Long-term ocular prognosis in 327 children with congenital toxoplasmosis

Employing digital PCR for enhanced detection of perinatal Toxoplasma gondii infection: A cross-sectional surveillance and maternal-infant outcomes study in El Salvador

Toxoplasma gondii is a parasitic infection that can be transmitted in utero, resulting in fetal chorioretinitis and other long-term neurological outcomes. If diagnosed early, pregnancy-safe chemotherapeutics can prevent vertical transmission. Unfortunately, diagnosis of acute, primary infection among pregnant women remains neglected, particularly in low-and-middle-income countries. Clinically actionable diagnosis is complex due to the commonality of infection during childhood and early adulthood which spawn long-last antibody titers and historically unreliable direct molecular diagnostics. The current study employed a cross-sectional T. gondii perinatal surveillance study using digital PCR, a next generation molecular diagnostic platform, and a maternal-fetal outcomes survey to ascertain the risk of vertical toxoplasmosis transmission in the Western Region of El Salvador. Of 198 enrolled mothers at the time of childbirth, 6.6% had evidence of recent T. gondii infection-85% of these cases were identified using digital PCR. Neonates born to these acutely infected mothers were significantly more likely to meconium aspiration syndrome and mothers were more likely to experience labor and delivery complications. Multivariable logistic regression found higher maternal T. gondii infection odds were associated with the presence of pet cats, the definitive T. gondii host. In closing, this study provides evidence of maternal T. gondii infection, vertical transmission and deleterious fetal outcomes in a vulnerable population near the El Salvador-Guatemala border. Further, this is the first published study to show clinical utility potential of digital PCR for accurate diagnosis of congenital toxoplasmosis cases.

Causes of infectious pediatric uveitis: A review

Infectious pediatric uveitis is a rare disease that can cause severe ocular damage if not detected rapidly and treated properly. Additionally, early identification of an infection can protect the child from life-threatening systemic infection. Infectious uveitis can be congenital or acquired and may manifest as a primary ocular infection or as a reactivation. Nevertheless, publications on infectious paediatric uveitis are usually limited to a small number of patients or a case report. So far, most studies on uveitis in children have focused primarily on noninfectious uveitis, and a systematic study on infectious uveitis is lacking. In this review, we summarize the literature on infectious uveitis in pediatric populations and report on the epidemiology, pathophysiology, clinical signs, diagnostic tests, and treatment. We will describe the different possible pathogens causing uveitis in childhood by microbiological group (i.e. parasites, viruses, bacteria, and fungi). We aim to contribute to early diagnosis and management of infectious pediatric uveitis, which in turn might improve not only visual outcome, but also the general health outcome.

Toxoplasma gondii Infection in Pregnancy - Recommendations of the Working Group on Obstetrics and Prenatal Medicine (AGG - Section on Maternal Disorders)

Aim The AGG (Working Group for Obstetrics and Prenatal Diagnostics, Section Maternal Diseases) has issued these recommendations to improve the detection and management of Toxoplasma gondii infection in pregnancy. Methods Members of the Task Force developed the recommendations and statements presented here using recently published literature. The recommendations were adopted after a consensus process by members of the working group. Recommendations This article focuses on the epidemiology and pathophysiology of Toxoplasma gondii infection in pregnancy and includes recommendations for maternal and fetal diagnosis, transmission prophylaxis, therapy, prevention, screening, and peripartum management.

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.

Intravitreal Clindamycin as an Adjuvant Therapy in Congenital Toxoplasma Retinochoroiditis in a Neonate - A Case Report

PURPOSE

To report a case of active retinochoroiditis in a neonate treated with intravitreal clindamycin as an adjuvant therapy.

CASE REPORT

A 10-day-old infant presented with active retinochoroiditis lesions in both eyes along with hepatosplenomegaly, abdominal distension, and thrombocytopenia. The mother had a history of fever in the third trimester for which she received symptomatic treatment. The infant was treated with systemic anti-toxoplasma therapy along with intravitreal clindamycin in the severely affected eye. There was a significant faster resolution in the retinochoroiditis lesions, which eventually lead to better anatomical and visual outcomes.

CONCLUSION AND IMPORTANCE

Active screening and timely intervention of the neonates who are born to mothers with fever during pregnancy can go a long way in preventing unlikely outcomes due to congenital toxoplasma retinochoroiditis. Intravitreal clindamycin can be considered as an adjuvant therapy in selected cases.

Toxoplasmosis: A Timeless Challenge for Pregnancy

This study aimed to evaluate the prevalence of toxoplasmosis in pregnant women, as well as the general characteristics, clinical and laboratory findings, and pregnancy and fetal outcomes of pregnant women diagnosed with acute toxoplasma infection (ATI). The toxoplasma IgM, IgG, and IgG avidity test results of pregnant women who applied to our referral hospital between January 2016 and June 2022, and among them, those diagnosed with ATI, were analyzed. The 119 patients diagnosed with ATI during this time period were included for further analysis. The prevalence of toxoplasmosis in pregnant women was found to be 46.2%, and the rate of ATI was 4%. The total mother-to-child transmission rate was 5% (5/101). Congenital toxoplasmosis (CT) was observed in 1 (1.1%) child of the 87 pregnant women who received spiramycin prophylaxis, though it was found in 4 (30.8%) of the children of the 13 untreated mothers. With respect to prenatal treatment, CT rates were significantly higher in the children born to untreated mothers (p = 0.001). In conclusion, although toxoplasma seroprevalence was found to be high in our region, there was a paucity in diagnosis, follow-up, and treatment. Our findings support that prenatal spiramycin prophylaxis is effective in preventing the transmission of parasites from mother to child.

