Guía de la Sociedad Española de Infectología Pediátrica para el diagnóstico y tratamiento de la toxoplasmosis congénita

Diagnosis of Congenital Toxoplasmosis: Challenges and Management Outcomes

Introduction Congenital toxoplasmosis (CT), despite being mostly subclinical at birth, can cause disabling disease in the fetus and lead to long-term sequelae. It is an important cause of chorioretinitis in infants and adolescents. Data on postnatal treatment are controversial, and there is a lack of universal guidelines. Methods A cross-sectional study of newborns with suspected CT was conducted between January 2007 and December 2021. Results Seventy-one patients with suspected CT were included. During pregnancy, 64 (90.1%) of the mothers underwent therapy, of which 59 (83.1%) with spiramycin. Amniocentesis identified one positive polymerase chain reaction assay. Most newborns were asymptomatic with normal laboratory, ophthalmological, and hearing screening. There was one case of hyperproteinorrachia. Fifty-seven patients (80.3%) started treatment: 42 (73.7%) with spiramycin, seven (12.3%) with pyrimethamine, sulfadiazine, and folinic acid (P+S+FA), and eight (14%) with P+S+FA intercalated with spiramycin. Adverse effects were found in 11 (19.3%) cases, mainly neutropenia. After investigation, we found three confirmed CT cases corresponding to 4.2% of suspected cases and an incidence of 0.4 per 10,000 births. All had normal clinical and laboratory exams in the neonatal period and started P+S+FA, fulfilling 12 months of therapy. During the follow-up, all presented normal psychomotor development without any long-term sequelae. Conclusion The lower incidence in our study, compared to the incidence in Europe, may be related to the decline in the prevalence of toxoplasmosis as well as the effectiveness of measures to prevent primary infection and a well-established program of antenatal screening, followed by the early initiation of treatment during pregnancy to prevent vertical transmission.

The imbalance in the relationship between inflammatory and regulatory cytokines during gestational toxoplasmosis can be harmful to fetuses: A systematic review

Objective

To evaluate the available information on inflammatory and regulatory plasma mediators in pregnant women (PW) diagnosed with toxoplasmosis. Source: The PubMed, Embase, Scopus, and Lilacs databases were evaluated until October 2022. Study eligibility criteria: This review was carried out following the PRISMA and registered on the PROSPERO platform (CRD42020203951). Studies that reported inflammatory mediators in PW with toxoplasmosis were considered.

Evaluation methods

After excluding duplicate articles, two authors independently carried out the process of title and abstract exclusion, and a third resolved disagreements when necessary. The full text was evaluated to detect related articles. The extraction table was built from the following data: Author, year of publication, journal name and impact factors, country, study design, number of gestations and maternal age (years), gestational period, diagnosis of toxoplasmosis, levels of inflammatory markers, laboratory tests, and clinical significance. Methodological quality was assessed using Joanna Briggs Institute tools.

Results

Of the 1,024 studies reported, only eight were included. Of the 868 PW included in this review, 20.2% were IgM+/IgG- and 50.8% were IgM-/IgG+ to T. gondii, and 29.0% uninfected. Infected PW presented higher plasma levels ofIL-5, IL-6, IL-8, IL-17, CCL5, and IL-10. Regarding the methodological quality, four studies obtained high quality. Data from this review pointed out the maintenance of the inflammatory pattern during pregnancy with a closely related to the parasite.

Conclusion

Immune status in PW defined the course of the T. gondii infection, where the equilibrium between inflammatory and regulatory cytokines mitigated the harmful placenta and fetus effects.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD420203951.

Quality of clinical practice guidelines for gestational and congenital toxoplasmosis: A systematic review of the literature

OBJECTIVE

To evaluate the methodological quality and transparency of the clinical practice guidelines (CPGs) for the prevention, diagnosis, and treatment of gestational and congenital toxoplasmosis (CT).

METHODS

Systematic review of the literature on gestational and CT CPGs conducted in the MEDLINE, Embase, TripDatabase, Biblioteca Virtual en Salud databases and extensive manual searches in 19 CPG repositories. The characteristics of each of the guidelines were extracted using My AGREE PLUS on-line. Three reviewers assessed overall quality using the Appraisal of Guidelines for Research and Evaluation II (AGREE II) tool.

