Diagnosis Of Acute Toxoplasmosis Research Articles

Evaluation of different cut-off points for IgG avidity and IgM in the diagnosis of acute toxoplasmosis in pregnant women participating in a congenital toxoplasmosis screening program.

The main social impact of toxoplasmosis stems from its ability to be vertically transmitted. Postnatally acquired infection is generally asymptomatic in approximately 70-90% of cases, making diagnosis often dependent on laboratory tests using serological methods to search for anti-T. gondii antibodies. This study aimed to investigate the ability of the VIDAS TOXO IgG avidity and VIDAS TOXO IgM assays to confirm recent toxoplasmosis. In total, 341 pregnant women with suspected acute toxoplasmosis were systematically monitored in the Program for Control of Congenital Toxoplasmosis in Minas Gerais State, Brazil. We conducted an observational analytical-descriptive cross-sectional study and grouped according to clinical and laboratory criteria as having acute or chronic toxoplasmosis. The VIDAS TOXO IgG avidity and VIDAS TOXO IgM assays were evaluated to investigate the capacity to identify acute infection. IgG avidity showed good performance in identifying acute toxoplasmosis when the IgG avidity index was lower than or equal to 0.1. Values greater than or equal to 3.16 according to the TOXO IgM kit were associated with a greater chance of acute infection. These results may contribute to a more adequate diagnosis of acute gestational toxoplasmosis and, consequently, the avoidance of inadequate or unnecessary treatments.

Detection of persistent low IgG avidity-an interpretative problem in the diagnosis of acute toxoplasmosis.

For the proper diagnosis of toxoplasmosis it is essential to determine the stage of the infection, for which the most preferred method is IgG avidity test. The avidity index (AI) should initially be low (AI≤0.3) in the acute phase and increase during the infection. However, persistent low avidity can occur in patients with latent toxoplasmosis, which can complicate the interpretation of the results. The aim of the study is to explain the causes of this phenomenon. A retrospective study was carried out with 717 serum samples collected from 442 patients from the categories of pregnant and non-pregnant women, men, and newborns + infants (age < 0.5 year). The trends of AI kinetics were evaluated in repeatedly examined patients. The frequency of cases with low avidity was compared in individual categories of patients and in groups of people with acute and non-acute toxoplasmosis. The proportion of patients with initially low avidity was 42.1% in the acute toxoplasmosis group while it was 13.0% in the non-acute groups. In uninfected newborns with anti-Toxoplasma antibodies transmitted from the mother, a decrease in IgG avidity levels over time was observed, resulting in 29.2% of samples showing low (improper) avidity. While the dynamics of IgG avidity and the frequency of cases of improperly low avidity were similar in men and pregnant and non-pregnant women, the category of newborns and infants differed substantially for these indicators. Due to acceptable specificity and negative predictive value, high avidity can rule out acute toxoplasmosis, but moderate sensitivity complicates the possibility of its confirmation. The results of the avidity test must be interpreted in the context of the results of other methods.

Diagnosis of Acute Toxoplasmosis in the First Trimester of Pregnancy by IgG Avidity

Diagnosis of Acute Toxoplasmosis in the First Trimester of Pregnancy by IgG Avidity

Restriction fragment length polymorphism analysis of genes of virulent strain isolate of Toxoplasma gondii using enzyme DdeI

