Survey of European programmes for the epidemiological surveillance of congenital toxoplasmosis

Results of the REIV-TOXO national survey on prenatal screening for toxoplasmosis in Spain

INTRODUCTION

Currently, the status of serological screening for toxoplasmosis in pregnant women in Spain is unknown, and there is no official recommendation. The objective of this study is to show the current practice of gestational screening for toxoplasmosis in hospitals belonging to the Spanish Network for Research on Congenital Toxoplasmosis (REIV-TOXO).

METHODS

An electronic survey was sent between April 2021 and September 2021 to investigators from 118 hospitals of REIV-TOXO, representing all Spanish regions. Nine items related to gestational screening for toxoplasmosis were collected. This information was compared with cases of congenital toxoplasmosis (CT) identified in REIV-TOXO to determine if these were diagnosed in the presence of gestational screening.

RESULTS

During the study period, serological screening was performed in 53.3% (63/118) hospitals, with variations between regions and even among hospitals within the same region. Testing performed in each trimester was the most common practice (57.7%), followed by a single determination (24.4%). 89.4% of CT cases between January 2015 and September 2021 were diagnosed due to gestational screening.

CONCLUSION

The decision to perform gestational screening for toxoplasmosis in Spain is highly heterogeneous, with significant local and regional differences. Despite this, screening still allows the diagnosis of most CT cases. It is urgent to have current epidemiological data to inform decision-making in public health.

Maternal and congenital toxoplasmosis in Mayotte: Prevalence, incidence and management

BACKGROUND

Toxoplasmosis is an infection caused by an intracellular protozoan, Toxoplasma gondii. It is usually asymptomatic, but toxoplasmosis acquired during pregnancy can cause congenital toxoplasmosis, potentially resulting in fetal damage. Epidemiological information is lacking for toxoplasmosis in Mayotte (a French overseas territory). We evaluated (1) the prevalence of maternal toxoplasmosis, (2) the incidence of maternal and congenital toxoplasmosis, and (3) the management of congenital toxoplasmosis in Mayotte.

METHODOLOGY / PRINCIPAL FINDINGS

We collected all the available data for toxoplasmosis serological screening during pregnancy and maternal and congenital cases of toxoplasmosis obtained between January 2017 and August 2019 at the central public laboratory of Mayotte (Mamoudzou). Using toxoplasmosis serological data from samples collected from 16,952 pregnant women we estimated the prevalence of toxoplasmosis in Mayotte at 67.19%. Minimum maternal toxoplasmosis incidence was estimated at 0.29% (49/16,952, 95% CI (0.0022-0.0038)), based on confirmed cases of maternal primary infection only. The estimated incidence of congenital toxoplasmosis was 0.09% (16/16,952, 95% CI (0.0005-0.0015). Missing data made it difficult to evaluate management, but follow-up was better for mothers with confirmed primary infection and their infants.

CONCLUSIONS / SIGNIFICANCE

The seroprevalence of toxoplasmosis among pregnant women and the incidence of toxoplasmosis are higher in Mayotte than in mainland France. There is a need to improve the antenatal toxoplasmosis screening and prevention programme, providing better information to physicians and the population, to improve management and epidemiological monitoring.

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.

The Importance of Use of the On-line Databases as a Source for Systematic Review of Toxoplasmosis Screening During Pregnancy

BACKGROUND

Infection with the parasite Toxoplasma gondii is a common infection in animals and humans worldwide. This infection can occur after ingestion of water or food contaminated with cat oocytes, ingestion of tissue cysts in mammalian and avian meat and congenitally. The prenatal infection can lead to Congenital Toxoplasmosis with miscarriage or stillbirth. After infection, laboratory tests are positive within 2-3 weeks and remain positive throughout life. However, testing for Toxoplasma infection during pregnancy is necessary in some countries, while in others it is not a mandatory "screening" test.

OBJECTIVE

The aim of this study was to review systematically the screening of toxoplasmosis in pregnancy in different countries worldwide.

METHODS

Cohorts, retrospective and cross-sectional studies were incorporated in our review, finally including 11 articles from an initial pool of 1532 related papers.

RESULTS

The seroprevalence of pregnant women varies from countries with low prevalence to regions with high prevalence and screening policies also differ. Most countries worldwide have control policies, while Germany and Mexico that do not have systematic screening for Toxoplasma during the prenatal period.

CONCLUSION

Our results show that Congenital Toxoplasmosis is very rare in some countries and it is very difficult to find a balance between potential risk and benefit of a screening program. For this reason, some countries are limited to prenatal counseling to reduce CT. In addition, the reduction of major sources of contamination especially in developing countries is the most important prevention measure.

Seroprevalence of Toxoplasma gondii in Cats from Cyprus

Toxoplasma gondii is a cosmopolitan protozoon parasite, and the causative agent of toxoplasmosis, one of the most prevalent zoonotic parasitic diseases. Cats, as definitive hosts, spread the parasite via their faeces, but this occurs only for a very short period in their life. Seropositivity in cats, although not associated with current shedding of the parasite, is indicative of the infection in a cat population and can be used to assess the infection risk for definitive and intermediate hosts in that area. In order to assess the prevalence of infection in cats living in Cyprus, 155 cats, originating from all districts of the country, were examined for the presence of T. gondii antibodies. Additionally, parameters such as age, sex, health status, lifestyle and concomitant infections were statistically assessed as potential risk factors for T. gondii seropositivity. Specific anti-T. gondii antibodies were detected in 50 (32.3%) cats, while the presence of feline immunodeficiency virus antibodies and a history of never having been vaccinated were statistically associated with T. gondii seropositivity on multivariate logistic regression analysis. This is the first report of T. gondii seroprevalence in cats in Cyprus and indicates that raised public awareness should be considered to prevent infection of animals and humans.

