Epidemiological factors associated with seropositivity for toxoplasmosis in pregnant women from Gurupi, State of Tocantins, Brazil

Introduction Knowledge of the prevalence and risk factors for Toxoplasma gondii dissemination among pregnant women is relevant because the parasite can be spread from mother to infant. The objective of this study was to assess the epidemiology and risk factors of toxoplasmosis in pregnant women from Gurupi, State of Tocantins, Brazil, from February 2012 to June 2013. Methods The study population included 487 pregnant women. Sociodemographic, dietary and cultural data were collected using a standardized and validated form. Peripheral blood was collected for serologic testing using the ELISA test (IgM/IgG antibodies). The data were analyzed by comparing seropositivity with risk factors using crude and adjusted odds ratios. Results The prevalence rate for IgG and IgM antibodies was 68.7% and 5.7%, respectively. Sociodemographic characteristics associated with toxoplasmosis risk included the following: education level ≤ 8 years (OR: 6.612; CI: 1.450-30.144), age ≥ 30 years (OR: 5.273; CI: 1.166-23.844), working outside the home (OR: 1.604; CI: 1.015-2.536), and family income of two minimum wages or lower (OR: 2.700; CI: 1.891-8.182). Regarding dietary habits, there was a significant association of seropositivity with meat intake (OR: 1.78; CI: 1.149-4.080), cutting vegetables without washing the cutting board beforehand (OR: 2.051; CI: 1.165-3.614), frequent intake of vegetables (OR: 2.051; CI: 1.368-3.006) and in natura milk intake (OR: 2.422; CI: 1.014-5.785). Conclusions The high prevalence rates of toxoplasmosis in Gurupi are related to age, raw meat and in natura milk intake, as well as education level, working outside the home, and poor hygienic habits during meal preparation.

Progression of the load of waterborne and intestinal parasitic diseases in the State of Amazonas

In the State of Amazonas, Brazil, urban expansion together with precarious basic sanitation conditions and human settlement on river banks has contributed to the persistence of waterborne and intestinal parasitic diseases. Time series of the recorded cases of cholera, typhoid fever, hepatitis A and leptospirosis are described, using data from different levels of the surveillance systems. The sources for intestinal parasitosis prevalence data (non-compulsory reporting in Brazil) were Medical Literature Analysis and Retrieval System Online (MEDLINE), Literatura Latino-Americana (LILACS) and the annals of major scientific meetings. Relevant papers and abstracts in all languages were accessed by two independent reviewers. The references cited by each relevant paper were scrutinized to locate additional papers. Despite its initial dissemination across the entire State of Amazonas, cholera was controlled in 1998. The magnitude of typhoid fever has decreased; however, a pattern characterized by eventual outbreaks still remains. Leptospirosis is an increasing cause of concern in association with the annual floods. The overall prevalence of intestinal parasites is high regardless of the municipality and the characteristics of areas and populations. The incidence of hepatitis A has decreased over the past decade. A comparison of older and recent surveys shows that the prevalence of intestinal parasitic diseases has remained constant. The load of waterborne and intestinal parasitic diseases ranks high among the health problems present in the State of Amazonas. Interventions aiming at basic sanitation and vaccination for hepatitis A were formulated and implemented, but assessment of their effectiveness in the targeted populations is still needed.

A new page on the road book of inorganic mercury in fish body - tissue distribution and elimination following waterborne exposure and post-exposure periods

prova tipográfica / uncorrected proof

Regulation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-[kappa]B) by protein Kinase C theta (PKC-[theta]) and cylindromatosis (CYLD) in murine listeriosis and toxoplasmosis

Magdeburg, Univ., Fak. für Naturwiss., Diss., 2013

Indirect immunofluorescence(IgG and IgM) tests for toxoplasmosis on 203 persons, with no symptomatology suggesting the disease, located in the city of Rio de Janeiro. Serological follow up one to two years later.