Background and Aim: Toxoplasma gondii is a unicellular coccidian parasite distributed globally and is an important zoonotic pathogen. Approximately 30% of the human population worldwide is chronically infected with T. gondii. The pathogenicity of this species depends on the type originating from the clonal population. Techniques for more accurately determining the type of T. gondii have recently been developed using genetic markers. Specifically, T. gondii has been typed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). This study aimed to identify sets of PCR-RFLP markers that have high power to discriminate genotyping of T. gondii and are easy to use and are easy to use. The objective of this study was to characterize virulent strain isolates of T. gondii by PCR-RFLP using 10 markers with DdeI. Materials and Methods: T. gondii tachyzoites (RH virulent strain) were derived from culture cells at the Indonesian Research Center for Veterinary Sciences. Genotyping was performed on T. gondii DNA extracted from cell cultured tachyzoites using 10 genetic markers of PCR-RFLP, namely, B1#1, B1#2, B1#3, SAG1#1, SAG1#2, P30, BAG1, ROP1, GRA1, and GRA7, with digestion using the restriction enzyme DdeI. Results: The 10 genes were amplified by PCR. Among them, three genetic markers, B1#3, ROP1, and GRA1, were genotyped by the PCR-RFLP using restriction enzyme DdeI. Overall, the findings showed that the specific RFLP profile of digestion of gene regions by DdeI could be used as a specific marker for the virulent biotype causative of toxoplasmosis. In addition, virulent strains of T. gondii can be easily detected by these markers. Conclusion: Three pairs of primers (B1#3, ROP1, and GRA1) with DdeI have proven useful for the diagnosis of acute toxoplasmosis (virulent strain biotype I). This proposed method is relatively simple, rapid, cheap, and can be performed in most laboratories, providing a practical approach for the routine analysis of T. gondii strains.

&lt;i&gt;Toxoplasma gondii&lt;/i&gt; infection in patients with malignant and benign bone tumours

Toxoplasma gondii (T. gondii) is an intracellular parasite that infects humans, and seroprevalence of its infection varies from about 10 to 80 percent in different countries with a higher prevalence in warmer and humid regions. In this study, the rate of acute and chronic toxoplasmosis in patients with benign or malignant bone tumours was investigated. Fifty-three patients who suffered from various bone tumours, as well as sixty-five healthy controls with an unknown sero-logical profile for anti-Toxoplasma antibodies, were enrolled in this cross-sectional study. Anti-Toxoplasma antibodies were detected in serum samples using enzyme-linked immunosorbent assay (ELISA) and blood samples of them were used for real-time PCR. Thirty-two (60.32%) and twenty-one (39.63%) of patients had malignant tumours and benign tumours, respectively. The results showed a higher and significant seropositivity rate of IgM antibodies in primary bone tumour patients compared to the control group and Toxoplasma DNA became positive in 18.86% of patients with primary bone tumours and 6.15% of controls. Surprisingly, the high presence of parasite DNA was detected in patients with malignant tumours. The seroprevalence of T. gondii IgM antibodies and DNA positivity among the cancer patients were significantly higher than healthy individuals. Also, chronic toxoplasmosis (it was shown with IgG positive) appears to be more common in people with benign cancers than malignancies. The study showed a relatively high seroprevalence of anti-T. gondii antibodies in patients with primary bone cancer. However, the considerable rate of positive blood samples for the presence of parasite’s DNA should not be ignored. A key to the effective management of diseases in immunosuppressed individuals is prompt and accurate diagnosis of toxoplasmosis. Moreover, it seems that PCR tests may be more reliable than serological methods and it could be considered as a precise method for diagnosis of acute toxoplasmosis.

Congenital Toxoplasmosis: Missed Opportunities for Diagnosis and Prevention.

Identify missed opportunities for the prevention and early diagnosis of congenital toxoplasmosis (CT) in infants followed up in a reference center for pediatric infectious diseases (PID) in Rio de Janeiro between January 2007 and December 2016. Descriptive study including infants with CT, diagnosis established based on Brazil's Ministry of Health's criteria. All data regarding the infants and their mother's prenatal care were collected from the medical records of the Instituto de Puericultura e Pediatria Martagão Gesteira (IPPMG)-a tertiary public pediatric university hospital. The study enrolled infants aged between 0 and 12 months followed up in the PID department of IPPMG and with confirmed infection by Toxoplasma gondii in the period between January 2007 and December 2016. All patients with diagnosis of CT registered in the PID database of the IPPMG and admitted in the above-mentioned period were included in the study. Patients whose records were not available, or who went to just one clinic appointment were excluded. The obstetric history of all 44 women, whose infants (45) were diagnosed with CT, was analyzed. Their median age was 22 years. None had undergone preconception serological testing for toxoplasmosis. Only 20 (45%) of them started antenatal care during the first trimester of gestation, a total of 24 (55%) had more than six antenatal care visits, and 16% of those did not undergo serological testing for toxoplasmosis. None were adequately informed of preventive measures. The diagnosis of acute toxoplasmosis was made in 50% of these pregnancies but 32% of the women were not treated. Only 10 children of these mothers were adequately screened and treated at birth. Despite the existence of national recommendations, several opportunities were missed to prevent CT during the antenatal period and to diagnose and treat this condition in the neonatal period.