National perinatal survey demonstrates a decreasing seroprevalence of Toxoplasma gondii infection among pregnant women in France, 1995 to 2016: impact for screening policy

Background

Toxoplasmosis during pregnancy can result in congenital anomalies or fetal death. Universal antenatal screening is recommended in France, a strategy in place since the 1970s.

Aim

We determined the seroprevalence of toxoplasmosis among pregnant women participating in the 2016 national perinatal survey (ENP), compared results with previous ENPs, and investigated factors associated with Toxoplasma gondii infection.

Methods

Using the 2016 ENP data, which contain sociodemographic and clinical information from all women giving birth during a one week period, we calculated adjusted prevalence ratios (aPR) by sociodemographic factors. Using available data from prior ENPs (1995, 2003 and 2010), we calculated age-standardised seroprevalences and aPRs for French women.

Results

In 2016, seroprevalence was 31.3% overall. Among French women, associations with increasing age (aPR: 1.54; 95% CI: 1.39–1.70), residence in Paris (aPR: 1.19; 95% CI: 1.08–1.31) or south-western regions (aPR: 1.19; 95% CI: 1.08–1.31), and higher professional status (aPR: 1.12; 95%CI 1.04–1.21) were observed. An association with increasing age was also evident among women from North Africa and sub-Saharan Africa. Age-standardised seroprevalence decreased from 55.0% in 1995 to 33.7% in 2016. Among French women, significant associations with age, Paris and south-west regions persisted across all ENPs.

Conclusion

Higher prevalences in older women may reflect a higher past risk of exposure while persistent geographical differences may reflect dietary or environmental differences. Toxoplasma seroprevalence among pregnant women continues to fall and will impact screening effectiveness. This warrants a comprehensive review to determine the appropriate future of prevention in France.

A contemporary insight into the sero-epidemiology of Toxoplasma gondii infection in the foot-hills of Himalayas: A cross-sectional study from a tertiary care center in Northern India

Background

Toxoplasma gondii infects 30-50% of the world's population with high diversity in the geo-epidemiology and seroprevalence. The burden of toxoplasmosis and its determinants from remote and vulnerable regions of India is unknown. Therefore, this study aim to evaluate the prevalence of toxoplasma antibodies and factors associated with seropositivity among individuals from Uttarakhand and adjoining areas.

Methods

Serum samples from 442 cases were tested for anti-Toxoplasma IgG and IgM antibodies by Enzyme-linked Immunosorbent Assay. Association of seropositivity of toxoplasmosis with age, gender, place of residence, dietary habits, and comorbidities were analyzed using binary logistic regression analysis.

Results

The overall Toxoplasma seropositivity was found to be 36.88% [95% Confidence Interval (CI)=30.40-39.28]. While anti-T. gondii IgG was present in 34.84% [95% CI=30.40-39.28], anti-IgM was detected in 6.33% [95% CI=4.06-8.61]. The overall and IgG seroprevalence increased with age in both the genders and there was a sharp increase in the seropositivity after the age of 40 years [adjusted Odds Ratio (aOR)=2.98, p-value=0.030]. The seropositivity rate was significantly higher in individuals from Uttarakhand in both the hilly region (aOR=5.61; 95%CI:[2.14-14.68]) and plains (aOR=5.14; 95%CI:[2.2-12.02]). Multivariable logistic regression analysis also showed that being rural residents (aOR=3.23; 95%CI:[1.67-6.23]) and presence of comorbidities (aOR=8.64; 95%CI:[4.62-16.18]) were potential risk factors of Toxoplasmosis. On the other hand, consumption of vegetarian diet was found to have a protective effect (aOR=0.46; 95%CI:[0.28-0.75]).

Conclusion

Seroprevalence of T. gondii antibodies was relatively high in Uttarakhand, particularly in rural and hilly terrain, indicating a necessity for the implementation of integrated public health strategies to prevent and control toxoplasmosis in this region.

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.

Toxoplasma gondii in women of childbearing age and during pregnancy: seroprevalence study in Central and Southern Italy from 2013 to 2017

Toxoplasmosis is a worldwide health problem. Infection in pregnant women can result in severe fetal morbidity or in subclinical neonatal infection; most subclinical cases develop ocular and neurological sequelae. The purpose of this serological study was to assess the prevalence of Toxoplasma gondii in two populations of women of childbearing age in Siena (Tuscany, Central Italy) and Bari (Apulia, Southern Italy) between 2013 and 2017 and in a group of pregnant women in Bari in 2016–2017. Serum samples were tested for the presence of specific anti-Toxoplasma gondii IgG antibodies by a commercially available ELISA test. The percentage of seropositive subjects in Bari was significantly higher than in Siena (22.4% vs. 12.4%) and an age-related trend was observed. A low prevalence of T. gondii infection (13.8%) was observed among the pregnant women tested. In addition to showing a significant difference between Central and Southern Italy, this study provides updated data on T. gondii seroprevalence in women during childbearing age and pregnancy. The results confirm a trend toward a decrease, especially in younger people and pregnant women.

The association of ToRCH infection and congenital malformations: A prospective study in China

OBJECTIVE

ToRCH infections (toxoplasmosis, rubella, cytomegalovirus and Herpes simplex virus) have long been known to be associated with bad obstetric outcomes. Little information is available about the impact of ToRCH infection on reproduction in china nearly for ten years. We designed a prospective study among 1863 pregnant women to investigate the association of ToRCH infection and congenital malformations.

