Outcome of treatment for congenital toxoplasmosis, 1981-2004: the National Collaborative Chicago-Based, Congenital Toxoplasmosis Study

Effective factors in the pathogenesis of Toxoplasmagondii

Toxoplasma gondii (T. gondii) is a cosmopolitan protozoan parasite in humans and animals. It infects about 30 % of the human population worldwide and causes potentially fatal diseases in immunocompromised hosts and neonates. For this study, five English-language databases (ScienceDirect, ProQuest, Web of Science, PubMed, and Scopus) and the internet search engine Google Scholar were searched. This review was accomplished to draw a global perspective of what is known about the pathogenesis of T. gondii and various factors affecting it. Virulence and immune responses can influence the mechanisms of parasite pathogenesis and these factors are in turn influenced by other factors. In addition to the host's genetic background, the type of Toxoplasma strain, the routes of transmission of infection, the number of passages, and different phases of parasite life affect virulence. The identification of virulence factors of the parasite could provide promising insights into the pathogenesis of this parasite. The results of this study can be an incentive to conduct more intensive research to design and develop new anti-Toxoplasma agents (drugs and vaccines) to treat or prevent this infection. In addition, further studies are needed to better understand the key agents in the pathogenesis of T. gondii.

Molecular functions of ANKLE2 and its implications in human disease

Ankyrin repeat and LEM domain-containing 2 (ANKLE2) is a scaffolding protein with established roles in cell division and development, the dysfunction of which is increasingly implicated in human disease. ANKLE2 regulates nuclear envelope disassembly at the onset of mitosis and its reassembly after chromosome segregation. ANKLE2 dysfunction is associated with abnormal nuclear morphology and cell division. It regulates the nuclear envelope by mediating protein-protein interactions with barrier to autointegration factor (BANF1; also known as BAF) and with the kinase and phosphatase that modulate the phosphorylation state of BAF. In brain development, ANKLE2 is crucial for proper asymmetric division of neural progenitor cells. In humans, pathogenic loss-of-function mutations in ANKLE2 are associated with primary congenital microcephaly, a condition in which the brain is not properly developed at birth. ANKLE2 is also linked to other disease pathologies, including congenital Zika syndrome, cancer and tauopathy. Here, we review the molecular roles of ANKLE2 and the recent literature on human diseases caused by its dysfunction.

Could PLATELIA Toxo IgM be the new gold standard for the serological diagnosis of congenital toxoplasmosis: a French multicenter study

To assess the performance of PLATELIA Toxo IgM (Bio-Rad) and Toxo ISAGA (BioMérieux) to detect anti-Toxoplasma IgM in infants at risk of congenital toxoplasmosis, a retrospective multicenter study was conducted comparing serological results obtained in the framework of routine diagnosis work-up for congenital toxoplasmosis. All infants born to mothers infected with T. gondii during pregnancy from 2010 to 2020 with at least 6 months of serological follow-up were included (n = 1,010). One thousand ten cases were included, of which 250 infants (24.75%) had congenital toxoplasmosis. A total of 1039 sera were included. The concordance between the two techniques was 96%, with kappa coefficient of 0.87, showing an almost perfect agreement between ISAGA and PLATELIA. Cumulative sensitivity and specificity were 73.2% and 99.5.% and 74.8% and 100% for ISAGA and PLATELIA, respectively. The mean time to detect IgM using ISAGA and PLATELIA tests was 6.9 ± 20.1 days and 5.6 ± 14.7 days, respectively not significant (ns). Finally, the sensitivity of ISAGA and PLATELIA to detect IgM antibodies in infected neonates at 5 days of life was 62% and 64%, respectively. Performances of PLATELIA Toxo IgM assay were comparable to the gold standard ISAGA. This enzyme-linked immunosorbent assay is suitable for routine serology for the diagnosis of congenital toxoplasmosis in newborns. IMPORTANCE This study will help clinical microbiologists to chose an alternative serological method for the neonatal diagnosis of congenital toxoplasmosis, once the gold standard technique ISAGA will be withdrawn next year.

Toxoplasma gondii infections in pediatric neurosurgery

Toxoplasma gondii is a parasite that is estimated to infect one-third of the world's population. It is acquired by ingesting contaminated water and food specially undercooked meat, contact with domestic or wild feline feces, and during pregnancy by transplacental transmission.Immunocompetent hosts are usually asymptomatic, and infection will be self-limited, while those patients whose immune system is debilitated by HIV infection, immunosuppressive therapy, long-term steroid treatment, and fetuses infected during gestation will show evidence of systemic activity which is more severe in the central nervous system and eyes due to insufficient immune response caused by their respective blood barriers. Congenital toxoplasmosis has an estimated incidence of 8% in mothers who were seronegative at the beginning of their pregnancy. Infection in the first trimester may result in spontaneous abortion or stillbirth; however, it is estimated that the highest risk for vertical transmission is during the second and third trimesters when blood flow and placenta thickness favor parasitic transmission.Congenital toxoplasmosis can be detected with periodic surveillance in endemic areas, and with appropriate treatment, the risk of vertical transmission can be reduced, and the severity of the disease can be reversed in infected fetuses.While most infected newborns will show no evidence of the disease, those who suffer active intrauterine complications will present with cerebral calcifications in 8-12% of cases, hydrocephalus in 4-30%, and chorioretinitis in 12-15%. Also, seizure disorders, spasticity, and varying degrees of neurocognitive deficits can be found in 12%.Four distinct patterns of hydrocephalus have been described: aqueductal stenosis with lateral and third ventricle dilatation, periforaminal calcifications leading to foramen of Monro stenosis with associated asymmetrical ventricle dilatation, a mix of aqueductal and foramen of Monro stenosis, and overt hydrocephalus without clear evidence of obstruction with predominant dilatation of occipital horns (colpocephaly).While all patients diagnosed with congenital toxoplasmosis should undergo pharmacological treatment, those presenting with hydrocephalus have traditionally been managed with CSF shunting; however, there are reports of at least 50% success when selected cases are treated with endoscopic third ventriculostomy. Successful hydrocephalus management with appropriate treatment leads to better intellectual outcomes.

Congenital toxoplasmosis and audiological outcome: from a case series to a suggestion of patient-based schedule

Introduction

Sensorineural hearing loss (SNHL) has been suggested to be possibly related to congenital toxoplasmosis (CT), although its prevalence varies from 0% to 26%. This variance appears to be dependent especially on early timing of treatment. However, the available data are based on outdated studies conducted on small groups of patients that lack homogeneity. Therefore, to establish evidence-based guidelines for audiologic monitoring in CT, we conducted a comprehensive evaluation of a large case series over a long period of time.

Patients and methods

This is a single-center, retrospective cohort that enrolled all infants and children who were exposed in utero to Toxoplasma gondii and/or congenitally infected between September 1980 and December 2022. They underwent standard serial audiological evaluations to detect possible SNHL at an early stage. The first evaluation was performed during the initial assessment to define the onset of congenital toxoplasmosis, with another evaluation conducted at least at 12 months of life.

Results

We collected data from 1,712 patients, and 183 (10.7%) were diagnosed with CT. Among these cases, 78 children (42.6%) presented with symptomatic CT at the onset, exhibiting ocular findings (21.1%), clinical cerebral manifestations (6.1%), and/or abnormal findings on neuroimaging (35.5%). Therapy was administrated at the onset in 164 patients (89.6%) with 115 of them starting treatment prior to 2.5 months of age (0-388, median 32.00 ± 92.352 days of life). Only one patient presented with SNHL at the onset, but this was apparently unrelated to CT. The median number of audiological assessments was 2.2 ± 1.543 (2-10). No patients developed any grade of delayed hearing loss, both in treated and untreated groups. The median age at last audiological evaluation was 2.3 ± 2.18 years (1-8), although the median follow-up period was 12.4 years (±6.3), ranging from 1 to 27 years.

Conclusions

Based on these data, it appears that SNHL may be less frequent in CT than previously assumed. We recommend conducting an audiological assessment at the onset (within the first 2.5 months of life) to comprehensively define the type of CT onset, and then conducting another evaluation within 9 months of life.

