Molecular and serological diagnosis of toxoplasmosis: a systematic review and meta-analysis

ABSTRACT Toxoplasmosis is an infection of vast worldwide distribution whose etiologic agent is Toxoplasma gondii. This disease can cause problems ranging from mild symptoms to serious conditions, such as encephalitis, miscarriage and blindness. Therefore, it is of utmost importance to perform a diagnosis with reproducible techniques in order to obtain a good prognosis. The aim of this review was to analyze the efficiency of toxoplasmosis diagnostic techniques based on sensitivity and specificity results. Five research platforms in English language were used (Eric, Elsevier, Google Scholar, PubMed and SciELO), which contained data on the diagnosis of toxoplasmosis. The search and selection were performed for studies published prior to June 2021. The search resulted in the inclusion of 13 articles published from 2005 to 2020. The data revealed the use of different samples in the standardization of techniques such as serum, total blood, colostrum and amniotic fluid. The flow cytometry, lateral flow immunoassay and qPCR techniques showed 100% sensitivity, whereas the ELISA, western blotting, qPCR and RE-LAMP techniques achieved 100% specificity. Significantly, the qPCR and LAMP techniques were more accurate when the likelihood ratio was assessed. The meta-analysis identified that ISAGA and western blotting have low sensitivity values and LIASON, ELFA and ELISA, using a silica bioconjugate, also have low specificity values. It was noted that a wide range of methods have high values of sensitivity and specificity. Therefore, the choice of the method will be based on the conditions and its financial viability.

Occurrence of potentially highly pathogenic free-living amoebae in ready made salads from restaurants in Jatai, Goias, Brazil

Free-living amoebae (FLA) are part of a group of protozoa found worldwide and in the most diverse environments. They resist various temperatures and disinfection methods, and are a risk to human health. Pathogenic strains grow at high temperatures and under hyperosmolarity conditions. Some FLA genera are mainly related to primary amoebic meningoencephalitis (PAM), skin ulcerations, corneal lesions, kidney and lung infections and keratitis. Therefore, studies that assess the pathogenic potential of FLA are public health issues of great concern. We aimed to evaluate the pathogenic potential of FLA isolated in salads from restaurants in vitro, using osmotolerance and thermotolerance tests. Forty-five isolates were used from ready-made salads purchased in restaurants in Jatai, Goias. Twelve isolates subjected to the osmotolerance test (26.6%) showed growth in 0.5 M mannitol, 18 (40.0%) in 1.0 M mannitol and 16 (35.5%) in 1.5 M mannitol, 13 (28.8%) isolates did not show growth. Four isolates that underwent the thermotolerance test (8.9%) showed growth at 25°C, 8 (17.8%) showed growth at 30°C, 3 (6.7%) showed growth at 37°C and 30 (66.7%) did not show growth. With the indices obtained in the present study, we concluded that 15.6% of the isolates were osmotolerant and thermotolerant. Our findings highlight a public health problem once these FLA are associated with harboring or being harbored by microorganisms responsible for diseases such as diarrhea and meningitis. Measures are required to improve food hygiene and so avoid FLA-related health problems.

IgG Avidity in Samples Collected on Filter Paper: Importance of The Early Diagnosis of Congenital Toxoplasmosis / Avidez de IgG em amostras coletadas em papel filtro: Importância no diagnóstico precoce da toxoplasmose congênita

Abstract Objective The purpose of the present study is to standardize and evaluate the use of the immunoglobulin G (IgG) antibody avidity test on blood samples from newborns collected on filter paper to perform the heel test aiming at its implementation in ongoing programs. Methods Blood samples from newborns were collected on filter paper simultaneously with the heel prick test. All samples were subjected to immunoglobulin M IgM and IgG enzyme-linked immunosorbent assays (ELISA). Peripheral blood was collected again in the traditional way and on filter paper from newborns with high IgG levels (33). Three types of techniques were performed, the standard for measuring IgG in serum, adapted for filter paper and the technique of IgG avidity in serum and on filter paper. The results of the avidity test were classified according to the Rahbari protocol. Results Among the 177 samples, 17 were collected in duplicate from the same child, 1 of peripheral blood and 1 on filter paper. In this analysis, 1 (5.88%) of the 17 samples collected in duplicate also exhibited low IgG avidity, suggesting congenital infection. In addition, the results obtained from serum and filter paper were in agreement, that is, 16 (94.12%) samples presented high avidity, with 100% agreement between the results obtained from serum and from filter paper. Conclusion The results of the present study indicate that the avidity test may be another valuable method for the diagnosis of congenital toxoplasmosis in newborns.