Risk factors for recurrences and visual impairment in patients with ocular toxoplasmosis: A systematic review and meta-analysis

BACKGROUND

Ocular toxoplasmosis (OT) is caused by the parasite Toxoplasma gondii. OT is the leading cause of posterior uveitis globally; it is a recurrent disease that may result in visual impairment and blindness. This systematic review and meta-analysis aim to summarize and evaluate the risk factors for recurrences, visual impairment, and blindness described in the literature worldwide.

METHODS AND FINDINGS

We performed a systematic literature search in PubMed, Embase, VHL, Cochrane Library, Scopus, and DANS EASY Archive. All studies reporting patients with clinically and serologically confirmed OT presenting any clinical or paraclinical factor influencing recurrences, visual impairment, and blindness were included. Studies presenting secondary data, case reports, and case series were excluded. An initial selection was made by title and abstract, and then the studies were reviewed by full text where the eligible studies were selected. Then, the risk of bias was assessed through validated tools. Data were extracted using a validated extraction format. Qualitative synthesis and quantitative analysis were done. This study was registered on PROSPERO (CRD42022327836).

RESULTS

Seventy two studies met the inclusion criteria. Fifty-three were summarized in the qualitative synthesis in three sections: clinical and environmental factors, parasite and host factors, and treatment-related factors. Of the 72 articles, 39 were included in the meta-analysis, of which 14 were conducted in South America, 13 in Europe, four in Asia, three multinational, two in North America and Central America, respectively, and only one in Africa. A total of 4,200 patients with OT were analyzed, mean age ranged from 7.3 to 65.1 year of age, with similar distribution by sex. The frequency of recurrences in patients with OT was 49% (95% CI 40%-58%), being more frequent in the South American population than in Europeans. Additionally, visual impairment was presented in 35% (95% CI 25%-48%) and blindness in 20% (95% CI 13%-30%) of eyes, with a similar predominance in South Americans than in Europeans. On the other hand, having lesions near the macula or adjacent to the optic nerve had an OR of 4.83 (95% CI; 2.72-8.59) for blindness, similar to having more than one recurrence that had an OR of 3.18 (95% CI; 1.59-6.38). Finally, the prophylactic therapy with Trimethoprim/Sulfamethoxazole versus the placebo showed a protective factor of 83% during the first year and 87% in the second year after treatment.

CONCLUSION

Our Systematic Review showed that clinical factors such as being older than 40 years, patients with de novo OT lesions or with less than one year after the first episode, macular area involvement, lesions greater than 1 disc diameter, congenital toxoplasmosis, and bilateral compromise had more risk of recurrences. Also, environmental and parasite factors such as precipitations, geographical region where the infection is acquired, and more virulent strains confer greater risk of recurrences. Therefore, patients with the above mentioned clinical, environmental, and parasite factors could benefit from using prophylactic therapy.

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.

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.

Altered Offspring Immunity in Maternal Parasitic Infections

Maternal infection during pregnancy is known to alter the development and function of offspring's immune system, leading to inappropriate immune responses to common childhood infections and immunizations. Although this is an expanding field, maternal parasitic infections remain understudied. Millions of women of reproductive age are currently at risk for parasitic infection, whereas many pregnant, chronically infected women are excluded from mass drug administration due partially to a lack of resources, as well as fear of unknown adverse fetal developmental outcomes. In areas endemic for multiple parasitic infections, such as sub-Saharan Africa, there are increased rates of morbidity and mortality for various infections during early childhood in comparison with nonendemic areas. Despite evidence supporting similar immunomodulatory effects between various parasite species, there is no clear mechanistic understanding of how maternal infection reprograms offspring immunity. This brief review will compare the effects of selected maternal parasitic infections on offspring immunity.

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.

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.

Atypical Bilateral Multifocal Congenital Toxoplasmosis Retinochoroiditis: Case Report With Literature Review

Background

Toxoplasmosis gondii is ubiquitously present on earth and infection, including congenital infection, is common. Neurological, developmental, and ocular effects can be devastating in the congenital toxoplasmosis population. At present, there is no standard, nation-wide neonatal screening for this disease in the United States.

Case Presentation

A 17-month-old Caucasian female presented to our institution by way of referral for macular scarring. She was diagnosed with intrauterine growth retardation and born with low birth weight and microcephaly at an outside institution, but no systemic workup was conducted at that time. On ocular examination, she was found to have nystagmus and extensive multifocal chorioretinal pigmented scars involving the macula and peripheral retina in both eyes with fibrous vitreous strands extending between scars in the right eye. Toxoplasmosis immunoglobulin G was found to be highly positive. Magnetic resonance imaging of the brain showed supratentorial intracranial calcifications.

Conclusions

Our patient presented with severe chorioretinal lesions, microcephaly, and nystagmus with a positive immunoglobulin G toxoplasmosis titer. She did not receive any evaluation, including TORCH infectious panel workup, on being born with low birth weight and microcephaly. There are currently no national programs in place for toxoplasmosis to be included in routine neonatal screening, despite the grave sequelae of congenital infection or that studies in other countries have shown cost-effectiveness in early screening and treatment.

Estimates of Toxoplasmosis Incidence Based on Healthcare Claims Data, Germany, 2011-2016

Toxoplasmosis is a zoonotic infection contracted through Toxoplasma gondii–contaminated food, soil, or water. Seroprevalence in Germany is high, but estimates of disease incidence are scarce. We investigated incidences for various toxoplasmosis manifestations using anonymized healthcare claims data from Germany for 2011–2016. Patients with a toxoplasmosis diagnosis during the annual observational period were considered incident. The estimated incidence was adjusted to the general population age/sex distribution. We estimated an annual average of 8,047 toxoplasmosis patients in Germany. The average incidence of non–pregnancy-associated toxoplasmosis patients was 9.6/100,000 population. The incidence was highest in 2011, at 10.6 (95% CI 9.4–12.6)/100,000 population, and lowest in 2016, at 8.0 (95% CI 7.0–9.4)/100,000 population. The average incidence of toxoplasmosis during pregnancy was 40.3/100,000 pregnancies. We demonstrate a substantial toxoplasmosis disease burden in Germany. Public health and food safety authorities should implement toxoplasmosis-specific prevention programs.