Contribution of serology in congenital toxoplasmosis diagnosis: results from a 10-year French retrospective study

This study aimed to evaluate different serological strategies for the postnatal diagnosis of congenital toxoplasmosis (CT) and establish a biological algorithm for CT diagnosis. The study analyzed serological data of immunoglobulins M, A, and G (IgM, IgA, IgG) performed by immunoenzymatic and compared immunological profile (CIP) assays in 668 newborns with CT diagnosis across four testing periods: P1 (D0- D10), P2 (D11-D35), P3 (D36-D45), and P4 (>D45). Forty-nine percent of the 668 CT cases were diagnosed during P1 and 34%, 4%, and 12% during P2, P3, and P4, respectively. CIP assays detected neosynthetized IgMs/IgGs in 98% of CT cases diagnosed during P1, while IgMs and IgAs were detected in 90% and 57% of CT cases diagnosed during P2 and in 88% and 67% of diagnoses made during P3, respectively. Detection of neosynthesized IgMs/IgGs, IgMs, and IgAs by immunoassay contributed to CT diagnosis in 81%, 77%, and 60% of cases, respectively. In total, 46% of serum samples were positive for all three parameters, 27% for two, and 27% for one of the three. The study recommends using the CIP assay as standard during P1 for CT diagnosis and IgM and IgA immunoassays after P1. A clinical and biological follow-up in a specialized center with a close collaboration between biologists and clinicians is highly recommended to increase the chances of early diagnosis. Overall, this study provides useful information for the development of a biological algorithm for CT diagnosis, which can aid in early detection and appropriate treatment of this disease.

Clinical value of placental examination for paediatricians

The placenta contains valuable clinical information that is linked to fetal development, neonatal morbidity and mortality, and future health outcomes. Both gross inspection and histopathological examination of the placenta may identify intrinsic or secondary placental lesions, which can contribute directly to adverse neonatal outcomes or indicate the presence of an unfavourable intrauterine environment. Placental examination therefore forms an essential component of the care of high-risk neonates and at perinatal post-mortem examination. In this article, we describe the clinical value of placental examination for paediatricians and perinatal clinicians. We discuss common pathological findings on general inspection of the placenta with photographic examples and provide an overview of the placental pathological examination, including how to interpret key findings. We also address the medico-legal and financial implications of placental examinations and describe current and future clinical considerations for clinicians in regard to placental examination.

Ocular Toxoplasmosis

INTRODUCTION

Ocular toxoplasmosis is the leading cause of posterior uveitis worldwide, affecting individuals acrossdifferent age groups. The key to reducing vision loss includes prompt diagnosis and treatment. However, despite the prevalence of ocular toxoplasmosis, there has been little consensus regarding its pathophysiology,clinical features, diagnosis, and especially management.

METHODS

The data sources were literature reviews, including Pub Med and Medline databases. Search terms included toxoplasmosis, retinitis, vasculitis, vitritis, uveitis alone or in combination with, serum, aqueous, vitreous eye, ocular and review.

RESULTS

In this review paper, we have sought to provide an overview of the pathophysiology, epidemiology, and clinical features of the disease, both based on current literature and our own clinical experience. We have also discussed the use of serology, ocular fluid, and ophthalmic investigations that could further facilitate the diagnosis of ocular toxoplasmosis.Different management strategies have been reported worldwide, including newer approaches such as local therapy.

CONCLUSION

A better understanding of critical aspects of ocular toxoplasmosis will hopefully lead to reduced morbidity, including blindness associated with this condition.

Maternal anti-Toxoplasma gondii antibodies IgG2, IgG3 and IgG1 are markers of vertical transmission and clinical evolution of toxoplasmosis in the offspring

Toxoplasma gondii can be transmitted vertically during pregnancy and may cause neurological, ocular, and even systemic damage to the offspring. Congenital toxoplasmosis (CT) can be diagnosed during gestation and/or after birth in the postnatal period. The timely diagnosis is highly relevant for efficient clinical management. The most common laboratory methods for diagnosing CT are based on Toxoplasma-specific humoral immune responses. However, these methods are of low sensitivity or specificity. In a previous study with a small number of cases, the comparison of anti-T. gondii IgG subclasses between mothers and their offspring showed promising results for CT diagnosis and prognosis. Thus, in this work, we analyzed specific IgG subclasses and IgA in 40 T. gondii-infected mothers and their children, of which 27 were congenitally infected and 13 uninfected. A higher frequency of anti-Toxoplasma IgG2, IgG3, IgG4, and IgA antibodies was observed in mothers and congenitally infected offspring. Of these, IgG2 or IgG3 were statistically the most conspicuous. In the CT group, maternal IgG3 antibodies were significantly associated with severe disease of the infants and IgG1 and IgG3 with disseminated disease. The results support that maternal anti-T. gondii IgG3, IgG2 and IgG1 are markers of congenital transmission and severity/spread of disease in the offspring.

Toxoplasmosis Infection during Pregnancy

This literature review aims to give an overview of the current knowledge concerning how a toxoplasmosis infection affects the mother and her fetus. A thorough search of PubMed and a complimentary search of Google Scholar databases were used to identify relevant studies for this review. Although a Toxoplasma gondii infection is preventable, this infection is contracted by consuming contaminated food and water and by exposure to environmental sources of infection such as contaminated soil. Maternal-to-fetal transmission of this infection can result in devastating ophthalmic and neurological consequences for the fetus. Although a toxoplasmosis infection can result in long-term effects on the fetus, chronic disease is also associated with mental illness in mothers. Effective treatment can reduce the risk of congenital toxoplasmosis and the long-term consequences of infection in the fetus. Without appropriate screening and education programs, this infection will remain largely undiagnosed.

Inhibition of Toxoplasma gondii by 1,2,4-triazole-based compounds: marked improvement in selectivity relative to the standard therapy pyrimethamine and sulfadiazine

A safer treatment for toxoplasmosis would be achieved by improving the selectivity profile of novel chemotherapeutics compared to the standard therapy pyrimethamine (PYR) and sulfadiazine (SDZ). We previously reported on the identification of the compounds with imidazole-thiosemicarbazide scaffold as potent and selective anti-Toxoplasma gondii (T. gondii) agents. In our current research, we report on the optimisation of this chemical scaffold leading to the discovery cyclic analogue 20 b with s-triazole core structure. This compound displayed prominent CC₃₀ to IC₅₀ selectivity index (SI) of 70.72, making it 160-fold more selective than SDZ, 11-fold more selective than PYR, and 4-fold more selective than trimethoprim (TRI). Additionally, this compound possesses prerequisite drug-like anti-Toxoplasma properties to advance into preclinical development; it showed ability to cross the BBB, did not induce genotoxic and haemolytic changes in human cells, and as well as it was characterised by low cellular toxicity.

A Systematic Review to Evaluate a Possible Association Between Congenital Toxoplasmosis and Preterm Labor

BACKGROUND

Congenital toxoplasmosis (CT) is a widespread infection in several countries, and it is defined as an infection of a fetus, newborn, or infant under 1 year of age. Moreover, it represents a thread to pregnant women globally. The objective of our study is to evaluate a potential association between prematurity and CT and whether intrauterine transmission impacts gestational length during pregnancy.

METHODS

PubMed, Cochrane Library and Google Scholar databases were searched from 1950 to 2019. Case-control studies, retrospective, and prospective cohort studies were eligible. Seven studies were included from a total of 314. The Newcastle-Ottawa scale was used to establish the quality of the articles included.

RESULTS

Based on our review, an association between CT and preterm labor was not established, which may reflect heterogeneity in screening, treatments administered, and differing reported incidences of CT across continents over 69 years. A multicenter prospective cohort study powered to investigate a potential association is indicated.

CONCLUSION

Further studies are needed including multicenter prospective cohort studies powered to investigate key clinical associations such as vertical transmission and preterm birth.

Prevention of congenital toxoplasmosis in France using prenatal screening: A decision-analytic economic model

Background

Toxoplasma gondii is one of the world’s most common parasites. Primary infection of the mother during pregnancy can lead to transmission to the fetus with risks of brain and eye lesions, which may cause lifelong disabilities. France instituted a national program based on monthly retesting of susceptible pregnant women to reduce the number of severe cases through prompt antenatal and postnatal treatment and follow-up.

Objective

To evaluate the ability of the French prenatal retesting program to reduce the lifetime costs of congenital toxoplasmosis.

Methods

We measured and then compared the costs and benefits of screening vs. not screening using decision-tree modelling. It included direct and indirect costs to society of treatment and care, and the lifetime lost earnings of children and caregivers. A probabilistic sensitivity analysis was carried out.

Findings

Total lifetime costs per live born child identified as congenitally infected were estimated to be €444 for those identified through prenatal screening vs €656 for those who were not screened. Estimates were robust to changes in all costs of diagnosis, treatment, and sequelae.