Clinical and serological follow up examinations were performed on 203 persons, from three to twenty years of age, from the otolaryngology department of a hospital in the city of Rio de Janeiro, with no symptomatology suggesting toxoplasmosis, but suffering from chronic tonsillitis. According to results obtained during the first indirect immunofluorescence tests, the patients were divided into following groups: Group I (non-reactive IgG and IgM), 98 persons (48.3%); Group II (1:16 ≤ IgG ≤ 1:256 and non-reactive IgM), 74 persons (36.5%); Group III (IgM ≥ 1:1024 and non-reactive IgM), 18 persons (8.8%), and Group IV (IgG and IgM reactive), 13 persons (6.4%). One to two years later, 131 (64.5%) of the 203 persons were reexamined by a second indirect immunofluorescence test. In the case of 66 persons (Group I) whose serum was non-reactive in the IgG and IgM classes during the first indirect immunofluorescence test, serum conversion was observed in aproximately 21.2%. in 65 individuals (49.6%), (Groups II, III and IV),with reactive serum in the IgG classes during the first indirect immunofluorescence test, the second reaction showed an increase in titres in 20% of the cases, a decrease in 67.7% of the cases, or no alterations in 12.3 of the cases. In the IgM class, all 131 sera were non-reactive at 116 dilution the second immunofluorescence test, including the 13 cases that had previously been reactive in the immunoglobulin class, Symptomatology suggesting toxoplasmosis was only observed in one case during the second testing, this patient's principal physical sign being hypertrophied lymph nodes. during this period, the Toxoplasma antibodies showed titres of IgG 1:32000 and non-reactive IgM, whilst one year previously, during the first test, these titres were IgG 1:1024 and IgM 1:64. Differences in the age, sex and skin coloring of patients were not statistically significant as regards alterations in the indirect immunofluorescence test titres.

Outbreak of human toxoplasmosis in a rural area. A three year serologic follow-up study

Thirty-six persons living on a farm located in the state of Minas Gerais (Brazil) were studied. Nine of them had the glandular form of toxoplasmosis, between May and August, 1976. These nine cases of toxoplasmosis were confirmed serologically by immunefluorescence-IF-, presenting IgG antibody titres between 1:4096 and 1:32000 and IgM antibody titres between 1:16 and 1:8000. Twelve out of thirty-six persons studied were considered to be "dubious cases". They were defined either by presenting a clinical picture compatible with acquired toxoplasmosis, yet having low serologic titres, or inversely they did not have a clear clinical picture but had serologic evidence of recent Toxoplasma infection. Fifteen out of thirty-six persons studied showed neither serologic nor clinical evidence of recent Toxoplasma infection. The epidemiologic information suggests two possible modes of transmission: a) poorly cooked pork at a barbecue party; b) farm vegetables and soil contaminated with Toxoplasma gondii oocysts (rat-cat cycle). Serologic follow-up nine months later in the human farm population demonstrated still high IgG titres, yet they tended to decline and IgM titres became negative. Three years later most of the IgG titres continued to decline and were almost compatible with the titres obtained in Brazilian population surveys.

Epidemiological aspects of toxoplasmosis in schoolchildren residing in localities with urban or rural characteristics within the city of Rio de Janeiro, Brazil

Immunofluorescence tests (IF) for toxoplasmosis were performed on a total of 608 schoolchildren in elementary and junior high grades. 166 being in the Bonsucesso district (an urban region of Rio de Janeiro) and 442 children from locations within the lowlands of Jacarepaguá (with rural characteristics). All the IF-IgM were nonreactive, whilst 416 schoolchildren (68.4%) were IF-IgG serum-reactive ([greater than or equal to] 1:16). The percentages of serum-reactives in Jacarepaguá were significantly higher than in Bonsucesso, both as regards the total number of schoolchildren (p < 0.001), as also when subdivided according to the age-grades from six to eight years (p < 0.001) or from twelve to fourteen (p < 0.05). Both in Jacarepaguá and in Bonsucesso, the prevalence of reactions in the 12 to 14 year age-grade was significantly greater than in the 6 to 8 year age-grade (p < 0.001 in both cases). Expressively larger prevalences of serum reactions were found in Jacarepaguá among schoolchildren who preferred eating raw or undercooked meat, as well as among those having cats as pets; this occurred equally in the 6 to 8 year and in the 12 to 14 year age-grades. In Bonsucesso, the only significant difference was in the 6 to 8 year age-grades that had cats as pets. Thus, it has been verified that the risk of infection is greater and more precocious in localities with rural characteristics than in urban regions.

