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PubMed1993

[Prophylactic effects of trimethoprim-sulfamethoxazole in Toxoplasma-infected mice].

This study was performed to evaluate the prophylactic effects of trimethoprim-sulfamethoxazole (TMP-SMZ) in mice experimentally infected with virulent RH strain and avirulent Beverley strain of T. gondii. The mice infected with 1 x 10(5) tachyzoites were used in the measurement of mean survival days, and the mice infected with 10 cysts were used in the titrations of specific antibodies and enumeration of brain cysts. Mean survival days of mice were significantly increased in mice treated with TMP-SMZ as compared with spiramycin-treated and untreated control group. Mean survival days and survival rates of mice were increased according to the increment of dosages, and TMP-SMZ protected 100% of mice after fifteen daily dose of 24 mg/mouse or more administered orally. Toxoplasma-specific serum IgG and IgM antibody titers were significantly lower in mice treated with TMP-SMZ than those of spiramycin-treated and untreated control group. Toxoplasma cysts were not found in mice treated with TMP-SMZ at a dose of 24 mg/mouse or more per day, but the group of spiramycin treatment and untreated controls were found in the brain from 20 days after infection. The present results revealed that TMP-SMZ can be used as a prophylactic agent against murine toxoplasmosis after intraperitoneally challenges with the virulent or avirulent strain of T. gondii.

Animals↗
PubMed2002

Phenotype and regulation of persistent intracerebral T cells in murine Toxoplasma encephalitis.

Toxoplasma gondii is a parasite causing asymptomatic, persistent encephalitis. Protective CD4 and CD8 T cells are recruited to and accumulate in the brain in acute Toxoplasma encephalitis (TE), with slowly decreasing numbers in chronic TE. It is unclear how the size of the intracerebral T cell pool is regulated. Conceivably, permanent recruitment, proliferation, and apoptosis may be involved. We observed that in murine TE recruitment of T cells to the brain was terminated in chronic TE. In vivo 5-bromo-2'-deoxyuridine incorporation and in vitro T cell proliferation experiments revealed that intracerebral T cells did not proliferate, which was explained by the expression of the cell cycle inhibitors p21(Waf/cip1) and p27(Kip1) and the inhibitory activity of intracerebral F4/80(+) cells. TUNEL staining detected apoptotic T cells at low frequency corresponding to an increased expression of the anti-apoptotic molecules Bcl-2 and Bcl-x(L) and a reduced expression of the pro-apoptotic molecules Bad, Bax, and Fas ligand in CD4 and CD8 T cells. During progression from acute to chronic TE, both CD4 and CD8 T cells down-regulated CD45RB expression and expressed a differential pattern of cytokines. From these experiments it is concluded that the number of intracerebral T cells increases by recruitment of T cells during acute infection, whereas proliferation of intracerebral T cells does not play a role. In chronic TE, T cell recruitment is terminated, the phenotype of intracerebral T cells changes, and their number is gradually downsized by low level apoptosis, which, however, does not completely resolve the T cell infiltrates.

Animals↗
PubMed2004

The effect of pinealectomy and zinc deficiency on nitric oxide levels in rats with induced Toxoplasma gondii infection.

PRINCIPLES: This study aims at investigating how zinc deficiency and pinealectomy affect nitric oxide levels in rats infected by Toxoplasma gondii. METHODS: The study was conducted on a total of 50 adult, male rats of Spraque-Dawley species. The study groups were as follows: General, intact control group (Group I, n = 10), infected control group (Group II, n = 10), infected and zinc-deficient group (Group III, n = 10), infected and pinealectomized group (Group IV, n = 10), infected, zinc-deficient and pinealectomized group (Group V, n = 10). After the experiment the rats were decapitated and levels of zinc, melatonin and total nitrite were identified in the blood samples collected. RESULTS: The total nitrite levels in groups IV and V were more than those in all other groups (p <0.01). The total nitrite levels in Group II were also higher than those in Groups I and III (p <0.01). Plasma zinc levels in the zinc-deficient group and zinc-deficient and pinealectomized group were lower than those in all other groups, while melatonin levels were lower in infected pinealectomized group (Group IV) and infected, zinc-deficient and pinealectomized group (Group V) than all others (p <0.01). CONCLUSIONS: The present study shows that plasma nitric oxide levels increase during Toxoplasma gondii infection, but this increase becomes more apparent in the presence of melatonin deficiency and is inhibited by zinc deficiency.

Animals↗
PubMed2000

[Immunity in Toxoplasma gondii infections].

