Prevalence of toxoplasmosis in pregnant women and vertical transmission of Toxoplasma gondii in patients from basic units of health from Gurupi, Tocantins, Brazil, from 2012 to 2014

Seroinfection of Antibodies to Toxoplasma gondii, Parvovirus B19, Treponema pallidum, and HIV in a Pregnant Attending a Medical Center in Northern Peru

Introduction

Transplacental infections are frequent, especially in developing countries, where limited screening is performed to find infectious agents in the pregnant population. We aim to determine the clinical and epidemiological characteristics and seroinfection of antibodies against Toxoplasma, parvovirus B19, T. pallidum, and HIV in pregnant women who attended the Motupe Health Center in Lambayeque, Peru during July-August 2018.

Methods

A descriptive cross-sectional study was conducted in 179 pregnant women interviewed with a standardized questionnaire. ELISA was used to determine antibodies to Toxoplasma and parvovirus B19. The detection of syphilis and HIV was conducted using immunochromatography, while the detection of hepatitis B was conducted using FTA-ABS and immunofluorescence, respectively.

Results

Of 179 pregnant women, syphilis and HIV infections routinely included in the screening of pregnant women presented a seroinfection of 2.2 and 0.6%, respectively. Toxoplasmosis seroinfection was 25.1%, while IgM antiparvovirus B19 was 40.8%, revealing that pregnant women had an active infection at the time of study.

Conclusion

The level of seroinfection of toxoplasmosis reveals the risk to which pregnant women who participated in the study are exposed. The high seroinfection of parvovirus B19 could explain the cases of spontaneous abortion and levels of anemia in newborn that have been reported in Motupe, Lambayeque, Peru. However, future causality studies are necessary to determine the significance of these findings.

Serosurvey of Toxoplasma gondii and Toxocara spp. co-infection in pregnant women in low-income areas of Brazil

Introduction

Despite human toxoplasmosis and toxocariasis having been listed among the top six most neglected parasitic zoonoses worldwide, presenting similar associated risk factors and transmission routes, few studies have been conducted in pregnant women and the consequences of concurrent infection remain to be fully established. Accordingly, the present study has serologically assessed the co-infection and associated risk factors for Toxoplasma gondii and Toxocara spp. in pregnant women, assisted by the public Unified National Health System (SUS) in southeastern Brazil.

Materials and Methods

Blood samples were collected and tested for IgG antibodies against Toxoplasma gondii by chemiluminescence immunoassay and against Toxocara spp. by enzyme-linked immunosorbent assay (ELISA). An epidemiological questionnaire was applied to gather socioeconomic information to assess the risk factors associated with seropositivity to toxocariasis/toxoplasmosis by univariate analysis followed by logistic regression.

Results

Overall, seropositivity was 69/280 (24.6, 95% CI: 19.96-30.01) for T. gondii and 56/280 (20.0, 95% CI: 15.73-25.08) for Toxocara spp. Co-infection was observed in 25/280 (8.9, 95% CI: 6.12-12.85) pregnant women, with increased odds (OR: 3.3, CI 95%: 1.77-6.14, p = 0.0002). Logistic regression revealed that a higher educational level (high school or college) significantly reduced the likelihood of co-infection seropositivity, owning cats increased the odds of toxocariasis, and older pregnant women presented significantly higher T. gondii seropositivity.

Conclusion

Co-infection herein highlights the importance of educational programs in the prevention of toxocariasis and toxoplasmosis in pregnant women and other high-risk populations.

Seroprevalence of Toxoplasmosis in Puerperal Women Treated at a Tertiary Referral Hospital

OBJECTIVE

 To evaluate the seroprevalence of toxoplasmosis among puerperal women cared for at a tertiary university hospital and the level of understanding of these puerperal women about toxoplasmosis, vertical transmission, and its prophylaxis.

METHODS

 For this cross-sectional study, we evaluated 225 patients using presential interviews, prenatal documentation, and electronic medical records. Data were stored using Research Electronic Data Capture (REDCap) software. Prevalence rates were estimated by the presence of reactive IgG antibodies against Toxoplasma gondii. Data analysis was performed using the chi-square test and calculation of the odds ratio (OR). Seroreactivity to T. gondii and exposure variables (age, educational level, and parity) were analyzed using a confidence interval (95%CI) and a significance level of 5% (p < 0.05).

RESULTS

 The seropositivity rate for T. gondii was 40%. There was no association between seroprevalence and age. Primiparity was a protective factor against seropositivity and low education was a risk factor.

CONCLUSION

 Knowledge of T. gondii infection and its transmission forms was significantly limited, presenting a risk for acute maternal toxoplasmosis and vertical transmission of this protozoan. Increasing the education level regarding the risk of toxoplasmosis during pregnancy could reduce the rates of infection and vertical transmission of this parasite.

Screening for the Detection of Toxoplasma gondii IgG, IgM and IgA in Females of Reproductive Age from Western Romania

Toxoplasma gondii, a zoonotic protozoan parasite, has the capacity to infect the fetus if the pregnant woman primarily acquires the infection during pregnancy. We evaluated the prevalence of T. gondii IgG, IgM and IgA antibodies in women of reproductive age residing in Western Romania. We also assessed the value of adding a T. gondii IgA test to the serologic panel for the diagnosis of toxoplasmosis, including the detection of a recently acquired infection. Serologic testing to demonstrate the presence of T. gondii IgG antibodies was conducted in 1317 females aged 15−45 years. T. gondii IgM and IgA antibody tests were performed in those with detectable IgG antibodies and IgG avidity test was performed if IgM and/or IgA screening test results were positive. T. gondii IgG were detected in 607 (46.09%; 95%CI: 43.41−48.79) of 1317 study participants and IgG seroprevalence tended to increase with age from 35.44% (95%CI: 29.89−41.30) in age group 15−24 years to 62.85% (95%CI: 56.57−68.82) in age group 35−45 years, showing a significant age-associated increase (p < 0.001). Of the 607 persons with detectable T. gondii IgG antibodies, T. gondii IgM antibodies were demonstrated in 8.90% (95%CI: 6.88−11.43), T. gondii IgA in 1.65% (95%CI: 0.90−3.01) and both T. gondii IgM and IgA in 0.99% (95%CI: 0.45−2.14). The prevalence of IgA antibodies tended to decrease with increasing avidity, from 75% (95%CI: 19.41−99.37) in samples with low avidity to 11.76% (95%CI: 4.44−23.87) in those with high avidity (p = 0.01). Of the study participants who were positive for both T. gondii IgM and IgA antibodies, 66.67% had low or equivocal IgG avidity test results compared to 6.25% who tested positive for IgM, were negative for IgA and in whom low or equivocal IgG avidity test results were noted (p = 0.001). This study indicates that in Western Romania, T. gondii IgG seroprevalence is high in females of reproductive age and T. gondii IgA antibodies may be rarely detected during a serologic screening. However, in individuals with demonstrable T. gondii IgG and IgM antibodies, testing for T. gondii IgA may improve the rate for the detection of a recently acquired toxoplasmosis.

