Toxoplasmosis Screening during Pregnancy in a Romanian Infectious Diseases Tertiary Center: Results of a 15 Years Follow-Up Program

Maternal infection with Toxoplasma gondii during pregnancy may have serious consequences for the fetus. In Romania, screening for toxoplasmosis is included in the first antenatal visit. A retrospective study was performed on all toxoplasmosis antenatal screening patients between May 2008 and February 2023. Twenty-seven thousand one hundred sixty-nine (27,169) pregnant women presented for prenatal screening once (22,858) or several times: during the same pregnancy (209) or during multiple pregnancies (4102). Thirty-one thousand six hundred fifty-eight (31,658) tests for IgM and IgG antibodies were performed. Nine thousand eighty-three (9083) tests (28.69%), corresponding to 7911 women (29.12%), were positive for IgG antibodies. The seroprevalence increased with patients' age, decreased in time intervals, and was more frequently associated with rural residence. At risk for acquiring the infection during the pregnancy were women with negative anti-Toxoplasma IgG antibodies (70.88%), but only 0.9% of them presented for rescreening during the same pregnancy. Acute Toxoplasma infection (ATI) was suspected in 44 patients (0.16%) due to IgG seroconversion and/or low or borderline IgG avidity. A questionnaire follow-up interview was performed, and no congenital toxoplasmosis was identified in children born from mothers with probable ATI. Our study demonstrates poor compliance with the screening program in the Romanian population.

Toxoplasma gondii Seroprevalence and Trends in Women Presenting for Toxoplasma Screening in South-West Romania

Toxoplasmosis, caused by the obligate intracellular protozoan parasite Toxoplasma gondii (T. gondii), is a globally prevalent zoonotic disease with potentially severe implications for immunocompromised individuals, pregnant women, and their fetuses/children. This study examined the prevalence of anti-T. gondii IgM and IgG antibodies in two groups of childbearing age women, including 653 participants in Group 1 (2013-2016) and 3221 participants in Group 2 (2019-2022). Our results revealed a decrease in the overall positivity rate of anti-T. gondii IgM antibodies from 2.32% to 1.06%, suggesting improved public health interventions over time. However, there were variations among different age groups and between rural and urban environments, with a significant decrease in urban areas across all age groups from Group 1 to Group 2. Regarding anti-T. gondii IgG antibodies, we did not observe a significant change in the seropositivity rate between the two groups. In the rural population with an age group over 35 years, we observed the highest positivity rate in Group 2. This study provided information on the risk factors and burden of toxoplasmosis in women of childbearing age with data that can be valuable to public health policies and the planning of healthcare measures for effective toxoplasmosis management.

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.

The cost-effectiveness of neonatal versus prenatal screening for congenital toxoplasmosis

Background

Congenital Toxoplasmosis (CT) can have severe consequences. France, Austria, and Slovenia have prenatal screening programs whereas some other countries are considering universal screening to reduce congenital transmission and severity of infection in children. The efficiency of such programs is debated increasingly as seroprevalence among pregnant women and incidence of congenital toxoplasmosis show a steady decrease. In addition, uncertainty remains regarding the effectiveness of pre- and postnatal treatments.

Method

To identify cost-effective strategies, prenatal and neonatal screenings were compared using a decision-analytic model based on French guidelines and current knowledge of long-term evolution of the disease in treated children. Epidemiological data were extracted from the scientific literature and clinical data from the French Lyon cohort. Strategies were compared at one year of age, when infection can be definitively evaluated, and at 15 years of age, after which validated outcome data become scarce. The analysis was performed from the French Health Insurance System perspective and included direct medical costs for pregnant women and their children.

Results

The 1-year Incremental Cost-Effectiveness Ratio showed that prenatal screening would require investing €14,826 to avoid one adverse event (liveborn with CT, fetal loss, neonatal death or pregnancy termination) compared to neonatal screening. Extra investment increased up to €21,472 when considering the 15-year endpoint.

Conclusions

Prenatal screening is cost-effective as compared to neonatal screening in moderate prevalence areas with predominant Type II strains. In addition, prenatal screening, by providing closer follow-up of women at risk increases the number of occasions for education avoiding toxoplasmosis.

Toxoplasma Screening Results of 84587 Pregnant Women in a Tertiary Referral Center in Turkey

Aim: To determine the seroprevalence of Toxoplasma in a tertiary referral center in Turkey and to discuss the benefits and drawbacks of routine antenatal screening. Materials and methods: A serologic test for Toxoplasma is free of charge for all pregnant women as part of routine antenatal care at their first prenatal visit. The study was conducted between 2008 and 2017. Results: The frequency of Toxoplasma IgG and IgM seropositivity was 22.3% and 0.64%, respectively. Low avidity was detected in 142 patients and 60 PCR tests were performed with no positive result. A total of 33 mothers with low IgG avidity and negative PCR received prophylactic treatment, and no congenital toxoplasmosis was documented in this study. Conclusion: Universal screening for Toxoplasma in pregnancy is a subject of debate. As the prevalence in Turkey is higher compared to other countries, more studies are needed to identify the necessity of routine screening.

Survey of obstetrician-gynecologists in the United States about toxoplasmosis: 2012 update

PURPOSE

Toxoplasmosis, caused by the parasite Toxoplasma gondii, can have serious impacts on fetal development in the setting of acute maternal primary infection. The American College of Obstetricians and Gynecologists (ACOG) sought to determine current knowledge, practices, opinions, and educational preferences regarding T. gondii infection in pregnancy among ACOG members practicing prenatal care.