Toxoplasmosis and mental retardation: report of a case-control study

A case-control study evaluating the association between mental retardation and toxoplasmosis was conducted among 845 school children in Belo Horizonte, MG, Brazil. Cases (450) were mentally retarded children attending a public school for special education. Controls (395) were children from the regular public school system. Clinical and anthropometric examinations and interviews were carried out to determine risk factors for toxoplasmosis and mental retardation. Diagnosis of Toxoplasma gondii infection was based upon an indirect immunofluorescent test (IFA); 55% of cases and 29% of controls were positive. The Relative Odds of mental retardation in children with positive serology was 3.0 (95% CI 2.2-4.0). Maternal exposure to cats and contact with soil were associated with an increased risk of mental retardation. Retinochoroiditis was fourfold more prevalent among cases than controls and was only diagnosed in T. gondii IFA positive participants. Congenital toxoplasmosis, in its subclinical form, appears to be an important component in the etiology of mental retardation, especially in high risk (lower socio-economic) groups. The population attributable risk was estimated as 6.0 - 9.0%, suggesting the amount of mental retardation associated with this infection.

A simple and economic slide micro-immunoenzymatic (Micro-SIA) test for epidemiological studies of toxoplasmosis

A slide micro-immunoenzymatic assay (micro-SIA) to detectantibodies to non-particulate Toxoplasma gondii antigens is described. This assay allows the diagnosis of toxoplasmosis infection in about 1 hr. Twenty-four determinations can be performed per slide. Five hundred ng of antigen and 5 or 10 µl drop of each reactive are necessary per well. The clear contrast of colours obtained for negative and positive sera after the test is finished, allows direct discrimination of the results. However, it is possible to quantify the results of the reaction using a minireader. Sera dilution cutoff value, determined as themost frequent titre for the general population, is 1:100. The toxoplasma micro-SIA correlates well with indirect immunofluorescence (IIF), its sensitivity is atleast three times as much as IIF. The test has an intra and inter assay variation coefficient of 5.46 per cent and of 6.24 per cent respectively. Sera obtained at random from argentinian people were analyzed and a 56 per cent of infection was found. The main features of the Toxoplasma micro-SIA are its simplicity, sensitivity, reproducibility, and the virtual absence of background making it very suitable for screening tests.

Evolutionary Control of Infectious Disease: Prospects for Vectorborne and Waterborne Pathogens

Evolutionary theory may contribute to practical solutions for control of disease by identifying interventions that may cause pathogens to evolve to reduced virulence. Theory predicts, for example, that pathogens transmitted by water or arthropod vectors should evolve to relatively high levels of virulence because such pathogens can gain the evolutionary benefits of relatively high levels of host exploitation while paying little price from host illness. The entrance of Vibrio cholerae into South America in 1991 has generated a natural experiment that allows testing of this idea by determining whether geographic and temporal variations in toxigenicity correspond to variation in the potential for waterborne transmission. Preliminary studies show such correspondences: toxigenicity is negatively associated with access to uncontaminated water in Brazil; and in Chile, where the potential for waterborne transmission is particularly low, toxigenicity of strains declined between 1991 and 1998. In theory vector-proofing of houses should be similarly associated with benignity of vectorborne pathogens, such as the agents of dengue, malaria, and Chagas' disease. These preliminary studies draw attention to the need for definitive prospective experiments to determine whether interventions such as provisioning of uncontaminated water and vector-proofing of houses cause evolutionary reductions in virulence

Acquired and Congenital Ocular Toxoplasmosis Experimentally Induced in Calomys callosus (Rodentia, Cricetidae)

An experimental model for acquired and congenital ocular toxoplasmosis as well as a model to induce experimental autoimmune uveitis (EAU) was investigated in Calomys callosus. Toxoplasma gondii, ME-49 strain, was used to infect males and pregnant- and not pregnant-females while S-antigen, a major glycoprotein of the retinal photoreceptor cell, was used to induce EAU. The ocular lesions elicited by T. gondii were characterized by the presence of cysts, free tachyzoites and inflammatory cells in the retina or related tissues. In the congenital form, 40% of the fetus presented ocular lesions, i.e., presence of cysts in the retina, vitreous, and extra-retinal tissues. In the acquired form, 75% of the females and 50% of the males presented unilateral ocular cysts both at 21 and 47 days post-infection. It was also demonstrated that S-antigen was not uveitogenic in the C. callosus model. No lesion was observed in the animals exclusively immunized with this retinal component, even when jacalin was used as additional adjuvant for polyclonal response to the retinal antigen. It can be concluded that C. callosus may constitute in a promising model for study both acquired and congenital ocular toxoplasmosis, particularly when it is important to make sure that a non autoimmune process is involved in the genesis of the ocular infection.