STUDY DESIGN

All participants had set up a maternal health Handbook and were managed through the maternal and child health care system. They underwent regular pregnancy check-up, including physical measurements (weight, abdominal circumference and blood pressure), laboratory examinations (blood, urine) and ultrasound scan. ToRCH IgM antibodies were tested by chemiluminescence immunoassay.

RESULTS

102 participants were infected with ToRCH and the total infection rate was 6.06% (102/1683). CMV infection rate (3.15%, 53/1683) was the highest. The positive rate of ToRCH IgM antibodies increased significantly in participant with upper respiratory tract infection (14.6%, 32/219) or with adverse pregnancy history (4.8%, 70/1464). Among 85 ToRCH infected participants, adverse pregnancy outcome were observed in 57 cases which included abortions (31.8%, 27/85), premature births (8.2%, 7/85), congenital malformations (12.9%, 11/85), and stillbirths (9.4%, 8/85). Furthermore, congenital malformations was much higher than that in those without ToRCH infection (1.1%, 17/1598) (P＜0.001).

CONCLUSION

ToRCH infection was a significant risk factor of severe damage to the fetus, especially congenital malformations. ToRCH screening for pregnant women can reduce the incidence of adverse pregnancy and prevent birth defects in china.

Toxoplasmosis: Overview from a One Health perspective

Toxoplasmosis is paradigmatic of the One Health approach, as the causative parasite Toxoplasma gondii infects virtually all warm-blooded animals, including humans. This makes T. gondii one of the most successful parasites on earth, infecting up to a third of the global human population. Moreover, the T. gondii disease burden has been ranked among the highest of all parasitic diseases. To reduce the disease burden of toxoplasmosis in humans, interventions are needed in the animal reservoirs, necessitating close collaboration between both the human and veterinary medical sectors. In the present special issue of FAWPAR, several of the most pertinent topics related to the impact and control of toxoplasmosis are addressed by leading experts in the field. This collection of papers highlights state-of-the-art knowledge, gaps in knowledge and future perspectives, as well as the benefits of current and proposed future activities to tackle toxoplasmosis within the One Health context.

Toxoplasmosis in female high school students, pregnant women and ruminants in Cyprus

BACKGROUND

The protozoan parasite Toxoplasma gondii is important to human and animal health worldwide. This is the first study of prevalence of infection with T. gondii and associated risk factors in human populations and small ruminants in Cyprus.

METHODS

A random sample of 18 schools out of 46 participated: 1056 girls aged 16 to 18 years completed a questionnaire and were serologically tested for Toxoplasma between 2008 and 2011 (response rate 30%). In addition, infection with T. gondii laboratory results of 23 076 pregnant women tested between 2009 and 2014 were obtained from hospital records. Finally, 163 (out of 3123) farms were randomly sampled and blood samples from 515 sheep and 581 goats were obtained.

RESULTS

Estimated seropositivity prevalence in female students was 6.5% (95% CI 4.3 to 8.7%) and 18% (95% CI 17 to 19%) in pregnant women. Overall, 40.1% of the ruminants tested were seropositive (95% CI 37.2% to 43.0%). Seropositivity differed according to geographical region in all three groups.

CONCLUSIONS

Further studies are needed to investigate the differences between regions that lead to differing prevalence levels and patterns between ruminants and humans so that health education policies can be developed to help prevent infection and reduce environmental contamination.

Toxoplasma infection in individuals in central Italy: does a gender-linked risk exist?

An accurate estimate of the impact of toxoplasmosis on the population in Italy is not available. We performed a cross-sectional study on individuals living in Italy to assess: (1) differences in access to Toxo testing and in the prevalence of recent and past Toxoplasma gondii infection according to gender and age, and (2) the clinical impact of disease burden on the male patient subset. Reason for testing, condition of in- or outpatient and clinical data were analysed. Between-gender differences were observed in access to the test. Immunoglobulin M (IgM) prevalence was increased in males in the age range 5-34 years [odds ratio (OR) = 2.03, 95% confidence interval (CI) 1.18-3.49, p = 0.01), with a peak at 25-34 years. In females, it decreased in the age range 20-39 years (OR = 0.49, 95% CI 0.32-0.74, p = 0.0008). The attack rate of recent infection was twice as high for males than for females. Estimates pointed out 3.3 and 1.7 events in 1000 at-risk person-years in the male and female cohorts, respectively. Most IgM-positive subjects did not experience severe forms of toxoplasmosis, with 35% having lymphadenopathy. Chorioretinitis, systemic and neurological manifestations were also observed. Our findings suggest that the acute phase of toxoplasmosis is largely unapparent or clinically mild in this area. It is also possible that the disease burden for Toxoplasma infection in Italy is underestimated. Further study should focus on information acquisition and Toxo test access in hospital units for a better estimation of the real burden of mild and severe forms of the disease.