Scoping Review of Toxoplasma Postinfectious Sequelae

Previous economic estimates of infection with Toxoplasma gondii and chronic sequelae following infection lack sufficient data to establish the true burden of disease and its chronic sequelae. This scoping review aims to fill this gap by updating existing literature regarding the development of postinfectious sequelae following T. gondii infection. Literature published between January 1, 2000, and November 6, 2018, in PubMed, EMBASE, and Scopus was searched for a wide range of postinfectious sequelae and economic estimate terms. This scoping review includes summaries from the 108 articles covering 5 main groupings of outcomes (categories are not exclusive) including vision disorders (n = 58), psychological and mental health disorders (n = 27), neurological disorders (n = 17), fetal death and infection (n = 15), and hearing loss (n = 6), as well as a description of other outcomes reported. While the majority of the included studies assessed the incidence of these outcomes postinfection, very few followed participants long-term. These prospective studies are needed to understand the true burden of postinfectious sequelae over the life course, particularly because congenital infection with Toxoplasma can lead to severe outcomes for newborns. This scoping review can be used as an important resource for other researchers wishing to conduct future systematic reviews and meta-analyses, as well as for policy makers interested in developing guidance for public and health care partners.

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.

Synthesis and In Vitro Anti-Toxoplasma gondii Activity of Novel Thiazolidin-4-one Derivatives

Recent findings on the biological activity of thiazolidin-4-ones and taking into account the lack of effective drugs used in the treatment of toxoplasmosis, their numerous side effects, as well as the problem of drug resistance of parasites prompted us to look for new agents. We designed and synthesized a series of new thiazolidin-4-one derivatives through a two-step reaction between 4-substituted thiosemicarbazides with hydroxybenzaldehydes followed by the treatment with ethyl bromoacetate; maleic anhydride and dimethyl acetylenedicarboxylate afforded target compounds. The thiazolidin-4-one derivatives were used to assess the inhibition of Toxoplasma gondii growth in vitro. All active thiazolidine-4-one derivatives (12 compounds) inhibited T. gondii proliferation in vitro much better than used references drugs both sulfadiazine as well as the synergistic effect of sulfadiazine + trimethoprim (weight ratio 5:1). Most active among them derivatives 94 and 95 showed inhibition of proliferation at about 392-fold better than sulfadiazine and 18-fold better than sulfadiazine with trimethoprim. All active compounds (82–88 and 91–95) against T. gondii represent values from 1.75 to 15.86 (CC₃₀/IC₅₀) lower than no cytotoxic value (CC₃₀).

Cytomegalovirus and Toxoplasma Gondii: Common Causes of Profound Sensori Neural Hearing Loss in Children with Cochlear Implant Surgery in a Highly Immune Population: Tehran; Iran

Background:

Iranian population is highly immune from T.Gondii and CMV infection.

Objective:

To determine the immunity to T.Gondii and CMV in children with the cochlear implant surgery accompanied with the profound Idiopathic type of SNHL

Methods and Materials:

We studied 45 cases with the cochlear implant surgery (Idiopathic profound SNHL) and 30 controls with the normal OAEs in a cross-sectional study in Rasoul Akram Hospital in Tehran (2010 -2012). Blood samples (2 ml) were centrifuged and were kept frozen at -20°C. Sera searched for the specific antibodies against CMV and T.Gondii. The enzyme-linked immunosorbent assay (ELISA; BioChem Immune System) was calculated qualitatively. (P value< 0.05)

Results:

Range of age in cases with profound SNHL (<95 dB) was 6 months- to-14 years; mean=3.4+3.16 y; Idiopathic type of SNHL children diagnosed in 45 cases were younger than cases with non-Idiopathic SNHL (mean age=20 months; PV=0.05). Positive T.Gondii - IgM was found in 8 /45 (17.7%) and also one of these cases (2.2%) had positive T.Gondii –IgG test. Positive CMV- IgM & IgG were determined in 23% and 51% of cases, respectively. Positive T.Gondii –IgG was observed in 60% (18/30) of controls but none of them had positive T.Gondii – IgM. Positive CMV- IgM & IgG in controls was 3.3% and 90%, respectively.

Conclusion:

CMV infection is one of the most common infections found in profound idiopathic SNHL children especially in younger cases (< 2 years) even in highly immune Iranian populations. Probably, T.Gondii infection has a relative role in younger cases with profound SNHL but a higher role in mild to moderate SNHL in our pediatric population. Most of the T.Gondii infected SNHL cases never require cochlear implant surgery.

In future, a cohort study for prenatal diagnosis of the intrauterine infection and the role of infection in producing SNHLwould be very helpful. It has been recommended to search the specific antibodies against these two common infections in all types of SNHL in pediatric groups which are treatable especially in younger cases (<2 year).

Maternal and Congenital Toxoplasmosis: Diagnosis and Treatment Recommendations of a French Multidisciplinary Working Group

Women infected with toxoplasmosis during pregnancy do not present symptoms in most cases, but the consequences of the congenital infection may be severe for the unborn child. Fetal damage can range from asymptomatic to severe neurological alterations to retinal lesions prone to potential flare up and relapses lifelong. Despite the possible severity of outcome, congenital toxoplasmosis (CT) is a neglected disease. There is no consensus regarding screening during pregnancy, prenatal/postnatal treatment or short or medium term follow-up. Since 1992, France has offered systematic serological testing to non-immune pregnant women, monthly until delivery. Any maternal infection is thus detected; moreover, diagnosis of congenital infection can be made at birth and follow-up can be provided. “Guidelines” drawn up by a multidisciplinary group are presented here, concerning treatment, before and after birth. The recommendations are based on the regular analysis of the literature and the results of the working group. The evaluation of the recommendations takes into account the robustness of the recommendation and the quality of the evidence.