The article presents selected data concerning pathogenesis, clinical manifestations, natural and specific resistance and vaccines against T. gondii infections. Toxoplasma gondii protozoan has been recognized as one of the most successful parasites infecting any nucleated cell of human individuals and most warm-blooded animals. The infection causes life-threatening disease in individuals with defective immunity such as fetuses, AIDS patients and transplant recipients. In immunocompetent humans toxoplasmosis is usually asymptomatic. Following an acute phase of infection characterized by systemic spread of rapidly dividing tachyzoites, bradyzoites encyst in various host tissues (brain, muscles) and may persist there lifelong. Toxoplasmosis in controlled by vigorous cell-mediated immune response capable of killing infected cells and parasites. As shown in the mouse experimental model natural killer cells (NK) are critical for the resistance at the early stage of primary infections, whereas adaptive immunity depends on T lymphocytes. Both CD4+ Th1 and CD8+ Tc1 lymphocytes are believed to mediate protection by producing of IFN-gamma, a pitoval cytokine that induces anti-Toxoplasma effector mechanisms in macrophages.

Animals↗
PubMed2000

Toxoplasma gondii pneumonia in a pancreas transplant patient.

A 41-year-old woman had fever of 3 days' duration. She had had pancreas transplantation 2 years previously and had recently completed a course of antirejection medication. Temperature spikes occurred during treatment with broad spectrum antibiotics. No obvious cause for the fever was found. The patient's condition worsened, with development of shortness of breath, bilateral pulmonary infiltrates on chest radiographs, sepsis, and shock. Fiberoptic bronchoscopy with bronchoalveolar lavage showed the presence of Toxoplasma gondii. Pyrimethamine and clindamycin were started, and the patient improved. Toxoplasma gondii occurs in contaminated food containing oocysts or cysts. Organ transplantation and blood transfusions are other routes of transmission. Most recent cases have occurred in human immunodeficiency virus (HIV) patients with reactivation of previous infection. Serology and tissue biopsies are used for diagnosis. Treatment includes a combination of pyrimethamine and sulfadiazine or trisulfapyrimidines.

Adult↗
PubMedDate not supplied

[Chorioretinitis caused by toxoplasma in children].

In a period of 5 years, 21 children with ocular lesions caused by toxoplasma (chorioretinitis due to toxoplasma) were seen at "Pedro Kourí" Tropical Medicine Institute. Of the 21 children, 5 (23.8%) had lesions in both eyes and 16 (76.1%) in one eye (9 in the left eye and 7 in the right one). 9 children (42.8%) initially had active lesions that responded satisfactorily to medical treatment whereas 12 (57.1%) came to the hospital with healed lesions that did not require any treatment. They were all followed up as outpatients with favorable evolution in all cases.

Adolescent↗
PubMed2001

Seroepidemiological study of Toxoplasma gondii infection in the human population in the Eastern Region.

OBJECTIVE: Toxoplasma gondii is an an obligate intracellular protozoan parasite that causes toxoplasmosis. The infection is worldwide, particularly in warm and moist climates. Few studies have been conducted on the prevalence of subclinical or overt disease in Saudi Arabia. No population-based study was conducted or the seroprevalence of toxoplasmosis in humans in Saudi Arabia and this initiated the present study. The present study aimed at studying seroprevalence of Toxoplasma IgG and IgM antibodies in sera from 5 areas in the Eastern Region of Saudi Arabia. METHODS: A population based epidemiological approach, prevalence according to lifestyle (urban or rural), gender (male or female) occupation and age. RESULTS: Inactive toxoplasmosis (IgG levels) is of rather high prevalence in the human population in the Eastern Region of Saudi Arabia (25%). On the other hand, active toxoplasmosis (acquired during pregnancy) is of rather low prevalence in this study (5%). Active toxoplasmosis (IgM levels) is positively related to the level of exposure, high in farmers and employees in village rural areas and low in children and students in urban areas. CONCLUSION: Patients with active toxoplasmosis are to be treated and made aware of their situation. Hygienic conditions in areas of rather high prevalence of active toxoplasmosis are to be more strictly imposed to minimize transmission of the disease.

Adolescent↗
PubMed1975

[Studies on the significane of sexual intercourse for the transmission of Toxoplasma gondii (author's transl)].

From 285 ejacula and 23 biopsy specimens of the testicles of men from childless marriages, no toxoplasms at all could be cultured in the mouse inoculation test. Testicles and accessory gonads of artificially infected male rabbits contained infective toxoplasms only up to the 29th day p.i. 8 artificially infected male rabbits did not transmit any agents through sexual intercourse to 13 toxoplasma-free female rabbits. One female animal became infected during the experiment. The route of infection is discussed. Experiments with ejacula of 4 artificially and freshly infected male rabbits did not lead to any Toxoplasma infection in mice, which had been inoculated with this material. From 50 testicles of sheep bound for slaughter, only in one case toxoplasms could be isolated in the mouse inoculation test. In virtue of the results in the literature and of our own experiments, the transmission of toxoplasms through sexual route does not seem to be of any vital epidemiological significance for men and animals.