Toxoplasmosis in pregnancy: a clinical, diagnostic, and epidemiological study in a referral hospital in Rio de Janeiro, Brazil

Toxoplasmosis in pregnant women can cause significant morbidity and mortality in the fetus, which may be mitigated by early diagnosis and treatment. Social factors have also been related to the risk of developing the congenital form of toxoplasmosis, since some of these factors interfere directly in the quality of prenatal care. This study aimed to describe the clinical, laboratory, and epidemiological data of pregnant women diagnosed with toxoplasmosis and their newborns followed up at a referral hospital in Rio de Janeiro, Brazil. This was descriptive cohort study of 334 pregnant women with toxoplasmosis followed from May 2014 to December 2017. We conducted interviews to assess knowledge about the disease and its preventive measures, analyzed clinical and laboratory data during antenatal visits, and collected data from the newborns’ medical charts. ResultsThis was a predominantly low-income women cohort study, with little schooling, mainly referred from public health services late in pregnancy (178; 53.3%), in the second and third trimesters (286; 85.6%). Diagnosis of acute toxoplasmosis had not been confirmed in 171 cases (51.2%). Out of 183 (54.9%) women who had initiated treatment at the original health services, 45 (24.6%) received an incorrect prescription. Seventy-two amniocenteses were performed, with positive real-time polymerase chain reaction (qPCR) in the amniotic fluid in two cases (2.8%). Congenital toxoplasmosis at birth was identified in eight newborns (5.4%). ConclusionLate referral to specialized medical services, inadequate toxoplasmosis management at the original prenatal care services, and social vulnerabilities are contributing factors to the persistent occurrence of congenital toxoplasmosis cases.

Severe toxoplasmosis imported from tropical Africa in immunocompetent patients: A case series.

Toxoplasmosis is a zoonosis caused by the protozoan Toxoplasma gondii. In immunocompetent patients the infection is usually benign. However, cases of severe and even lethal primo-infections are regularly reported in South America. In contrast, data from tropical Africa are fragmentary. Data for French cases of severe toxoplasmosis acquired between 2013 and 2018, in tropical Africa and among immunocompetent patients were collected retrospectively in 2018. Four male patients with a mean age of 34-years were identified. All infections originated in West or Central Africa. The clinical presentations were heterogeneous: two patients had severe disseminated toxoplasmosis, of which one presented with chorioretinitis associated with myositis and the other with febrile pneumopathy; one patient presented with post-infectious acute cerebellar ataxia and the final case had general symptoms and skin manifestations. The diagnosis of acute toxoplasmosis was confirmed by serology in four patients. Molecular diagnosis confirmed T. gondii infection in three patients with Africa 1 as the dominant genotype. The infection was cured with anti-infective treatment in all four patients. Ocular sequelae were reported in the two patients with chorioretinitis. Imported cases of severe toxoplasmosis in immunocompetent patients are rare in France. However, this aetiology should be evoked rapidly in a patient with a severe infectious syndrome who has recently visited or originated from tropical Africa.

Diagnosis of acute toxoplasmosis by IgG avidity method in pregnant women referred to health centers in south-eastern Iran.

Toxoplasmosis, one of the most common parasitic infections, can cause abortions in human. The purpose of this study was to determine seroprevalence of toxoplasmosis and acute form of toxoplasmosis in pregnant women. 208 pregnant women who referred to health centers in south-eastern Iran were taken under study after signing the informed consent forms and filling out the checklists. For those with high levels of IgG or IgM antibody titers, IgG Avidity test was performed to determine the acute infection. High level of IgG anti-body were found in sera of 81 pregnant women and 7 persons had borderline titer. IgM antibody results were positive in 33 and borderline in 4 cases. Then, the samples with positive and borderline results for IgM and IgG were evaluated by IgG avidity test. In this study, approximately 60% of pregnant women were not immune torisks posed by Toxoplasma gondii. Therefore, this group are at risk of acquiring primary infection of toxoplasmosis during gestation.