Resumo Objetivo O objetivo do presente estudo é padronizar e avaliar a utilização do teste de avidez de anticorpos imunoglobulina G (IgG) em amostras de sangue de recémnascidos (RNs) coletadas em papel filtro para a realização do teste do pezinho visando a implementação nos programas já vigentes. Métodos Foram coletadas amostras de sangue de recém-nascidos em papel filtro simultaneamente ao teste do pezinho. Em todas as amostras, foram realizados os testes imunoenzimáticos (ELISA) imunoglobulina M (IgM) e IgG. Dos RNs que apresentaram altos índices de IgG (33), foi novamente coletado sangue periférico da forma tradicional e em papel filtro. Foram realizadas técnicas padrão para a dosagem de IgG em soro, adaptadas para papel filtro, e a técnica de avidez de IgG em soro e em papel filtro. Os valores obtidos para o teste de avidez foram classificados de acordo com o protocolo de Rahbari. Resultados Dentre as 177 recoletas, em 17 amostras foi realizada a coleta simultânea de sangue periférico e papel filtro da mesma criança. Nesta análise, 1 (5,88%) das 17 amostras coletadas em duplicata obteve também baixa avidez de IgG, sugerindo infecção congênita da criança, e houve concordância entre os resultados obtidos em soro e em papel filtro: 16 (94,12%) das amostras apresentaram alta avidez, com concordância de 100% entre os resultados obtidos em soro e em papel filtro. Conclusão Os dados do presente trabalho evidenciam que o teste de avidez poderá ser mais um método valioso a ser utilizado no diagnóstico da toxoplasmose congênita em RNs.

Ocorrência de anemia em idosos atendidos na Estratégia da Saúde da Família em Aparecida de Goiânia, Goiás / Occurrence of anemia in elderly serverd by the Family Health Strategy in Aparecida de Goiânia, Goiás

Objetivo: Avaliar a ocorrência de anemia e presença de enteroparasitos relacionados a condições socioeconômicas e demográficas em idosos atendidos na Estratégia Saúde da Família (ESF) no município de Aparecida de Goiânia, Goiás, Brasil. Métodos: Trata-se de um estudo transversal, realizado com idosos atendidos na ESF do município de Aparecida de Goiânia. Foram coletadas fezes frescas e recém-eliminadas, as quais foram processadas pela técnica de Hoffman, Pons e Janer de 24 horas e coletadas amostras de sangue analisadas no aparelho automatizado Pentra 60®. Realizou-se análise estatística pelo programa BioEstat® versão 5.1 com medidas de associação odds ratio entre a presença de parasitos com a anemia, e as variáveis pesquisadas com o intervalo de confiança de 95% (IC 95%) e nível de significância de 5% (p < 0,05). Resultados: Foram avaliados os materiais biológicos de 101 idosos, e, destes, 15 (14,8%) apresentaram anemia. O estado civil, sexo, renda familiar, número de pessoas em casa, ocupação, consumo de frutas, verduras e legumes e hábitos comportamentais não apresentaram significância em relação à anemia. As variáveis com associação significativa (p<0,005) foram: nível baixo de escolaridade (p=0,05) e sedentarismo com consumo de álcool e/ou tabaco (p=0,05). Na análise das fezes encontrou-se positividade em uma amostra com presença de ovo de Ascaris lumbricoides. Conclusão: Os dados sobre a ocorrência de anemia podem variar bastante, dependendo da região e população estudada. O presente estudo demonstrou os fatores socioeconômicos e geográficos associados e baixa ocorrência de anemia e associação com parasitoses. A anemia não deve ser uma condição negligenciada durante o envelhecimento, portanto merece atenção e tratamento adequado.