Interpretation

Screening for the prevention of the congenital T. gondii infection in France is cost saving at €212 per birth. Compared with no screening, screening every pregnant woman in France for toxoplasmosis in 2020 would have saved the country €148 million in addition to reducing or eliminating the devastating physical and emotional suffering caused by T. gondii. Our findings reinforce the conclusions of other decision-analytic modelling of prenatal toxoplasmosis screening.

Long-Term Outcomes in Children with Congenital Toxoplasmosis-A Systematic Review

Even in the absence of manifestations at birth, children with congenital toxoplasmosis (CT) may develop serious long-term sequelae later in life. This systematic review aims to present the current state of knowledge to base an informed decision on how to optimally manage these pregnancies and children. For this, a systematic literature search was performed on 28 July 2022 in PubMed, CENTRAL, ClinicalTrials.gov, Google Scholar and Scopus to identify all prospective and retrospective studies on congenital toxoplasmosis and its long-term outcomes that were evaluated by the authors. We included 31 research papers from several countries. Virulent parasite strains, low socioeconomic status and any delay of treatment seem to contribute to a worse outcome, whereas an early diagnosis of CT as a consequence of prenatal screening may be beneficial. The rate of ocular lesions in treated children increases over time to 30% in European and over 70% in South American children and can be considerably reduced by early treatment in the first year of life. After treatment, new neurological manifestations are not reported, while ocular recurrences are observed in more than 50% of patients, with a mild to moderate impact on quality of life in European cohorts when compared to a significantly reduced quality of life in the more severely affected South American children. Though CT is rare and less severe in Europe when compared with South America, antenatal screening is the only effective way to diagnose and treat affected individuals at the earliest possible time in order to reduce the burden of disease and achieve satisfying outcomes.

Building Programs to Eradicate Toxoplasmosis Part I: Introduction and Overview

Purpose of Review

Review building of programs to eliminate Toxoplasma infections.

Recent Findings

Morbidity and mortality from toxoplasmosis led to programs in USA, Panama, and Colombia to facilitate understanding, treatment, prevention, and regional resources, incorporating student work.

Summary

Studies foundational for building recent, regional approaches/programs are reviewed. Introduction provides an overview/review of programs in Panamá, the United States, and other countries. High prevalence/risk of exposure led to laws mandating testing in gestation, reporting, and development of broad-based teaching materials about Toxoplasma. These were tested for efficacy as learning tools for high-school students, pregnant women, medical students, physicians, scientists, public health officials and general public. Digitized, free, smart phone application effectively taught pregnant women about toxoplasmosis prevention. Perinatal infection care programs, identifying true regional risk factors, and point-of-care gestational screening facilitate prevention and care. When implemented fully across all demographics, such programs present opportunities to save lives, sight, and cognition with considerable spillover benefits for individuals and societies.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40124-022-00269-w.

Building Programs to Eradicate Toxoplasmosis Part IV: Understanding and Development of Public Health Strategies and Advances “Take a Village”

Purpose of Review

Review international efforts to build a global public health initiative focused on toxoplasmosis with spillover benefits to save lives, sight, cognition and motor function benefiting maternal and child health.

Recent Findings

Multiple countries’ efforts to eliminate toxoplasmosis demonstrate progress and context for this review and new work.

Summary

Problems with potential solutions proposed include accessibility of accurate, inexpensive diagnostic testing, pre-natal screening and facilitating tools, missed and delayed neonatal diagnosis, restricted access, high costs, delays in obtaining medicines emergently, delayed insurance pre-approvals and high medicare copays taking considerable physician time and effort, harmful shortcuts being taken in methods to prepare medicines in settings where access is restricted, reluctance to perform ventriculoperitoneal shunts promptly when needed without recognition of potential benefit, access to resources for care, especially for marginalized populations, and limited use of recent advances in management of neurologic and retinal disease which can lead to good outcomes.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40124-022-00268-x.

From Fetal to Neonatal Neuroimaging in TORCH Infections: A Pictorial Review

Congenital infections represent a challenging and varied clinical scenario in which the brain is frequently involved. Therefore, fetal and neonatal neuro-imaging plays a pivotal role in reaching an accurate diagnosis and in predicting the clinical outcome. Congenital brain infections are characterized by various clinical manifestations, ranging from nearly asymptomatic diseases to syndromic disorders, often associated with severe neurological symptoms. Brain damage results from the complex interaction among the infectious agent, its specific cellular tropism, and the stage of development of the central nervous system at the time of the maternal infection. Therefore, neuroradiological findings vary widely and are the result of complex events. An early detection is essential to establishing a proper diagnosis and prognosis, and to guarantee an optimal and prompt therapeutic perinatal management. Recently, emerging infective agents (i.e., Zika virus and SARS-CoV2) have been related to possible pre- and perinatal brain damage, thus expanding the spectrum of congenital brain infections. The purpose of this pictorial review is to provide an overview of the current knowledge on fetal and neonatal brain neuroimaging patterns in congenital brain infections used in clinical practice.

Congenital toxoplasmosis: Should we still care about screening?

Prenatal systematic screening for congenital toxoplasmosis has been performed in Austria and France since 1975 and neonatal screening for congenital toxoplasmosis has been part of the New England Newborn screening program since 1986.

In this narrative review we review the data leading up to the systematic screening programs in Austria and France, highlighting the main finding of the European Union funded research in the 1990s and early 2000s. Different descriptive studies of the effect of pre- or postnatal treatment are discussed. Toxoplasma gondii has different genetic lineages with different pathogenicity in humans. This means that results in areas with a low pathogenic lineage cannot be extrapolated to an area with highly pathogenic lineages. The importance of meat as a source of infection is discussed in the light of an increased prevalence of T.gondii in organic livestock production .

Congenital Toxoplasmosis: The State of the Art

Infection with the protozoan parasite Toxoplasma gondii occurs worldwide and usually causes no symptoms. However, a primary infection of pregnant women, may infect the fetus by transplacental transmission. The risk of mother-to-child transmission depends on week of pregnancy at the time of maternal infection: it is low in the first trimester, may reach 90% in the last days of pregnancy. Inversely, however, fetal disease is more severe when infection occurs early in pregnancy than later. Systematic serologic testing in pregnant women who have no antibodies at the beginning of pregnancy, can accurately reveal active maternal infection. Therefore, the risk of fetal infection should be assessed and preventive treatment with spiramycin must be introduced as soon as possible to reduce the risk of mother-to-child transmission, and the severity of fetal infection. When maternal infection is confirmed, prenatal diagnosis with Polymerase Chain Reaction (PCR) on amniotic fluid is recommended. If fetal infection is certain, the maternal treatment is changed to a combination of pyrimethamine-sulfonamide and folinic acid. Congenitally infected newborns are usually asymptomatic at birth, but at risk for tardive sequelae, such as blindness. When congenital infection is evident, disease include retinochoroiditis, cerebral calcifications, hydrocephalus, neurocognitive impairment. The diagnosis of congenital infection must be confirmed at birth and management, specific therapy, and follow-up with multidisciplinary counseling, must be guaranteed.

Early Life Inflammation and the Developing Hematopoietic and Immune Systems: The Cochlea as a Sensitive Indicator of Disruption

Emerging evidence indicates that perinatal infection and inflammation can influence the developing immune system and may ultimately affect long-term health and disease outcomes in offspring by perturbing tissue and immune homeostasis. We posit that perinatal inflammation influences immune outcomes in offspring by perturbing (1) the development and function of fetal-derived immune cells that regulate tissue development and homeostasis, and (2) the establishment and function of developing hematopoietic stem cells (HSCs) that continually generate immune cells across the lifespan. To disentangle the complexities of these interlinked systems, we propose the cochlea as an ideal model tissue to investigate how perinatal infection affects immune, tissue, and stem cell development. The cochlea contains complex tissue architecture and a rich immune milieu that is established during early life. A wide range of congenital infections cause cochlea dysfunction and sensorineural hearing loss (SNHL), likely attributable to early life inflammation. Furthermore, we show that both immune cells and bone marrow hematopoietic progenitors can be simultaneously analyzed within neonatal cochlear samples. Future work investigating the pathogenesis of SNHL in the context of congenital infection will therefore provide critical information on how perinatal inflammation drives disease susceptibility in offspring.