Diagnosis of acute toxoplasmosis in pregnant women referred to therapeutic centers of Alborz Province (Iran) using immunoglobulin G avidity ELISA technique

ObjectiveTo evaluate immunoglobulin G (IgG) avidity as a useful and reliable technique in diagnosing toxoplasmosis in pregnant women referring to therapeutic centers of Alborz Province (Iran) in 2014, against two other tests, IgG and immunoglobulin G (IgM) anti-Toxoplasma. MethodsSerum samples (468 in total) were obtained from different therapeutic centers in Karaj City. ELISA method was used to test the anti-Toxoplasma avidity of IgG, IgM and IgG. The data were analyzed by descriptive statistical methods and Chi-square test (P < 0.05) using SPSS 17.0. ResultsAnti-Toxoplasma tests of IgM and IgG were positive in 9 and 86 samples respectively. Also, a borderline IgM was detected in 2 suspected samples. In addition, among all positive and suspected samples, 79 cases indicated high titers of IgG avidity, 7 cases were of low titers and 1 case was of a borderline titer. The prevalence of anti-Toxoplasma antibodies was 20%. The sera which showed high avidity index was obtained from patients at chronic phase of infection (92%) while those which showed low avidity levels were from patients at acute toxoplasmosis (77.7%). ConclusionsThis study clearly showed that acute and chronic phases of toxoplasmosis could be differentiated with the aid of IgG avidity test. This test may also assist in recognizing old and newly acquired infections.

Toxoplasma gondii specific IgG avidity assay: Role and implication in the confirmatory diagnosis of acute toxoplasmosis in seropositive pregnant women

This study was undertaken to apply Toxoplasma gondii specific IgG avidity test in seropositive pregnant women to differentiate acute and past infection. T. gondii specific IgG avidity test was conducted in 39 seropositive pregnant women and their pregnancy outcomes were observed later on. Out of 39 T. gondii seropositive pregnant women 33 (84%) were only IgG positive and 6 (15.4%) were both IgG-IgM positive. All the IgG positive cases (100%) and 2(33.3%) IgG-IgM positive cases had high avidity antibodies and they gave birth to healthy babies. Rest of the 4 (66.7%) IgG-IgM positive women had low avidity and 50% of them had abortion and 50% gave birth to unhealthy babies. This reveals that the seropositive mothers having high IgG avidity had past infection and no risk of congenital transmission. Seropositive mothers having low IgG avidity had acute infection and so congenital transmission occurred. Presence of T. gondii specific IgG and IgM antibody does not indicate acute infection always. IgG-IgM positive pregnant women should be further evaluated by IgG avidity assay to confirm acute infection.

Twenty-six circulating antigens and two novel diagnostic candidate molecules identified in the serum of canines with experimental acute toxoplasmosis.

BackgroundThe protozoan Toxoplasma gondii is a pathogen that causes severe opportunistic disease in a wide range of hosts. Efficient methods to diagnose acute T. gondii infection are essential for the administration of appropriate treatments and to reduce economic losses. In animals with acute infections, circulating antigens (CAgs) were detected as early as two days post-infection; these CAgs were reliable diagnostic indicators of acute infection. However, only a limited number of CAgs have been identified to date. The objective of this study was to identify a broader spectrum of CAgs and to explore novel diagnostic candidates in serum.MethodsA canine model of acute toxoplasmiosis was established. For this purpose, six dogs were infected by intraperitoneal inoculation of tachyzoites. The CAgs spectrum in the serum was identified with the immunoprecipitation-shotgun approach. Two CAgs with low homology to other species, coronin protein (TgCOR) and ELMO protein (TgELMO), were heterologously expressed in Escherichia coli. Polyclonal antibodies against these two proteins were prepared, and the presence of these proteins in the serum was verified by Western blotting. The two CAgs were detected and evaluated by indirect ELISA methods.ResultsThe CAgs levels peaked between two and five days after inoculation, and twenty-six CAgs were identified. Western blotting showed the presence of the two proteins in the serum during acute infection. Based on ELISA tests, the two CAgs were detected during acute infection.ConclusionsWe identified twenty-six CAgs in the serum of canines with experimental acute toxoplasmosis and discovered two novel diagnostic candidates. We also provide new insights into the diagnosis of acute toxoplasmosis.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-016-1643-x) contains supplementary material, which is available to authorized users.

