti- Toxoplasma IgG and IgM antibodies and were subjected to an IgG avidity test. After the serological screening, only 54 women (42.4%) were tested positive for IgG antibodies and five women (3.9%) were tested positive for both anti- Toxoplasma IgG and IgM antibodies. Four IgM-negative women had low-avidity antibodies. However, none of the IgG-avidity test had detected low-avidity antibodies in the five IgM-positive women; three women (60%) had high-avidity antibodies, indicating that the infection was acquired in the distant past. Conclusion The avidity test is a helpful tool to exclude a recently acquired toxoplasmosis infection within IgM-positive serum samples in pregnant women during their first trimester of pregnancy. Thus, allowing to perform an appropriate therapeutic intervention. [ABSTRACT FROM AUTHOR]

Little is known about toxoplasmosis in animals of the Fernando de Noronha Island, Brazil. Therefore, we investigated the prevalence of Toxoplasma gondii infection in the total population of pet cats ( n = 348), dogs ( n = 320), pigs ( n = 27), equines ( n = 101), as well as a significant portion of the population of feral cats ( n = 247) of the Island by Indirect Fluorescent Antibody Test. Anti - T. gondii IgG antibodies were found in 71.26%, 54.74%, 48.75%, 51.85% and 22.7%, of the pet and feral cats, dogs, pigs and equines, respectively, demonstrating a high prevalence of T. gondii infection in the wild and domestic animals of the Island. The Kernel intensity estimator showed a correlation between areas with high prevalence of infection in cats and occurrence of infection in the other studied species. We suggest that the island's health authorities should develop initiatives to reduce the population of cats and alert the island's population about the risk of T. gondii infection. [ABSTRACT FROM AUTHOR]

Toxoplasma gondii is a protozoan parasite infecting up to one third of the world's population. T . gondii infection is usually benign in immunocompetent patients but can be life-threatening when congenitally transmitted. Congenital toxoplasmosis presentation ranges from severe central nervous system and ocular features, to a well appearing newborn with onset of complications late in childhood. The diagnosis of subclinical form remains important since early treatment reduces later complications such as chorioretinitis. We report an atypical case of congenital toxoplasmosis with a delayed diagnosis, based on Toxoplasma -specific serological follow-up. The infant was born to a mother who became infected during pregnancy, thus inducing infant biological and clinical follow-up. Neither biological nor clinical arguments favored a diagnosis of congenital toxoplasmosis until ten months of life. Congenital toxoplasmosis was then suspected because of an unusual increase of specific IgG levels. Diagnosis was confirmed by detection of newly synthesized newborn Ig isotypes using complementary comparative mother-to-child immunological profile techniques and specific treatment therefore administered. This report highlights the importance to follow up newborns at risk of congenital toxoplasmosis with specific and newborn-appropriate techniques until Toxoplasma -IgG titers are completely negative. This allows not only the exclusion of congenital toxoplasmosis when serology becomes negative, but also the diagnosis and treatment of congenital toxoplasmosis when infection is detected later in development. [ABSTRACT FROM AUTHOR]

When acquired during pregnancy toxoplasmosis can have devastating consequences on the fetus. As maternal infection is in the majority of cases subclinical, the diagnosis of toxoplasmosis relies on serological tests for the detection of IgG, IGM and the mesure of IgG avidity. We evaluated the performance of IDS-iSYS a new automatized instrument based on chemiluminescence for the diagnosis of the disease. Our study was based on non-selected samples received in our laboratory either for the determination of serological status or for distinguishing acute from chronic infection. Seven hundred eighty three samples were enrolled in the study. Compared with Architect IgG and IgM assays, the sensitivity and specificity were respectively 99% and 99% for IgG, and 75% and 97% for IgM. We observed higher remaining titers for IDS iSYS IgG, which could reduce the proportions of patients who have to be retested because of doubtful titers. IgM detection and avidity scored equivalent performance with both methods. This automate appears to be a reliable and easy-to-use tool for diagnosing toxoplasmosis in different clinical settings. [ABSTRACT FROM AUTHOR]

Humans can be infected by the intracellular parasite Toxoplasma gondii , which causes toxoplasmosis, a common parasitic disease. Although the infection is generally asymptomatic for most adults, severe complications may occur in some individuals, especially women in early pregnancy. Serologic diagnosis is used as a routine practice to determine the immune status for infection by T. gondii. In this review, we attempt to provide an overview of the serological diagnosis of toxoplasmosis, including diagnostic strategy, current problems in detection with specific antibodies, and the standardization of T. gondii serological detection. [ABSTRACT FROM AUTHOR]