OUTCOMES OF TRANSPLACENTAL TRANSMISSION OF TOXOPLASMA GONDII FROM CHRONICALLY INFECTED FEMALE RED RUFFED LEMURS (VARECIA RUBRA)

Ten red ruffed lemurs (Varecia rubra)-two adult females and their eight offspring-were evaluated in this case series. Two adult females were diagnosed with chronic, latent toxoplasmosis based on serologic testing. The first female lemur had two successive pregnancies. The first pregnancy resulted in transplacental transmission of Toxoplasma gondii. The only surviving offspring was diagnosed with congenital toxoplasmosis based on serologic testing and compatible ophthalmic lesions. The two deceased offspring had disseminated nonsuppurative inflammation and intralesional protozoal organisms consistent with T. gondii, which was confirmed by polymerase chain reaction. The second pregnancy did not result in transplacental transmission. The second chronically infected adult female lemur had one pregnancy that resulted in a single stillborn fetus without evidence of transplacental transmission of T. gondii. Treatment with trimethoprim-sulfamethoxazole and folinic acid was administered to the first adult female and one offspring, but no treatment was given to the second adult female. All surviving lemurs had no further complications associated with toxoplasmosis. This case series demonstrates that chronic, latent infection of reproductive female red ruffed lemurs with T. gondii may result in variable outcomes: (1) transplacental transmission with disseminated fetal infection and stillbirth, (2) transplacental transmission with congenital infection and survival, or (3) lack of transplacental transmission and healthy offspring. Information gained from these cases may help guide recommendations for breeding of this critically endangered species.

Behavioral alterations in long-term Toxoplasma gondii infection of C57BL/6 mice are associated with neuroinflammation and disruption of the blood brain barrier

The Apicomplexa protozoan Toxoplasma gondii is a mandatory intracellular parasite and the causative agent of toxoplasmosis. This illness is of medical importance due to its high prevalence worldwide and may cause neurological alterations in immunocompromised persons. In chronically infected immunocompetent individuals, this parasite forms tissue cysts mainly in the brain. In addition, T. gondii infection has been related to mental illnesses such as schizophrenia, bipolar disorder, depression, obsessive-compulsive disorder, as well as mood, personality, and other behavioral changes. In the present study, we evaluated the kinetics of behavioral alterations in a model of chronic infection, assessing anxiety, depression and exploratory behavior, and their relationship with neuroinflammation and parasite cysts in brain tissue areas, blood-brain-barrier (BBB) integrity, and cytokine status in the brain and serum. Adult female C57BL/6 mice were infected by gavage with 5 cysts of the ME-49 type II T. gondii strain, and analyzed as independent groups at 30, 60 and 90 days postinfection (dpi). Anxiety, depressive-like behavior, and hyperactivity were detected in the early (30 dpi) and long-term (60 and 90 dpi) chronic T. gondii infection, in a direct association with the presence of parasite cysts and neuroinflammation, independently of the brain tissue areas, and linked to BBB disruption. These behavioral alterations paralleled the upregulation of expression of tumor necrosis factor (TNF) and CC-chemokines (CCL2/MCP-1, CCL3/MIP-1α, CCL4/MIP-1β and CCL5/RANTES) in the brain tissue. In addition, increased levels of interferon-gamma (IFNγ), TNF and CCL2/MCP-1 were detected in the peripheral blood, at 30 and 60 dpi. Our data suggest that the persistence of parasite cysts induces sustained neuroinflammation, and BBB disruption, thus allowing leakage of cytokines of circulating plasma into the brain tissue. Therefore, all these factors may contribute to behavioral changes (anxiety, depressive-like behavior, and hyperactivity) in chronic T. gondii infection.

Congenital toxoplasmosis in humans: an update of worldwide rate of congenital infections

The morbidity due to congenital toxoplasmosis in humans is very high. Most of these infected children are likely to develop symptoms of clinical toxoplasmosis. Sequelae in fetus resulting from Toxoplasma gondii infections in women who become infected with this parasite during pregnancy can be devastating and enormous efforts are directed in some countries to prevent these consequences. Here, an update on congenital toxoplasmosis in humans, especially the rate of congenital infections in humans worldwide, is provided. Although several countries have surveillance programmes, most information on the rate of congenital transmission is from France and Brazil. Because of compulsory national screening programme in France to detect and treat women with recently acquired T. gondii infection with anti-toxoplasma therapy, the rate of congenital transmission and the severity of disease in children are declining. Infections by this parasite are widely prevalent in Brazil. The severity of clinical toxoplasmosis in Brazilian children is very high and may be associated with the genetic characteristics of T. gondii isolates prevailing in animals and humans in Brazil. Virtually little or no information is available on this topic from China, India and other countries in Asia.

Long-term impact of congenital toxoplasmosis on phenotypic and functional features of circulating leukocytes from infants one year after treatment onset

Changes in immune response of children with congenital toxoplasmosis (CT) regarding infection evolution and therapeutic intervention was addressed. Infants with CT presented increased counts of monocytes, CD3^-CD16^-CD56^High, CD3⁺CD56⁺ and CD4⁺ T-cells 1-year after treatment onset (TOXO_1-yearAT). Smaller numbers of CD3^-CD16^-CD56⁺ and TCRγδ⁺ T-cells were specifically observed in infants with retinochoroidal lesions (L(+)). When infants were classified based on the baseline status, expansion of CD3^-CD16^-CD56^High and CD4⁺ T-cells were observed in L(+) who had active, active/cicatricial or cicatricial lesions. Infants who had active or active/cicatricial lesions display augmented numbers of monocytes, CD3^-CD16⁺CD56⁺, CD3⁺CD56⁺, CD8⁺DR⁺ and TCRγδ⁺ T-cells and those with active/cicatricial or cicatricial at baseline displayed increase in CD14⁺CD64⁺ monocytes. Moreover, all L(+) had increased IFN-γ⁺ and IL-10⁺ CD4⁺ T-cells, while L(-) had increased ratios of TNF⁺, IFN-γ⁺ and IL-4⁺ NK-cells upon antigen-specific stimulation. Persistent alterations in leukocytes in TOXO_1-yearAT suggest long-term sequels in the immune system of infants with CT.

In vitro Effect of Harmine Alkaloid and Its N-Methyl Derivatives Against Toxoplasma gondii

Toxoplasmosis is one of the most prevalent and neglected zoonotic global diseases caused by Toxoplasma gondii. The current pharmacological treatments show clinical limitations, and therefore, the search for new drugs is an urgent need in order to eradicate this infection. Due to their intrinsic biological activities, β-carboline (βC) alkaloids might represent a good alternative that deserves further investigations. In this context, the in vitro anti-T. gondii activity of three βCs, harmine (1), 2-methyl-harminium (2), and 9-methyl-harmine (3), was evaluated herein. Briefly, the three alkaloids exerted direct effects on the parasite invasion and/or replication capability. Replication rates of intracellular treated tachyzoites were also affected in a dose-dependent manner, at noncytotoxic concentrations for host cells. Additionally, cell cycle analysis revealed that both methyl-derivatives 2 and 3 induce parasite arrest in S/M phases. Compound 3 showed the highest irreversible parasite growth inhibition, with a half maximal inhibitory concentration (IC50) value of 1.8 ± 0.2 μM and a selectivity index (SI) of 17.2 at 4 days post infection. Due to high replication rates, tachyzoites are frequently subjected to DNA double-strand breaks (DSBs). This highly toxic lesion triggers a series of DNA damage response reactions, starting with a kinase cascade that phosphorylates a large number of substrates, including the histone H2A.X to lead the early DSB marker γH2A.X. Western blot studies showed that basal expression of γH2A.X was reduced in the presence of 3. Interestingly, the typical increase in γH2A.X levels produced by camptothecin (CPT), a drug that generates DSB, was not observed when CPT was co-administered with 3. These findings suggest that 3 might disrupt Toxoplasma DNA damage response.

High performance of a novel point-of-care blood test for Toxoplasma infection in women from diverse regions of Morocco

Point-of-care (POC) testing for Toxoplasma infection has the potential to revolutionize diagnosis and management of toxoplasmosis, especially in high-risk populations in areas with significant environmental contamination and poor health infrastructure precluding appropriate follow-up and preventing access to medical care. Toxoplasmosis is a significant public health challenge in Morocco, with a relatively heavy burden of infection and, to this point, minimal investment nationally to address this infection. Herein, we analyse the performance of a novel, low-cost rapid test using fingerstick-derived whole blood from 632 women (82 of whom were pregnant) from slums, educational centres, and from nomad groups across different geographical regions (i.e. oceanic, mountainous) of Morocco. The POC test was highly sensitive and specific from all settings. In the first group of 283 women, sera were tested by Platelia ELISA IgG and IgM along with fingerstick whole blood test. Then a matrix study with 349 women was performed in which fingerstick – POC test results and serum obtained by venipuncture contemporaneously were compared. These results show high POC test performance (Sensitivity: 96.4% [IC95 90.6–98.9%]; Specificity: 99.6% [IC95 97.3–99.9%]) and high prevalence of Toxoplasma infection among women living in rural and mountainous areas, and in urban areas with lower educational levels. The high performance of POC test confirms that it can reduce the need for venipuncture and clinical infrastructure in a low-resource setting. It can be used to efficiently perform seroprevalence determinations in large group settings across a range of demographics, and potentially expands healthcare access, thereby preventing human suffering.