Congenital toxoplasmosis: An overview of the neurological and ocular manifestations

Toxoplasma gondii is an obligate intracellular parasite which is known to infect one-third of the total world population chronically though it is asymptomatic in immunocompetent patients. However, in an immunocompromised patient or an infected fetus, it may cause devastating effects. The parasite may cross the placenta of an infected pregnant woman and probably infect the fetus congenitally. The severity of the infection depends on the gestational age at which the infection has occurred i.e., if it has occurred in the early phase, the rate of transmission is low but the severity is high if the fetus is infected and if it has occurred in the later phase then transmission rate is higher while the severity would be low. Congenital toxoplasmosis may result in non-specific consequences like abortion, intra-uterine growth restriction, jaundice, hepatosplenomegaly or even intra-uterine death. It may also result in neurological or ocular manifestations like intracranial calcifications, hydrocephalus or retinochoroiditis. The diagnosis may be done by serological screening of anti-Toxoplasma antibodies (IgM and IgG) while PCR of the amniotic fluid or the placenta is the confirmatory test. Acute or chronic infections may be differentiated by IgG avidity tests. The treatment regimens include spiramycin to prevent congenital transmission from an infected mother, pyrimethamine, sulfadoxine and folinic acid to treat the infected fetus, CSF shunting for the treatment of hydrocephalus and a combination of pyrimethamine, azithromycin, and corticosteroids for treating ocular toxoplasmosis.

High Frequency of Bone Marrow Depression During Congenital Toxoplasmosis Therapy in a Cohort of Children Identified by Neonatal Screening in Minas Gerais, Brazil

BACKGROUND

There are few studies reporting frequency and control of adverse events associated with congenital toxoplasmosis treatment. The objective of this study is to describe treatment adherence and adverse hematologic events in a cohort of children identified with congenital toxoplasmosis in Minas Gerais, Brazil.

METHODS

Children were treated with sulfadiazine, pyrimethamine and folinic acid and were evaluated clinically and by laboratory tests at regular intervals.

RESULTS

Of 146,307 live newborns who participated in the Neonatal Screening Program in Minas Gerais in 2006-2007, 190 had congenital toxoplasmosis. Among the 171 children whose treatment data were available, 73.1% completely adhered to antiparasitic therapy. Hematologic adverse events (macrocytic anemia and/or neutropenia and/or thrombocytopenia) were diagnosed in 44% of them. The most common adverse event was neutropenia (31%). In most cases, it was not severe and reversed after increase in folinic acid dosage (25.7%) or temporary treatment suspension (1.8%). No infections were observed in association with neutropenic events. Significant associations were detected between macrocytic anemia and lower weight Z score at first medical appointment (P = 0.03), and between severe neutropenia (<500/mm) and lower weight Z score toward the end of treatment (P = 0.04).

CONCLUSIONS

The high frequency of hematologic adverse events found, especially in malnourished children, highlight the importance of careful monitoring of these children throughout treatment, as well as considering nutritional aspects and the need for higher doses of folinic acid. With adequate monitoring, antiparasitic treatment was feasible and relatively safe in the setting of this large screening program for congenital toxoplasmosis.

Congenital toxoplasmosis in Austria: Prenatal screening for prevention is cost-saving

BACKGROUND

Primary infection of Toxoplasma gondii during pregnancy can be transmitted to the unborn child and may have serious consequences, including retinochoroiditis, hydrocephaly, cerebral calcifications, encephalitis, splenomegaly, hearing loss, blindness, and death. Austria, a country with moderate seroprevalence, instituted mandatory prenatal screening for toxoplasma infection to minimize the effects of congenital transmission. This work compares the societal costs of congenital toxoplasmosis under the Austrian national prenatal screening program with the societal costs that would have occurred in a No-Screening scenario.

METHODOLOGY/PRINCIPAL FINDINGS

We retrospectively investigated data from the Austrian Toxoplasmosis Register for birth cohorts from 1992 to 2008, including pediatric long-term follow-up until May 2013. We constructed a decision-analytic model to compare lifetime societal costs of prenatal screening with lifetime societal costs estimated in a No-Screening scenario. We included costs of treatment, lifetime care, accommodation of injuries, loss of life, and lost earnings that would have occurred in a No-Screening scenario and compared them with the actual costs of screening, treatment, lifetime care, accommodation, loss of life, and lost earnings. We replicated that analysis excluding loss of life and lost earnings to estimate the budgetary impact alone. Our model calculated total lifetime costs of €103 per birth under prenatal screening as carried out in Austria, saving €323 per birth compared with No-Screening. Without screening and treatment, lifetime societal costs for all affected children would have been €35 million per year; the implementation costs of the Austrian program are less than €2 million per year. Calculating only the budgetary impact, the national program was still cost-saving by more than €15 million per year and saved €258 million in 17 years.

CONCLUSIONS/SIGNIFICANCE

Cost savings under a national program of prenatal screening for toxoplasma infection and treatment are outstanding. Our results are of relevance for health care providers by supplying economic data based on a unique national dataset including long-term follow-up of affected infants.

The Impact of Short-Term, Intensive Antifolate Treatment (with Pyrimethamine and Sulfadoxine) and Antibiotics Followed by Long-Term, Secondary Antifolate Prophylaxis on the Rate of Toxoplasmic Retinochoroiditis Recurrence

PURPOSE

To assess the impact of intensive antifolate treatment, followed by secondary antifolate prophylaxis (A-SP) on the recurrence rate of toxoplasmic retinochoroiditis (TRC). To investigate whether there are any other factors potentially predisposing for recurrence.