Seroprevalence of Gestational and Neonatal Toxoplasmosis as well as Risk Factors in Yaoundé, Cameroon

Background. Toxoplasmosis, caused by Toxoplasma gondii in pregnant women, is a significant public health problem due to risk of mother to child transmission. The aim of the study was to determine the seroprevalence of toxoplasmosis in pregnant women and corresponding cord blood among women attending Biyem-Assi and CASS Nkoldongo hospitals in Yaoundé, Cameroon. Methods. An institutional based cross-sectional study was conducted between June 2019 and May 2020 on 300 pregnant women from late second trimester to third trimester. A total of 259 cord blood samples were collected at birth from these women. Toxoplasma gondii-specific IgG and IgM antibodies in maternal and cord blood were detected using the Toxoplasma Enzyme Immunosorbent Assay kit, and potential risk factors captured through questionnaire were identified using binary logistic regression model. Statistical significance was measured at $P<0.05$ . Results. The overall seroprevalence of gestational and neonatal toxoplasmosis was 80% and 88%, respectively. IgG seropositivity was 72.7%, IgM only was 1.3% and cooccurrence of IgG/IgM was 6% amongst pregnant women. Out of 259 newborn cord bloods, 72.2% were positive for IgG only, 8.9% for IgM only, and 23.9% for both IgG/IgM. Pregnant women 15-24 years ( $\text{AOR}=4.6$ , $P=0.011$ ) and women with primary level of education ( $\text{AOR}=3.9$ , $P=0.042$ ) were significantly at risk of infection with Toxoplasma gondii. Conclusion. Gestational and neonatal toxoplasmosis appears to be more common with higher risk of infection in younger women and less educated women. Hence, these findings will serve as baseline data for further investigations on mother to child transmission of toxoplasmosis in Yaoundé and the need for reinforcement of pregnant women toxoplasmosis-related health measures.

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

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

Prevalence of Anti-Toxoplasma gondii and Anti-Brucella Spp. Antibodies in Pregnant Women From Mogadishu, Somalia

Toxoplasmosis and brucellosis are zoonotic diseases of worldwide distribution. They both cause abortion and infertility in human and animals. Limited data are available about these pathogens in Somali people and their animals. Hence, this study has evaluated the prevalence of anti-Toxoplasma gondii and anti-Brucella spp. antibodies in pregnant women in Mogadishu, Somalia. Serum samples from 307 pregnant women from Mogadishu, Somalia were tested for anti-T. gondii antibodies by Latex Agglutination Test (LAT) and anti-Brucella spp. antibodies by Rose Bengal Plate Test (RBPT) and a commercial competitive-ELISA (cELISA). A total of 119/307 (38.76%) pregnant women had a prior history of abortion. A total of 159/307 (51.79%; 95% CI: 46.2–57.35%) pregnant women were seroreactive for T. gondii by LAT at different stages of pregnancy. For Brucella spp., when RBPT and cELISA were combined 4/307 (1.30%; 95% CI: 0.36–3.30%) pregnant women were seroreactive to anti-Brucella spp. antibodies, being 2/307 (0.65%; 95% CI: 0.18–2.34%) by RBPT and 3/307 (0.98%; 95% CI: 0.33–2.83%) by cELISA. Two women were seroreactive for both agents. A high seropositivity to T. gondii and low seropositivity to Brucella spp. have been found in pregnant women from Mogadishu, Somalia. Considering the high number of abortions in the country associated to the fact that awareness on other zoonotic abortifacient pathogens in Somalis is very low, further studies should be conducted to evaluate the potential causes of abortions.

Toxoplasmosis infection among pregnant women in Africa: A systematic review and meta-analysis

The epidemiology of toxoplasmosis in pregnancy is a major issue in public health. Toxoplasmosis is caused by the protozoan parasite. Toxoplasma parasite is at high risk for life-threatening diseases during pregnancy. Congenital toxoplasmosis results from a maternal infection acquired during gestation. Therefore, this systematic review and meta-analysis was aimed to determine the seropositive prevalence of toxoplasmosis infection among pregnant women who attended antenatal care in a health facility in Africa. A systematic review and meta-analysis of published and unpublished studies were included. Databases such as MEDLINE, PubMed, EMBASE, CINAHL, Web of Science, African Journals Online were used with relevant search terms. The quality of the articles was critically evaluated using the tool of the Joanna Briggs Institute. Data were extracted on Microsoft word 2016. Meta-analysis was conducted using STATA 14 software. The heterogeneity and publication bias were assessed using the I² statistics and Egger’s test, respectively. Forest plots were used to present the pooled prevalence and odds ratio with a 95% confidence interval of meta-analysis using the random effect model. In total, 23 studies comprising 7,579 pregnant women across ten countries in Africa were included in this meta-analysis. The overall prevalence of seropositive toxoplasmosis among pregnant women in Africa was 51.01% (95% CI; 37.66, 64.34). The heterogeneity test showed that heterogeneity was high, I² = 99.6%, P-value < 0.001. The variables responsible for the source of heterogeneity were included from Cameroon, the Democratic Republic of Congo, and Ethiopia. Overall prevalence of toxoplasmosis in Africa showed that more than one-half of pregnant women were infected. The risk of acquiring toxoplasmosis infection during pregnancy is high; hence, preventive measures to avoid exposure of pregnant women to Toxoplasma infection should be strictly applied.

Screening for infections in pregnancy - An overview of where we are today

Although most infections in pregnancy have very little impact, some affect either the mother or fetus or both. Screening must target those infections with consequences and furthermore, must be cost-beneficial. The introduction of any screening test for infections should take into consideration the prevalence of the condition, its consequences (health impact), the accuracy of the test and whether there are remedial steps including primary and secondary prevention to take with a positive or negative test. For some of these infections (for example syphilis and rubella) universal screening of all pregnant women has been the norm world-wide but as the epidemiology of these infections continue to change, a review of this practice must evolve. Furthermore, emerging infections line severe acute respiratory syndrome coronavirus-2 pose greater public health challenges. This article provides an overview of screening for infections in pregnancy, critically appraising screening for the common infections and arguing for abandoning of universal screening for rubella but advocating for universal screening for GBS and selective screening for CMV and toxoplasmosis.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

LEPTOSPIRA, PARVOVIRUS, AND TOXOPLASMA IN THE NORTH AMERICAN RIVER OTTER (LONTRA CANADENSIS) IN NORTH CAROLINA, USA

The North American river otter (Lontra canadensis) is the largest mustelid in North Carolina, US, and was once extirpated from the central and western portions of the state. Over time and after a successful reintroduction project, otters are now abundant and occur throughout North Carolina. However, there is a concern that diseases may have an impact on the otter population, as well as on other aquatic mammals, either through exposure to emerging diseases, contact with domestic animals such as domestic cats (Felis catus), or less robust condition of individuals through declines in water quality. We tested brain and kidney tissue from harvested otters for the pathogens that cause leptospirosis, parvovirus, and toxoplasmosis. Leptospirosis and toxoplasmosis are priority zoonoses and are maintained by domestic and wild mammals. Although parvovirus is not zoonotic, it does affect pets, causing mild to fatal symptoms. Across the 2014-15 and 2015-16 trapping seasons, we tested 220 otters (76 females, 144 males) using real-time PCR for Leptospira interrogans, parvovirus, and Toxoplasma gondii. Of the otters tested, 1% (3/220) were positive for L. interrogans, 19% (41/220) were positive for parvovirus, and 24% (53/220) were positive for T. gondii. Although the pathogens for parvovirus and toxoplasmosis are relatively common in North Carolina otters, the otter harvest has remained steady and the population appears to be abundant and self-sustaining. Therefore, parvovirus and toxoplasmosis do not currently appear to be negatively impacting the population. However, subsequent research should examine transmission parameters between domestic and wild species and the sublethal effects of infection.