Congenital Infections of the Nervous System

PURPOSE OF REVIEW

This article provides an overview of congenital infections affecting the central nervous system (CNS), discussing the epidemiology, clinical features, diagnostic tools, and preventive and treatment measures for a variety of pathogens with the potential to infect the developing fetal brain.

RECENT FINDINGS

Contrary to popular belief, many congenital CNS infections are preventable and treatable. Treatment options exist for congenital cytomegalovirus, human immunodeficiency virus (HIV), herpes simplex virus, toxoplasmosis, and syphilis, although the efficacy of these treatments and the populations that may benefit from treatment are variable. Zika virus has recently emerged as a pathogen affecting the fetal brain, and new data suggest that the pathogenesis of Zika virus involves direct infection of neuronal progenitor cells leading to destruction of CNS tissue. The incidence of congenital syphilis has been increasing in the United States over the past decade as a direct result of new syphilis cases among adults and poor access to adequate maternal health care.

SUMMARY

Congenital CNS infections often result in significant neurologic morbidity in pediatric patients. Therefore, early identification of maternal illness and implementation of preventive measures are important in improving developmental outcomes and quality of life.

In vitro anti-Toxoplasma gondii efficacy of synthesised benzyltriazole derivatives

Toxoplasma gondii, an obligate intracellular parasite, is the aetiological agent of toxoplasmosis, a disease that affects approximately 25% – 30% of the world’s population. At present, no safe and effective vaccine exists for the prevention of toxoplasmosis. Current treatment options for toxoplasmosis are active only against tachyzoites and may also cause bone marrow toxicity. To contribute to the global search for novel agents for the treatment of toxoplasmosis, we herein report the in vitro activities of previously synthesised benzyltriazole derivatives. The effects of these compounds against T. gondii in vitro were evaluated by using a expressing green fluorescent protein (GFP) type I strain parasite (RH-GFP) and a type II cyst-forming strain of parasite (PruΔku80Δhxgprt). The frontline antitubercular drug isoniazid, designated as Frans J. Smit -isoniazid (FJS-INH), was also included in the screening as a preliminary test in view of future repurposing of this agent. Of the compounds screened, FJS-302, FJS-303, FJS-403 and FJS-INH demonstrated > 80% parasite growth inhibition with IC₅₀ values of 5.6 µg/mL, 6.8 µg/µL, 7.0 µg/mL and 19.8 µg/mL, respectively. FJS-302, FJS-303 and FJS-403 inhibited parasite invasion and replication, whereas, sulphadiazine (SFZ), the positive control, was only effective against parasite replication. In addition, SFZ induced bradyzoite differentiation in vitro, whilst FJS-302, FJS-303 and FJS-403 did not increase the bradyzoite number. These results indicate that FJS-302, FJS-303 and FJS-403 have the potential to act as a viable source of antiparasitic therapeutic agents.

Identification of Biomarkers for Diagnosis and Prognosis of Congenital and Acute Toxoplasmosis

BACKGROUND

The diagnosis of congenital toxoplasmosis can be inconclusive in many cases. Despite the several serological tests developed, the literature on biomarkers that can assist in the diagnosis of congenital an acute toxoplasmosis is limited. The objective of this study was to analyze the immunoreactive profile of Toxoplasma gondii protein bands with the potential to be biomarkers for diagnosis and prognosis of congenital and acute toxoplasmosis.

METHODS

Peripheral blood samples from women of childbearing age and/or pregnant women diagnosed with acquired toxoplasmosis as well as from congenitally infected children were selected and submitted to immunoblotting for analysis of the immunoreactive bands profile by immunoglobulin G (IgG) antibodies.

RESULTS

When comparing the immunoreactive bands profile for antibodies present in samples from different groups and subgroups, the 150, 18.5, and 16.96-kDa bands were more immunoreactive with the antibodies present in serum samples from the acquired infection group. The 343, 189, 150, 75, and 42-kDa bands showed more chance to be detected by the symptomatic congenital infection subgroup samples, while the 61, 50, and 16.96-kDa bands were significantly immunoreactive with the acute infection subgroup samples.

CONCLUSIONS

The identification of these potential biomarkers can assist in early diagnosis and treatment of congenital toxoplasmosis.

Hearing brain evaluated using near-infrared spectroscopy in congenital toxoplasmosis

Congenital toxoplasmosis (CT) is a known cause of hearing loss directly caused by Toxoplasma gondii. Hearing loss might result from sensory, neural, or sensorineural lesions. Early treated infants rarely develop hearing loss, but retinochoroidal lesions, intracranial calcifications and hydrocephalus are common. In this study, we aimed to evaluate the brain evoked hemodynamic responses of CT and healthy infants during four auditory stimuli: mother infant directed speech, researcher infant directed speech, mother reading and researcher recorded. Children underwent Transitionally Evoked Otoacoustic Emission Auditory Testing and Automated Brainstem Auditory Response tests with normal auditory results, but with a tendency for greater latencies in the CT group compared to the control group. We assessed brain hemodynamics with functional near-infrared spectroscopy (fNIRS) measurements from 61 infants, and we present fNIRS results as frequency maps of activation and deactivation for each stimulus. By evaluating infants in the three first months of life, we observed an individual heterogeneous brain activation pattern in response to all auditory stimuli for both groups. Each channel was activated or deactivated in less than 30% of children for all stimuli. There is a need of prospective studies to evaluate if the neurologic or auditory changes course with compromise of children outcomes.

Autoantibodies Against Ubiquitous and Confined Antigens in Patients With Ocular, Neuro-Ophthalmic and Congenital Cerebral Toxoplasmosis

Toxoplasma gondii infection can trigger autoreactivity by different mechanisms. In the case of ocular toxoplasmosis, disruption of the blood-retinal barrier may cause exposure of confined retinal antigens such as recoverin. Besides, cross-reactivity can be induced by molecular mimicry of parasite antigens like HSP70, which shares 76% identity with the human ortholog. Autoreactivity can be a determining factor of clinical manifestations in the eye and in the central nervous system. We performed a prospective observational study to determine the presence of autoantibodies against recoverin and HSP70 by indirect ELISA in the serum of 65 patients with ocular, neuro-ophthalmic and congenital cerebral toxoplasmosis. We found systemic autoantibodies against recoverin and HSP70 in 33.8% and 15.6% of individuals, respectively. The presence of autoantibodies in cases of OT may be related to the severity of clinical manifestations, while in cases with CNS involvement they may have a protective role. Unexpectedly, anti-recoverin antibodies were found in patients with cerebral involvement, without ocular toxoplasmosis; therefore, we analyzed and proved cross-reactivity between recoverin and a brain antigen, hippocalcin, so the immunological phenomenon occurring in one immune-privileged organ (e.g. the central nervous system) could affect the environment of another (egg. the eye).

A First Report on Experience in Managing Infants with Congenital Toxoplasmosis in Ethiopia: Case Reports and a Review of Evaluation and Treatment

Background. Congenital toxoplasmosis is a major sequela of untreated primary maternal infection. With or without symptoms, untreated infections eventually lead to multiple neurologic complications. Despite the high Toxoplasma gondii seroprevalence in the Ethiopian population, there are no reports of newborns diagnosed and treated for congenital toxoplasmosis. Presentation of Cases. The clinical presentation, evaluation, and management of three infants with congenital toxoplasmosis are described. Two were symptomatic at birth. All three had confirmed diagnoses using Toxoplasma serologic tests. Two completed their treatment with one infant developing complications of strabismus and seizure disorder. Discussion and Conclusions. There is little experience in managing congenital toxoplasmosis in Ethiopia due to constraints in diagnostics and therapy. The description of this first such report underscores the need for risk assessment and evaluation during antenatal care to obtain favorable fetal outcomes.

Ocular Findings in Infants with Congenital Toxoplasmosis after a Toxoplasmosis Outbreak

PURPOSE

We investigated the prevalence of ocular abnormalities in infants vertically exposed to Toxoplasma gondii infection during an outbreak in Santa Maria City, Brazil.

DESIGN

Consecutive case series.