MATERIAL AND METHODS

A total of 637 medical records of TRC patients, who had been treated in the years 1994-2013 were reviewed. All patients were treated with pyrimethamine /sulfadoxine one 25mg/500mg tablet daily (P/S 25/500mg) for 21 days with a double loading dose for the first two days. From Day 2 the patients also received prednisone at a starting dose of 40mg and spiramycine 3 million IU three times daily, given for 10 days followed by azithromycin 500mg once daily for another 6 days. The analysis of the recurrence rate involved 352 patients who had completed 6-month secondary prophylaxis (P/S one 25 mg/500mg tablet twice a week).

RESULTS

When secondary antifolate prophylaxis (A-SP) was instituted immediately after the treatment for TRC, the probability of 3-year recurrence-free survival after the first course of A-SP was 90.9%. A recurrence was most likely approximately 3.5 years after the first treatment. A univariate Cox regression model demonstrated that a risk for recurrence was 2.82 times higher (p = 0.02) in patients with retinal scars. In the multivariate analysis, the risk for recurrence was 2.41 higher (p = 0.06). In patients with haemorrhagic lesions the risk for recurrence was lower, aRR = 0.17 (approaching borderline statistical significance p = 0.08).

CONCLUSIONS

With the institution of A-SP of immediately after the intensive treatment for TRC, i.e. when a reactivation was most likely, there was no recurrence during A-SP. Following A-SP the recurrence rates were low and recurrence-free periods tended to be longer. The treatment regimen employed had a beneficial effect on the recurrence interval as it reduced and delayed the highest probability of recurrence.

An alternative nested-PCR assay for the detection of Toxoplasma gondii strains based on GRA7 gene sequences

Toxoplasma gondii is a widespread parasite able to infect virtually any nucleated cells of warm-blooded hosts. In some cases, T. gondii detection using already developed PCR primers can be inefficient in routine laboratory tests, especially to detect atypical strains. Here we report a new nested-PCR protocol able to detect virtually all T. gondii isolates. Analyzing 685 sequences available in GenBank, we determine that GRA7 is one of the most conserved genes of T. gondii genome. Based on an alignment of 85 GRA7 sequences new primer sets that anneal in the highly conserved regions of this gene were designed. The new GRA7 nested-PCR assay providing sensitivity and specificity equal to or greater than the gold standard PCR assays for T. gondii detection, that amplify the B1 sequence or the repetitive 529bp element.

Treatment of Congenital Toxoplasmosis: Safety of the Sulfadoxine-Pyrimethamine Combination in Children Based on a Method of Causality Assessment

BACKGROUND

The treatment of newborns and infants with congenital toxoplasmosis is standard practice. Some observational studies have examined safety in newborns, but most of these failed to provide sufficient details for a provisional assessment of causality. The aim of this study was to evaluate the clinical and biological adverse effects of the combination of sulfadoxine-pyrimethamine.

METHODS

Sixty-five children treated for 1 year with a combination of sulfadoxine-pyrimethamine (1 dose every 10 days) for congenital toxoplasmosis were followed up to evaluate abnormal hematological values and potential adverse events using a standardized method of causality assessment.

RESULTS

Nine patients (13.8%) presented at least 1 adverse clinical event that was nonspecific, such as diarrhea on the day of drug administration, vomiting and agitation. In 1 patient, erythema appeared at the end of the treatment and resolved within 10 days. None of these events was attributed to the treatment. Six patients (9.2%) developed an adverse hematological event (neutropenia, n = 3; eosinophilia, n = 2 and both anemia and eosinophilia, n = 1) that was considered to be possibly related to the sulfadoxine-pyrimethamine combination. Four treatments were temporarily interrupted, and toxicity was observed after readministration of treatment in 1 case only. However, none of these adverse events was life threatening.

CONCLUSIONS

According to our results and previously published data, the combination of sulfadoxine-pyrimethamine seems to be well tolerated. However, the sample size of our study was too small to rule out the risk of less frequent, but nevertheless severe, reactions and, in particular, of hypersensitivity reactions.

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.

The Austrian Toxoplasmosis Register, 1992-2008

BACKGROUND

We aimed to determine the incidence of primary gestational infections with Toxoplasma gondii and congenital toxoplasmosis in Austria, a country with a nationwide prenatal serological screening program since 1974.

METHODS

We analyzed retrospective data from the Austrian Toxoplasmosis Register of pregnant women with Toxoplasma infection and their offspring with births between 1992 and 2008, identified by the prenatal mandatory screening program. Treatment was administered to women from diagnosis of a Toxoplasma infection until delivery. Infected infants were treated up to 1 year of life routinely. Clinical manifestations in infected infants were monitored at least for 1 year and documented in the register.

RESULTS

The Austrian Toxoplasmosis Register included 2147 pregnant women with suspected Toxoplasma infection. Annually, 8.5 per 10 000 women acquired Toxoplasma infection during pregnancy, and 1.0 per 10 000 infants had congenital toxoplasmosis (13% mean transmission rate). Our data showed that women treated according to the Austrian scheme had a 6-fold decrease in the maternofetal transmission rate compared to women without treatment.

CONCLUSIONS

Results from the Austrian Toxoplasmosis Register show the efficiency of the prenatal screening program. Our results are of clinical relevance for infants, healthcare systems, and policy makers to consider preventive Toxoplasma screening as a potential tool to reduce the incidence of congenital toxoplasmosis.

1,4-Disubstituted thiosemicarbazide derivatives are potent inhibitors of Toxoplasma gondii proliferation

A series of 4-arylthiosemicarbazides substituted at the N1 position with a 5-membered heteroaryl ring was synthesized and evaluated in vitro for T. gondii inhibition proliferation and host cell cytotoxicity. At non-toxic concentrations for the host cells all studied compounds displayed excellent anti-parasitic effects when compared to sulfadiazine, indicating a high selectivity of their anti-T. gondii activity. The differences in bioactivity investigated by DFT calculations suggest that the inhibitory activity of 4-aryl-thiosemicarbazides towards T. gondii proliferation is connected with the electronic structure of the molecule. Further, these compounds were tested as potential antibacterial agents. No growth-inhibiting effect on any of the test microorganisms was observed for all the compounds, even at high concentrations.