First isolation and genotyping of Toxoplasma gondii strains from domestic animals in Tunisia

The isolation and molecular typing of Toxoplasma gondii strains provide an essential basis for a better understanding of the parasite’s genetic diversity, determinants of its geographical distribution and associated risks to human health. In this study, we isolated and genetically characterized T. gondii strains from domestic animals in Southern and coastal area of Tunisia. Blood, hearts and/or brains were collected from 766 domestic animals (630 sheep and 136 free-range chickens). Strain isolation from these samples was performed using mouse bioassay and genotyping was carried out with a multiplex PCR technique using 15 microsatellite markers. Thirty viable strains of T. gondii were successfully isolated from tissues of sheep (19/142) and chickens (11/33). In addition, 3 strains could be successfully genotyped from animal tissues for which mouse bioassay was unsuccessful. A large predominance of type II strains (n = 29) was found in the sampled regions, followed by type III (n = 3) and, for the first time in Tunisia, a single isolate of Africa 4 lineage from a sheep. Analyses of population genetics showed the presence of a divergent population of type II lineage in Tunisia, supporting limited recent migrations of strains between Tunisia and other countries of the world.

Evaluation of implementation of the primary, secondary and tertiary prevention measures of the Surveillance Program of Gestational and Congenital Toxoplasmosis in the city of Londrina-PR

Toxoplasmosis acquired during pregnancy is one that can lead to death or malformations of the foetus, and it is a complex disease to diagnose. The objective of the study was to evaluate the Surveillance Program of Gestational and Congenital Toxoplasmosis. To assess primary prevention, 424 pregnant women were interviewed regarding their knowledge of prevention measures in 2019. Secondary prevention measures were assessed, and the results of anti-Toxoplasma gondii serological tests were collected from pregnant women, from 2015 to 2018. In tertiary prevention measures, babies of mothers with a recent suspicion of T. gondii infection were screened to verify forwarding to the reference service. As a result, 45.5% (192/424) reported that they had received guidance from health professionals; 35.4% (68/192) changed their risk habits. The variables of schooling and age, having received prior guidance from health professionals and feline possession, proved to be significant when associated with the notions of preventive measures. 90.2% (17,423/19,319) of pregnant women had undergone serological tests to detect anti-T. gondii antibodies, but there was an excess in requests for tests and medication and only 40.6% (26/64) of the children were referred to the reference hospital. The Program presents positive results about the performance of serological screening in prenatal care; however, the dissemination of knowledge as for the prevention of toxoplasmosis and the request for tests need to be improved.

Serosurvey of Anti-Toxoplasma gondii Antibodies in Homeless Persons of São Paulo City, Southeastern Brazil

Seroprevalence of Toxoplasma gondii has been extensively studied in a variety of different human populations. However, no study has focused on homeless populations. Accordingly, the present study aimed to assess the seroprevalence of anti-T. gondii antibodies and the risk factors associated in homeless persons from homeless shelter of São Paulo city, southeastern Brazil. In addition, anti-HIV antibodies and associated risk of T. gondii and HIV coinfection have been evaluated. Anti-T. gondii antibodies were detected by indirect fluorescent antibody test. In addition, anti-HIV levels were tested by chemiluminescence enzyme immunoassay, with positive samples confirmed by rapid immunoblot assay. Overall, IgG anti-T. gondii seropositivity was found in 43/120 (35.8%) homeless persons, with endpoint titers varying from 16 to 1,024. The only two pregnant women tested were negative for IgM by chemiluminescence enzyme immunoassay, with normal parturition and clinically healthy newborns in both cases. There were no statistical differences in the risk factors for anti-T. gondii serology (p > 0.05). Anti-HIV seropositivity was found in 2/120 (1.7%) homeless persons, confirmed as HIV-1. One HIV seropositive individual was also sero-reactive to IgG anti-T. gondii, and both were negative to IgM anti-T. gondii. This is the first study that reports the serosurvey of T. gondii in homeless persons worldwide. Despite the limited sample size available in the present study, our findings have shown that the prevalence of anti-T. gondii antibodies in homeless persons herein was lower than the general population, probably due to homeless diet habit of eating mainly processed food intake. No statistical differences were found regarding risk factors for anti-T. gondii exposure in homeless persons. Future studies should be conducted to fully establish risk factors for anti-T. gondii exposure in homeless persons.

Role of Toxoplasma gondii IgG Avidity Testing in Discriminating between Acute and Chronic Toxoplasmosis in Pregnancy

Risk of mother-to-child transmission of Toxoplasma gondii during pregnancy is much greater in women who are exposed to primary T. gondii infection (toxoplasmosis) after conception compared to those who were exposed to the infection before conception. Therefore, laboratory tests that help classify recent primary toxoplasmosis are important tools for the management of pregnant women suspected to have T. gondii exposure. Detection of Toxoplasma IgM (Toxo IgM) is a sensitive indicator of primary toxoplasmosis, but the indicator specificity is low because sometimes natural IgM antibodies react with Toxoplasma antigens in the absence of the infection. Furthermore, Toxo IgM sometimes persists in blood serum for several months or years following the primary infection. In recent decades, Toxo IgG avidity assay has been used as a standard diagnostic technique for a better estimation of the infection acquisition time and identification of the primary T. gondii infection during pregnancy. Avidity is described as the aggregate strength; by which, a mixture of polyclonal IgG molecules reacts with multiple epitopes of the proteins. This parameter matures gradually within 6 months of the primary infection. A high Toxo IgG avidity index allows a recent infection (less than 4 months) to be excluded, whereas a low Toxo IgG avidity index indicates a probable recent infection with no exclusions of the older infections. This minireview is based on various aspects of T. gondii IgG avidity testing, including (i) description of avidity and basic methods used in primary studies on T. gondii IgG avidity and primary infections; (ii) importance of IgG avidity testing in pregnancy; (iii) result summary of the major studies on the use of T. gondii IgG avidity assay in pregnancy; (iv) brief explanation of the T. gondii IgG avidity values in newborns; (v) result summary of the major studies on T. gondii IgG avidity and PCR; (vi) discussion of commercially available T. gondii IgG avidity assays, including newer automated assays; and (vii) current issues and controversies in diagnosis of primary T. gondii infections in pregnancy.