Prevalence, incidence estimations, and risk factors of Toxoplasma gondii infection in Germany: a representative, cross-sectional, serological study

Representative data on the extent of endemicity, burden, and risk of human toxoplasmosis are scarce. We assessed the prevalence and determinants of seropositivity of Toxoplasma gondii among adult participants of a nationwide representative cross-sectional survey in Germany. Sera collected from a representative cohort of adults (age 18-79; n = 6,663) in Germany were tested for anti-T. gondii IgG antibodies. Interview-derived data were used to evaluate associated factors. Multivariable logistic regression was applied using sampling weights and accounting for survey design cluster effects. Seroprevalence increased from 20% (95%-CI:17-23%) in the 18-29 age group to 77% (95%-CI:73-81%) in the 70-79 age group. Male gender, keeping cats and BMI ≥30 were independent risk factors for seropositivity, while being vegetarian and high socio-economic status were negatively associated. Based on these data, we estimate 1.1% of adults and 1.3% of women aged 18-49 to seroconvert each year. This implies 6,393 seroconversions annually during pregnancies. We conclude that T. gondii infection in Germany is highly prevalent and that eating habits (consuming raw meat) appear to be of high epidemiological relevance. High numbers of seroconversions during pregnancies pose substantial risks for unborn children. Efforts to raise awareness of toxoplasmosis in public health programs targeting to T. gondii transmission control are therefore strongly advocated.

Awareness of Cytomegalovirus Infection among Pregnant Women in Geneva, Switzerland: A Cross-sectional Study

BACKGROUND

Cytomegalovirus (CMV) is the most frequent cause of congenital infection and commonly associated with sensorineural deficit. At present, there is neither prophylaxis nor treatment during pregnancy. The objective of this study was to evaluate the level of awareness regarding CMV infection and its consequences in women delivering at the University of Geneva Hospitals (Geneva, Switzerland).

METHODS

The study consisted of a validated questionnaire completed by women in the immediate postpartum period.

RESULTS

The questionnaire was completed by 59% (314/528) of delivering women. Only 39% (123/314) knew about CMV and 19.7% (62/314) had received information about preventive measures. Women were more aware about other congenital diseases, such as toxoplasmosis (87%); human immunodeficiency virus (99%); syphilis (85.5%); rubella (92.3%); and group B Streptococcus (63%). Factors associated with CMV awareness were Swiss nationality, high education level, employment in health care or with children, and being followed by an obstetrician. Regarding quality of information, few were aware of the main CMV complications (deafness, 25.2%; mental retardation, 34.5%). Among those informed about CMV, most (74.6%) knew about preventive measures. Among these, 82.5% thought that these were easily applicable.

CONCLUSIONS

Most women were unaware of CMV infection and its potential risks during pregnancy. It is crucial to improve CMV information given to pregnant women to prevent the risks for the fetus/newborn.

Serological diagnosis of Toxoplasma gondii infection: Recommendations from the French National Reference Center for Toxoplasmosis

Toxoplasmosis manifests no clinical signs in 80% of cases in immunocompetent patient, causing immunization characterized by the persistence of cysts, particularly in brain, muscles, and retina. Assessing the serological status, based on testing for serum toxoplasma IgG and IgM antibodies, is essential in cases that are increasingly at risk for the more severe disease forms, such as congenital or ocular toxoplasmosis. This disease also exposes immunosuppressed patients to reactivation, which can lead to more widespread forms and increased mortality. By interpreting the serological results, we can estimate the risk of contamination or reactivation and define appropriate prophylactic and preventive measures, such as hygienic and dietetic, therapeutic, biological, and clinical follow-up, according to the clinical context. We hereby propose practical approaches based on serological data, resulting from a consensus of a group of experts from the French National Reference Center Network for Toxoplasmosis, according to both routine and specific clinical situations.

Toxoplasma gondii seropositivity and risk factors in pregnant women followed up by the Family Health Strategy

INTRODUCTION

Toxoplasmosis is a zoonotic infection caused by Toxoplasma gondii. It is transmitted by the ingestion of contaminated water and foods, by soil contaminated with cat feces, especially while handling it, and congenitally via the placenta. The diagnosis of maternal infection is made by serological detection of either IgM or IgG antibodies. This study assessed the seropositivity in pregnant women followed up by the Family Health Strategy (FHS) in Lages, Santa Catarina, Brazil.

METHODS

The study was performed in 19 FHS units and included 148 childbearing women. The outcomes evaluated were IgM and IgG seropositivity and behavioral variables.

RESULTS

IgG yielded positive results in 16% of the pregnant women, whereas IgM was positive in only 1%.

CONCLUSIONS

The 1% IgM positivity rate for T. gondii indicates congenital toxoplasmosis is not common in Lages.

Comparison of immunofluorescence and enzyme-linked immunosorbent assay and immunoglobulin G avidity techniques for screening of anti: Toxoplasma antibodies among single serum sample pregnant women in Tabriz, Iran

BACKGROUND

Congenital toxoplasmosis is that pregnant women acquire the infection during gestation; diagnosis of the acute infection during pregnancy is a complex subject of maternal toxoplasmosis. Thus, the presence of immunoglobulin G (IgG) and/or IgM Toxoplasma antibodies in a single serum sample drawn during gestation cannot be used to define whether the infection was recently acquired or chronic.

MATERIALS AND METHODS

At this cross-sectional descriptive study, sera of 391 pregnant women examined and compared. They were in an age range of 21-35 years, referred by gynecologists and infectious disease specialists, during March 2012-April 2013. They have referred, 215 (54.98%), 102 (26%), 74 (18.92%) in the first, second and third trimesters of gestation, respectively. For each of them, a questionnaire was completed and serum samples were prepared in an equal condition, examined according to the procedures of indirect immunofluorescence (IIF), enzyme-linked immunosorbent assay (ELISA) and IgG Avidity techniques.

RESULTS

We have found 111 (28.38%) seronegative and 280 (71.61%) seropositive cases by IIF and 124 (31.70%) seronegative, 267 (68.28%) seropositive cases by ELISA. The IgG avidity test confirmed 45 (69.23%) and 7 (10.76%) doubtful cases of IgM test in IIF and ELISA techniques.