Whether Toxoplasma gondii genotype is associated with disease severity in naturally occurring toxoplasmosis in domestic cats is unknown. The aim of this study was to compare genotypes of T. gondii in latently infected cats with those in cats with clinical toxoplasmosis. Results of a PCR targeting the B1 gene to detect T. gondii DNA were positive in tissue samples from 11 of 17 (65%) seropositive cats tested including four with clinical toxoplasmosis and seven with latent infections, as determined by serology, histologic findings and immunohistochemistry. Three of the four cats with clinical toxoplasmosis were immunosuppressed. Complete genotyping was performed in seven cats using PCR-RFLP at 12 loci ( SAG1 , 5′SAG2 and 3′SAG2 , altSAG2 , SAG3 , BTUB , GRA6 , c22-8 , c29-2 , L358 , PK1 and Apico ) and direct sequencing of the multi-copy B1 gene. Partial genotyping using six loci was performed in one cat with latent infection. T. gondii type II (ToxoDB genotype #3) was determined in four cats with clinical toxoplasmosis and three cats with latent toxoplasmosis Novel T. gondii B1 gene polymorphisms were detected in two strains (at nucleotide posititions 233, 366 and 595) and a B1 gene polymorphism unique to Australia was identified in another (guanine/adenine at nucleotide position 378). One cat was co-infected with two or more type-II like strains at 3′SAG2 . The results of this study suggest that the infecting T. gondii genotype, based on these 12 loci, is not a determinant of clinical disease in cats naturally infected with T. gondii and type II strains are prevalent in Australia. [ABSTRACT FROM AUTHOR]

Toxoplasmosis is a widespread parasitic disease caused by the intracellular parasite Toxoplasma gondii with a wide spectrum of clinical outcomes. The biological diagnosis of toxoplasmosis is often difficult and of paramount importance because clinical features are not sufficient to discriminate between toxoplasmosis and other illnesses. Serological tests are the most widely used biological tools for the diagnosis of toxoplasmosis worldwide. This review focuses on the crucial role of serology in providing answers to the most important questions related to the epidemiology and diagnosis of toxoplasmosis in human pathology. Notwithstanding their undeniable importance, serological tools need to be continuously improved and the interpretation of the ensuing results remains complex in many circumstances. [ABSTRACT FROM AUTHOR]

Immunoproteomic technology offers an exceptional tool to fill the blanks that still exist in diagnosis of Toxoplasma gondii infection despite its annotated sequence. The pitfalls of serological assays and current immunoproteomic approaches are accentuated, and new approaches are presented to improve the signal and to eliminate the noise produced by blocking-specific background. This review also highlights examples where immunoproteomic studies have contributed to broaden our understanding of toxoplasmosis diagnosis. Further promising solutions, which immunoproteomic technology can grant for toxoplasmosis diagnosis are part of an intense discussion. [ABSTRACT FROM AUTHOR]

The aim of the study was to evaluate the usefulness of 3 chimeric Toxoplasma gondii antigens, P35-MAG1, MIC1-ROP1 and MAG1-ROP1, in the serodiagnosis of an acute toxoplasmosis in humans. Proteins were produced as fusion proteins containing His tags ends and then further purified by metal affinity chromatography. Their application for the diagnosis of recently acquired T . gondii infection was tested in IgG and IgM enzyme-linked immunosorbent assays (ELISAs). At 100%, 77.3%, and 86.4%, respectively, the reactivity of the IgG ELISA using P35-MAG1, MIC1-ROP1, and MAG1-ROP1 for sera from patients where acute toxoplasmosis was suspected was significantly higher than for the samples from people with a chronic infection, at 26.2%, 36.1%, and 32.8%, respectively. Moreover, P35-MAG1, MIC1-ROP1, and MAG1-ROP1 detected IgM antibodies with a reactivity at 81.8%, 72.7%, and 59.1%, respectively. The results presented in the article show that, particularly, P35-MAG1 may be useful in the preliminary detection of recent T . gondii infection. [ABSTRACT FROM AUTHOR]

Toxoplasma gondii is widely distributed in humans and other animals including birds throughout the world. However, little is known of the molecular epidemiology and genotypes of T. gondii infecting quails in China. Therefore, the present study was conducted to characterize T. gondii genotypes in common quails in China. During December 2014 to October 2015, a total of 390 muscle tissue samples of common quails were collected and the T. gondii B1 gene was amplified using a nested PCR, and the positive samples were genotyped at 11 genetic markers (SAG1, 5′-and 3′-SAG2, alternative SAG2, SAG3, BTUB, GRA6, L358, PK1, c22-8, c29-2, and Apico) using multilocus polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technology. Twenty-five of the 390 common quails (6.41%) were tested positive by nested PCR. Three DNA samples from the 25 positive samples were typed completely and were identified as ToxoDB Genotype #9 ( http://toxodb.org/toxo/ ). The results of the present study indicated that T. gondii infection in common quails was common in China, which provided the information of T. gondii genetic diversity in this host species. This is the first genetic characterization of T. gondii isolates from quails in China, which is useful for monitoring and controlling the T. gondii infection in quails, other animals and humans. [ABSTRACT FROM AUTHOR]