Toxoplasma gondii infections in birds, companion, food and recreational animals in Nigeria: A systematic review and meta-analysis

Toxoplasma gondii is a protozoan pathogen of zoonotic and economic importance with a global distribution. The pathogen is associated with abortion, stillbirth, neonatal mortalities and mummification in sheep and goats which may also serve as sources of human infections. In pregnant women, the parasite undergoes intrauterine transmission to cause neonatal complications like miscarriage, chorioretinitis, hydrocephalus, cerebral calcification and foetal death. Here, we determine the prevalence and geographical distribution of T. gondii infections in Nigeria using the PRISMA protocol. Prevalence estimates (PE) and heterogeneity were determined by the random-effects model and the Cochran's Q-test respectively. Twenty-eight articles identified, reported 2311 positive cases of Toxoplasma gondii from a total of 9847 animals examined across 15 Nigerian States. Overall PE was 20.70% (95% CI: 15.05-27.78) with a range of 10.18% (95% CI: 2.66-31.98) to 94.00% (95% CI: 89.73-96.56) across sub-groups. PEs varied significantly (p < .05) across host species, with a range of 4.06% (95% CI: 2.47-6.87) to 40.65% (95% CI: 19.88-65.40). PEs in females (22.65%, 95% CI: 15.78-31.72) was significantly higher (p < .05) than that in males (18.97%, 95% CI: 12.78-27.22), while those for adult and young animals were 20.23% (95% CI: 13.42-29.33) and 18.96% (95% CI: 11.11-30.45) respectively. The majority of the studies were published from the south-western region. Toxoplasma gondii infection is prevalent among birds, companion, food and recreational animals from Nigeria. Integrated control strategies including adequate sanitation, cat movement restrictions, public enlightenment are recommended to curtail the menace of T. gondii in animals and its public health consequences in humans.

Serological and molecular detection of Neospora caninum and Toxoplasma gondii in human umbilical cord blood and placental tissue samples

Neosporosis primarily affects cattle and dogs and is not currently considered a zoonotic disease. Toxoplasmosis is a zoonosis with a worldwide distribution that is asymptomatic in most cases, but when acquired during pregnancy, it can have serious consequences. The seropositivity rates determined by the indirect fluorescent antibody test for Neospora caninum (N. caninum) and Toxoplasma gondii (T. gondii) were 24.3% (49 samples) and 26.8% (54 samples), respectively. PCR positivity for N. caninum was observed in two samples of cord blood (1%) using the Nc5 and ITS1 gene, positivity for T. gondii was observed in 16 samples using the primer for the B1 gene (5.5% positivity in cord blood and 2.5% positivity in placental tissue). None of the samples showed structures characteristic of tissue cysts or inflammatory infiltrate on histopathology. Significant associations were observed only between N. caninum seropositivity and the presence of domestic animals (p = 0.039) and presence of dogs (p = 0.038) and between T. gondii seropositivity and basic sanitation (p = 0.04). This study obtained important findings regarding the seroprevalence and molecular detection of N. caninum and T. gondii in pregnant women; however, more studies are necessary to establish a correlation between risk factors and infection.

Prospection of immunological biomarkers for characterization and monitoring of asymptomatic Leishmania (Leishmania) infantum infection

In areas endemic for Leishmania infantum, an asymptomatic infection may be an indicator of the extent of transmission. The main goal of this study was to evaluate the applicability of measuring circulating immunological biomarkers as an alternative strategy to characterize and monitor L. infantum asymptomatic infections in combination with serological methods. To this end, 179 children from a region endemic for visceral leishmaniasis (VL), aged 1-10 years old, selected from a cross-sectional study, were identified as asymptomatic (n = 81) or uninfected (n = 98) by qPCR and/or serological tests (ELISA using L. infantum soluble antigen and rK39), and, together with serum samples of children diagnosed with VL (n = 43), were subjected to avidity tests and cytokine levels measurement. Avidity rates (AR) ranging from 41 to 70% were found in 29 children (66%) from the asymptomatic group. On the other hand, high AR (above 70%) were observed in 27 children (64%) from the VL group. Logistic Regression and Classification and Regression Tree (CART) analyses demonstrated that lower AR and IFN-γ production associated with higher IL-17A levels were hallmarks in asymptomatic L. infantum infections. Therefore, this study proposes an association of immunological biomarkers that can be used as a complementary strategy for the characterization and monitoring of asymptomatic VL infections in children living in endemic areas.

Seroprevalence of Toxoplasma gondii infection among pregnant women in Windhoek, Namibia, in 2016

Background

When a pregnant woman contracts Toxoplasma gondii (T. gondii) infection during pregnancy, it may be vertically transmitted to the foetus. Information on the incidence of congenital toxoplasmosis (CT) in developing countries is scarce. Most studies focus on the seroprevalence of T. gondii infection among pregnant women. This study aimed to determine the seroprevalence of T. gondii infection among pregnant women attending public antenatal care in Windhoek, Namibia, in 2016.

Methods

In this descriptive study, 344 urban pregnant women attending public antenatal care were voluntarily enrolled in the study. Seroprevalence of anti-T. gondii Immunoglobulin G (IgG) was determined by automated immunoassay. Samples with a positive T. gondii IgG result were tested for T. gondii Immunoglobulin M (IgM) and specific IgG avidity by using an enzyme-linked immunosorbent assay (ELISA) test. A questionnaire captured demographic data and exposure to risk factors. Data were analysed using Statistical Package for the Social Sciences (SPSS) and R.

Results

Anti-T. gondii IgG was found in nine (2.61%) pregnant women. There was no association of anti-T. gondii IgG with demographic characteristics or exposure to risk factors.Anti-T. gondii IgM was positive in one (0.3%) woman, while three (0.9%) women had borderline anti-T. gondii IgM results. Specific IgG avidity was low, equivocal and high in 0%, 33% and 67% of seropositive pregnant women, respectively.

Conclusion

Seroprevalence of anti-T. gondii IgG is much lower in Namibia than is reported in other developing countries. Investigation into specific IgM seropositivity and IgG avidity showed that pregnant women in the central region of Namibia are at low risk of vertical transmission and development of CT.

Seroprevalence and risk factors associated with T. gondii infection in pregnant individuals from a Brazilian Amazon municipality

The aim of this study was to determine the prevalence and to identify the risk factors associated with T. gondii infection in pregnant individuals living in the Ponta de Pedras municipality, Marajó Archipelago, State of Pará, where an outbreak of toxoplasmosis occurred in 2013. From 2014 to March 2017, a cross-sectional study was conducted, including 555 pregnant individuals aged 13- to 42-years-old. Serological tests (enzyme immunoassays) were performed, and socioenvironmental and behavioral information were obtained through the application of a questionnaire. A prevalence of 68.3% was detected, and older age, having contact with soil and living in an urban area were the risk factors associated with seropositivity. The study confirmed the high prevalence of infection among pregnant individuals in the region. The association of the infection with the variables of residential area and contact with soil indicates that there was environmental contamination by T. gondii oocysts in the municipality.

Serological evidence of Toxoplasma gondii infection in Melanosuchus niger (Spix, 1825) and Caimam crocodilus (Linnaeus, 1758)

Toxoplasma gondii is a protozoan with worldwide prevalence, known to affect a large variety of warm-blooded hosts. However, its ability to induce long-lasting infections in cold-blooded animals remains unclear. The most likely source of infection is through consumption of meat containing tissue cysts or by ingestion of food or water contaminated with oocysts. The current global climate change trend and the progressive degradation of natural habitats are prone to alter the distribution of ectotherm populations over a short period of time, which may favor contact between these animals and the protozoan. In association, alligator meat is considered a delicacy in many regions and its consumption has been previously related to a diversity of foodborne diseases. In that sense, we proposed in this study to search for specific antibodies against T. gondii in serum samples of two common species of alligators from the Brazilian fauna (Melanosuchus niger and Caimam crocodilus). We obtained the serum samples from 84 alligators from the Araguaia region, which were tested by agglutination assays that do not require species-specific secondary antibodies (Modified Agglutination Test – MAT; Indirect Hemagglutination Assay – IHA). From the 84 samples tested, eight (9.5%) were positive by MAT. From those, seven (87.5% of MAT+, 8.3% of the total) were also positive by IHA, reassuring a probable exposure of these animals to the parasite. Direct parasite detection in muscle fragments of one serologically reactive alligator did not yield positive results. Our results provide serological evidence that Brazilian alligators may be exposed to T. gondii and further studies should be performed to elucidate whether alligators are natural hosts of this ubiquitous protozoan parasite.