Animals↗
PubMed2002

[Toxoplasma infections in early pregnancy: consequences and management].

OBJECTIVE: To assess the consequences for the fetus of maternal toxoplasma infection acquired during the first 8 weeks of gestation and to set guidelines on how to manage these maternal infections. METHODS: Data were prospectively analyzed on 360 pregnancies followed-up in our department due to a toxoplasma infection during the 8 first weeks of pregnancy. Estimates of the risk of fetal infection were based on all cases, including those which could not be followed up until infection was ruled out or confirmed. Severity of infection was estimated based on ultrasound findings during pregnancy, neonatal and long-term postnatal clinical, neurological and ophthalmologic work up. RESULTS: Out of the 360 included women, 336 gave birth to a live born child: 7 (2%) were infected, 302 (90%) were free of infection and follow-up was insufficient to conclude about the 27 (8%) remaining infants. The estimated risk of fetal infection ranged between 2 and 10% based on live born children and between 3 and 14% when the 24 interrupted pregnancies were included. At their last clinical evaluation at 70 months of age, all 7 children, including the 2 who had inactive peripheral eye lesions and the one who had a unique intracranial calcification were free of any ophthalmologic or neurological impairment. CONCLUSION: Our study confirms that in the event of a maternal infection during the first 8 weeks of pregnancy the risk of fetal infection is low and results mainly in a spontaneous termination of pregnancy. Future parents should be assured that conversely to a common opinion, the prognosis of congenital toxoplasmosis in live-born children is good. For these early maternal infections as for those acquired later, we recommend immediate treatment with spiramycin, monthly ultrasound surveillance, amniocentesis and treatment with pyrimethamine and sulphamides if the PCR is positive. Abortion should be restricted to cases with ultrasound lesions

Amniocentesis↗
PubMed2002

[Maternal toxoplasma infection and mosaic trisomy 8 syndrome].

INTRODUCTION: Mosaic trisomy 8 syndrome shows significant phenotypic variability. High forehead, deep set eyes, wide base of the nose, upturned tip of the nose, protruding lips, prominent ears, strabism, corpus callosum agenesia, deep plantar furrow and variable degree of psychomotor retardation are present in most patients. PATIENTS/METHODS: The authors describe a patient with severe motor and mental retardation, optic disc hypoplasia, cardiomyopathy and partial extrahepatic bile-duct atresia, who's mother was treated for toxoplasma infection in her pregnancy. Perinatal infection of the child was ruled out by the documentation of decreasing IgG values in the mother and newborn and normal IgM levels in the newborn. RESULTS: Facial characteristics and the bilateral deep plantar furrow raised the possibility of trisomy 8 syndrome. Routine chromosomal analysis and fluorescent in situ hybridization studies revealed a normal cell line, mosaic trisomy 8 in 13% of the cells, and a pericentric marker 8 ring chromosome in 27% of the cells. CONCLUSION: The authors suggest that the periconceptional toxoplasma infection may play a role in the occurrence of the mosaic trisomy presenting with cardiomyopathy and partial bile-duct atresia previously undescribed in this syndrome.

Bile Ducts↗
PubMedDate not supplied

A seroepidemiological study of toxoplasma gondii infection in children of northern Greece.

The aims of this study were to determine the incidence of toxoplasmosis in children ofthe northern Greece region through the evaluation of serologic examination. Sera of 486 children, aged between 6 months and 15 years, suffering from different clinical entities, were tested for anti-Toxoplasma gondii specific IgG antibodies, using an ELISA (enzyme linked immunosorbent assay) technique. In this survey, a high percentage (11.1 percent) of the hospitalized children reacted positively to this method. Males and females had equal prevalence, 11 percent and 11.2 percent, respectively. Seropositivity rate was higher in children aged between 6 and 10 years old. In conclusion, our results indicate toxoplasma infection is an important public health problem affecting children and adolescents in northern Greece. We believe that the study described here could be considered for inclusion in existing national screening programs for hospitalized children.

Journal Article↗
PubMed1992

Newborn screening for congenital Toxoplasma infection: five years experience in Massachusetts, USA.

Since 1986, all Massachusetts newborn filter paper blood specimens, and some from New Hampshire, have been screened for the presence of IgM antibodies to Toxoplasma gondii using an enzyme-linked IgM capture assay. Among approximately 530,000 infants screened, 40 had serologically confirmed congenital toxoplasma infection, and 4 additional infants had borderline serologies, for an overall identification and treatment rate of 1:12,000. False positive results from the newborn's filter paper specimen occurred in 22 infants (1/24,000); these were clarified by tests for IgM and IgG in serum specimens obtained 2-3 weeks later from the infant and mother. The screening program would have failed to detect 3 infants with severe infection who were diagnosed on clinical grounds prenatally or at birth and lacked IgM. No infants with a later diagnosis of congenital toxoplasmosis that was missed by screening are known to our statewide network of pediatric infectious disease consultants. Follow-up studies are in progress to evaluate more completely the sensitivity of the IgM assay in newborns and the efficacy of treatment.