Highlights: [•] The synthesis/characterization of polystyrene and carboxylated latexes is described. [•] The acute phase recombinant-antigen P35 (P35Ag) of Toxoplasma gondii was produced. [•] Physical adsorption and chemical coupling of P35Ag onto latex particles were studied. [•] Antigenicity of P35Ag coupled onto the particles surface was evaluated. [•] Acute sera were differentiated from negative and chronic sera. [ABSTRACT FROM AUTHOR]

Abstract: The preliminary diagnostic utility of two mixtures of Toxoplasma gondii recombinant antigens (rROP1+rSAG2 and rROP1+rGRA6) in IgG ELISA and IgG avidity test has been evaluated. A total of 173 serum samples from patients with toxoplasmosis and seronegative people were examined. The sensitivity of IgG ELISA for rROP1+rSAG2 and rROP1+rGRA6 was 91.1% and 76.7%, respectively, while the reactivity for sera from patients where acute toxoplasmosis was suspected was higher, at 100% and 95.4%, respectively, than for people with chronic infection, at 88.2% and 70.6%. In this study a different trend in avidity maturation of IgG antibodies for two mixtures of proteins in comparison with native antigen was observed. The results suggest that a new IgG avidity test using the mixtures of recombinant antigens may be useful for the diagnosis of difficult-to-identify phases of toxoplasmosis. For this reason, selected mixtures after the additional tests on groups of sera with well-defined dates of infection could be used as a better alternative to the native antigens of the parasite in the serodiagnosis of human T. gondii infection. [Copyright &y& Elsevier]

Abstract: Early, accurate and effective diagnosis of toxoplasmosis can make an important contribution to the prevention and control of disease, especially in people who are at risk. In this study, two commonly used genomic repeats of Toxoplasma gondii, RE (GenBank accession number AF146527) and B1, were compared to each other in nested-PCR assay. Five hundred and thirty-five blood samples from children with leukemia were tested for the presence of T. gondii antibodies using enzyme immunoassays. One hundred and ten DNA samples of these patients (50 IgM+, IgG+, 10 IgM−, IgG+, and 50 IgM−, IgG−) were analyzed by nested-PCR. The specificity of two nested PCR assays was determined using the DNA samples of other parasites and human chromosomal DNA. As a result, 82% (41/50) and 68% (34/50) of the IgM+, IgG+ samples were positive on duplicate RE and B1-nested PCR analyses, respectively. None of the 10 IgM−, IgG+ seropositive samples was detected positive after testing RE and B1-nested PCR assays in duplicate. One (2%) of the 50 seronegative samples was positive by duplicate RE-nested PCR but none of them were positive by duplicate B1-nested PCR. The detection limit of the RE-nested PCR assay was 640fg of T. gondii DNA whereas this rate for B1-nested PCR was 5.12pg of the DNA template. No cross-reactivity with the DNA of other parasites and human chromosomal DNA was found. The results indicate that an RE-based nested PCR assay is more sensitive than B1 genomic target, of those tested, for detection of T. gondii. It is noteworthy that in comparison with B1-nested PCR, RE-nested PCR could detect the T. gondii DNA in seronegative samples too. [Copyright &y& Elsevier]

Highlights: [•] Toxoplasmosis is a high-profile zoonosis and pigs represent a risk to humans. [•] A new commercial ELISA to diagnose Toxoplasma gondii infections in pigs is evaluated. [•] A novel approach for test evaluation in the absence of a ‘gold standard’ is presented. [Copyright &y& Elsevier]

Abstract: This study describes toxoplasmosis in a by caught Guiana dolphin (Sotalia guinensis) from Paranaguá Bay, Paraná, Brazil. Interstitial pneumonia, multisystemic arteritis, multifocal adrenalitis and hepatitis were the primary lesions observed. These tissues had moderate to severe necrosis and mononuclear cells infiltration usually surrounded by tachyzoites and tissue cysts. Moderate lymphoid depletion was evident in the spleen. Toxoplasma gondii was positive by immunohistochemical and ultrastructural evaluation. Furthermore, the animal was negative for Morbillivirus by immunohistochemistry and had low levels of persistent organochlorines. There is evidence of environmental changes in the Paranaguá Bay that could justify the occurrence of toxoplasmosis in Guiana dolphin. The sewage run-off from main urban areas and the presence of domestic and wild felids in areas surrounding the bay could be a source of T. gondii oocysts from land to sea. Based on its habitat, the authors recommend this dolphin species as sentinels for the health of bays and estuaries where they occur. [Copyright &y& Elsevier]