RESULTS

The combined systematic review found 8651 citations. Of them 46 full texts were reviewed, and eight documents were finally included: four toxoplasmosis CPGs, three prenatal care CPGs that included recommendations on toxoplasmosis, and one pregnancy infection guideline that also included recommendations on toxoplasmosis. The AGREE II domains found to have the highest scores were 'clarity of presentation' (85%; [37%-100%]), followed by 'scope and purpose' (73%; [33%-98%]), and 'editorial independence' (51%; [3%-94%]); the domains with the lowest scores were 'rigour of development' (36%; [11%-79%]), 'stakeholder involvement' (34%; [24%-85%]), and 'applicability' (17%; [6%-83%]). The Colombian and Spanish-Agencia de Evaluación de Tecnologías Sanitarias de Andalucía (AETSA) CPGs had the highest global AGREE II scores. Absolute interrater agreement was good to excellent.

CONCLUSION

Substantial quality variation was found among CPGs, which provided recommendations in accordance with the context of the disease in the corresponding country or region. Only two of the CPGs appraised obtained a good score and are classified as 'recommended'.

Effect of Domestic Freezing on the Viability of Toxoplasma gondii in Raw and Dry-Cured Ham from Experimentally Infected Pigs

ABSTRACT

Toxoplasma gondii is the causative agent of the parasitic disease toxoplasmosis, which is an important foodborne zoonosis. Eating undercooked meat of infected animals has been considered the major transmission route of T. gondii to humans. The present study was conducted to evaluate the efficacy of domestic freezing for inactivation of T. gondii bradyzoites in ham. Raw and dry-cured ham from a pig experimentally inoculated orally with 4,000 oocysts of T. gondii VEG strain was subjected to domestic freezing at -20°C for up to 14 days. The effect was evaluated by bioassay in mice and a quantitative PCR assay. In raw and dry-cured ham, -20°C for 7 and 14 days, respectively, did not inactivate T. gondii. More studies are needed to find the correct temperature and time needed to render the bradyzoites noninfectious for humans. Meanwhile, the recommendations for freezing to inactivate T. gondii in raw or dry-cured meats must be revisited because domestic freezing conditions do not reduce the risk of infection.

HIGHLIGHTS

Current Situation of Congenital Toxoplasmosis in Ecuador

Congenital toxoplasmosis (CT) is a zoonosis resulting from the fetal transmission of the obligate intracellular parasite, T. gondii, transplacentally in pregnant women usually in the first trimester of pregnancy. This research consisted in the review of indexed articles made in the Ecuador in the period between the years 2012 and 2017 with prevalence studies of the aforementioned pathology. The purpose of this collection was to determine the current situation of this disease in the Ecuadorian territory and, in addition, to recognize the risk factors involved, affected age groups, signs and symptoms, diagnosis and prevalence of the infection. Among the risk factors were the consumption of raw or undercooked meat, contact with feces of young cats and climatic conditions that stimulate the spread of oocysts, among others. Most affected ages by this disease fluctuate between 20 and 30 years. In 90% of the cases, the disease is asymptomatic or it may present adenopathies, maculo papular erythema, hepatosplenomegaly and other general signs such as fever, malaise, headache and myalgias. According to studies conducted with specific populations, it was established that the causative agent remains latent in first-trimester pregnant women from the provinces of Pichincha (71.4% of 140 pregnant women), Guayas (73% of 5683) and El Oro (16% of 250). The results of this research evidenced missing information in Ecuador, finding few and isolated studies regarding to this pathology. Therefore, it is concluded that an updated research should be conducted in order to elucidate the true epidemiological situation of congenital toxoplasmosis in Ecuador.

Characterization of prenatal healthcare for implementation of congenital toxoplasmosis surveillance program: cross-sectional study

BACKGROUND

Prenatal toxoplasmosis remains a neglected disease worldwide and few government programs focusing on its prevention are available. Success in these programs has been extensively reported in the literature, yet the strategies used for their implementation, as a model for such actions in different communities, have not been described.

OBJECTIVE

To describe the aspects of prenatal care strategies in 13 municipalities within the regional healthcare unit of Araçatuba, in the northwestern region of the state of São Paulo in 2017, focusing on congenital toxoplasmosis.

DESIGN AND SETTING

Descriptive study on prenatal healthcare within the Brazilian National Health System, in 13 participating municipalities.

METHODS

Data on serological tests, referral clinics, notifications, healthcare strategies, health education and drugs for infected children were requested through a questionnaire that was sent via e-mail to people responsible for healthcare services in these municipalities.

RESULTS

Major differences relating to diagnoses, reference outpatient clinics, notifications, health education and healthcare and drugs for infected children were reported among the prenatal strategies of these 13 municipal healthcare services.

CONCLUSION

The lack of standardized prenatal strategy in the study area may compromise the prevention of infection. However, our identification of each aspect of prenatal care corroborates the need to implement a healthcare surveillance program relating to congenital toxoplasmosis.