Protection against Toxoplasmosis in Mice Immunized with Different Antigens of Toxoplasma gondii Incorporated into Liposomes

Different toxoplasma antigens were entrapped within liposomes and evaluated, in this form, for their ability to protect Swiss mice against toxoplasma infection: soluble tachyzoite antigen (L/TAg), tissue cyst (L/CAg), tachyzoite plus tissue cyst (L/TCAg) or purified antigen of tachyzoite (L/pTAg). The protein used in L/pTAg was purified from tachyzoites using a stage-specific monoclonal antibody which reacted at a molecular weight of 32 kD in SDS PAGE and silver stain using reduced condition. To compare the immuno-adjuvant action of liposomes and of Freund's Complete Adjuvant (FCA), another group of mice was immunized with soluble tachyzoite antigen (STAg) emulsified in FCA (FCA/TAg). Control groups were inoculated with (STAg) alone, phosphate-buffered saline (PBS), FCA with PBS (FCA/PBS) and empty liposomes (L/PBS). Mice were inoculated subcutaneously with these antigens six, four and two weeks before a challenge with 80 tissue cysts of the P strain of Toxoplasma gondii orally. All mice immunized with or without adjuvant showed a humoral response, as measured by Elisa. However, no correlation was found between antibody titer and protection against the challenge. All mice immunized with L/pTAg or L/TCAg survived (100), whereas 80% and 90% of mice from groups which received respectively PBS or FCA/PBS and L/PBS died. All mice immunized with antigens entrapped within liposomes (L/TAg, L/CAg, L/TCAg and L/pTAg) showed low numbers of intracerebral cysts.

Frequency of specific anti-Toxoplasma gondii IgM, IgA and IgE in Colombian patients with acute and chronic ocular toxoplasmosis

We studied the frequency of specific anti-Toxoplasma IgM, IgA and IgE antibodies in serum of 28 immunocompetent Colombian patients, selected by ophthalmologists and with lesions that were compatible with ocular toxoplasmosis. Patients were classified in three groups: (i) group 1 consisted of ten patients with a first episode; (ii) group 2, with seven patients with a recurrence and (iii) group 3, consisted of eleven patients with chronic chorioretinal lesion without uveitis. We found that 10/28 (35%) of Colombian patients with ocular toxoplasmosis possessed at least one serological marker for Toxoplasma infection different from IgG. In group 1 (first episode), we found simultaneous presence of specific IgM plus IgA plus IgE in 1/10 (10%). In group 2 (recurrences) in 1/7 (14%) we found IgM and IgA test positives and in 1/7 (14%) we found IgM and IgE tests positives. In group 3 (toxoplasmic chorioretinal scar) the IgA serological test was positive in 2/11 (18%). These results show that serum IgM or IgA or IgE can be present during recurrences.

Experimental toxoplasmosis in Balb/c mice. Prevention of vertical disease transmission by treatment and reproductive failure in chronic infection

In a study of congenital transmission during acute infection of Toxoplasma gondii, 23 pregnant Balb/c mice were inoculated orally with two cysts each of the P strain. Eight mice were inoculated 6-11 days after becoming pregnant (Group 1). Eight mice inoculated on the 10th-15th day of pregnancy (Group 2) were treated with 100 mg/kg/day of minocycline 48 h after inoculation. Seven mice inoculated on the 10th-15th day of pregnancy were not treated and served as a control (Group 3). Congenital transmission was evaluated through direct examination of the brains of the pups or by bioassay and serologic tests. Congenital transmission was observed in 20 (60.6%) of the 33 pups of Group 1, in one (3.6%) of the 28 pups of Group 2, and in 13 (54.2%) of the 24 pups of Group 3. Forty-nine Balb/c mice were examined in the study of congenital transmission of T. gondii during chronic infection. The females showed reproductive problems during this phase of infection. It was observed accentuated hypertrophy of the endometrium and myometrium. Only two of the females gave birth. Our results demonstrate that Balb/c mice with acute toxoplasmosis can be used as a model for studies of congenital T. gondii infection. Our observations indicate the potential of this model for testing new chemotherapeutic agents against congenital toxoplasmosis.