PARTICIPANTS

A total of 187 infants were included.

METHODS

The infants were recruited from January 2018 to November 2019. All mothers were screened for syphilis and human immunodeficiency virus before delivery. Toxoplasmosis infection was confirmed in all mothers and infants based on the presence of serum anti-T. gondii immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies. All infants underwent an ophthalmologic examination; ocular abnormalities were documented using a wide-field digital imaging system. Neonatal cranial sonography or head computed tomography was performed in 181 infants, and the cerebrospinal fluid (CSF) was screened for anti-T. gondii IgG and IgM antibodies in 159 infants. Peripheral blood samples from 9 infants and their mothers were analyzed for the presence of T. gondii DNA by real-time polymerase chain reaction.

MAIN OUTCOME MEASURES

Ocular abnormalities associated with congenital toxoplasmosis.

RESULTS

A total of 187 infants were examined. Twenty-nine infants (15.5%) had congenital toxoplasmosis, of whom 19 (10.2%) had ocular abnormalities, including retinochoroiditis in 29 of 38 eyes (76.3%), optic nerve abnormalities in 5 eyes (13.2%), microphthalmia in 1 eye (2.6%), and cataract in 2 eyes (5.3%). Bilateral retinal choroidal lesions were found in 10 of 19 infants (52.6%). Nine eyes of 6 infants had active lesions, with retinal choroidal cellular infiltrates at the first examination. Thirteen (7.2%) of 181 infants screened presented with cerebral calcifications. Eighty-three percent of the screened infants were positive for anti-T. gondii IgG and negative for IgM antibodies in the CSF. Congenital toxoplasmosis was higher in mothers infected during the third pregnancy trimester, and maternal treatment during pregnancy was not associated with a lower rate of congenital toxoplasmosis.

CONCLUSIONS

High prevalence rates of clinical manifestations were observed in infants with congenital toxoplasmosis after a waterborne toxoplasmosis outbreak, the largest yet described. Cerebral calcifications were higher in infants with ocular abnormalities, and maternal infection during the third pregnancy trimester was associated with a higher rate of congenital toxoplasmosis independent of maternal treatment.

Seroprevalence and risk factors of Toxoplasma gondii infection in women with recurrent fetal loss from the province of Khyber Pakhtunkhwa, Pakistan

BACKGROUND

In women with a bad obstetric history (BOH), infection is an established cause of recurrent fetal loss. A common infecting agent is the protozoan parasite Toxoplasma gondii (T. gondii). The aim of this study was to measure the prevalence of toxoplasmosis in women with recurrent fetal loss from the Khyber Pakhtunkhwa province of Pakistan.

METHODS

The study included 360 females aged 16-40 years, of which 180 had a bad obstetric history (study group) and the other 180 had no such history (control group). Blood serum samples were tested for toxoplasma IgM antibodies by Enzyme Linked Immunosorbent Assay and for toxoplasma IgG antibodies using an Immunochromatographic technique.

RESULTS

The overall seroprevalence of toxoplasma infection in study group females was 40.6% and in control group females it was 7.2%. Specifically, IgM prevalence was 12.8% in the study group and 1.1% in the control group. IgG prevalence was 23.9% in the study group and 6.1% in the control group. IgM and IgG combined prevalence was 3.9% in the study group cases. There is a statistically significant association between BOH and seropositivity for T. gondii (p < 0.0001, Chi square test). Various risk factors associated with T. gondii seroprevalence in study and control groups were analyzed.

CONCLUSION

The seroprevalence of toxoplasmosis was significantly higher in women with a bad obstetric history compared to those with no such history. Associated risk factors had no significant effects on the results.

Protective efficacy by a novel multi-epitope vaccine, including MIC3, ROP8, and SAG1, against acute Toxoplasma gondii infection in BALB/c mice

Toxoplasma gondii is an intracellular apicomplexan parasite, which can cause a serious infectious disease in pregnant women and immunocompromised individuals. Therefore, the development of a polyvalent vaccine consisting of all stages of the parasite life cycle using the epitopes from tachyzoites, bradyzoites, and sporozoites is likely to be required for complete protective immunity. In this study, we designed protein vaccine candidate based on the prediction of specific epitopes (i.e., B cell and T cell) from three Toxoplasma gondii antigens. The MRS protein (MIC3: 30-180, ROP8: 85-185, and SAG1: 85-235) was expressed in Escherichia coli, and purification was performed using a HisTrap HP column and then we evaluated immunogenicity and protective property in BALB/c mice. Seventy-two mice were randomly divided into six groups, including three vaccinations (i.e., MRS, MRS-Freund, and MRS-Calcium Phosphate Nanoparticles (MRS-CaPNs)) and three control (i.e., Phosphate-buffered saline, Freund, and CaPNs) groups. All groups were immunized three times via subcutaneous injection within three-week intervals. In the vaccination groups, the BALB/c mice were injected with 20 μg of MRS protein for the first time and 10 μg of MRS for the next two times. Antibodies, cytokines, and splenocytes proliferation in the immunized mice were assayed using the enzyme-linked immunosorbent assay. Protective efficacy was analyzed by challenging the immunized mice with T. gondii of RH strain. Antibody, cytokine, and lymphocyte proliferation assays showed that the mice immunized with MRS induced stronger humoral and T helper type 1 cell-mediated immune responses, compared to the control mice. However, co-immunization with adjuvants (i.e., Freund and CaNPs) resulted in impaired immune responses. Effective protection against the parasite achieved an increase in survival time in the immunized mice, especially in the MRS-CaNPs group. The obtained results of the present study demonstrated that multi-epitope protein vaccination, MRS, is a potential strategy against toxoplasmosis infection. In addition, the vaccine co-delivered with CaPNs could provide an important key for vaccine candidate to control T. gondii infection.

Ocular Outcome of Brazilian Patients With Congenital Toxoplasmosis

BACKGROUND

Retinochoroiditis is the most frequent manifestation of congenital toxoplasmosis. We aimed to describe the ocular outcome and factors that may influence the visual prognosis of these patients.

METHODS

Cohort of patients with confirmed congenital toxoplasmosis seen between 1996 and 2017 in Porto Alegre, southern Brazil.

RESULTS

Seventy-seven patients were included, of which 65 (85.5%) were identified by routine screening. Median age at the end of the follow-up was 10 years (minimum 2, maximum 25). Retinochoroiditis was present in 55 patients (71.4%). New retinochoroidal lesions developed after the first year of life in 77.8% of the patients who began treatment after the fourth month of life, compared with 35.2% among those treated before 4 months of life (relative risk = 0.45, 95% confidence intervals: 0.27-0.75, P = 0.02) and 33.3% among those treated before 2 months of life (relative risk = 0.42, 95% confidence intervals: 0.25-0.72, P = 0.01). There was a peak incidence of new retinochoroidal lesions between 4 and 5 years and another peak between 9 and 14 years, the latter only among girls. Thirty-four patients with retinochoroiditis were followed up for 10 years or more, and the school performance was appropriate in 28 (82.4%).

CONCLUSIONS

The high incidence of new retinochoroidal lesions during the follow-up period indicates the importance of long-term follow-up of patients with congenital toxoplasmosis. Initiating treatment within the first 4 months of life, especially within the first 2 months, was a protective factor against the later development of retinochoroiditis. Despite the usual favorable prognosis, the high morbidity of congenital toxoplasmosis in Brazil was confirmed.

Toxoplasmosis in pregnancy

Toxoplasmosis is one of the common chronic infections caused by the parasite Toxoplasma gondii. Even though its infection in healthy non-pregnant women is self-limited and largely asymptomatic, the main concern is the risk to the fetus by vertical transmission in pregnancy. Congenital toxoplasmosis can result in permanent neurological damage and even serious morbidity such as blindness. Screening programs are implemented in various countries depending on the prevalence and virulence of the parasite in the respective regions. Upon diagnosis of infection, appropriate antibiotic therapy should be initiated as it has been proven to reduce the risk of fetal transmission. Primary prevention remains the key intervention to avoid the infection and hence patient education is an important aspect of the management.