[Role of systematic ophthalmological screening for congenital toxoplasmosis: epidemiological study of an Alsatian cohort from 1990 to 2011]

INTRODUCTION

Ophthalmologic complications of congenital toxoplasmosis, such as retino-choroiditis, are particularly feared. Any child with confirmed congenital toxoplasmosis is systematically treated and followed regularly with multiple fundus examinations. The goal of our study is to describe the management and monitoring of a cohort of patients with congenital toxoplasmosis in Alsace, and the impact of this disease in terms of parental anxiety using a standardized questionnaire.

MATERIALS AND METHODS

Our study recorded 35 children with congenital toxoplasmosis, born between 1990 and 2011 in Alsace. All patients were followed by an ophthalmologist. A standardized questionnaire concerning the experience of pregnancy and post-natal follow-up was administered to the parents.

RESULTS

At birth, retinochoroiditis was detected in 2 of the 35 children, and only one child developed chorioretinitis detected during follow-up monitoring (follow-up ranged from 1 to 22 years). Brain abnormalities were noted in 3 children at birth; none of them have presented with chorioretinitis to this day. An average score of 15 out of 23 was found by our standardized questionnaire, reflecting significant anxiety due to congenital toxoplasmosis.

DISCUSSION

Parental anxiety due to congenital toxoplasmosis is obvious, as demonstrated by our standardized questionnaire. Follow-up, directed by comprehensive pediatric examination at birth, including fundus examination, and good information on functional signs of ocular toxoplasmosis may improve screening, so as to avoid impact on visual function.

Case report of a neonate with ocular toxoplasmosis due to congenital infection: estimation of the percentage of ocular toxoplasmosis in Greece caused by congenital or acquired infection

We report a case of a newborn male child with congenital toxoplasmosis. During pregnancy seroconversion occurred and positive titers of antitoxoplasmic antibodies (immunoglobulin M and G) were found in the mother, in the third trimester. She received treatment with spiramycin. After birth, the neonate presented with chorioretinitis and intracranial calcifications. The neonate received treatment with pyrimethamine, sulfadiazine, and leucovorin for 1 year. In addition to using a previously described method, we report for the first time in Greece an estimation regarding the percentage of ocular toxoplasmosis caused by congenital or acquired infection. We estimate that ocular toxoplasmosis in Greece is caused in 7% of the cases by congenital infection, and in 93% of the cases by acquired infection.

It is not only the cat that did it: how to prevent and treat congenital toxoplasmosis

The apicomplexan parasite Toxoplasma gondii was discovered a little over one hundred years ago and was soon recognized as a pathogen responsible for congenital infection. But detailed understanding of its epidemiology emerged only after 1970 with the discovery of its life cycle. In the last ten years, high resolution molecular tools have allowed the characterization of various strain types with different virulence patterns, and current studies are exploring the distribution of these different genotypes. In parallel, sophisticated diagnostic tools have been developed and awareness of disease burden has led some European countries with high prevalence rates to implement screening of pregnant women. In this article, the screening options and therapies used to prevent congenital toxoplasmosis are dissected in the light of recent data from cohort studies and other epidemiological data.

[Congenital toxoplasmosis: long-term ophthalmologic follow-up praised by patients]

INTRODUCTION

Ocular lesions of congenital toxoplasmosis may occur and relapse unpredictably even a long time after birth. There is no consensus concerning the necessity or timing of ophthalmologic follow-up for these patients. We surveyed adults with congenital toxoplasmosis followed regularly since birth, in order to learn their perceptions of this follow-up. The goal of this study was to provide doctors with patient-reported information on how they perceived the long-term monitoring of their disease.

METHODS

Enrolled patients were given a two-question questionnaire addressing the way they perceived the long-term follow-up and their attitudes toward continuing it. Eligible patients had to be 18 years or older and to have undergone ophthalmologic follow-ups, including funduscopy, every year since birth. The last ophthalmologic examination had to be within one year of the patient's inclusion in the study.

RESULTS

Of the 102 patients finally included in the study, 98% stated that the follow-up was useful and 92% reassuring. Among the 11% of patients who found the follow-ups frightening, the proportion of patients with low visual acuity and low score on the visual function test was significantly higher than among the others. All patients except two wished to continue with regular follow-up.

CONCLUSION

Without general agreement or guidelines on how patients with congenital toxoplasmosis should be monitored, the patient's wishes are important in making a decision. Our study brought out a clear fact; the majority of patients found long-term follow-up useful and reassuring and wished to continue.

Congenital toxoplasmosis

Congenital toxoplasmosis results from the transplacental transmission of the parasite Toxoplasma gondii after a maternal infection acquired in pregnancy. Prevalence of congenital infection ranges from 0.1 to 0.3 per 1000 live births. The maternal-fetal transmission rate increases with gestational age at maternal seroconversion, from less than 15% at 13 weeks of gestation to over 70% at 36 weeks. Conversely, the later the maternal infection, the lower the risk of symptomatic congenital infection (infections acquired during the third trimester are most often asymptomatic at birth). Prenatal diagnosis is currently performed by PCR analysis in amniotic fluid. Antenatal management and treatment vary considerably among countries. In some European countries, maternal infections are detected through serological screening allowing a prompt treatment with spiramycin, which is expected to reduce the risk of vertical transmission. If PCR analysis in amniotic fluid is positive or if maternal infection was acquired in the third trimester of pregnancy, a combination with pyrimethamine and sulphonamide is given until delivery. Benefits of antenatal treatments remain controversial. Infected newborns are prescribed pyrimethamine and sulphonamide for 12 months. Despite antenatal and postnatal treatment, chorioretinitis can occur at any age (prevalence>20% at 10 years of age): long-term ophthalmological follow-up remains necessary.