Antibodies, Protozoan↗
PubMed1992

Toxoplasma gondii pneumonitis in patients infected with the human immunodeficiency virus.

Pulmonary toxoplasmosis is a rarely recognized opportunistic infection in immunocompromised patients. A few case reports have described pulmonary toxoplasmosis in human immunodeficiency virus-infected patients in association with Toxoplasma gondii central nervous system disease. We encountered six cases of pulmonary toxoplasmosis in human immunodeficiency virus-infected patients who presented with a protracted febrile illness, respiratory symptoms, and an abnormal chest roentgenogram in the absence of neurologic findings. No clinical or roentgenographic features distinguished T gondii pneumonitis from more common opportunistic pulmonary infections. As the acquired immunodeficiency syndrome epidemic progresses, the presenting illnesses have evolved. Toxoplasma gondii must be considered a potential cause of pulmonary disease during the evaluation of human immunodeficiency virus-infected patients with respiratory symptoms.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

[Itraconazole action on Toxoplasma gondii].

With the purpose to increase our knowledge about the spectrum of therapeutic action of itraconazole, the activity of a new triazolic derivative against Toxoplasma gondii was studied in vivo and in vitro with the aid of an experimental infection model in mice. The trial also aimed at a possible improvement of the therapy of toxoplasmosis in regard to safety and dosing easiness. The present study has not shown significant activity of itraconazole against Toxoplasma gondii, differing from a previous observation that showed it's activity against Trypanosoma cruzi.

Animals↗
PubMed1992

Toxoplasma colitis in the acquired immunodeficiency syndrome.

In patients with acquired immunodeficiency syndrome (AIDS), toxoplasmosis almost exclusively involves the central nervous system (CNS), and extra-CNS organ infection is rare. We report a case of Toxoplasma gondii colitis in a patient with AIDS characterized by the following: 1) onset of diarrhea was simultaneous with disseminated toxoplasmosis; 2) T. gondii was found in colonic biopsies, whereas other infectious causes of diarrhea had been ruled out; 3) diarrhea was cured by anti-Toxoplasma therapy.

Acquired Immunodeficiency Syndrome↗
PubMed2005

[Acute myocarditis with Toxoplasma gondii. A case report in a newborn].

Acute myocarditis with Toxoplasma Gondii in immunocompetent patients is rare and the paediatric cases touch old children. These myocarditis lead sometimes cardiac insufficiency and sometimes mimic a myocardial infarction. The evolution is often favorable, even when there is no pest-destroying treatment. We report a case of myocarditis toxoplasma Gondii with which has occurred in a 11 month and half old infant, whose evolution was favorable with a symptomatic and pest-destroying treatment. The interest of this observation is related to the scarcity of acute myocarditis caused by toxplasmosis in infant without immunoinsufficiency.

Acute Disease↗
PubMed1991

[Serology against Toxoplasma gondii in pregnant women. Development of prevalence rates in the course of 4 years].

Sera from 1,221 pregnant women were screened for antibodies against Toxoplasma gondii. The prevalence rate of antibodies was 38.9%. We have observed specific IgM antibodies 15 pregnant women (1.2%). The prevalence rate was not increased significantly with the age and number of pregnancies. The seropositivity was reduced significantly in the 4th year studied. The high rate of seronegativity observed in the pregnant women represent a high risk of Toxoplasma infestation.

Antibodies, Protozoan↗
PubMed1991

[Relation between abnormal pregnancies and Toxoplasma gondii infection].

3,012 pregnant women were divided into three groups according to the status of Toxoplasma gondii infection, and the pregnancy outcomes were followed up. Results showed that the total incidence rates of spontaneous abortion, premature birth, still birth and congenital defects were 0.70, 3.39, 0.83 and 0.90% respectively. The incidence rates of the four groups of abnormal pregnancies having serologically diagnosed recent or active infection were significantly higher than that having no evidence of infection. The relative risk estimates (ORmh) of the 4 groups were 7.01, 3.44, 8.76 and 9.34% respectively. The incidence rates of the groups diagnosed as having past infection were not significantly different from that having no evidence of infection. Analysis of the time lapse from positive serodiagnosis to the appearance of abnormal pregnancies showed that the development of congenital defects was statistically related with Toxoplasma gondii infection in the first trimester of gestation.

Abortion, Spontaneous↗