Fifteen-minute consultation: Management of the infant born to a mother with toxoplasmosis in pregnancy

Congenital toxoplasmosis occurs following transplacental transfer of Toxoplasma gondii Irrespective of symptom status at birth, infants with congenital infection may develop serious long-term sequelae, including learning disability, seizures, hydrocephalus, motor and hearing deficits, chorioretinitis and retinal scarring with impaired vision. Timely diagnosis facilitates early initiation of therapy, aimed at prevention or amelioration of adverse clinical consequences. Diagnosis can be difficult, however, since acutely infected mothers are often asymptomatic and laboratory testing can be complex. Moreover, any decision to start treatment in the newborn must include careful consideration of the benefits and risks. This paper outlines a structured approach for managing an infant born to a woman with possible or confirmed T. gondii infection during pregnancy, including key aspects of the antenatal history, interpretation and timing of investigations, treatment and appropriate follow-up. Our recommendations are based on current evidence in the literature, consensus from two UK paediatric infectious disease centres and the UK specialist Toxoplasma Reference Unit.

Emerging Therapeutic Targets Against Toxoplasma gondii: Update on DNA Repair Response Inhibitors and Genotoxic Drugs

Toxoplasma gondii is the causative agent of toxoplasmosis in animals and humans. This infection is transmitted to humans through oocysts released in the feces of the felines into the environment or by ingestion of undercooked meat. This implies that toxoplasmosis is a zoonotic disease and T. gondii is a foodborne pathogen. In addition, chronic toxoplasmosis in goats and sheep is the cause of recurrent abortions with economic losses in the sector. It is also a health problem in pets such as cats and dogs. Although there are therapies against this infection in its acute stage, they are not able to permanently eliminate the parasite and sometimes they are not well tolerated. To develop better, safer drugs, we need to elucidate key aspects of the biology of T. gondii. In this review, we will discuss the importance of the homologous recombination repair (HRR) pathway in the parasite's lytic cycle and how components of these processes can be potential molecular targets for new drug development programs. In that sense, the effect of different DNA damage agents or HHR inhibitors on the growth and replication of T. gondii will be described. Multitarget drugs that were either associated with other targets or were part of general screenings are included in the list, providing a thorough revision of the drugs that can be tested in other scenarios.

Congenital toxoplasmosis: What is the evidence for chemoprophylaxis to prevent fetal infection?

Although prenatal diagnosis and prenatal and neonatal therapy of congenital toxoplasmosis are available, there is controversy concerning the effectiveness of prophylaxis to prevent placental transmission. Experimental, parasitological, and clinical data suggest a "window of opportunity" following maternal infection. Among medications active against Toxoplasma gondii, mainly spiramycin (Spy) and pyrimethamine + sulfonamide combinations (P-S) have been evaluated. Results from observational studies suffered treatment bias, since prescriptions differed according to the gestational age at seroconversion, which is the major risk factor for transmission, and many lacked precise timing. Some large retrospective studies found no difference in transmission according to prophylactic treatment, but transmission was lower when treatment started promptly after maternal seroconversion. A few recent studies adjusting for timing of infection observed lower transmission in case of P-S than other or no prophylaxis. In the only randomized controlled trial, transmission was lower with P-S than S (18.5% vs 30%, P = .147); this association was strengthened when the treatment was started within 3 weeks of seroconversion, and the incidence of fetal cerebral ultrasound signs was significantly reduced in the P-S group. Rapid initiation of prophylactic therapy following maternal infection, which is usually asymptomatic, requires systematic screening for maternal seroconversion during pregnancy.

Treatment with melatonin induces a reduction of Toxoplasma gondii development in LLC-MK2 cells

It is known that the current treatment for toxoplasmosis causes side effects. Thus, it is essential to develop new therapies with reduced adverse effects while concurrently maintaining broad coverage and prophylactic therapy. Melatonin is a hormone that participates in the circadian cycle in vertebrates and has antioxidant, immunomodulatory, and antitumoral functions. In addition, it has been shown that melatonin can modulate immune responses and parasitic development during infection by Trypanosoma cruzi and Leishmania spp. Furthermore, studies indicate that melatonin increases the number of lymphocytes in rats infected by Toxoplasma gondii. However, there is no information on the possible effects of melatonin in T. gondii-infected host cells in vitro. This study analyzed the effects of melatonin treatment in the monkey kidney cell epithelial cell line, LLC-MK2, after infection with T. gondii. LLC-MK2 cells were infected and treated/not treated with melatonin, and the infection index was then quantified. Melatonin treatment did not alter host cell viability and was able to reduce parasite proliferation in LLC-MK2 cells at 24 and 48 h and at 6 days. Analysis by scanning electron microscopy confirmed reduction of parasite proliferation and alterations of tachyzoite shapes. Transmission electron microscopy images showed parasites with ruptured plasma membranes and cytoplasmic leakage. After treatment, parasites showed positive staining for apoptotic-like cell death. These results suggest that the use of melatonin as the lead compound for the synthesis of new compounds may constitute an alternative treatment for toxoplasmosis.

Toxoplasmosis screening during pregnancy in France: Opinion of an expert panel for the CNGOF

Prenatal screening to prevent congenital toxoplasmosis as performed in France for several decades has been questioned in view of the decreasing incidence of this infection and the cost of testing. The French College of Obstetrics and Gynecology mandated a multidisciplinary panel of experts to perform a reassessment of the screening program in accordance with international good practice. In France, about 70% of pregnant women are not immune to T. gondii, and 0.2-0.25% become infected during pregnancy. The risk of maternal-fetal transmission of infection is on average 25-29% and depends greatly on the gestational age at seroconversion. In case of fetal transmission, the outcome is livebirth in 95% of cases, with latent congenital toxoplasmosis in 90% of cases and symptomatic forms in 10% of cases, of which 1/3 are severe and 2/3 moderate. Biological techniques have satisfactory performance regarding serologies for the diagnosis of maternal infections and PCR on amniotic fluid for the prenatal diagnosis of congenital toxoplasmosis. Primary prevention of toxoplasmosis is based on hygiene measures that are relatively simple, but poorly implemented. In case of maternal seroconversion, there is a strong case for prenatal prophylactic treatment as soon as possible (ideally within 3 weeks of seroconversion), spiramycin before 14 weeks of gestation (WG), and with a tendency to superiority of the pyrimethamine/sulfadiazine association over spiramycin beyond 14 W G, in order to reduce the risk of symptomatic congenital toxoplasmosis. In case of congenital toxoplasmosis, prompt initiation of treatment reduces the occurrence of cerebral signs and symptoms, as well as retinal lesions. Several medico-economic evaluations of the French toxoplasmosis screening program have been conducted including an individual cost-effectiveness approach with decision analysis which concluded on the profitability of prenatal screening as carried out in France (monthly surveillance of seronegative women, prenatal treatment in case of seroconversion, termination of pregnancy in severe forms). Though most international societies do not recommend systematic screening for mainly financial reasons, if congenital toxoplasmosis appears benign in France today, it is probably thanks to screening and the possibility of early treatment of fetuses and/or newborns. Thus, the panel recommends continuing for now the program in France for prevention of congenital toxoplasmosis.

Disease of the Year 2019: Ocular Toxoplasmosis in HIV-infected Patients

Ocular toxoplasmosis (OT) may be an initial manifestation of acquired immunodeficiency syndrome (AIDS) in human immunodeficiency virus (HIV)-infected patients. OT has different clinical manifestations and can mimic other intraocular infections. Clinical findings may show single or multifocal retinochoroidal lesions or panuveitis. Atypical presentations are associated with extensive uni- or bilateral areas of retinal necrosis. OT lesions not associated with preexisting retinochoroidal scars are usually due to acquired rather than congenital infection. When CD4+ T cell counts are <100 c/uL, vitritis is frequently mild. Isolated anterior uveitis has been reported in single cases. Positive immunoglobulin M (IgM) antibodies are rare but their presence can support the diagnosis. As atypical presentations of OT are common, anterior chamber puncture for multiplex polymerase chain reaction amplification of infectious DNA should be considered, as early diagnosis and treatment can prevent massive tissue destruction and preserve vision. This review provides an overview of OT in HIV-infected patients.