High heterogeneity, mixed infections and new genotypes in human congenital toxoplasmosis cases in the mega-metropolis of Central Mexico

Mexico presents high prevalence of Toxoplasma gondii infection, including the congenital form, but there are few data about the genetic diversity of the parasite, so we attempted parasite isolation and genotyping in nine mother/children pairs with congenital toxoplasmosis (CT), living in the Valley of Mexico, who were part of a 30 cases cohort that started 12 years ago. They were recruited through research projects which included pre- and postnatal screening of congenital infections or directly CT, and cases referred to INP for management because they had clinical abnormalities. Genotyping was performed by PCR-RFLP of SAG1, SAG2, SAG3, BTUB GRA6, c22-8, c29-2, L358, PK1 and Apico markers, followed by sequencing. Sixty seven percent of samples were typed for the SAG3 locus, 39% for Apico and 33% for BTUB, while Alt. SAG2, GRA6 and c29-2 types could be labelled in less cases. Type I alleles predominated, followed by II and III. We isolated the first strain obtained from humans in Mexico and found three genotypes not previously found in the world. The presence of ToxoDB#10 clonal type was documented in one pair, as well as mixed infections in five mothers. No relation of genotype or parasite load with clinical signs was found. In conclusion, we encountered great genetic diversity and mixed T. gondii infections among mother/children pairs with congenital toxoplasmosis in the mega-metropolis of the Valley of Mexico.

Alterações auditivas em crianças expostas à toxoplasmose durante a gestação

RESUMO Objetivo: verificar a ocorrência e o tipo mais frequente de alteração auditiva em crianças expostas a toxoplasmose durante a gestação. Métodos: estudo retrospectivo longitudinal realizado em instituição pública de saúde de São Paulo. Análise de prontuários de crianças nascidas entre 2010 e 2015 distribuídos em dois grupos: grupo estudo, composto por 48 crianças de mães com diagnóstico de toxoplasmose durante a gestação; e grupo controle, composto por 43 crianças sem infecção congênita que foram acompanhadas por apresentar baixo peso ao nascimento. As crianças foram avaliadas de duas a quatro vezes durante os dois primeiros anos de vida, por meio de testes que avaliam a função auditiva periférica e central. Resultados: 47 crianças fizeram apenas duas avaliações e apenas 11 completaram todas as avaliações até 24 meses. No grupo controle 58,1% apresentaram audição normal, 37,2% perda condutiva, 4,7% perda coclear e ausência de alteração retrococlear, enquanto o grupo estudo apresentou 56,3% de audição normal, 20,8% de perda condutiva, 2,1% de perda coclear e 20,8% de alteração retrococlear. Conclusão: crianças expostas à toxoplasmose durante a gestação não diferiram das não expostas em relação à ocorrência de perda auditiva coclear e condutiva. Entretanto, apresentaram maior ocorrência de alteração retrococlear.

[Effect of antenatal spiramycin treatment on the frequency of retinochoroiditis due to congenital toxoplasmosis in a Colombian cohort]

INTRODUCTION

Gestational toxoplasmosis is frequent and severe. There is still debate about the benefits of treatment against ocular manifestations in the newborn. Spiramycin treatment is used for this purpose, unfortunately prenatal diagnosis is sometimes delayed and pregnant women are not treated.

OBJECTIVE

To describe the relationship between treatment with spiramycin during pregnancy in mothers with gestational toxoplasmosis and development of ocular toxoplasmosis in newborns.

MATERIALS AND METHODS

We conducted a descriptive study of a case series. We evaluated a prospective cohort of patients diagnosed with gestational toxoplasmosis during three years at the Retinology Service at the Clínica Universitaria Bolivariana in Medellín.

RESULTS

Gestational toxoplasmosis was found in 23 mothers; 15 (65%) were treated during pregnancy with 3 g per day of spiramycin, eight (35%) patients were untreated. In the treated group just one newborn developed ocular toxoplasmosis (6.6%), in contrast with five (62.5%) of the eight patients who did not receive treatment. These results suggest that pregnancy treatment reduces the relative risk of ocular toxoplasmosis in the newborn by 96% (95% CI: 33 - 100%). Only two (14%) of the patients who were evaluated, had nervous system involvement related to toxoplasmosis in CT scan or cerebral ultrasound. These two patients also developed ocular pathology and were diagnosed at the time of birth, so they did not received antenatal treatment.

CONCLUSIONS

A protective effect was found against the ocular involvement in patients whose mother received treatment with spiramycin (OR=0.04;95% CI: 0.00-0.67), p<0.01 (Fisher's Exact Test).