Objective: To evaluate the occurrence of anemia and presence of enteroparasites related to socioeconomic and demographic conditions in the elderly attending the Family Health Strategy (FHS) in the municipality of Aparecida de Goiânia, Goiás, Brazil. Methods: This is a cross-sectional study, conducted with elderly people attended at the FHS of Aparecida de Goiânia. Fresh, newly disposed stools were collected and processed by the 24-hour Hoffman, Pons, and Janer technique and blood samples were collected on the Pentra 60® automated device. Statistical analysis was performed using the BioEstat® version 5.1 program, with odds ratios, between the presence of parasites with the anemia and variables surveyed with the 95% confidence interval (95% CI) and level. significance level of 5% (p <0.05). Results: The biological materials of 101 elderly individuals were evaluated, of which 15 (14.8%) presented anemia. Marital status, gender, family income, number of people at home, occupation, consumption of fruits, vegetables and behavioral habits were not significant in relation to anemia. The variables with significant association (p <0.005) were: low level of education (p = 0.05) and physical inactivity with alcohol and / or tobacco consumption (p = 0.05). In the analysis of feces was found positivity in one sample, presence of egg Ascaris lumbricoides. Conclusion: Data on the occurrence of anemia may vary widely, depending on the region and population studied. We demonstrated the associated socioeconomic and geographic factors and low occurrence of anemia and association with parasites. Anemia should not be a neglected condition during aging, so it deserves proper attention and treatment.

Occurrence of parasites in salads in restaurants in Aparecida de Goiânia, Goiás, Brazil

Parasitoses are the most widespread diseases in the world. They are transmited via contaminated water or food. Considering that the daily consumption of vegetables is estimated at 142g per person, the purpose of this study was to evaluate the occurrence of parasites in salads available for consumption in restaurants in Aparecida de Goiânia, Goiás State. Salad samples were collected from the restaurants and parasitological analysis was performed using the Willis, Hoffman, Faust and Ziehl Neelsen techniques as well as cultures for the isolation of free-living amoebae. 51 samples were analyzed, 16 (31.4%) were positive. The parasites detected were: Acanthamoeba spp. in 12 (23.5%); free-living larvae, Schistosoma mansoni and Entamoeba coli in 1 (2.0%); Endolimax nana in 2 (3.9%). The PCR technique determined that 17.6% of the samples presented Toxoplasma gondii DNA. These techniques evidenced that the salad samples presented parasite contamination not only in the restaurants with the lowest price per Kg, but also in the most expensive ones. Therefore, in addition to effective sanitary surveillance, prophylactic measures are necessary regarding suppliers, handlers and restaurant owners to prevent the spread of these and other parasites.

Validação do teste sorológico para toxoplasmose em papel filtro / Validation of serological test for toxoplasmosis in filter paper

Objetivo: Validar o uso do teste sorológico para toxoplasmose em papel filtro em amostras de sangue de gestantes do município de Goiânia e região metropolitana. Métodos: Trata-se de um estudo prospectivo, onde foram coletadas 1.006 amostras de sangue em gestantes no município de Goiânia e região metropolitana. Todas as gestantes que concordaram participar da pesquisa assinaram um Termo de Consentimento Livre e Esclarecido. A avaliação do perfil sorológico foi realizada pela técnica de ELISA (ensaio imunoenzimático), com amostras de soro e papel filtro, para pesquisa de anticorpos anti-Toxoplasma gondii das classes IgM e IgG, sendo que o kit utilizado não é padronizado para a pesquisa de anticorpos IgM no papel filtro. A análise estatística foi processada no banco de dados do programa EpiInfo® versão 3.2.1, que avaliou a prevalência de soropositividade, frequência de positividade no soro, frequência de positividade no papel filtro, sensibilidade, especificidade, valor preditivo positivo, valor preditivo negativo e índice kappa. Resultados: Na análise realizada no soro obtiveram-se 421 amostras positivas para anticorpos da classe IgG e três positivas para anticorpos da classe IgM. Em papel filtro obtiveram-se 443 positivas para anticorpos da classe IgG e uma positiva para anticorpos da classe IgM. Conclusão: O estudo permitiu identificar a semelhança de amostras positivas tanto com o uso do soro como no papel filtro para pesquisas de anticorpos da classe IgG, porém, para a pesquisa de anticorpos da classe IgM, o uso do soro apresentou maior sensibilidade quando comparado ao exame realizado com o papel filtro.