CONCLUSIONS

This study highlights how to manage pregnant women with toxoplasmosis, especially in a single serum sample condition.

Diagnosis of congenital syphilis and toxoplasmosis

Syphilis, toxoplasmosis, and cytomegalovirus represent disparate entities. The bacterial spirochaete Treponema pallidum ssp. pallidum causes syphilis, the ‘The Great Imitator'; the organism's sole natural host is humans and it remains exquisitely sensitive to penicillin. By contrast, the zoonotic parasite Toxoplasma gondii causes toxoplasmosis. Infection is usually self-limited, although serious disease can occur in the immunocompromised. Meanwhile, the human cytomegalovirus (CMV; human herpesvirus 5) is a relatively prevalent enveloped DNA betaherpesvirus with infection specific to humans. Despite nomenclatural, ecological and therapeutic disparities, however, these agents exhibit several concordances, including various, and at times, cryptic syndromes in child and often mother; congenital infections with potentially devastating outcomes; diagnostic dilemmas. This article primarily discusses the latter of these issues in relationship to congenital syphilis and toxoplasmosis in the Australian context.

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.

How to use... neonatal TORCH testing

Toxoplasma gondii, rubella, cytomegalovirus and herpes simplex virus have in common that they can cause congenital (TORCH) infection, leading to fetal and neonatal morbidity and mortality. During the last decades, TORCH screening, which is generally considered to be single serum testing, has been increasingly used inappropriately and questions have been raised concerning the indications and cost-effectiveness of TORCH testing. The problems of TORCH screening lie in requesting the screening for the wrong indications, wrong interpretation of the single serum results and in case there is a good indication for diagnosis of congenital infection, sending in the wrong materials. This review provides an overview of the pathogenesis, epidemiology and clinical consequences of congenital TORCH infections and discusses the indications for, and interpretation of, TORCH screens.

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.

Toxoplasma gondii infection in Kyrgyzstan: seroprevalence, risk factor analysis, and estimate of congenital and AIDS-related toxoplasmosis

Background

HIV-prevalence, as well as incidence of zoonotic parasitic diseases like cystic echinococcosis, has increased in the Kyrgyz Republic due to fundamental socio-economic changes after the breakdown of the Soviet Union. The possible impact on morbidity and mortality caused by Toxoplasma gondii infection in congenital toxoplasmosis or as an opportunistic infection in the emerging AIDS pandemic has not been reported from Kyrgyzstan.

Methodology/Principal Findings

We screened 1,061 rural and 899 urban people to determine the seroprevalence of T. gondii infection in 2 representative but epidemiologically distinct populations in Kyrgyzstan. The rural population was from a typical agricultural district where sheep husbandry is a major occupation. The urban population was selected in collaboration with several diagnostic laboratories in Bishkek, the largest city in Kyrgyzstan. We designed a questionnaire that was used on all rural subjects so a risk-factor analysis could be undertaken. The samples from the urban population were anonymous and only data with regard to age and gender was available. Estimates of putative cases of congenital and AIDS-related toxoplasmosis in the whole country were made from the results of the serology. Specific antibodies (IgG) against Triton X-100 extracted antigens of T. gondii tachyzoites from in vitro cultures were determined by ELISA. Overall seroprevalence of infection with T. gondii in people living in rural vs. urban areas was 6.2% (95%CI: 4.8–7.8) (adjusted seroprevalence based on census figures 5.1%, 95% CI 3.9–6.5), and 19.0% (95%CI: 16.5–21.7) (adjusted 16.4%, 95% CI 14.1–19.3), respectively, without significant gender-specific differences. The seroprevalence increased with age. Independently low social status increased the risk of Toxoplasma seropositivity while increasing numbers of sheep owned decreased the risk of seropositivity. Water supply, consumption of unpasteurized milk products or undercooked meat, as well as cat ownership, had no significant influence on the risk for seropositivity.

Conclusions

We present a first seroprevalence analysis for human T. gondii infection in the Kyrgyz Republic. Based on these data we estimate that 173 (95% CI 136–216) Kyrgyz children will be born annually to mothers who seroconverted to toxoplasmosis during pregnancy. In addition, between 350 and 1,000 HIV-infected persons are currently estimated to be seropositive for toxoplasmosis. Taken together, this suggests a substantial impact of congenital and AIDS-related symptomatic toxoplasmosis on morbidity and mortality in Kyrgyzstan.

A serological study on toxoplasmosis was undertaken in a rural and urban population in Kyrgyzstan. The observed seroprevalence was adjusted because of differences between age and gender stratifications in the study group compared to population census figures. This gave an estimated seroprevalence in rural and urban populations of 5.1% and 16.4% respectively. In our analysis we determined the risk-factors for infection in the rural population to be age, low social-status and low number of sheep owned. While the seroprevalence in this rural population was relatively low, the seroprevalence found in the urban population of Bishkek correlated better with international data. Extrapolating from our data, about 173 seroconversions during pregnancy may be expected annually in Kyrgyzstan. In addition, considering a prevalence of HIV-Toxoplasma-co-infection between 7/100,000 (official HIV-prevalence data) and 19.4/100,000 (UNAIDS-estimates), 350–1,000 people are at risk for AIDS-related toxoplasmosis. Therefore, in the face of the rising prevalence of HIV infection education of medical personnel on treatment and prevention of toxoplasmosis is recommended.