Comparative assessment of a commercial kit and two laboratory-developed PCR assays for molecular diagnosis of congenital toxoplasmosis

Toxoplasmosis is a worldwide infection that may cause severe disease and is regarded as a serious health problem in France. Detection of the parasite by molecular methods is crucial for diagnosing the disease. The extreme diversity of methods and performances of Toxoplasma PCR assays makes the use of commercial PCR kits an attractive alternative, as they offer a chance for standardization. We compared the performances of three molecular methods for the detection of Toxoplasma gondii DNA in amniotic fluid: a commercial method using nested PCR and two laboratory-developed methods, one using conventional PCR and the other one real-time PCR. This evaluation was based upon a T. gondii DNA serial dilution assay, three amniotic fluid samples spiked with T. gondii at different concentrations, and a clinical cohort of 33 amniotic fluid samples. The T. gondii DNA serial dilution assay showed a much lower sensitivity for the commercial kit than for the laboratory-developed methods. Moreover, out of 12 proven congenital toxoplasmosis cases, 91.7% were detected by the laboratory-developed assays, whereas only 50% were detected by the commercial kit. A lack of sensitivity of the method, partly due to the presence of PCR inhibitors, was the main drawback of the commercial method. This study emphasizes that commercial PCR diagnostic kits do not systematically perform better than carefully optimized laboratory-developed methods. There is a need for thorough evaluation of such kits by proficient groups, as well as for performance standards that commercial kits can be tested against to improve confidence in those selected by health care providers.

Profile of pregnant women and children treated at a reference center for congenital toxoplasmosis in the northern state of Minas Gerais, Brazil

INTRODUCTION

To describe the clinical and epidemiological profile of pregnant women and children treated at a reference outpatient clinic for congenital toxoplasmosis.

METHODS

Pregnant women potentially exposed to Toxoplasma gondii were observed. Diagnoses were made using serologic tests compatible with acute toxoplasmosis. Children presenting with: Toxoplasma-specific antibodies (IgM or IgA or ascending IgG titers higher than maternal titers in the first 3 months of life) coupled with toxoplasmosis symptoms; intracranial calcifications (by transfontanelar ultrasound or cephalic segment tomography); or retinochoroiditis (by fundoscopy examination) in the first 8 months of life were also included in the study.

RESULTS

Fifty-eight mother-child pairs were observed (mean age of the mothers was 22.1 years). Most patients lived in urban areas (86.2%) and had attended less than 8 years of school (51.7%). Diagnosis was made after birth in 19 (32.8%) children. Thirty-four (58.6%) women received some type of treatment during pregnancy. Most (72.4%) of the children did not present with clinical alterations at birth. The main findings were ophthalmological: 20 (34.5%) children with retinochoroiditis, 17 (29.3%) with strabismus, and 7 (12.1%) with nystagmus. Of the children with retinochoroiditis, 9 presented with subnormal vision. Ten (32.3%) out of 31 children presented with intracranial calcifications by cephalic segment congenital toxoplasmosis, and 9 (42.9%) children presented with delayed psychomotor development.

CONCLUSIONS

Our results highlight a critical situation. Protocols for follow-up of pregnant women and their children must be created to improve medical care and minimize sequelae.

Ocular toxoplasmosis: clinical characteristics in pediatric patients

PURPOSE

To describe the clinical features of Ocular Toxoplasmosis in pediatric patients.

METHODS

A retrospective, non-comparative series of cases was studied. We reviewed the clinical records of patients 16 year old or younger diagnosed with Ocular Toxoplasmosis.

RESULTS

Forty patients (56 eyes) were included. The mean age was 9.5 yrs old. Twenty were female. Unilateral involvement was noticed in 60% of patients. The most common symptoms were strabismus (32.1%) and reduced VA in (23.2%). An inactive retinal scar was observed in most cases (71.4%). Panuveitis was found in 8 eyes (14.2%), and posterior uveitis in 7 eyes of 7 patients (12.5%); one eye presented neuroretinitis. The most frequent location of retinochoroidal lesions was the posterior pole (72.7%).

CONCLUSIONS

In children, ocular toxoplasmosis is most commonly diagnosed during the inactive stage. When inflammation is present, it can be severe and frequently associated with other complications such vasculitis and papillitis.

Prevalence and genotypes of Toxoplasma gondii in pork from retail meat stores in Eastern China

Pork is known as one of the most important sources of Toxoplasma gondii infection in China. In the present study, 416 fresh pork samples were collected from different locations of Anhui province, Eastern China. Tissue fluid ELISA was conducted to detect the antibodies to T. gondii. Real-time PCR and bioassay were performed to identify the presence of T. gondii DNA and viable parasites, respectively. Seventy-five out of 416 samples (18.03%) demonstrated real-time PCR positive reaction and 42 out of 416 samples (10.1%) showed tissue fluid ELISA positive reaction. One isolate (Tgpkfx171) was obtained through bioassay in mice from 14 samples that demonstrated both PCR and ELISA positive reaction. The isolate and seven positive DNA samples were genotyped using 9 PCR-RFLP markers including SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico. Among these, only the isolate and two positive DNA samples were genotyped with complete data for all loci, belonging to ToxoDB#9 (Chinese 1) and ToxoDB#213, respectively. This is the first report of the prevalence and genetic typing of T. gondii from pork in retail meat stores in China. The present results provide an accurate picture of the risk of exposure to T. gondii in retail pork in China.