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Exposure to T. gondii was verified in sera of 84 Brazilian alligators.

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The serum samples were analyzed to 2 serological assays: MAT and HAI.

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7 samples were found to be positive in bothserological tests.

Toxoplasma gondii seropositivity associated to peri-urban living places in pregnant women in a rural area of Buenos Aires province, Argentina

Infection with Toxoplasma gondii is very common in humans throughout the world, the intake of raw or undercooked meat with tissue cysts and fruits, vegetables and water contaminated with parasite oocysts being the main routes of infection. Here, we analyzed the seroprevalence of anti-T. gondii antibodies in pregnant females (age 13–44 years; n = 920) between April 2014 and December 2017 from Chascomús (Argentina), a city immersed in a rural area. Altogether 320 tested positive for immunoglobulin G antibodies, yielding an overall seroprevalence of 34.8% (CI 95%: 31.7–37.9). No association was observed between seropositivity and age. In addition, by using the QGIS 3.2.1 software we analyzed the geographical distribution of 769 (83.6%) pregnant females in two main areas of the city: Urban (n = 157) and Peri-urban (n = 612) with a seroprevalence of 26.8% (CI 95%: 19.8–33.7) and 36.4% (CI 95%: 32.6–40.3) respectively, and this difference was statistically significant (p = 0.023). Furthermore, we assessed through a questionnaire survey, between April 2016 to December 2017, possible risk factors such as activity (urban and rural), home water supply, animal husbandry, presence of cats as pets, gardening and consumption of meat and its derivatives (pork, sheep meat and sausages) and their frequencies (consumption per week), not finding significant association with seropositivity. Significant differences was found when the seroprevalence was analyzed between the urban and peri-urban neighborhoods of the city of Chascomús. The higher seroprevalence in peri-urban neighborhoods could be due to an unfavorable socioeconomic situation and/or to undeveloped peri-urban environments, which is a risk factor that should be taken into account when planning the health care of pregnant females.

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

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

Seroprevalence of Toxoplasmosis at a Tertiary Care Centre in North India from 2004 to 2014

Purpose

This study was carried out to determine the seroprevalence of anti-Toxoplasma gondii antibodies in different groups of patients at a tertiary care hospital in North India.

Materials and Methods

Clinical and demographic data such as age and gender of patients who had undergone testing for the presence of anti-T. gondii IgG and IgM antibodies between January 2004 and October 2014 were retrospectively analysed.

Results

Amongst the 8397 serum samples, an overall seropositivity of 21% (n = 1763) and IgG and IgM seropositivity of 5.7% (n = 481) and 15.3% (n = 1282) were respectively observed. Compared to the period of 2004-2012 (median seroprevalence: 23.6%), a decline in seropositivity to 9.7% in 2013 and 8.1% in 2014 was noted. A rising seroprevalence with age and a higher seroprevalence in females versus males (29.5%, n = 1179 vs. 13.3%, n = 584) were recorded. The highest seroprevalence was observed in suspected ocular toxoplasmosis (47.2%, n = 47), followed by neurological (26.8%, n = 77), human immunodeficiency virus/acquired immunodeficiency syndrome (18.9%, n = 267), post-transplant (17.1%, n = 12) and congenital (7.2%, n = 144) toxoplasmosis. In patients screened for Toxoplasma exposure, the seropositivity was 47.8% (n = 11) in transplant screening and 44.9% (n = 781) in antenatal screening.

Conclusion

Toxoplasma infection is highly prevalent in the population of North India across various clinical categories of patients. Future studies focusing on continuous monitoring of seroprevalence trends and elucidation of the risk factors associated with seropositivity in more defined groups of patients are needed.

Seroprevalence of Toxoplasma gondii among School Children in Pyin Oo Lwin and Naung Cho, Upper Myanmar

Toxoplasma gondii is an apicomplexan parasite that can cause toxoplasmosis in a wide range of warm-blooded animals including humans. In this study, we analyzed seroprevalence of T. gondii among 467 school children living in the rural areas of Pyin Oo Lwin and Naung Cho, Myanmar. The overall seroprevalence of T. gondii among school children was 23.5%; 22.5% of children were positive for T. gondii IgG, 0.4% of children were positive for T. gondii IgM, and 0.6% of children were positive for both T. gondii IgG and IgM. Geographical factors did not significantly affect the seroprevalence frequency between Pyin Oo Lwin and Naung Cho, Myanmar. No significant difference was found between males (22.2%) and females (25.0%). The overall seroprevalence among school children differed by ages (10 years old [13.6%], 11–12 years old [19.8%], 13–14 years old [24.6%], and 15–16 years old [28.0%]), however, the result was not significant. Polymerase chain reaction analysis for T. gondii B1 gene for IgG-positive and IgM-positive blood samples were negative, indicating no direct evidence of active infection. These results collectively suggest that T. gondii infection among school children in Myanmar was relatively high. Integrated and improved strategies including reinforced education on toxoplasmosis should be implemented to prevent and control T. gondii infection among school children in Myanmar.

Basic heel prick test: inclusion of screening, diagnosis and criteria for early confirmation of congenital infection by Toxoplasma gondii

Toxoplasma gondii can cross the placental barrier, causing fetal infection with potentially severe sequelae. The aim of this study was to evaluate whether the serological screening for toxoplasmosis should be included in the basic neonatal heel prick test in order to establish criteria for the confirmation and/or exclusion of the diagnosis of congenital infection in newborns treated at three public health units in the metropolitan region of Goiania, Goias State, Brazil. Blood samples were collected on filter paper from newborns and later, peripheral blood samples from the mothers and their respective children were obtained to confirm or exclude the diagnosis of suspected congenital infection, by means of an enzyme-linked immunosorbent assay (IgM and IgG) and a polymerase chain reaction assay. From a total of 1,159 blood samples collected on filter paper, 43.92% were reactive to IgG and 0.17% to anti-T. gondii IgM and IgG. One hundred and twenty-seven paired samples (mother and child) were collected following consensual protocols for peripheral blood collection. Results obtained from the filter paper and peripheral blood of the newborns were 90.55% concordant. A comparison of the mother and child blood test results showed agreement regarding the detection of IgG in 90.48% of the samples. The parasite DNA was detected in the peripheral blood of one child. In view of the results obtained in this study, the inclusion of the serological screening for toxoplasmosis in the newborn heel prick test proved to be effective for the early detection of congenital T. gondii infection.