Abstract: To distinguish active from inactive/chronic infection in Toxoplasma gondii-seropositive individuals, we have developed an enzyme-linked immunosorbent assay (ELISA) using specific peptides derived from Toxoplasma matrix antigen MAG1. We used this assay to measure matrix specific antibodies and pilot studies with infected mice established the validity of two peptides. The immune response against MAG1 occurs in about 12 days postinfection and displays a sex difference later on in mouse model, with males producing higher antibody titers than females. Serum samples from 22 patients with clinical toxoplasmosis and from 26 patients with serological evidence of past exposure to Toxoplasma (more than one year infection history) were analyzed. Both MAG1 peptides detected antibodies significant frequently and robustly from active stage than from the chronic stage of toxoplasmosis. The results indicate that both MAG1 peptides may be used as a tool to differentiate active from inactive infection. It also may be considered in the design of potential vaccines in humans. [Copyright &y& Elsevier]

Abstract: Toxoplasma gondii, a ubiquitous intracellular protozoan, infects one third of the world human population. It is of great medical significance, especially for pregnant women and immune-compromised patients. Accurate and early detection of T. gondii infection is crucial in the management of this disease. To obtain potential diagnostic markers, immunoproteomics was employed to identify immunodominant proteins separated by 2-D immunobloting and probed with sera collected from Toxoplasma-positive pregnant women. MALDI-TOF MS and MS/MS analyses identified a total of 18 immunoreactive proteins that were recognized by Toxoplasma-positive sera, whereas none was reactive with the negative-control sera from healthy, Toxoplasma-negative volunteers. Pregnant women showed a diverse immunoreactivity pattern with each serum recognizing one to eight identified tachyzoite proteins. The identified proteins were localized in the membrane, cytoplasm and specific organelles of T. gondii, and are involved in host cell invasion, metabolism and cell structure. Among these 18 proteins, actin, catalase, GAPDH, and three hypothetical proteins had a broad reactivity with Toxoplasma-positive sera, indicating their potential as diagnostic markers for toxoplasmosis. Each of several combinations of the identified proteins offered 100% detection of Toxoplasma infections of all 28 Toxoplasma-positive women. The study findings suggest that Toxoplasma tachyzoites are highly immunogenic and highlights the heterogeneity of host responses to Toxoplasma infection and the importance of using combinations of immunogens as diagnostic antigens. The findings have significant implications to the development of diagnostic reagents with high sensitivity and specificity. [Copyright &y& Elsevier]

Abstract: The diagnosis of Toxoplasma infection or disease in hematopoietic stem cell transplantation (HSCT) patients is achieved mainly by PCR screening; however screening did not find wide field of use in practice due to costly expenditures of PCR. This study aimed to determine patients at high risk of Toxoplasma infection or disease before transplantation by stem cell originated buffy coat PCR and subsequently to screen them. Buffy coats collected from 12 autologous and 18 allogeneic HSCT patients'' donors were investigated by PCR before transplantation. After transplantation, blood and sera collected at fixed time intervals were screened by two PCR methods and serological assays. Screening results first time assessed a toxoplasmosis incidence level as 25% in autologous HSCT patients and increased incidence level in allogeneic HSCT patients to 22%. Importantly, buffy coat PCR was first time performed before transplantation, to determine the risk of toxoplasmosis. Buffy coat PCR results showed that four patients were at high risk of toxoplasmosis before transplantation. After transplantation, these patients experienced toxoplasmosis. In conclusion, for the determination of patients at risk of toxoplasmosis, clinicians should consider buffy coat PCR in combination with serology before transplantation. After transplantation, PCR screening can be initiated in high risk patients upon clinical suspicion. [Copyright &y& Elsevier]

Abstract: Six agglutination tests for detecting Toxoplasma gondii–specific antibodies (immunoglobulin G or M) in serum were performed and compared. In total, 599 sera were examined using direct and indirect agglutination assays. Sensitivity varied from 93.7% to 100% and specificity from 97.1% to 99.2%. In a selected population with interfering diseases, the percentage of false positives ranged from 4.3% to 10.9%. Although an overall agreement of 100% was found for chronic toxoplasmosis, sensitivity for the detection of confirmed acute toxoplasmosis ranged from 86.4% to 97.3%. Regarding the large variability in terms of the performance of the 6 assays, tests based on the hemagglutination principle were found to be better than the other agglutination tests for all the panels evaluated, meaning that they could be used as qualitative or semiquantitative low-cost screening assays. [Copyright &y& Elsevier]

Abstract: In the present study we evaluated the performance of a flow cytometry-based algorithm as a new serological approach to detect antibodies to T. gondii and specific IgG avidity to diagnose acute toxoplasmosis. The results showed that using FC-AFTA-IgM assay, all serum samples from patients with acute toxoplasmosis demonstrated seropositivity, whereas 90% of patients with chronic infection and 100% of non-infected individuals presented negative results. Thus, only 10% of patients with chronic toxoplasmosis showed residual IgM, in contrast with other methodologies used to diagnosis acute toxoplasmosis. On the order hand, FC-AFTA-IgG assay as well as FC-AFTA-IgG subclasses is unlikely to discriminate acute from chronic toxoplasmosis. We have also evaluated the performance of FC-AFTA-IgG avidity as a tool to exclude chronic toxoplasmosis in patients with positive FC-AFTA-IgM. Our data showed an excellent performance of FC-AFTA-IgG avidity employing the cut-off of 60% for Avidity Index (AI) with sensitivity and specificity of 100%. All serum samples from patients presenting acute toxoplasmosis showed low avidity index (AI≤60%), whereas all chronic patients showed high avidity index (AI>60%). The outstanding performance indexes of this novel flow cytometry-based algorithm support its use as a non-conventional alternative serological approach to diagnose human acute toxoplasmosis. [Copyright &y& Elsevier]