Objective: To validate the use of the serological test for toxoplasmosis in filter paper in blood samples from pregnant women from the city of Goiânia and the metropolitan region. Methods: This is a prospective study in which 1,006 blood samples were collected in pregnant women in the city of Goiânia and in the metropolitan region. All pregnant women who agreed to participate in the study signed a Free and Informed Consent Form. Serological profile evaluation was performed using ELISA (immunoenzymatic assay), with serum and filter paper samples, to investigate anti-Toxoplasma gondii antibodies of the IgM and IgG classes, and the kit used is not standardized for the research of IgM antibodies on the filter paper. Statistical analysis was performed in the database of the EpiInfo® version 3.2.1 program, which evaluated the prevalence of seropositivity, frequency of serum positivity, filter paper positivity frequency, sensitivity, specificity, positive predictive value, negative predictive value and index the kappa. Results: In the serum analysis, 421 samples were positive for antibodies of the IgG class and three were positive for antibodies of the IgM class. In the filter paper yielded 443 positive for antibodies of the IgG class and one positive for IgM class antibodies. Conclusion: The study allowed to identify the similarity of positive samples both with the use of serum and in the filter paper for IgG class antibodies. However, for serum IgM antibodies, the use of serum was more sensitive when compared to serum IgG. taken with the filter paper

Evaluation of toxoplasmosis risk factors and seroprevalence rates in the elderly

Toxoplasmosis is an infection caused by the protozoan Toxoplasma gondii, whose definitive hosts are cats and whose intermediate hosts include humans.This research aims to evaluate aspects related to seroprevalence rates of anti-T. gondii antibodies among elderly users of the Primary Health Care Service in the municipality of Aparecida de Goiânia, State of Goiás, Brazil. A total of 101 elderly people participated in the study, and a questionnaire was applied to examine sociodemographic factors related to risk factors for toxoplasmosis. Five mL of peripheral blood were collected from all the participants for serological tests. IgM and IgG antibody screening was performed using ELISA. The average age of the participants was 69.5 years, the seroprevalence rate was 75.2% (76/101) of reactive IgG, and 24.8% (25/101) were non-reactive. IgM and IgG antibodies were found in 2.9% (3/101) of the participants. An IgG avidity test was performed, which revealed that the antibodies in the three samples were of low avidity, thus indicating that these individuals were in the acute phase of the infection. It was suggested that, in terms of socioeconomic conditions, an income of one to three monthly minimum salaries is the predominant risk factor for toxoplasmosis in this group.

Analysis of the accuracy of different laboratory methods for the diagnosis of intestinal parasites from stray and domiciled cats (Felis catus domesticus) in Goiânia, Goiás, Brazil / Análise da acurácia de diferentes técnicas parasitológicas no diagnóstico de parasitos entéricos de gatos (Felis catus domesticus) errantes e domiciliados em Goiânia, Goiás, Brasil

Abstract Cats are carriers of zoonotic agents to humans, including intestinal parasites. The purpose of this study was to analyze the accuracy of different laboratory methods for the diagnosis of intestinal parasites. Fecal samples were processed by the Willis, Sheather, Faust and Hoffman-Janer-Pons-Lutz (HJPL) methods. Accuracy analysis was performed determining the sensitivity, specificity, positive and negative predictive value and Kappa. A total of 149 fecal samples were collected, 65 from stray cats and 84 from domiciled cats. The prevalence of intestinal parasites in stray cats was 60% while in domiciled cats it was 17%. In the analysis of accuracy, the techniques that showed the greatest accuracy for Ancylostomids were Willis and Faust, for Cystoisospora spp. Sheather with Faust or HPJL, and Toxoplasma gondii/Hammondia hammondi the association between Willis and Faust. Therefore, for a reliable evaluation of the prevalence of intestinal parasites, at least two different techniques should be used in parasitological exams of feces.

Resumo Gatos são veiculadores de agentes zoonóticos para o homem, entre eles os parasitos intestinais. O objetivo foi analisar a acurácia de diferentes métodos laboratoriais para o diagnóstico de parasitos entéricos. As amostras de fezes foram processadas pelos métodos de Willis, Sheather, Faust e Hoffman-Janer-Pons-Lutz (HJPL). A análise de acurácia foi realizada determinando a sensibilidade, especificidade, valor preditivo positivo e negativo e índice Kappa. Foram coletadas 65 amostras de fezes de gatos errantes e 84 amostras de gatos domiciliados, total de 149 amostras. A prevalência de parasitos entéricos nos errantes foi 60% e nos domiciliados 17%. Na análise de acurácia as técnicas que associadas apresentaram maior acurácia para Ancilostomídeos foram Willis e Faust, para Cystoisospora spp. Sheather com Faust ou HPJL, e para Toxoplasma gondii/Hammondia hammondi a associação entre Willis e Faust. Portanto, para uma avaliação fidedigna da prevalência de parasitos entéricos, deve-se usar no mínimo duas técnicas diferentes ao realizar os exames parasitológicos de fezes.