Congenital toxoplasmosis among Iranian neonates: a systematic review and meta-analysis

Toxoplasmosis is a serious zoonotic disease that can lead to abortion and congenital disorders and has a widespread global distribution in humans and animals. The objective of this review was to investigate the incidence of toxoplasmosis in Iranian neonates in order to obtain a comprehensive assessment of the overall situation of the disease for use in developing future interventions. Original studies investigating the incidence of Toxoplasma gondii infections in Iranian neonates were systematically searched in a number of English-language and Persian-language electronic databases. The search process resulted in the inclusion of a total of 11 studies in the systematic review, 10 of which were entered into the meta-analysis. The reviewed articles included 2,230 Iranian neonates investigated through January 1, 2018. Based on the retrieved studies, the overall weighted incidence rates of toxoplasmosis in the Iranian neonatal population and neonates with suspected congenital toxoplasmosis were estimated to be 0.64% (95% confidence interval [CI], 0.31 to 1.09) and 4.10% (95% CI, 2.68 to 5.77), respectively, using a fixed-effects model. The findings of the reviewed studies demonstrate that the incidence of toxoplasmosis is high in Iranian neonates. Accordingly, it can be concluded that toxoplasmosis is a serious public health concern that has been ignored by the Ministry of Health. Therefore, it is essential to perform further studies, in addition to implementing screening and detection programs, using standardized methods to estimate the incidence of toxoplasmosis in Iran and to determine its associated risk factors.

Índice de masa corporal asociado a las características de las puérperas y de los neonatos

Introducción: Un Índice de Masa Corporal (IMC) pregestacional inadecuado conlleva riesgos maternos/fetales. Objetivos: Identificar el IMC pregestacional y vincularlo a los datos sociodemográficos y obstétricos de las puérperas; e identificar el IMC pregestacional y el aumento de peso durante el embarazo relacionados con las características de los neonatos. Materiales y Métodos: Estudio cuantitativo, descriptivo, desarrollado en un hospital de referencia, con 187 binomios. Los datos fueron recolectados a partir de la libreta prenatal y de la Declaración de Nacido Vivo. Debido a la ausencia de distribución gaussiana, se compararon las variables continuas, utilizando pruebas no paramétricas (Mann-Whitney o Kruskal-Wallis). Las muestras pareadas fueron comparadas utilizando la prueba de Wilcoxon para datos pareados. Para comparar las variables categóricas, se utilizó la prueba exacta de Fisher o la prueba chi-cuadrado de Pearson. Resultados: El IMC pre-gestacional varió de 16 a 53kg/m², promedio 25,0 ±5,9kg/m²; 41,2% con sobrepeso y mujeres obesas; el promedio de aumento del peso gestacional fue de 11Kg ±30Kg; el promedio de edad fue de 26 años. Se observó un aumento progresivo del peso de acuerdo con el aumento de la edad (P=0,009); las mujeres obesas más propensas a ser hospitalizadas por Síndrome Hiperintensiva Gestacional (P=0,003) y por hipertensión arterial crónica (P=0,026); entre las mujeres con IMC elevado 24,0% eran primíparas y 23,5% multíparas; el promedio de peso de los neonatos fue de 3146,8g ±559,7g. El peso de los neonatos de las obesas fue superior (P=0,034). Se observó una correlación positiva entre el IMC materno pre-gestacional y el peso del RN al nacer (rho–0,219; P=0,003). Discusión: Los resultados demostraron un aumento de peso en las madres gestantes, lo que corrobora las investigaciones de la literatura. Conclusiones: La evaluación del estado nutricional se debe realizar en la fase de planeación de la gestación con el fin de evitar complicaciones futuras. Como citar este artigo: Tresso BD, Tavares BB. Índice de massa corporal associado às caractéristicas das puérperas e dos neonatos. Rev Cuid. 2019; 10(2): e678. http://dx.doi.org/10.15649/cuidarte.v10i2.678

Seroprevalence and risk factors of Toxoplasma gondii among pregnant women in Adwa district, northern Ethiopia

Background

Toxoplasma gondii infection is a great health concern to pregnant women and the developing fetus. The aim of this study was to determine the seroprevalence of T. gondii and its associated factors in Adwa district.

Methods

A facility based cross-sectional study was conducted from January to June 2018 in Adwa district. Structured, a pre-tested questionnaire was used to collect the demographic and risk factor related data. Serum sample, collected from each of the study subjects was tested for IgG and IgM anti T.godii specific antibodies using Enzyme-Linked Immunosorbent Assay. A bivariable and multivariable logistic regression model was applied to show association between the dependent and independent variables considering P < 0.05 and the 95% confidence interval.

Result

Out of the 360, 128 (35.6%) pregnant women were found to be positive for antibodies specific to T. gondii. Furthermore, 117 (32.5%) women were positive only for IgG, and 11 (3.1%) were positive both for IgM and IgG antibodies. Age, educational level, habit of hand washing after contact with garden soil or domestic animals, presence of domestic cat, history of contact with domestic dog and consumption of raw vegetables were significantly associated with T. gondii.

Conclusion

The seroprevalence of T. gondii among pregnant women in the study area is low compared to the other regions of Ethiopia, and within the range of the seroprevalences in the central and East Africa region. However, efforts should be done to create awareness on the potential risk factors of the parasite in the community.

Systematic review and meta-analysis of variation in Toxoplasma gondii cyst burden in the murine model

Toxoplasma gondii is an obligate intracellular protozoan parasite that infects approximately 30% of the population of the United States, with worldwide distribution. The chronic (latent) infection, mediated by the bradyzoite parasite life stage, has attracted attention due to possible links to host behavioral alteration and psychomotor effects. Mice are a common model organism for studying the chronic stage, as they are natural hosts of infection. Notably, published studies demonstrate vast ranges of measured cyst burden within the murine brain tissue. The inconsistency of measured cyst burden within and between experiments makes interpretation of statistical significance difficult, potentially confounding studies of experimental anti-parasitic approaches. This review analyzes variation in measured cyst burden in a wide array of experimental mouse infections across published literature. Factors such as parasite infection strain, mouse strain, mode of infection, and infectious dose were all examined. The lowest variation in measured cyst burden occurred with the commonly available Balb/c and CBA mice undergoing infection by the ME49 strain of T. gondii. A summary of cyst variation and average cyst counts in T. gondii mouse models is presented, which may be useful for designing future experiments.

Comparison of Placenta PCR and Maternal Serology of Aborted Women for Detection of Toxoplasma gondii in Ardabil, Iran

Primary maternal infection with toxoplasmosis during pregnancy is frequently associated with transplacental transmission of the parasite to the fetus. This study was conducted to test the utility of PCR assay to detect recent infections with Toxoplasma in aborted women at various gestational ages who referred to Obstetrics and Gynecology Department of Alavi Hospital in Ardabil during 2014 and 2016. Two hundred women with a history of single or repeated abortion were investigated in this study. Blood samples were tested for specific anti-Toxoplasma IgM and IgG antibodies by ELISA. According to the results, 53.5% of the women under study were positive for anti-Toxoplasma antibodies: 4.0% of them had IgM, 43.0% had IgG, and 6.5% had both IgM and IgG. Subsequently, Nested-PCR analysis was used to detect T. gondii DNA in the placenta of subjects. In 10.5% of the women, the results were positive for 529 bp element of T. gondii. Among them, 5 (23.8%) cases were IgM positive, 1 (4.8%) case was IgG positive, and 11 (52.4%) were both IgM and IgG positive. In 4 (19.0%) patients, none of the antibodies were found to be positive. In total, 16 patients had positive results in both ELISA and PCR methods, and 174 cases had negative results for new infection. The findings of this study revealed that T. gondii might be one of the significant factors leading to abortion, and that the analysis of placenta can be important in order to achieve increased detection sensitivity.