Seasonal variations in acute toxoplasmosis in pregnant women in the Rhône-Alpes region (France)

To search for seasonal variations we analysed data on 1998 acute toxoplasmic infections diagnosed between 1988 and 2009 in pregnant women. Two distinctive transmission profiles were observed: one in rural areas, which was strongly influenced by seasons with significantly fewer infections in the first half of the year but maximal risks at the end of summer and end of autumn, and a stable urban distribution with only moderate peaks. Further studies on individual risks and environmental and climatic factors are needed to understand what prevention message should be given to susceptible pregnant women.

Epidemiology of and diagnostic strategies for toxoplasmosis

The apicomplexan parasite Toxoplasma gondii was discovered a little over 100 years ago, but knowledge of its biological life cycle and its medical importance has grown in the last 40 years. This obligate intracellular parasite was identified early as a pathogen responsible for congenital infection, but its clinical expression and the importance of reactivations of infections in immunocompromised patients were recognized later, in the era of organ transplantation and HIV infection. Recent knowledge of host cell-parasite interactions and of parasite virulence has brought new insights into the comprehension of the pathophysiology of infection. In this review, we focus on epidemiological and diagnostic aspects, putting them in perspective with current knowledge of parasite genotypes. In particular, we provide critical information on diagnostic methods according to the patient's background and discuss the implementation of screening tools for congenital toxoplasmosis according to health policies.

Therapy for ocular toxoplasmosis

PURPOSE

To review current evidence for the treatment of ocular toxoplasmosis (OT).

DESIGN

Narrative review and expert recommendations.

METHODS

Meta-analysis and selected original articles from the medical literature were reviewed critically. Expert recommendations were analyzed.

RESULTS

Numerous observational studies suggest a benefit of short-term antimicrobial therapy for toxoplasmic retinochoroiditis in immunocompetent patients, although its efficacy has not been proven in randomized clinical trials. A randomized clinical trial revealed that intermittent trimethoprim/sulfamethoxazole treatment could decrease the rate of recurrence in high-risk patients. Intravitreal injection of clindamycin and dexamethasone was an acceptable alternative to the classic treatment for OT in a randomized clinical trial.

CONCLUSIONS

Opinions about therapy differ and controversy remains about its type, efficacy, and length. Intravitreal therapy may be promising for OT. A recent description of the presence of parasitemia in patients with active and inactive ocular toxoplasmosis raises new questions that need to be explored.

Congenital parasitic infections: a review

This review defines the concepts of maternal-fetal (congenital) and vertical transmissions (mother-to-child) of pathogens and specifies the human parasites susceptible to be congenitally transferred. It highlights the epidemiological features of this transmission mode for the three main congenital parasitic infections due to Toxoplasma gondii, Trypanosoma cruzi and Plasmodium sp. Information on the possible maternal-fetal routes of transmission, the placental responses to infection and timing of parasite transmission are synthesized and compared. The factors susceptible to be involved in parasite transmission and development of congenital parasitic diseases, such as the parasite genotypes, the maternal co-infections and parasitic load, the immunological features of pregnant women and the capacity of some fetuses/neonates to overcome their immunological immaturity to mount an immune response against the transmitted parasites are also discussed and compared. Analysis of clinical data indicates that parasitic congenital infections are often asymptomatic, whereas symptomatic newborns generally display non-specific symptoms. The long-term consequences of congenital infections are also mentioned, such as the imprinting of neonatal immune system and the possible trans-generational transmission. The detection of infection in pregnant women is mainly based on standard serological or parasitological investigations. Amniocentesis and cordocentesis can be used for the detection of some fetal infections. The neonatal infection can be assessed using parasitological, molecular or immunological methods; the place of PCR in such neonatal diagnosis is discussed. When such laboratory diagnosis is not possible at birth or in the first weeks of life, standard serological investigations can also be performed 8-10 months after birth, to avoid detection of maternal transmitted antibodies. The specific aspects of treatment of T. gondii, T. cruzi and Plasmodium congenital infections are mentioned. The possibilities of primary and secondary prophylaxes, as well as the available WHO corresponding recommendations are also presented.

Severe congenital toxoplasmosis in the United States: clinical and serologic findings in untreated infants

BACKGROUND

Congenital toxoplasmosis can cause significant neurologic manifestations and other untoward sequelae.

METHODS

The Palo Alto Medical Foundation Toxoplasma Serology Laboratory database was searched for data on infants 0 to 180 days old, in whom congenital toxoplasmosis had been confirmed and who had been tested for Toxoplasma gondii-specific immunoglobulin G (IgG), IgM, and IgA antibodies, between 1991 and 2005. Their clinical findings were confirmed at the National Collaborative Chicago-based Congenital Toxoplasmosis Study center. We reviewed available clinical data and laboratory profiles of 164 infants with congenital toxoplasmosis whose mothers had not been treated for the parasite during gestation.

RESULTS

One or more severe clinical manifestations of congenital toxoplasmosis were reported in 84% of the infants and included eye disease (92.2%), brain calcifications (79.6%), and hydrocephalus (67.7%). In 61.6% of the infants, eye disease, brain calcifications, and hydrocephalus were present concurrently. T. gondii-specific IgM, IgA, and IgE antibodies were demonstrable in 86.6%, 77.4%, and 40.2% of the infants, respectively. Testing for IgM and IgA antibodies increased the sensitivity of making the diagnosis of congenital toxoplasmosis to 93% compared with testing for IgM or IgA individually. IgM and IgA antibodies were still present in 43.9% of infants diagnosed between 1 and 6 months of life.

CONCLUSIONS

Our study reveals that severe clinical signs of congenital toxoplasmosis including hydrocephalus, eye disease, or intracranial calcifications occurred in 85% infants whose sera were referred to our reference Toxoplasma Serology Laboratory during a period of 15 years. Laboratory tests, including serologic and polymerase chain reaction tests, were critical for diagnosis in the infants. Our results contrast remarkably with those of European investigators who rarely observe severe clinical signs in infants with congenital toxoplasmosis.