Evaluation of serological prenatal screening to detect Toxoplasma gondii infections in Austria

BACKGROUND

In Austria, a nationally mandated prenatal serological congenital toxoplasmosis screening program was introduced in 1974 in response to a high incidence of 7.8 per 1,000 infected infants. Maternal prenatal recognition of acute gestational infection and early treatment of infants with congenital infection are important because prenatal and accurate postnatal antibiotic therapy improves the outcomes of infected infants.

OBJECTIVE

To determine the impact of additional maternal and/or fetal cord blood serology at birth on improving current prenatal maternal screening in detecting congenital toxoplasmosis.

METHODS

In this prospective observational study, 5,545 consecutive women were included over a 19-month period. Routine prenatal maternal toxoplasmosis serology screening was performed along with additional cord blood serology screening at delivery. Fetal cord blood serology included Sabin-Feldman dye and IgM immunosorbent agglutination assay testing.

RESULTS

Based on the initial prenatal maternal screening serology results, there was evidence of a prior chronic infection manifest in 1,830 (33.0%) women and 3,708 (66.9%) were not infected. Seven (0.13%) were diagnosed with acute toxoplasma infection based on seroconversion. Of these, 4 manifested transmission, and 3 did not. Of the seven infected women, routine prenatal maternal screening identified acute infection in only 2 of the women, 1 of whom had an infected fetus with abnormal prenatal ultrasound. Fetal cord blood serology screening identified an additional 5 women, 3 with infected fetuses.

CONCLUSIONS

Identification of Toxoplasma gondii infection by prenatal maternal serological testing is significantly improved by the addition of maternal and/or fetal serological testing at birth.

A 4-year evaluation of toxoplasmosis seroprevalence in the general population and in women of reproductive age in central Italy

This study aimed to estimate possible changes in seroprevalence of anti-Toxoplasma gondii IgG and IgM antibodies in people living in the area of Massa and Carrara (central Italy), in recent years. Serum samples from over 13 000 individuals were tested for both IgG and IgM anti- Toxoplasma antibodies using an immunoenzymatic method (Access® Toxo IgG, and Access® Toxo IgM II, Beckman Coulter Inc., USA). Our survey showed a decreasing trend of overall seroprevalence of 24.4% [95% confidence interval (CI) 22.62–25.71] in 2010 compared to 31.0% (95% CI 29.29–32.72) in 2007. A positive trend according to age was found, with low positivity observed in younger age groups. For women of reproductive age the prevalence of IgG antibodies was 30.2% (95% CI 28.44–31.96) in 2007 and 23.6% (95% CI 22.05–25.20) in 2010. IgM seroprevalence in women of this age group also progressively decreased from 1.6% to 0.97% during the study period. Our study confirms a decline of toxoplasmosis in Western countries.

A dedicated surveillance network for congenital toxoplasmosis in Greece, 2006-2009: assessment of the results

BACKGROUND

Toxoplasmosis is caused by infection with the protozoan parasite Toxoplasma gondii. Acute infections in pregnant women may be transmitted to the fetus and cause severe illness. The purpose of this study was to establish a dedicated surveillance network (DSN) for congenital toxoplasmosis (CT) in Greece, in order to assess the birth prevalence of CT.

METHODS

A DSN of thirty clinicians was established for reporting CT cases from hospitals throughout Greece. The clinicians were selected on the basis that there was a high possibility the suspected cases would be referred to them from district hospitals or private clinics. Suspected cases of CT were reported on a monthly basis with a zero reporting card during a surveillance period from April 2006 to December 2009. A questionnaire was sent for any suspected case to record information including demographic parameters, clinical signs and symptoms and laboratory results. Serological and molecular confirmation of cases was performed by the Pasteur Hellenic Institute. All newborns suspected of CT received treatment and were serologically and clinically followed up for one year.

RESULTS

The monthly response rate reached 100%, although only after reminders sent to 65% of the participant physicians. Sixty-three suspected CT cases were recorded by the DSN during the study period including fourteen confirmed and seven probable cases. Ten cases (47.6%) presented with symptoms at birth. Chorioretinitis was the most prominent manifestation, occurring in five symptomatic CT cases (50%). No other symptoms appeared by the end of the one year clinical follow up. No case was recorded by the existing surveillance system of the Hellenic Center of Disease Control and Prevention (HCDCP) during the same time period. Birth prevalence was estimated at 0.45, 0.51 and 0.51 per 10,000 births for 2007, 2008 and 2009 respectively. The incidence rate of symptomatic CT at birth was estimated at 0.10 cases per 10,000 births per year in Greece (for the period 2007-2009).

CONCLUSION

The DSN for CT proved to be more sensitive than the classical notification system, easy in application and very efficient in reporting rare diseases such as CT. Similar DSNs could be used to provide useful information on other rare diseases.

A review on human toxoplasmosis

Toxoplasmosis is a worldwide infection caused by the intracellular parasite Toxoplasma gondii. At least a third of the world human population are infected with the parasite, making it one of the most successful parasitic infections. Primary maternal infection may cause health-threatening sequelae for the foetus, or even cause death in uterus. Reactivation of a latent infection in immune deficiency conditions such as AIDS and organ transplantation can cause fatal toxoplasmic encephalitis. Toxoplasmosis is a major cause of retinochoroiditis, especially in individuals with an impaired immune system. Despite the usually 'asymptomatic' nature of the infection, a significant burden imposed by the parasite necessitates the implementation of effective means for the prevention, diagnosis, and management of this disease. Laboratory diagnosis, i.e. PCR and serologic assays, plays the main role in the diagnosis of congenital infection and assists in the confirmatory diagnosis of toxoplasmic encephalitis and ocular toxoplasmosis. Here, we briefly review general aspects of Toxoplasma infection and focus on the diagnostic methods currently used in medical laboratories for the diagnosis of Toxoplasma infection.