Abstract: Unidentified gestational infection with Toxoplasma gondii may lead to fetal infection with severe complications later in childhood. Because diagnosis of maternal infection solely depends on serology, routine tests with high sensitivity and specificity are required. In this study, the new Roche Elecsys Toxo IgG and IgM immunoassay was compared with Sabin–Feldman dye test and immunosorbent agglutination assay-IgM as reference test. Serum samples were analyzed from 927 pregnant women, including 100 negative, 706 chronic, and 121 acute infections. The combination of both Elecsys IgG and IgM assays demonstrated high sensitivity and specificity of 97.1% and 100.0%, respectively, and a positive and negative predictive value of 100.0% and 81.3%, respectively. The Elecsys assay is a useful tool as a first-line screening method to detect gestational infections. However, if gestational infection is assumed, confirmatory testing by a reference laboratory might be necessary to discriminate between pre- and postconceptional infection to start antiparasitic treatment to avoid mother-to-fetus transmission and severe sequelae. [ABSTRACT FROM AUTHOR]

Abstract: Little is known of the molecular detection of Toxoplasma gondii infection in chickens (Gallus domesticus). The objectives of the present study were to determine the suitable tissues of chickens infected with T. gondii for direct polymerase chain reaction (PCR) amplification of T. gondii DNA. Thirty, 35-day-old broiler chickens were divided into three groups of 10 birds (two replications of five chicks). Of these, two groups were experimentally inoculated intravenously with 4.3×106 or 4.3×107 tachyzoites of the low virulent T. gondii QHO strain. Two inoculated chickens from each of the two groups were killed on days 7, 14, 21, 28, and 35 post-inoculation, respectively, and two uninoculated chickens were also killed at the same time. Sera from chickens were collected for examination of anti-T. gondii antibodies by indirect hemagglutination test (IHAT) and the modified agglutination test (MAT). Brains, hearts, livers, lungs, spleens and eyes of chickens were sampled and DNA from each tissue was extracted as template for PCR assay. Specific anti-T. gondii antibodies were detected in all infected chickens from day 7 to day 35 p.i. with antibody titers between 1:5 and 1:640 by MAT. PCR assay can detect T. gondii DNA in tissues from the day 21 p.i. to day 28 p.i. This study demonstrates that MAT is more sensitive than IHAT for detecting antibodies to T. gondii in chickens, and PCR assay is a specific, speedy, sensitive and cost-effective method for detecting T. gondii DNA in chickens. [ABSTRACT FROM AUTHOR]

Résumé: Toxoplasma gondii est responsable d’infections graves après transmission maternofœtale ou chez les sujets immunodéprimés. Plus rarement, des formes sévères avec atteinte viscérale au décours d’une primo-infection toxoplasmique ont été décrites chez le sujet immunocompétent notamment en Guyane Française. Nous rapportons le cas d’un adulte non-VIH et non greffé qui a présenté en France un tableau infectieux sévère non spécifique avec atteinte pulmonaire et cérébroméningée. Le diagnostic de toxoplasmose disséminée a été posé sur un résultat de PCR spécifique de T. gondii positif dans le LCR. La primo-infection a été confirmée par la sérologie. L’histoire de la maladie a été reconstituée à partir des résultats obtenus rétrospectivement par PCR en temps réel sur des sérums et des lavages broncho-alvéolaires. La recherche d’un déficit immunitaire suspecté devant les antécédents médicaux du patient était négative à ce jour. L’évolution a été favorable sous traitement antitoxoplasmique spécifique. [Copyright &y& Elsevier]