Epidemiological factors associated with Toxoplasma gondii infection in postpartum women treated in the public healthcare system of Goiânia, State of Goiás, Brazil

Abstract INTRODUCTION: Knowledge of the epidemiological profile and risk factors for Toxoplasma gondii infection among postpartum women is a relevant issue, because this protozoan can be vertically transmitted to the developing fetus, which can cause severe and debilitating disease. The aim of this study was to assess the risk factors associated with T. gondii infection in postpartum women in Goiânia, GO, Brazil. METHODS: This cross-sectional study comprised 229 postpartum women, among whom 204 were chronically infected (IgG+/IgM-), and 25 were seronegative (IgG-/IgM-; control group). All the patients were asked to complete a form to provide sociodemographic, clinical, dietary, and cultural information. The data were analyzed to compare seropositivity and risk factors based on the odds ratio (OR) thereof. RESULTS: The sociodemographic characteristics associated with the risk for toxoplasmosis were: education ≤ 8 years [OR: 2.521, confidence interval (CI): 1.01-6.301, p=0.049], and age ≥ 30 years (OR: 4.090; CI: 1.180-14.112, p=0.023). Clinical and behavioral characteristics related to eating raw and undercooked meat, were not found to be risk factors associated with a positive test for toxoplasmosis. CONCLUSIONS: Our findings concur with the results of other studies conducted in Brazil and abroad, where variables such as low levels of schooling, and advanced age (≥ 30 years) are major risk factors for pregnant women to become infected with T. gondii.

Evaluation of the accuracy of parasitological techniques for the diagnosis of intestinal parasites in cats / Avaliação da acurácia de técnicas parasitológicos para o diagnóstico de parasitos intestinais em gatos

Abstract The accuracy of the parasitological techniques of Willis, Hoffman-Pons-Janer or Lutz (HPLJ), Sheather and Faust was evaluated in fecal samples from stray cats caught by the Zoonosis Control Center in Goiânia, Goiás, Brazil. These four techniques were applied separately to analyze 154 fecal samples, and their accuracy was analyzed based on an evaluation of their sensitivity, specificity, positive and negative predictive values, and Kappa index, resulting in the selection of the Willis technique as the nominal gold standard. Of the 154 samples, 115 (74.68%) tested positive for intestinal parasites. The analysis of the frequency of positivity indicated that the HPLJ technique detected 86.1% of the positive samples and was the closest to the gold standard. The analysis of the accuracy of the techniques was evaluated using the most prevalent parasites. The Sheather technique showed the highest accuracy in the detection of Ancylostomatidae, while the Sheather and HPLJ techniques showed similar accuracies in the detection of Cystoisospora spp. when compared to the gold standard. Lastly, the Faust technique showed the highest accuracy in the detection of Toxoplasma gondii when compared to the gold standard. This study underscores the importance of combining parasitological techniques in the diagnosis of intestinal parasites in cats.

Resumo A avaliação da acurácia das técnicas parasitológicas de Willis, Hoffman-Pons-Janer ou Lutz (HPJL), Sheather e Faust foram realizadas em amostras fecais de gatos capturados pelo Centro de Controle de Zoonoses em Goiânia, Goiás. Essas quatro técnicas foram utilizadas separadamente para análise de 154 amostras fecais. A análise de acurácia foi empregada, avaliando-se a sensibilidade, especificidade, valor preditivo positivo, valor preditivo negativo e índice kappa, sendo a técnica de Willis eleita como padrão-ouro. Das amostras analisadas 74,68% (115/154) foram positivas para enteroparasitos. A análise de frequência de positividade demonstrou que a técnica HPJL detectou 86,1% dos positivos, aproximando-se do padrão-ouro. A avaliação da acurácia foi realizada pela análise dos parasitos mais prevalentes, sendo que, para Ancilostomídeos, a técnica de Sheather apresentou melhor acurácia; para Cystoisospora spp., as técnicas de Sheather e HPJL foram semelhantes e para Toxoplasma gondii, a técnica de Faust apresentou melhor acurácia comparada ao padrão ouro. Este estudo demonstra a importância da associação de técnicas parasitológicas para o diagnóstico de enteroparasitos em gatos.