Toxoplasmose na gestação

No Brasil, a prevalência de infecção aguda é de aproximadamente 1-14 casos/ 1.000 nascidos vivos (NV) e a de infecção congênita é de 0,2-2,0/1.000 NV. A toxoplasmose aguda durante o período gestacional é assintomática em mais de 90% dos casos. Quando sintomática, consiste em quadro gripal (febre, linfadenopatia e mal estar) similar ao apresentado por não gestantes. A toxoplasmose congênita clássica é caracterizada pela tétrade: coriorretinite, hidrocefalia/microcefalia, calcificações cerebrais e alteração neurológica. O rastreio para T. gondii deve ser realizado com dosagem de anticorpos IgG e IgM em todas as gestantes. O diagnóstico de toxoplasmose aguda é realizado quando há IgM positivo associado a IgG negativo ou IgG e IgM positivos com baixa avidez para IgG no primeiro trimestre da gestação ou na presença de viragem sorológica. O diagnóstico de infecção fetal é feito pela identificação de T. gondii no líquido amniótico obtido por amniocentese e processado pela técnica de reação em cadeia de polimerase (PCR). O tratamento é indicado somente em casos de toxoplasmose aguda na gestação. Na suspeita de infecção aguda, deve-se iniciar imediatamente espiramicina. Se a infecção ocorrer após 30 semanas de gestação ou se houver infecção fetal comprovada, o tratamento tríplice materno com pirimetamina, sulfadiazina e ácido folínico é recomendado. O objetivo desta revisão é destacar a importância do diagnóstico precoce da toxoplasmose aguda na gestação, a fim de realizar a quimioprofilaxia da transmissão vertical, assim como o tratamento da infecção fetal na tentativa de minimizar ou evitar a manifestação fetal da toxoplasmose congênita. Descritores : Toxoplasmose; Gravidez; Diagnóstico; Tratamento.

Severe polymyositis due to Toxoplasma gondii in an adult immunocompetent patient: a case report and review of the literature

Toxoplasmosis, a worldwide zoonosis caused by a coccidian parasite Toxoplasma gondii, is more often asymptomatic in immunocompetent patients. We report the case of a 38-year-old immunocompetent male with a polymyositis as the presenting manifestation of T. gondii infection. The patient was hospitalized for a 30-day history of fever (T max 39.5°C), muscle pain, and progressive weakness of the muscles. A diagnosis of polymyositis was made, and he was started on corticosteroid treatment, which caused no reduction of symptoms. After finding a positive polymerase chain reaction (PCR) assay for T. gondii, together with additional clinical findings, a diagnosis of acute toxoplasmosis was made. Specific treatment with pyrimethamine and sulfadiazine was started, with a progressive reduction of symptoms and normalization of laboratory tests.