Clin Microbiol Infect 2010; 16: 363–368 Toxoplasma gondii can be responsible for congenital toxoplasmosis leading to mild or severe sequelae, and for life-threatening infections in immunocompromised hosts. A new 5′-nuclease real-time PCR assay that targets the 300-fold repeated AF146527 DNA sequence (TaqMan-AF-PCR) has been developed and its performance for diagnosis of toxoplasmosis and treatment follow-up has been assessed. A retrospective analysis was first performed with 144 clinical specimens previously analysed for the presence of T. gondii DNA by a PCR–ELISA assay that targets the B1 gene of T. gondii (B1-PCR–ELISA). Fifteen samples, all from patients with clinically proven toxoplasmosis, were negative according to B1-PCR–ELISA and positive according to TaqMan-AF-PCR. A prospective analysis was then performed with 203 consecutive clinical specimens received at the laboratory of Parasitology of Saint-Louis Hospital during a 4-month period. The diagnosis of toxoplasmosis in two patients was made according to the TaqMan-AF-PCR whereas the B1-PCR–ELISA failed to make diagnosis. Additionally, iterative samples from a patient with cerebral and disseminated toxoplasmosis, already tested using a B1 real-time PCR assay, were tested using the TaqMan-AF-PCR and a Light Cycler real-time PCR assay targeting the same repetitive AF146527 sequence (LC-AF-PCR). Detection was achieved with the TaqMan-AF-PCR, with a mean gain of 7.1 and 3.3 amplification cycles when compared with the B1 real-time PCR and the LC-AF-PCR, respectively. This study demonstrates the higher sensitivity of the 5′-nuclease real-time PCR assay developed for the AF146527 DNA sequence and confirms the interest of using this highly repeated target to improve the diagnosis of toxoplasmosis. [ABSTRACT FROM AUTHOR]

Abstract: Aims of the study: A sensitive, rapid and specific diagnostic method is essential for the diagnosis of toxoplasmosis in immunocompromised hosts or in congenital infection. We report the development of a real-time PCR assay for quantitative diagnosis of toxoplasmosis with competitive internal amplification control. This PCR was applied after allogeneic stem cell transplantation to estimate the frequency of reactivation. Methods and patients: Primers and Taqman probe (FAM-BHQ1) were designed to amplify the 529bp element of T. gondii. The internal amplification control was developed by cloning a fragment of Arabidopsis thaliana DNA flanked by sequences specific for T. gondii 529bp element. A Taqman probe specific for the competitive internal control was designed and tested (YY-BHQ1). We determined the repeatability and reproducibility of the method. A prospective study was performed on adults who received an allogeneic hematopoietic stem cell transplantation. After transplantation, patients were monitored once per week during the first 100 days; they were then monitored once every 2 weeks until day 180 after transplantation (i.e., day +180). Results: A total of 451 samples from 40 patients were tested. Twenty-five patients had both positive toxoplasmosis serology and an adequate chemoprophylaxis. One sample from one patient was found positive. The rate of reactivation in the population of this study is 4%. Conclusion: A monitoring by T. gondii PCR should be realized weekly for patients receiving an allogeneic hematopoietic stem cell transplantation, without an adequate chemoprophylaxis. [Copyright &y& Elsevier]

Abstract: We assessed the performance of the ARCHITECT Toxo IgG, IgM, and IgG Avidity assays against corresponding assays on AxSYM and Vidas using 730 sera from pregnant women. The ARCHITECT Toxo IgG and IgM assays showed a relative sensitivity of 97.5% and 89.9% and a relative specificity of 99.1% and 99.8%, respectively. If IgM sensitivity is calculated only for sera drawn less than 4 months after infection, the relative sensitivity rises to 98.1%. Correlation between the ARCHITECT and Vidas Avidity assays was 0.87 (n = 103). Testing 86 IgG-positive specimens from recent infection (<4 months), we never obtained high avidity results, but 2 specimens were in the gray zone, whereas sera from past infections (>4 months) exhibited high avidity results in 72.5% (137/189) of cases. The method can be used reliably to exclude recent infections in sera with concurrently positive results for IgM and IgG (IgG, >3 IU/mL). [Copyright &y& Elsevier]

Abstract: Toxoplasmosis acquired during pregnancy exposes the fetus to congenital toxoplasmosis. Avidity tests are commonly used to date time of infection to evaluate the fetal risk and to offer prenatal diagnosis. This study evaluated and compared 2 commercial avidity tests: Platelia™ Toxo IgG Avidity (Bio-Rad, Marnes la Coquette, France) and Liaison® Toxo IgG Avidity II (Diasorin, Saluggia, Italy) kits. In complement, a study of specific IgG and IgM in the 2 systems was carried out. Sensitivity and specificity of the avidity tests were 94.4% and 87.8% for the Liaison® and 91.3% and 98.5% for the Platelia™ methods, respectively. Percentages of complete discrepancies, partial discrepancies, and agreement between both tests were 1.1%, 23.6%, and 75.3%, respectively. Moreover, the combination of both avidity tests may be useful in some cases. Indeed, that strategy permitted to confirm without delay a chronic toxoplasmosis in 23 cases and avoid treatment in these pregnant women. [Copyright &y& Elsevier]