Comparison of mother and child antibodies that target high-molecular-mass Toxoplasma gondii antigens by immunoblotting improves neonatal diagnosis of congenital toxoplasmosis

This retrospective study proposes a new reading of immunoblotting (IB) in the diagnosis of congenital toxoplasmosis. Our findings demonstrate that a three-IgM-band association at 75, 90, and 100 kDa called the IgM triplet increases the sensitivity to 95.8% when combined with prenatal and serological neonatal tests.

"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.

Incidence of maternal Toxoplasma infections in pregnancy in Upper Austria, 2000-2007

Background

Despite three decades of prenatal screening program for toxoplasmosis in Austria, population-based estimates for the incidence of maternal infections with Toxoplasma gondii during pregnancy are lacking. We studied the incidence of primary maternal infections during pregnancy in the Federal State of Upper Austria.

Methods

Screening tests for 63,416 women and over 90,000 pregnancies (more than 84.5% of pregnancies in the studied region) in the time period between 01.01.2000 and 31.12.2007 were analysed. The incidence of toxoplasmosis was estimated indirectly by binomial and directly by interval censored regression.

Results

During the studied period, 66 acute infections (risk of 0.07% per pregnancy) were detected, but only 29.8% of seronegative women were tested at least three times during their pregnancies. The seroprevalence of Toxoplasma antibodies among all tested women was 31%. Indirectly estimated incidence (from differences in prevalence by age) was 0.5% per pregnancy, while directly estimated incidence (interval censored regression) was 0.17% per pregnancy (95% confidence interval: 0.13-0.21%).

Conclusions

Calculating incidence from observed infections results in severe underreporting due to many missed tests and potential diagnostic problems. Using statistical modelling, we estimated primary toxoplasmosis to occur in 0.17% (0.13-0.21%) of all pregnancies in Upper Austria.

Investigation and management of Toxoplasma gondii infection in pregnancy and infancy: a prospective study

AIM

Toxoplasma gondii infection during pregnancy poses a serious risk to the fetus, therefore timely and accurate diagnosis is essential. The aim of this study was to estimate the frequency of congenital infection via evaluating mother's immunological status and the possibility to improving the diagnostic and therapeutic approaches.

METHODS

Eighty five mothers with Toxoplasma seroconversion and their offspring were enrolled (among them, 2 spontaneous abortions were documented in the first trimester). Prenatal PCR diagnosis was carried out on 50 patients (60%), with 7 positive cases (14%). Morphological ultrasound scanning revealed anomalies in one fetus. Long-term follow-up included general physical examinations, serological status tested using Western blot, neuro-radiological, ophthalmologic and neurologic examinations, psychological and developmental tests, visual evoked potential tests and audiology tests, as well as anti-Toxoplasma treatment regimes.

RESULTS

Fourteen (17%) of the infants were infected at one-year serological follow-up. Chi-square for linear trend of vertical transmission from the first to the third trimester was significant (P=0.009). Western blot analysis showed IgM and IgA in half of the infected infants. In 69 uninfected infants, anti-Toxoplasma IgG immunoblot analysis excluded infection within the 3 months in 18 infants (26%) and in the others within 6 months of life. The most relevant instrumental findings are described.

CONCLUSION

Western blot analysis may help to evaluate infection within the 6 months of life. The accuracy of ultrasound imaging to determine the brain damage in the fetus and newborns is doubtful, and should be combined with MR imaging. Multistep approaches can improve the timing of postnatal follow-up.

Congenital toxoplasmosis--a report on the Danish neonatal screening programme 1999-2007

OBJECTIVES

This paper reports on the national neonatal screening programme for congenital toxoplasmosis (CT) in Denmark conducted from 1999 to 2007, including background, basis for initiation of screening, methods, results, and finally reasons for the discontinuation of the screening.

METHODS

A nationwide screening was conducted at Statens Serum Institut, including >98% newborns, and using filter paper eluates (Guthrie card, PKU card) obtained from newborns 5-10 days old. These were analysed for Toxoplasma gondii-specific antibodies (IgM), and if positive, then IgM (ISAGA). Confirmatory serology was performed on children and their mothers (IgM, IgG, IgA, dye test) where infection was suspected, and children with suspected or confirmed CT initiated a 3-month treatment regimen with pyrimethamine, sulfadiazine and folinic acid supplements. Selective cohorts were followed with regard to developmental and clinical outcome.

RESULTS

A total of 100 children were diagnosed with CT in the screening period, and only 2 cases were detected outside of the screening programme. CT prevalence was 1.6 per 10,000 live-born infants. Follow-up studies showed new retinochoroidal lesions in affected children despite treatment.

CONCLUSION

Screening was terminated August 2007, after it became apparent that no benefit of treatment could be shown. CT was evaluated using a Danish adaptation of the Uniform Screening Panel (ACMG), showing CT as an unlikely candidate for screening today. Whereas results might be comparable with other low-endemic countries with similar strains of T. gondii, neonatal screening and treatment might offer different results in regions with either high prevalence or different strains of T. gondii.