Toxoplasmosis and pregnancy: Perinatal results and association of the IgG avidity test with congenital infection in pregnant women with positive anti-&lt;i&gt;Toxoplasma gondii&lt;/i&gt; IgM &lt;b&gt;[Abstract in English]&lt;/b&gt;

AIMS: To verify the perinatal outcomes in pregnant women with acute toxoplasmosis, and to determine if there was association between the results of Toxoplasma gondii-specific IgG avidity test and the presence or absence of fetal/neonatal infection. METHODS: A cross-sectional study included pregnant women with serological diagnosis of acute toxoplasmosis (presenting a positive Toxoplasma gondii-specific IgM test) attended at the outpatient unit for high-risk pregnancy of the Faculty of Medicine, Federal University of Mato Grosso do Sul, Brazil, in the period from November 2002 to November 2007. Test results demonstrating IgG avidity index above 30% were considered high avidity, while values below 30% were considered low avidity. Fetal and/or neonatal infection was defined by positive result for the polymerase chain reaction in amniotic fluid, or by a positive Toxoplasma gondii-specific IgM test in the newborn's serum. RESULTS: Considering all pregnant women referred to the outpatient unit for high-risk pregnancy in the period of study, frequency of pregnant women with positive Toxoplasma gondii-specific IgM was 10.8% (176/1.634). The rate of congenital infection in these patients was 4% (7/176). The IgG avidity test was performed in 162 patients (92% of the 176 pregnant women with positive IgM), and the avidity was high in 144 (88.9%). There was an association (p=0.003) between high avidity and no fetal/neonatal toxoplasmosis in our sample, with a prevalence ratio of 13.4 (confidence interval [CI] 95% 2.2-86.6). The positive predictive value of the avidity test (probability of congenital infection with a low avidity) was 22% (95% 6%-47%), while the negative predictive value (probability of absence of congenital infection with a high avidity) was 98% (95% CI 94% -99%). CONCLUSIONS: In this study the rate of congenital infection in pregnant women diagnosed with acute toxoplasmosis was 4%. In pregnant women with positive Toxoplasma gondii-specific IgM, results of Toxoplasma gondii-specific IgG avidity test were associated with the presence or absence of congenital infection, with a high negative predictive value (no fetal/neonatal infection when avidity was high).

Diagnosis of Acute Toxoplasmosis in a Seronegative Transplant Patient from Bone Marrow Smears

Diagnosis of Acute Toxoplasmosis in a Seronegative Transplant Patient from Bone Marrow Smears

IgG avidity assay firms up the diagnosis of acute toxoplasmosis on the first serum sample in immunocompetent pregnant women

Rapid diagnosis of acute toxoplasmosis during pregnancy permits timely treatment and prevents or attenuates congenital toxoplasmosis. Specific IgM antibodies to Toxoplasma as marker of acute infection are often poorly informative, meaning that a complementary technique is needed to reach a diagnosis on the first sample. Here we evaluated 2 commercial kits designed to assist with the diagnosis of acute toxoplasmosis: Platelia® Toxo IgG Avidity Complementary Reagents and Platelia® Toxo IgA, both from BIO-RAD (Marnes La Coquette, France). We tested 2 groups of subjects: 36 patients with acute toxoplasmosis and 55 patients with chronic toxoplasmosis. The IgG avidity test had a sensitivity of 100% (36/36), a specificity of 92.7% (51/55), a positive predictive value of 90%, and a negative predictive value of 100%. Among the immunocompetent women population, the avidity test had perfect sensitivity and specificity, and positive and negative predictive values of 100%. The IgA test had a sensitivity of 88.8% (32/36) and a specificity of 85.4% (47/55), and positive and negative predictive values of 80% and 92.1%, respectively. When the 2 tests were combined, there was only 1 case in which the diagnosis of chronic toxoplasmosis could not be confirmed. The IgG avidity test can therefore be used to rapidly distinguish between chronic and acute infection on the first sample from a pregnant woman, provided there is no underlying immunodepression and no ongoing antitoxoplasmic treatment. In these 2 situations, the results must be interpreted with care, and other serologic markers, including IgA, should be tested. Determination of a pregnant woman's status on a first serum sample allows therapeutic and preventive management to be started without delay.