Abstract: The goal of the present study is to develop an enzyme-linked immunosorbent assay (ELISA) using a truncated surface antigen 1 (SAG1) gene of Toxoplasma gondii for the diagnosis of human toxoplasmosis. The truncated SAG1 gene was highly expressed in Escherichia coli. An ELISA kit based on the purified recombinant truncated SAG1 (rtSAG1) was developed, which was used to detect antibodies against T. gondii in human sera. The results showed that the infection of T. gondii could be detected sensitively and specifically by this serologic method. The positive concordance between rtSAG1-ELISA and Western blot, the gold standard, was 93.9% (31/33). However, the positive concordance between the commercial available ELISA Kit 1 (Haitai, Zhuhai, China) and ELISA Kit 2 (DiaSorin ETI-TOXOK-M reverse Plus, Italy) with Western blot was 79.5% (31/39) and 91.2% (31/34), respectively. Comparatively, the positive concordance of ELISA Kit 1 and 2 with Western blot was lower than rtSAG1-ELISA, in particular, the ELISA Kit 1 (P < 0.01), which indicated that the rtSAG1 protein could be used as the diagnostic antigen for human toxoplasmosis. [Copyright &y& Elsevier]

Abstract: Infection with Toxoplasma gondii is one of the most common parasitic infections in humans and other warm-blooded animals. This paper describes the development of loop-mediated isothermal amplification (LAMP) specific to the single-copy gene SAG1 as a diagnostic tool of toxoplasmosis. A set of primers, composed of outer primers, inner primers and loop primers was designed from a published sequence data (GeneBank Acc. no. AY651825). Experiments showed that when LAMP was applied to sample organs, amplification absolutely required the loop primers to complete. SAG1-based LAMP turned out to be very sensitive, exhibiting a degree of sensitivity higher than the conventional PCR. LAMP is a convenient and sensitive diagnostic tool for routine health control of toxoplasmosis. [Copyright &y& Elsevier]

Abstract: We report the case of an atypical localization of a spinal cord “toxoplasmic abscess”. The 46-year-old patient, HIV-1 positive, was admitted for acute urine retention and gait disorders. MRI revealed a T12–L1 medullary lesion suggesting a tumoral, inflammatory and infectious pathology. The radiological aspect and immunosuppression lead to the initiation of a treatment against Toxoplasma gondii, following the same treatment principles as for cerebral toxoplasmosis. The diagnosis can only be proved by data from autopsy or surgical biopsy, but toxoplasmosis PCR on CSF seems to be an interesting alternative to confirm the diagnosis. According to the literature, PCR is not sensitive enough as a diagnostic tool. Improvement after treatment supported the diagnosis confirmed by PCR. [Copyright &y& Elsevier]

Toxoplasmosis can have catastrophic consequences in immunocompromised patients if left untreated. Accurate diagnosis is difficult, as there is substantial overlap between the imaging findings and presenting clinical syndromes of cerebral toxoplasmosis and primary central nervous system lymphoma. This paper reviews the previously described and fairly well-known post-contrast computed tomography (CT) and T1-weighted (W) magnetic resonance imaging (MRI) target signs seen in toxoplasmosis. In addition, it offers a new imaging sign, the T2W/FLAIR (fluid attenuated inversion recovery) target sign, which is often seen in clinical practice but not well-published, as an aid to the diagnosis of cerebral toxoplasmosis. [Copyright &y& Elsevier]

In cardiac transplant, toxoplasmosis in the immunocompromised recipient can result either from the transmission of the parasite from a seropositive donor (D+) to a seronegative recipient (R-) with the transplanted organ (more common) or from the reactivation of a pre-transplant latent infection (D-/R+ or D+/R+). In the immunocompromised patient, toxoplasmosis is a life-threatening disease. We report a case of disseminated toxoplasmosis following heart transplantation in a Toxoplasma seropositive recipient before transplantation (R+) (lgG 1:160, IgM negative) who received an organ from a Toxoplasma seropositive donor (D+) (lgG 1:640, IgM negative). No anti-Toxoplasma prophylactic treatment was administered. A number of complications arose in the postoperative period, as well as Enterobacter cloacae and Cytomegalovirus (CMV) (reactivation) infections, but neither serological nor histological toxoplasma recrudescence was evidenced. The patient died on post transplant day 41. Post-autopsy histological examinations revealed an unexpected diffuse toxoplasmosis (lungs, brain, heart). [ABSTRACT FROM AUTHOR]

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 χ2 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. [Copyright &y& Elsevier]

Objective: Results obtained with commercial testing kits for immunoglobulin M Toxoplasma antibodies may be inaccurate or may be inaccurately interpreted, which may influence whether a woman decides to terminate the pregnancy. This study was undertaken to determine whether confirmatory testing at a reference laboratory and communication of the results and an expert interpretation to the patient’s physician would affect the rate of induced abortions among pregnant women with positive results of testing for immunoglobulin M Toxoplasma antibodies in outside laboratories. Study Design: This was a retrospective cohort study of 811 consecutive pregnant women for whom the toxoplasma serologic profile was performed at a reference laboratory. Almost all the patients had been informed by their physicians that a result of a test for immunoglobulin M Toxoplasma antibodies performed in an outside laboratory was positive. Women were separated into those with a toxoplasma serologic profile result suggestive of a recently acquired infection (group 1) and those with a result suggestive of an infection acquired in the more distant past (group 2). Physician reports of induced abortions were used to determine rates of induced abortion in groups 1 and 2. Results: Of the 811 women 321 (39.6%) were considered likely to have a recent infection (group 1) and 490 (60.4%) were considered likely to have a past infection (group 2). Physicians reported pregnancy outcomes for 433 (53.4%) of 811 women (65.1% and 45.7% in groups 1 and 2, respectively). Whereas 36 of 209 women in group 1 (17.2%) terminated the pregnancy, only 1 of 224 women in group 2 (0.4%) chose abortion ( P <.001). Conclusion: Confirmatory serologic testing in a reference laboratory and communication of the results and their correct interpretation by an expert to the patient’s physician decreased the rate of unnecessary abortions by approximately 50% among women for whom positive immunoglobulin M Toxoplasma test results had been reported by outside laboratories. (Am J Obstet Gynecol 2001;184:140-5.) [ABSTRACT FROM AUTHOR]