Congenital and perinatally-acquired infections in resource-constrained settings

INTRODUCTION

Congenital and perinatal infections are a leading cause of neonatal and infant morbidity and mortality. Maternal screening, vaccines or treatment where available, constitute effective prevention strategies to reduce the burden of these diseases. Data on the burden of congenital and perinatal infections are very limited for low and middle-income regions.

AREAS COVERED

This review aims to summarize the burden of congenital and perinatal infections and the main challenges for their control in resource-limited settings. Articles were identified through the main electronic databases and cover the period 1971-2016. Expert commentary: Estimates from low and middle-income countries indicate that the burden of congenital infections may be higher in these regions than in industrialized countries. As preventive and curative strategies are available to tackle some of these infections, efforts at the international and national levels must be made to implement those and thus reduce their burden in resource-limited countries.

Performance of Polymerase Chain Reaction Analysis of the Amniotic Fluid of Pregnant Women for Diagnosis of Congenital Toxoplasmosis: A Systematic Review and Meta-Analysis

Introduction

Congenital infection caused by Toxoplasma gondii can cause serious damage that can be diagnosed in utero or at birth, although most infants are asymptomatic at birth. Prenatal diagnosis of congenital toxoplasmosis considerably improves the prognosis and outcome for infected infants. For this reason, an assay for the quick, sensitive, and safe diagnosis of fetal toxoplasmosis is desirable.

Goal

To systematically review the performance of polymerase chain reaction (PCR) analysis of the amniotic fluid of pregnant women with recent serological toxoplasmosis diagnoses for the diagnosis of fetal toxoplasmosis.

Method

A systematic literature review was conducted via a search of electronic databases; the literature included primary studies of the diagnostic accuracy of PCR analysis of amniotic fluid from pregnant women who seroconverted during pregnancy. The PCR test was compared to a gold standard for diagnosis.

Results

A total of 1.269 summaries were obtained from the electronic database and reviewed, and 20 studies, comprising 4.171 samples, met the established inclusion criteria and were included in the review. The following results were obtained: studies about PCR assays for fetal toxoplasmosis are generally susceptible to bias; reports of the tests’ use lack critical information; the protocols varied among studies; the heterogeneity among studies was concentrated in the tests’ sensitivity; there was evidence that the sensitivity of the tests increases with time, as represented by the trimester; and there was more heterogeneity among studies in which there was more time between maternal diagnosis and fetal testing. The sensitivity of the method, if performed up to five weeks after maternal diagnosis, was 87% and specificity was 99%.

Conclusion

The global sensitivity heterogeneity of the PCR test in this review was 66.5% (I²). The tests show low evidence of heterogeneity with a sensitivity of 87% and specificity of 99% when performed up to five weeks after maternal diagnosis. The test has a known performance and could be recommended for use up to five weeks after maternal diagnosis, when there is suspicion of fetal toxoplasmosis.

Investigation of antimalarial drug pyrimethamine and its interaction with dsDNA by electrochemical and spectroscopic techniques

The electrochemical behavior of the antimalarial drug pyrimethamine (PMT) was examined at a screen printed carbon electrode (SPCE) in different aqueous supporting electrolytes using cyclic voltammetry (CV) and differential pulse voltammetry (DPV).

Comparative study on Toxoplasma infection between Malaysian and Myanmar pregnant women

Background

Toxoplasma gondii, an obligate intracellular protozoan parasite, causes a disease called toxoplasmosis which can sometimes be acquired congenitally by a newborn from an infected mother. This study aimed to determine the seroprevalence of Toxoplasma infection and its associated risks among 219 and 215 pregnant women from Malaysia and Myanmar, respectively.

Methods

Anti-Toxoplasma IgG and IgM antibodies were screened by using standard commercial ELISA kits. The socio-demographic, obstetrics and risk factors associated with Toxoplasma infection data were compared between the two countries.

Results

The overall prevalence of Toxoplasma infection in Malaysian pregnant women (42.47%; 95% CI = 36.11-49.09) was significantly higher (p < 0.05) than Myanmar pregnant women (30.70%; 95% CI = 27.92-37.16). By univariate analysis, this study identified that age group, education, parity, awareness on toxoplasmosis and consumption of undercooked meat were significantly associated (p < 0.05) with Toxoplasma seropositive Malaysian pregnant women but none of these factors associated with Toxoplasma seropositive Myanmar pregnant women. In comparison using univariate analysis between the two countries, it was found that Toxoplasma seropositive Malaysian pregnant women was associated with aged 30 years and above, secondary or lower-secondary level of education, the third trimester of pregnancy, having one child or more, lacking awareness of toxoplasmosis, absence of bad obstetrics history, having no history of close contact with cats or soil, living on a farm and also consumption of undercooked meat, unpasterized milk or untreated water. Avidity measurement was used to confirm the stages of Toxoplasma infection in pregnant women who were positive for both IgG and IgM antibodies and found all were infected in the past.