Decreased prevalence and age-specific risk factors for Toxoplasma gondii IgG antibodies in The Netherlands between 1995/1996 and 2006/2007

To estimate the change in the seroprevalence and risk factors for toxoplasmosis in The Netherlands, a study was conducted in the general population in 2006/2007, similarly designed as a previous study in 1995/1996. Testing 5541 sera for IgG antibodies against Toxoplasma gondii showed a marked decrease of the overall seroprevalence to 26·0% [95% confidence interval (CI) 24·0-28·0], compared to 40·5% (95% CI 37·5-43·4) in 1995/1996. In women of reproductive age the seroprevalence decreased from 35·2% (95% CI 32·9-38·6) in 1995/1996 to 18·5% (95% CI 16·2-20·7) in 2006/2007, leaving the majority of pregnant women susceptible to primary infection with T. gondii and their babies to congenital toxoplasmosis. In participants aged ≥20 years, Toxoplasma seropositivity was associated with living in the Northwest, living in urban areas, low educational level, consumption of raw pork, keeping a cat, and not having occupational contact with clients or patients. For younger participants, risk factors were keeping sheep or cattle, consumption of raw unwashed vegetables and putting sand in the mouth.

Seroprevalence of TORCH infections in women of childbearing age in Croatia

During 2005-2009, a seroepidemiological study was carried out in Croatia to define the population susceptible to common TORCH agents among pregnant and non-pregnant women of childbearing age. The IgG seroprevalence was 29.1% forT. gondii, 94.6% for rubella, 75.3% for cytomegalovirus (CMV), 78.7% for herpes simplex virus type 1 (HSV-1), and 6.8% for HSV-2. Acute toxoplasmosis and CMV infection (positive IgM antibodies with low IgG avidity) were documented in 0.25% and 0.09% women, respectively. IgM prevalence was 1.2% for both HSV-1 and HSV-2. None of the participants showed acute rubella infection. Seropositivity to T. gondii and HSV-2 varied significantly between age groups (p = 0.001 and p = 0.036, respectively). Women residing in rural regions showed a significantly higher seroprevalence rate for T. gondii, CMV, and HSV-1 than urban women (T. gondii: 44.0% vs. 25.4%, p < 0.001; CMV: 85.0% vs. 73.1%, p = 0.018; HSV-1: 86.0% vs. 76.4%, p = 0.041).

Options for clinical trials of pre and post-natal treatments for congenital toxoplasmosis

Clinical trials comparing different drug regimens and strategies for the treatment of congenital toxoplasmosis and its clinical manifestations in the liveborn child in different clinical settings should aim at formally evaluating the net benefit of existing treatments and at developing new therapeutic options. Currently, there is no ideal drug for congenital toxoplasmosis; future research should focus on the screening of new active drugs and on their pre-clinical and early clinical development, with a focus on pharmacokinetic/dynamic studies and teratogenicity. For the prenatal treatment of congenital toxoplasmosis, a trial comparing spiramycine to pyrimethamine-sulphadiazine and placebo would allow a formal estimation of the effect of both drugs in infected pregnant women. In newborn children, the net benefit of pyrimethamine-sulphadiazine should also be formally assessed. These trials will be implemented in settings where prenatal screening for Toxoplasma gondii is currently implemented. Trials should be carefully designed to allow for translation to other settings and modelling tools like cost-effectiveness analysis should be used to provide clinicians and founders with the best available evidence to establish recommendations.

When are we going to celebrate the centenary of the discovery of efficient treatment for congenital toxoplasmosis?

In 2008, we have celebrated the centenary of the discovery of Toxoplasma gondii.Although this ubiquitous protozoan can generate devastating damage in foetuses and newborns, its treatment is the only field in which we have made little progress, despite a huge body of research, and has not yet been validated. Pregnant women who seroconvert are generally given spiramycine in order to reduce the risk of vertical transmission. However, to date, we have no evidence of the efficacy of this treatment because no randomized controlled trials have as yet been conducted. When foetal contamination is demonstrated, pyrimethamine, in association with sulfadoxine or sulfadiazine, is normally prescribed, but the effectiveness of this treatment remains to be shown. With regard to postnatal treatment, opinions vary considerably in terms of drugs, regimens and length of therapy. Similarly, we do not have clear evidence to support routine antibiotic treatment of acute ocular toxoplasmosis. We must be aware that pregnant women and newborns are currently being given empirically potentially toxic drugs that have no proven benefit. We must make progress in this field through well-designed collaborative studies and by drawing the attention of policy makers to this disastrous and unsustainable situation.

Toxoplasmosis snapshots: global status of Toxoplasma gondii seroprevalence and implications for pregnancy and congenital toxoplasmosis

Toxoplasma gondii's importance for humans refers mainly to primary infection during pregnancy, resulting in abortion/stillbirth or congenital toxoplasmosis. The authors sought to evaluate the current global status of T. gondii seroprevalence and its correlations with risk factors, environmental and socioeconomic parameters. Literature published during the last decade on toxoplasmosis seroprevalence, in women who were pregnant or of childbearing age, was retrieved. A total of 99 studies were eligible; a further 36 studies offered seroprevalence data from regions/countries for which no data on pregnancy/childbearing age were available. Foci of high prevalence exist in Latin America, parts of Eastern/Central Europe, the Middle East, parts of south-east Asia and Africa. Regional seroprevalence variations relate to individual subpopulations' religious and socioeconomic practices. A trend towards lower seroprevalence is observed in many European countries and the United States of America (USA). There is no obvious climate-related gradient, excluding North and Latin America. Immigration has affected local prevalence in certain countries. We further sought to recognise specific risk factors related to seropositivity; however, such risk factors are not reported systematically. Population awareness may affect recognition of said risks. Global toxoplasmosis seroprevalence is continuingly evolving, subject to regional socioeconomic parameters and population habits. Awareness of these seroprevalence trends, particularly in the case of women of childbearing age, may allow proper public health policies to be enforced, targeting in particular seronegative women of childbearing age in high seroprevalence areas.