METHODS

ACOG sent a survey to 1,056 members chosen by stratified random sampling from membership lists, including 370 participants and 686 non-participants in the Collaborative Ambulatory Research Network (CARN). Mailings were sent up to four times to nonresponders.

RESULTS

Survey minimum response rates were 40.3% (CARN) and 19.7% (non-CARN); response rates adjusted for imputed non-eligibility were 59.7% (CARN) and 22.6% (non-CARN). Among providers, 80.2% had diagnosed no acute maternal T. gondii infections in the past 5 years, 12.7% correctly identified the screening role of the Toxoplasma avidity test, 42.6% performed serologic T. gondii screening for at least some asymptomatic pregnant women, and 62.1% of those who so did used appropriate approaches. Providers in the northeastern United States were 2.02 times more likely to routinely screen than those in the west (p = 0.025) and female providers were 1.48 times more likely than male providers (p = 0.047). The potential educational interventions considered useful by the most practitioners were updated ACOG guidelines on screening (81.4%) and management (71.7%) for acute T. gondii infection in pregnancy.

CONCLUSIONS

ACOG members would benefit from educational efforts targeted at risk factor counseling and screening approaches.

Neglected parasitic infections in the United States: toxoplasmosis

Toxoplasma gondii is a leading cause of severe foodborne illness in the United States. Population-based studies have found T. gondii infection to be more prevalent in racial/ethnic minority and socioeconomically disadvantaged groups. Soil contaminated with cat feces, undercooked meat, and congenital transmission are the principal sources of infection. Toxoplasmosis-associated illnesses include congenital neurologic and ocular disease; acquired illness in immunocompetent persons, most notably ocular disease; and encephalitis or disseminated disease in immunosuppressed persons. The association of T. gondii infection with risk for mental illness is intriguing and requires further research. Reduction of T. gondii in meat, improvements in hygiene and food preparation practices, and reduction of environmental contamination can prevent toxoplasmosis, but more research is needed on how to implement these measures. In addition, screening and treatment may help prevent toxoplasmosis or reduce the severity of disease in some settings.

Age-associated prevalence ofToxoplasma gondiiin 8281 pregnant women in Poland between 2004 and 2012

This study aimed to describeToxoplasma gondiiprevalence in Polish pregnant women and the incidence rates of congenital infections in their neonates observed between 2004 and 2012. Serological tests forT. gondii-specific IgG and IgM antibodies were performed on serum samples of 8281 pregnant women treated at the Polish Mother's Memorial Hospital Research Institute in Lodz. The yearly seroconversion rate forT. gondiiIgG antibodies was estimated using a mathematical model to determine the dependency between age and prevalence. Mean prevalence of IgG antibodies between 2004 and 2012 in pregnant women was 40·6% [95% confidence interval (CI) 39·6–41·7] and increased with age with a yearly seroconversion rate of 0·8% (95% CI 0·6–1·0,P < 0·001). Assuming aT. gondiimaterno-fetal transmission rate of 30% gave an estimate of 1·80/1000 neonates as congenitally infected. The increased mean age (28·7vs26·7 years,P < 0·001) of pregnant women was probably the most important factor in abolishing the effect of falling prevalence rates.

"Blind periods" in screening for toxoplasmosis in pregnancy in Austria - a debate

Recent studies from Austria, France and Italy have shown that there is a poor adherence to the screening scheme for maternal Toxoplasma infections in pregnancy demonstrated by the fact that many recommended examinations are missed. This leads to undetected infections and limits our knowledge of incidence of the disease. We discuss the negative consequences of this situation on research on treatment effectiveness and the outcomes of congenital toxoplasmosis. The responsible public health institutions should assume responsibility for appropriate surveillance of the screening programme and take measures to improve screening adherence during pregnancy. Screening should start as early as possible in pregnancy and the latest test should be done at delivery. Screening schedule should allow distinguishing infections from the first, second and third trimester of pregnancy, as the risk of materno-foetal transmission and outcomes in case of foetal infections varies by time.

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.

Maternal serologic screening to prevent congenital toxoplasmosis: a decision-analytic economic model

OBJECTIVE

To determine a cost-minimizing option for congenital toxoplasmosis in the United States.

METHODOLOGY/PRINCIPAL FINDINGS

A decision-analytic and cost-minimization model was constructed to compare monthly maternal serological screening, prenatal treatment, and post-natal follow-up and treatment according to the current French (Paris) protocol, versus no systematic screening or perinatal treatment. Costs are based on published estimates of lifetime societal costs of developmental disabilities and current diagnostic and treatment costs. Probabilities are based on published results and clinical practice in the United States and France. One- and two-way sensitivity analyses are used to evaluate robustness of results. Universal monthly maternal screening for congenital toxoplasmosis with follow-up and treatment, following the French protocol, is found to be cost-saving, with savings of $620 per child screened. Results are robust to changes in test costs, value of statistical life, seroprevalence in women of childbearing age, fetal loss due to amniocentesis, and to bivariate analysis of test costs and incidence of primary T. gondii infection in pregnancy. Given the parameters in this model and a maternal screening test cost of $12, screening is cost-saving for rates of congenital infection above 1 per 10,000 live births. If universal testing generates economies of scale in diagnostic tools-lowering test costs to about $2 per test-universal screening is cost-saving at rates of congenital infection well below the lowest reported rates in the United States of 1 per 10,000 live births.

CONCLUSION/SIGNIFICANCE

Universal screening according to the French protocol is cost saving for the US population within broad parameters for costs and probabilities.