Diagnóstico molecular da toxoplasmose: revisão

A toxoplasmose infecta milhões de pessoas no mundo inteiro, sendo que a prevalência da infecção humana na maioria dos países está entre 40% e 50%. No Brasil essa taxa aumenta até 80%, dependendo da área estudada. Na maioria dos hospedeiros a infecção é assintomática. A mulher grávida com sorologia negativa pode contribuir para o incremento da morbidade, transmitindo o Toxoplasma gondii para o feto, através da placenta, se adquirir toxoplasmose aguda durante a gravidez. O diagnóstico da toxoplasmose aguda é baseado na detecção de IgM anti-Toxoplasma gondii circulante. A alta sensibilidade das técnicas sorológicas atuais trouxe a realidade da presença de IgM residuais confundindo muitas vezes o diagnóstico final. Nesse sentido, as técnicas moleculares, tais como a reação em cadeia da polimerase (PCR), podem ajudar a uma melhor interpretação do estado real da interação parasito/homem, embora sejam ainda pouco validadas para uso na rotina de diagnóstico laboratorial da toxoplasmose.

Toxoplasmosis

Toxoplasma gondii is a unicellular protozoan. The definitive hosts, cats, produce hardy oocysts and sporozoites. Ingestion by a nonfeline leads to the formation of tachyzoites acutely, which cause parasitemia and further dissemination, and bradyzoites, which lead to latent infection with the formation of tissue cysts in skeletal muscle, heart muscle, and central nervous system (CNS) tissue. Toxoplasmosis can be transmitted to humans by ingestion of tissue cysts in raw or inadequately cooked infected meat or in uncooked foods that have come in contact with contaminated meat, by inadvertent ingestion of oocysts and sporozoites in cat feces, or transplacentally. Immunocompetent adults and adolescents with primary infection are generally asymptomatic, but symptoms may include mild malaise, lethargy, and lymphadenopathy. Specific treatment for nonpregnant adults and adolescents is not required. Immunosuppressed patients may experience more severe manifestations, including splenomegaly, chorioretinitis, pneumonitis, encephalitis, and multisystem organ failure. These patients are also prone to reactivation of latent infection involving the CNS. All patients with human immunodeficiency virus infection and CD4 counts <100 cells per cubic millimeter should be treated prophylactically with pyrimethamine-sulfonamide. Congenital toxoplasmosis is marked by the classic triad of chorioretinits, intracranial calcifications, and hydrocephalus. Current studies have determined that prolonged treatment (1–2 years) of neonates with fansidar is important to prevent serious sequelae. Diagnosis of acute toxoplasmosis is mainly by antibody detection and generally only undertaken in pregnant patients with risk factors for transplacental transmission. All positive screening tests in pregnant women must be confirmed at a toxoplasma reference laboratory. Recent studies have shown that polymerase chain reaction testing of amniotic fluid is useful for identification or exclusion of fetal T. gondii infection. Ultrasound can be used as an adjunct to serological screening but cannot itself definitively diagnose disease. Early–first-trimester maternal infections are less likely to result in congenital infection, but the sequelae are more severe. Transplacental passage is more common when maternal infection occurs in the latter half of pregnancy, but fetal injury is usually much less severe. Typically, infected pregnant patients are treated with pyrimethamine-sulfonamide for positive PCR–amniotic-fluid testing and with spiramycin for negative PCR-AF testing.

Blotting in Toxoplasma-seropositive heart

Abstract Toxoplasmosis is a life-threatening disease in heart- or lung transplant recipients that can result either from the reactivation of a latent infection or from an organtransmitted infection. The diagnosis of acute toxoplasmosis is easy in cases of seroconversion following a mismatch. However, when the recipient is Toxoplasma-seropositive before transplantation, usual serological techniques do not allow the differentiation between endogenous and organ-related reinfection. The aim of this study was to determine whether western blotting could contribute to this differentiation. Sequential sera from two heart- and one liver- and lung transplant patients whose anti- Toxoplasma antibody titers strongly increased after transplantation, were analyzed by western blotting. Neosynthesized IgG were observed on blots incubated with the sera from two patients who had received transplants from Toxoplasma-seropositive donors, whereas no neosynthesized IgG was detected on blots from the patient who had received a transplant from a Toxoplasma-seronegative donor. Our results suggest that the detection of neosynthesized IgG in the recipient may be related to the recognition of a new parasite strain possibly brought by the transplant from a Toxoplasma-seropositive donor.