Conclusion

From our study, Toxoplasma screening and its risk measurement in pregnant women is firmly recommended for monitoring purposes and assisting proper management, including diagnosis and treatment during antenatal period. Also, it is necessary to initiate preventive measures for Toxoplasma infection among reproductive-age women in general and seronegative pregnant women in particular. Avidity measurement should be incorporated in Toxoplasma routine screening, especially with the availability of a single serum sample to assist in the diagnosis.

Electronic supplementary material

The online version of this article (doi:10.1186/s13071-014-0564-9) contains supplementary material, which is available to authorized users.

Amniocentesis for the detection of congenital toxoplasmosis: results from the nationwide Austrian prenatal screening program

Prenatal diagnosis of congenital toxoplasmosis (CT) influences therapeutical management in pregnant women and their offspring. In Austria, a nationwide serological healthcare program to identify potential maternal toxoplasma infections during pregnancy exists. We assessed the clinical use of amniocentesis for toxoplasma-specific polymerase chain reaction (PCR) on amniotic fluid to detect CT. Data on serology, amniocentesis, PCR, complications, treatment, and paediatric clinical outcome were collected retrospectively among the birth cohort 1992-2008. There were 1386 women with amniocentesis, but only in 707 cases (51%) was acute maternal infection confirmed serologically. A high proportion (49%) of amniocenteses with negative PCR results in women with chronic infection or seronegativity were performed without clinical justification for the women or their foetuses. The positive and negative predictive values of PCR were 94.4% and 99.3%, respectively. Thirty-nine foetuses with CT, including four deaths, were reported. The five PCR-negative but infected infants were identified by the serological and clinical follow-up program. Thirty percent of amniocenteses were performed in the third trimester, and gestational age or treatment did not influence PCR sensitivity. Amniocentesis is indicated in women with acute maternal infection, and facilitated targeted therapies in pregnant women and their offspring. In women with late toxoplasma infection, negative amniotic fluid PCR made treatment of infants unnecessary. Serological and clinical follow-up of infants is important to confirm the infection status of the infant. Recommendations, based on our 17-year experience, to improve the current diagnostic strategies and to reduce unnecessary amniocentesis, are given.

Effect of pyrimethamine treatment on male rat testicular cell population development

Pyrimethamine (PYR) is a drug used in the treatment of newborn with congenital Toxoplasmosis. Even when PYR is highly specific against parasites, it may provoke neutropenia in the patients apart from other affectations, conditions that usually justify its suspension. Moreover, medication against congenital toxoplasmosis coincides with the proliferation stage of Sertoli and germ cells. Although, there are several reports on the effect of this drug on mature testes, records of its effects on the testes of young individuals yet in the process of growth are still lacking. This work was aimed to study the effects of in vivo administration of PYR in the first 21 days of life of male rat pups by evaluating their testicular alterations and its long-term sequels on fertility. Through the determination of the levels of seminiferous epithelium maturity, apoptotic index and cell proliferation index at 7, 14, 35 and 90 days post-natal using immunocytochemical studies. The fertility of the treated rats was evaluated at 90 days. PYR-treated animals were found to undergo some kind of delays in seminiferous epithelium maturity, decreased cell proliferation index and an increase in apoptosis when compared with the control (p < 0.05). Epididymal sperm counts were also affected (p < 0.05). The application of folic acid (FA) in newborns treated with PYR decreased the severity of the problem (p < 0.05). This study provides strong evidence that the effect of PYR on testicular development is specific. It reinforces the importance of FA application in neonates treated with PYR to prevent the effect of the later on spermatogenesis.

Toxoplasmosis and pregnancy

Question Congenital toxoplasmosis is a dangerous fetal infection. Why is routine screening for Toxoplasma gondii infection during pregnancy not available for most Canadians? Answer Low prevalence of the infection, high cost associated with testing, low sensitivity of screening tests, false-positive test results, and limitations of treatment effectiveness are all cited as reasons for not routinely screening for T gondii infection in Canada. Currently, screening for the detection of T gondii is only performed in Nunavik and other parts of northern Quebec owing to the high prevalence of infection in this region. Congenital toxoplasmosis causes neurologic or ocular disease (leading to blindness), as well as cardiac and cerebral anomalies.