Unpasteurised milk consumption as a potential risk factor for toxoplasmosis in females with recurrent pregnancy loss

In women with a bad obstetric history, certain infections are associated with recurrent foetal loss. One of the common infectious agents is a protozoan parasite, Toxoplasma gondii. The aim of this study was to assess unpasteurised milk consumption as a potential risk factor for toxoplasmosis in females with recurrent pregnancy loss from the province of Khyber Pakhtunkhwa, Pakistan. In this study, we recruited a total of 360 females, comprising a study group of 180 females with previous history of recurrent pregnancy loss and a control group of 180 females with no such history. Blood serum from the participants was analysed for Toxoplasma gondii IgM antibodies by enzyme linked immunosorbent assay. Among the study group, 23 (12.8%) females were serologically positive for IgM antibodies against Toxoplasma gondii, whilst 157 (87.2%) were IgM negative. In the control group, only two (4.8%) females were IgM positive, whilst 178 (95.2%) were IgM negative. Bad pregnancy outcome in the study group and control group was observed to be significantly different (p < .0001). In both of these groups, unpasteurised milk consumption was found as a major risk factor for Toxoplasma gondii infection. A routine serological investigation should be carried out in pregnant women to rule out toxoplasmosis and reduce the risk of recurrent pregnancy loss as well as congenital toxoplasmosis in newborns.Impact statementWhat is already known on this subject? Seropositivity for Toxoplasma gondii antibodies ranges from 7% to 51% in different regions of the world. The prevalence rate varies because of differences in climate, culture, food habits, behaviour, personal hygiene and cooking habits of different societies and ethnic groups. Various risk factors have been identified that contribute to a high prevalence rate of the disease, including consumption of raw or poorly cooked meat, physical contact with cats or cat litter, consumption of unwashed raw vegetables and fruits, drinking of contaminated water and milk. We presumed that consuming unpasteurised milk could be a potential risk factor for developing toxoplasmosis in pregnant women.What the results of this study add? This study demonstrates high seroprevalence of Toxoplasma gondii antibodies in females of child bearing age that have consumed unpasteurised milk and is a potential risk factor for developing toxoplasmosis.What the implications are of these findings for clinical practice and/or further research? Our findings suggest that primary preventive measures (personal hygiene, frequent hand washing and consuming pasteurised milk) should be taken by health surveillance authorities to focus on families, especially pregnant women, to educate them about personal hygiene, contact with cattle or using their milk and milk products. The latter is especially important to aware them about the hazards of consuming unpasteurised and contaminated milk.

Acute Toxoplasma infection in pregnant women worldwide: A systematic review and meta-analysis

BACKGROUND

Acute Toxoplasma infection (ATI) during pregnancy, if left untreated, can cause severe adverse outcomes for the fetus and newborn. Here, we undertook a meta-analysis to estimate the worldwide prevalence of ATI in pregnant women.

METHODS

We searched international databases for studies published between January 1988 and November 2018. We included population-based cross-sectional and prospective cohort studies that reported the prevalence of ATI in pregnant women. Data were synthesized using a random effect model to calculate the overall prevalence of ATI (with a 95% CI) in six WHO regions and globally. We also performed linear meta-regression analyses to investigate associations of maternal, socio-demographic, geographical and climate parameters with the prevalence of ATI.

RESULTS

In total, 217 studies comprising 902,228 pregnant women across 74 countries were included in the meta-analysis. The overall prevalence of ATI in pregnant women globally was 1.1% (95% CI: 0.9-1.2%). In studies where more strict criteria for ATI were used, the overall prevalence was 0.6% (95% CI: 0.4-0.7%). The prevalence was highest in the Eastern Mediterranean region (2.5%; 95%CI: 1.7-3.4%) and lowest in the European region (0.5%; 95% CI: 0.4-0.7%). A significantly higher prevalence of ATI was found in countries with lower income levels (P = 0.027), lower human development indices (P = 0.04), higher temperatures (P = 0.02) and lower latitudes (P = 0.005) and longitudes (P = 0.02).

CONCLUSIONS

The risk of acquiring ATI during gestation is clinically important and preventive measures to avoid exposure of pregnant women to Toxoplasma infection should be strictly applied.

Outcomes of hydrocephalus secondary to congenital toxoplasmosis

OBJECTIVE

Hydrocephalus occurs in children with congenital toxoplasmosis and can lead to severe disability. In these cases, the decision to intervene is often influenced by the expectation of neurological recovery. In this study, clinical responses to neurosurgical intervention in children with hydrocephalus secondary to congenital toxoplasmosis are characterized.

METHODS

Sixty-five participants with hydrocephalus due to congenital Toxoplasma gondii infection were evaluated as part of the National Collaborative Chicago-based Congenital Toxoplasmosis Study, and their neuroradiographic findings were reviewed. Clinical outcomes were scored on the basis of cognition and motor skills through the use of IQ scores and Gross Motor Function Classification System (GMFCS) level. Outcomes were then analyzed in relation to approach to management, anatomy of hydrocephalus, and time from diagnosis of hydrocephalus to surgical intervention.

RESULTS

There was considerable variation in the outcomes of patients whose hydrocephalus was treated in early life, ranging from normal cognitive and motor function to profound developmental delay and functional limitation. Of the 65 participants included in the study, IQ and GMFCS level were available for 46 (70.8%). IQ and motor score were highly correlated (r = -0.82, p < 0.001). There were people with differing patterns of hydrocephalus or thickness of cortical mantle on initial presentation who had favorable outcomes. Time to neurosurgical intervention data were available for 31 patients who underwent ventriculoperitoneal (VP) shunt placement. Delayed shunt placement beyond 25 days after diagnosis of hydrocephalus was associated with greater cognitive impairment (p = 0.02). Motor impairment also appeared to be associated with shunt placement beyond 25 days but the difference did not achieve statistical significance (p = 0.13). Among those with shunt placement within 25 days after diagnosis (n = 19), the mean GMFCS level was 1.9 ± 1.6 (range 1-5). Five (29.4%) of 17 of these patients were too disabled to participate in formal cognitive testing, after excluding 2 patients with visual difficulties or language barriers that precluded IQ testing. Of the patients who had VP shunt placement 25 or more days after diagnosis (n = 12), the mean GMFCS level was 2.7 ± 1.4 (range 1-4). Of these, 1 could not participate in IQ testing due to severe visual difficulties and 8 (72.7%) of the remaining 11 due to cognitive disability.

CONCLUSIONS

VP shunt placement in patients with hydrocephalus caused by congenital toxoplasmosis can contribute to favorable clinical outcomes, even in cases with severe hydrocephalus on neuroimaging. Shunt placement within 25 days of diagnosis was statistically associated with more favorable cognitive outcomes. Motor function appeared to follow the same pattern although it did not achieve statistical significance.

Prevention and mitigation of congenital toxoplasmosis. Economic costs and benefits in diverse settings

Congenital toxoplasmosis (CT), the result of a primary infection of pregnant women with Toxoplasma gondii which was transmitted to the fetus, may result in mild to deep injuries occurring in the newborn or later in its development or in adolescence. The visual and cognitive impairment that can result imposes substantial economic costs on the individual and society. Numerous observational studies favor the conclusion that, with preventive measures currently available, it is possible to reduce the incidence of infections in pregnant women, the incidence of fetal infection by preventing transplacental transmission, and the gravity of injury in infected newborns. Treatment of infected newborns can also reduce the severity of consequences and the frequency of their occurrence later in life. Prevention programs, however, are applied in only a few countries; in most countries implementation of a national prevention program has not been considered or has been thought to be too expensive. This article lists the methods of prevention of CT and describes existing national prevention programs in France and Austria. It analyzes the economic costs and benefits of maternal screening for CT prevention and mitigation for society and for health systems. The economic feasibility of implementing national screening in low-prevalence, high-cost countries is illustrated with the example of the United States. New diagnostic tools are discussed and the implication of lower costs is considered, for countries with well-established screening programs as well as those with inadequate prenatal care networks.

Adjunctive bradyzoite-directed therapy for reducing complications of congenital toxoplasmosis

Congenital toxoplasmosis is caused by in utero infection of the fetus with the intracellular parasite Toxoplasma gondii. Upon infection, the parasite forms life-long cysts in fetal brain and eyes which are resistant to the currently accepted therapy of pyrimethamine and sulfadiazine. These cysts commonly reactivate later in life causing chorioretinitis and visual impairment, and rarely cause neurological complications. I hypothesize that adjunctive, bradyzoite-directed therapies have the potential to alleviate a significant burden of disease by reducing cyst burden in neonatal brain and eyes. Atovaquone is perhaps the most promising drug for further evaluation given its low side-effect profile, established safety, and efficacy in animal models reducing cyst burden. Very limited observational data in humans suggests atovaquone may prevent Toxoplasma-associated chorioretinitis recurrence. Clinical trials are needed to evaluate it and other potential drugs as adjunctive treatment in congenital toxoplasmosis.

Treatment of toxoplasmosis: Current options and future perspectives

Toxoplasmosis is a worldwide parasitic disease infecting about one third of humans, with possible severe outcomes in neonates and immunocompromised patients. Despite continuous and successful efforts to improve diagnosis, therapeutic schemes have barely evolved since many years. This article aims at reviewing the main clinical trials and current treatment practices, and at addressing future perspectives in the light of ongoing researches.