An updated literature review on maternal-fetal and reproductive disorders of Toxoplasma gondii infection

BACKGROUND

Toxoplasma gondii infection is one of the most prevalent infectious disease with worldwide distribution. Congenital toxoplasmosis is annually responsible for 1.20 million disability-adjusted life years around the world, but often it is overlooked many countries.

METHODS

We performed an updated review to summarize the current researches on fetal, neonatal and maternal consequences of T. gondii infection and also adverse effects of toxoplasmosis on women reproductive organs.

RESULTS

T. gondii infection could be cause of several abnormalities from hydrocephalus, microcephaly, deafness, abortion and still birth in fetal to psychomotor retardation, intellectual disability, hearing loss, slower postnatal motor development during the first year of life; and chorioretinitis, cryptogenic epilepsy and autism spectrum disorders in newborns. Moreover, this infection is related with neuropsychiatric disorders such as anxiety, schizophrenia spectrum disorders, depression, decreased weight, autoimmune thyroid diseases, self-directed violence, violent suicide attempts in mothers. This literature review emphasized that toxoplasmosis could be an important neglected factor endometritis, ovarian dysfunction, impaired folliculogenesis, ovarian and uterine atrophy, decrease in reproductive organs weight and reproductive performance in women. We reviewed role of the immunological profile such as pro-infiammatory cytokines and hormonal changes as main potential mechanisms related to this infection and development of maternal-fetal and reproductive disorders.

CONCLUSION

T. gondii is associated with several brain related disorders in both mothers and newborns, and also it is cause of several abnormalities in reproductive organs. Early diagnosis and treatment of the infection could be effective to significantly improve the clinical outcome.

Decidual Macrophage Functional Polarization during Abnormal Pregnancy due to Toxoplasma gondii: Role for LILRB4

During gestation, Toxoplasma gondii infection produces a series of complications including stillbirths, abortions, and congenital malformations. The inhibitory receptor, LILRB4, which is mainly expressed by professional antigen-presenting cells (especially macrophages and dendritic cells) may play an important immune-regulatory role at the maternal-fetal interface. To assess the role of LILRB4 during T. gondii infection, LILRB4^-/- and T. gondii infected pregnant mouse models were established. Further, human primary-decidual macrophages were treated with anti-LILRB4 neutralizing antibody and then infected with T. gondii. These in vivo and in vitro models were used to explore the role of LILRB4 in T. gondii-mediated abnormal pregnancy outcomes. The results showed that abnormal pregnancy outcomes were more prevalent in LILRB4^-/- infected pregnant mice than in wild-type infected pregnant mice. In subsequent experiments, expression levels of LILRB4, M1, and M2 membrane-functional molecules, arginine metabolic enzymes, and related cytokines were assessed in uninfected, infected, LILRB4-neutralized infected, and LILRB4^-/- infected models. The results demonstrated T. gondii infection to downregulate LILRB4 on decidual macrophages, which strengthened M1 activation functions and weakened M2 tolerance functions by changing M1 and M2 membrane molecule expression, synthesis of arginine metabolic enzymes, and cytokine secretion profiles. These changes contributed to abnormal pregnancy outcomes. The results of this study provide not only a deeper understanding of the immune mechanisms operational during abnormal pregnancy, induced by T. gondii infection, but also identify potential avenues for therapeutic and preventive treatment of congenital toxoplasmosis.

Establishing tools for early diagnosis of congenital toxoplasmosis: Flow cytometric IgG avidity assay as a confirmatory test for neonatal screening

The aim of this study was to evaluate the performance of conventional serology (Q-Preven™ and ELFAVIDAS™) and flow cytometry-based serologic tools for early serologic diagnosis of congenital toxoplasmosis. The study groups included prospectively confirmed cases of congenital toxoplasmosis (TOXO=88) and age-matching non-infected controls (NI=15).The results demonstrated that all samples tested positive/indeterminate for anti-T. gondii IgM screening at birth using air-dried whole blood samples. Serum samples collected at 30-45days after birth tested positive for ELFAVIDAS™ IgG in both groups. While all NI tested negative for ELFAVIDAS™ IgM and IgA, only 78% and 36% of TOXO tested positive for IgM and IgA, respectively. Flow cytometry-based anti-T. gondii IgM, IgA and IgG reactivity displayed moderate performance with low sensitivity (47.6%, 72.6% and 75.0%, respectively). Regardless the remarkable specificity of IgG1, IgG2 and IgG3 subclasses for early diagnosis, weak or moderate specificity was observed (Se=73.9%, 60.2% and 83.0%, respectively). The analysis of IgG avidity indices (AI) demonstrated the highest performance among the flow cytometry-based methods (Se=96.6%; Sp=93.3%), underscoring the low avidity index (AI<60%) within TOXO (97.0%) in contrast with the high avidity index (AI>60%) in NI (93%). Analysis of anti-T. gondii IgG and IgG3 reactivity for mother:infant paired samples may represent a relevant complementary tests for early diagnosis. In conclusion, a feasible high-standard algorithm (Accuracy=97.1%) was proposed consisting of Q-Preven™ IgM screening at birth, followed by ELFAVIDAS™ IgM and flow cytometric IgG avidity analysis at 30-45days after birth as a high performance tool for early serological diagnosis of congenital toxoplasmosis.

Toxoplasma genotyping in congenital toxoplasmosis in Upper Egypt: evidence of type I strain

Toxoplasma gondii has subpopulation structures in different geographical regions caused by less frequent sexual recombination, population sweeps, and biogeography. The majority of strains isolated in North America and Europe fall into one of three clonal lineages, referred to as types I, II, and III. So far, little is known about genetics of Toxoplasma strains in Africa. The present study aimed to determine the genotype of Toxoplasma strains obtained directly from trophoblastic/placental tissues of 29 complicated pregnant women using multilocus nested-PCR-RFLP technique depending on four independent genetic loci (5' SAG2 and 3' SAG2), SAG3, GRA6, and BTUB genes. All samples gave positive amplicons at 5'-3' SAG2 and SAG3 genes. Meanwhile, no amplification products were observed in 12 (41.37%) and 10 (34.48%) samples with GRA6 and BTUB genes, respectively. The restriction pattern revealed the presence of genotype I in all samples, except one sample, which revealed atypical genotype with unusual restriction pattern at 3' SAG2 gene. The negative amplifications in some samples could be due to presence of mutations or polymorphisms in the primer binding sites of these isolates, raising the possibility of mixed or recombinant genotypes. To the best of our knowledge, this is the first time to perform genotype analysis study based on Multiplex nPCR-RFLP technique for genetic characterization of T. gondii in Egypt. Besides, it is the first time to prove that the most prevalent strain of T. gondii, responsible for congenital toxoplasmosis in Upper Egypt, is the highly virulent type I. Atypical genotype was detected as well.