Early detection of Toxoplasma tachyzoites circulating in blood using PCR is recommended for immunosuppressed patients at high risk for disseminated toxoplasmosis. Using a toxoplasmosis mouse model, we show that the sensitivity of detection is higher using buffy coat isolated from a large blood volume than using whole blood for this molecular monitoring. [ABSTRACT FROM AUTHOR]

Objective: Our purpose was to evaluate different methods of diagnosing congenital toxoplasmosis prenatally by amniocentesis and cordocentesis.Study Design: In a retrospective multicenter study, we investigated consecutive women who had seroconversion for Toxoplasma gondii during pregnancy and who underwent either amniocentesis or cordocentesis or both to obtain a prenatal diagnosis of fetal toxoplasmosis. Data were obtained from 122 patients recruited in 6 different European Toxoplasma reference centers. Infants born to these mothers were followed up until 1 year of age to confirm or exclude congenital toxoplasmosis. Sensitivity, specificity, positive predictive value, and negative predictive value were measured for the following parameters: (1) detection of the parasite in amniotic fluid by mouse inoculation, (2) detection of the parasite in amniotic fluid by in vitro cell culture, (3) detection of Toxoplasma deoxyribonucleic acid in amniotic fluid by a polymerase chain reaction assay, (4) detection of the parasite in fetal blood by mouse inoculation, (5) detection of specific immunoglobulin M antibodies in fetal blood, and (6) detection of specific immunoglobulin A antibodies in fetal blood.Results: The polymerase chain reaction test performed on amniotic fluid had the highest level of sensitivity (81%) and also a high level of specificity (96%). The combination of the polymerase chain reaction test and mouse inoculation of amniotic fluid increased sensitivity to 91%. The sensitivity of immunoglobulins M and A in fetal blood was 47% and 38%, respectively. In congenitally infected fetuses a negative correlation was observed between positive serologic parameters and gestational age at the time of maternal infection and at prenatal diagnosis.Conclusion: Congenital toxoplasmosis is best predicted by prenatal examination with the combination of T gondii polymerase chain reaction and mouse inoculation of amniotic fluid. The role of cordocentesis in the diagnosis of congenital toxoplasmosis is limited. [ABSTRACT FROM AUTHOR]

Nucleic acid-based testing has become crucial for toxoplasmosis diagnosis. For retrospective (forensic or scientific) studies, optimal methods must be employed for DNA long-term storage. We compared Toxoplasma gondii detection before and after DNA storage using real-time PCR. No significant differences were found depending on duration or storage conditions at −20 °C or −80 °C. [ABSTRACT FROM AUTHOR]

Abstract: In a cohort of 12 consecutive neonates, polymerase chain reaction (PCR) established the diagnosis of 5 of 6 cases of congenital toxoplasmosis and did so earlier than serologic methods. We validated that PCR using neonatal peripheral blood is a sensitive, rapid, and cost-effective method to affirm the diagnosis of previously undiagnosed congenital toxoplasmosis. [Copyright &y& Elsevier]

Abstract: We report a case of microsporidiosis in a 72-year-old woman presenting with prolymphocytic leukemia. The underlying conditions 7 months after leukemia was diagnosed were pancytopenia and immunosuppression due to alemtuzumab and pentostatin. The patient''s status had worsened and she presented with dysuria. Urine cultures for bacteria were repeatedly negative. She was first empirically treated with broad-spectrum antibiotics. Three months later, urinary symptoms were persisting. Her blood lymphocyte count was 90/μl. Urine examination was positive for microsporidia using modified trichrome staining and Uvitex® 2B fluorescence. Microsporidia were also detected in stools. The patient was cured by albendazole. This was consistent with an infection due to Encephalitozoon sp. Concurrently, disseminated toxoplasmosis was diagnosed. Toxoplasma gondii was detected in bone marrow, broncho-alveolar lavage and cerebrospinal fluid. She was successfully treated with sulfadiazine–pyrimethamine. Four cases of microsporidiosis in myeloid leukemic patients have been already described. The present case in a patient with lymphoid leukemia is the first to be reported. [Copyright &y& Elsevier]