IgG Avidity Test in Congenital Toxoplasmosis Diagnoses in Newborns

The goal of this study was to investigate the importance of IgG avidity testing in newborns (NBs) diagnosed with early congenital toxoplasmosis. We collected samples from 88 puerperae infected by Toxoplasma gondii (T. gondii) and their NBs (48 acutely-infected puerperae (AIP) and 40 chronically-infected puerperae (CIP)), from two public maternity hospitals in Goiania city, Goias, Brazil, from 2010 to 2015. Specific anti-T. gondii IgM and IgG serum levels and IgG avidity tests were evaluated using chemiluminescence. Congenital toxoplasmosis was observed in 66.66% (n = 32) of NBs with AIP, 94.1% presenting low avidity (LA) and 51.61% presenting high avidity (HA) test results. The IgG and IgM levels of NBs with LA and their puerperae were higher in comparison with HA NBs and puerperae (p = 0.0001). The avidity tests showed 100% specificity and 50% sensitivity (p = 0.0001). NBs with LA had a 15-fold increased risk of developing congenital toxoplasmosis in comparison with HA NBs. The IgG avidity test could be used to assist in early congenital toxoplasmosis diagnoses in NBs and LA, identifying a greater probability of vertical transmission.

Evaluation of serological and molecular tests used to identify Toxoplasma gondii infection in pregnant women attended in a public health service in São Paulo state, Brazil

Toxoplasmosis during pregnancy can have severe consequences. The use of sensitive and specific serological and molecular methods is extremely important for the correct diagnosis of the disease. We compared the ELISA and ELFA serological methods, conventional PCR (cPCR), Nested PCR and quantitative PCR (qPCR) in the diagnosis of Toxoplasma gondii infection in pregnant women without clinical suspicion of toxoplasmosis (G1=94) and with clinical suspicion of toxoplasmosis (G2=53). The results were compared using the Kappa index, and the sensitivity, specificity, positive predictive value and negative predictive value were calculated. The results of the serological methods showed concordance between the ELISA and ELFA methods even though ELFA identified more positive cases than ELISA. Molecular methods were discrepant with cPCR using B22/23 primers having greater sensitivity and lower specificity compared to the other molecular methods.

Molecular Detection and Genetic Characterization of Toxoplasma gondii in Farmed Minks (Neovison vison) in Northern China by PCR-RFLP

Toxoplasma gondii is a worldwide prevalent parasite, affecting a wide range of mammals and human beings. Little information is available about the distribution of genetic diversity of T. gondii infection in minks (Neovison vison). This study was conducted to estimate the prevalence and genetic characterization of T. gondii isolates from minks in China. A total of 418 minks brain tissue samples were collected from Jilin and Hebei provinces, northern China. Genomic DNA were extracted and assayed for T. gondii infection by semi-nested PCR of B1 gene. The positive DNA samples were typed at 10 genetic markers (SAG1, SAG2 (5'+3' SAG2, alter.SAG2), SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico) using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technology. 36 (8.6%) of 418 DNA samples were overall positive for T. gondii. Among them, 5 samples were genotyped at all loci, and 1 sample was genotyped for 9 loci. In total, five samples belong to ToxoDB PCR-RFLP genotype#9, one belong to ToxoDB genotye#3. To our knowledge, this is the first report of genetic characterization of T. gondii in minks in China. Meanwhile, these results revealed a distribution of T. gondii infection in minks in China. These data provided base-line information for controlling T. gondii infection in minks.

Intranasal immunization with recombinant Toxoplasma gondii actin depolymerizing factor confers protective efficacy against toxoplasmosis in mice

Background

Toxoplasma gondii is an opportunistic protozoan closely associated with AIDS and vertical transmission. T. gondii actin depolymerizing factor (TgADF) plays an important role in actin cytoskeleton remodeling, and it is required to invade host cells. TgADF was a promising vaccine candidate. To observe the immunological changes and protective efficacy of recombinant TgADF protein (rTgADF) against T. gondii infection, we optimized the intranasal immunization dose of rTgADF and analyzed the survival rate and tachyzoite loads in mouse tissues after oral challenge with T. gondii tachyzoites.

Results

rTgADF was prepared, purified, and combined with mouse anti-His antibody and rabbit anti-T. gondii serum. After intranasal immunization with 10 μg, 20 μg, 30 μg, or 40 μg of rTgADF, the 30-μg group elicited high levels of secretory IgA (sIgA) in nasal, intestinal, and vesical washes, raised IgG titres in the sera, strong proliferation of splenocytes, and increased secretion of IL-2 and IFN-γ when compared with the control group. When the mice were orally challenged with T. gondii, an increase in the survival rate (36.36 %) and a decrease in the tachyzoite loads in the liver (67.77 %) and brain (51.01 %) were observed.

Conclusions

Our findings demonstrate that intranasal immunization with rTgADF can simultaneously trigger mucosal and systemic immune responses and protect the mice against T. gondii infection.

Towards Universal Screening for Toxoplasmosis: Rapid, Cost-Effective, and Simultaneous Detection of Anti-Toxoplasma IgG, IgM, and IgA Antibodies by Use of Very Small Serum Volumes

Rapid, cost-effective, and early determination of the serological status of potentially infected individuals, particularly pregnant women, can be critical in preventing life-threatening infections and subsequent fetal congenital abnormalities. An article in this issue of the Journal of Clinical Microbiology (X. Li, C. Pomares, G. Gonfrier, B. Koh, S. Zhu, M. Gong, J. G. Montoya, and H. Dai, J Clin Microbiol 54:1726-1733, 2016, http://dx.doi.org/10.1128/JCM.03371-15) describes an innovative multiplexed immunoassay that offers a path toward universal screening.

Toxoplasmosis awareness, seroprevalence and risk behavior among pregnant women in the Gampaha district, Sri Lanka

BACKGROUND

Primary gestational toxoplasmosis can be transmitted to the fetus with deleterious effects on the pregnancy. There is very little information regarding gestational toxoplasmosis in Sri Lanka. This survey was done to determine the prevalence and awareness of toxoplasmosis and to identify risk factors of infection among pregnant women in the Gampaha district, Sri Lanka.

METHODS

Women attending obstetric clinics at the Colombo North Teaching Hospital in 2014 were tested for Toxoplasma gondii (T. gondii) specific Immunoglobulins G (IgG) and M (IgM) subtypes using the OnSite Toxo IgG/IgM Rapid Test-Dip Strip(®). Disease awareness and risk behaviors of the participants were investigated.

RESULTS

Of the 293 participants (mean age 27 years, SD ± 5.92), 38% were primigravidae with a mean gestational age of 16.2 weeks (SD 7). The prevalence of anti-T. gondii IgG and IgM antibodies was 12.3% (n = 36) and zero, respectively. Unadjusted and adjusted odds ratios were calculated to determine risk factors of infection (cat-ownership, handling cats, consumption of meat, commercial meals and unwashed raw vegetables and fruits, handling soil and not washing hands after handling soil). On bivariate analysis, eating commercially prepared meals weekly or more was associated with toxoplasma seroprevalence with marginal statistical significance. On multivariate analysis, none of the considered risk factors were significant. Toxoplasma awareness was 4.4% (n = 13); health personnel (46.2%, n = 6) and media (53.8%, n = 7) being sources of information.

CONCLUSIONS

Health education programs to increase awareness of toxoplasmosis is recommended at antenatal clinics.