Prematurity and Low Birth Weight did not Correlate with Anti-Toxoplasma gondii Maternal Serum Profiles--a Brazilian Report

Seroprevalence, Risk Factors and Maternal-Fetal Outcomes of Toxoplasma gondii in Pregnant Women from WHO Eastern Mediterranean Region: Systematic Review and Meta-Analysis

BACKGROUND

The protozoan parasite Toxoplasma gondii may cause serious illness in the immunocompromised. The Toxoplasma gondii seropositive prevalence in pregnant women in WHO Eastern Mediterranean Region countries is inconsistent in the literature and it is associated with outcomes that have not be fully elucidated, hence the need for a better understanding of the pooled seroprevalence and associated maternal and fetal outcomes.

OBJECTIVE

The objective was to conduct a systematic literature review and determine the pooled prevalence of WHO Eastern Mediterranean Regional countries' pregnant women's seroprevalence of Toxoplasma gondii and the maternal-fetal outcomes.

METHODS

This quantitative study examined WHO Eastern Mediterranean countries' maternal-fetal outcomes and Toxoplasma gondii prevalence in pregnant women. The targeted population was pregnant women, while the primary outcome was seropositivity of Toxoplasma gondii, while other outcomes such as maternal and fetal associations and risk factors were determined PubMed, SCOPUS, MEDLINE, and Index Medicus for the Eastern Mediterranean Region (IMEMR) databases were searched up until 30 January 2023. The search terms used were "Toxoplasma gondii" OR "Toxoplasma infection" AND "Pregnant woman" or pregnan* OR Antenatal OR Prenatal OR Gravidity OR Parturition OR Maternal AND WHO Eastern Mediterranean Region). OpenMeta-Analyst and Jamovi were used to analyze the generated data.

RESULTS

In total, 95 of 2947 articles meeting the inclusion criteria examined Toxoplasma gondii prevalence in pregnant women from WHO Eastern Mediterranean countries. The pooled prevalence of Toxoplasma gondii in pregnant women was 36.5% (95%CI: 32.6-40.4) with a median value of 35.64%, range values of 1.38-75.30%, with 99.61% heterogeneity. The pooled seroprevalence of IgG of Toxoplasma gondii was 33.5% (95%CI: 29.8-37.2) with a median value of 33.51%, and a range values of 1.38-69.92%; the pooled seroprevalence of IgM was 3.6% (95%CI: 3.1-4.1)) with a median value of 3.62 and range values of 0.20-17.47%, while cases of pooled seroprevalence of both IgG and IgM positivity was 3.0% (95%CI: 1.9-4.4) with a median value of 2.05 and a range values of 0.05-16.62%. Of the Toxoplasma gondii seropositive women, 1281/3389 (34.8%) 174/1765 (32.9%), 1311/3101 (43.7%), and 715/1683 (40.8%) of them had contact with cats, drank unprocessed milk, ate raw or undercooked meat and ate unwashed raw vegetables, respectively. The maternal-fetal outcomes associated with Toxoplasma gondii seropositivity were a history of abortions, miscarriage, stillbirth, intrauterine fetal death, and premature birth, which were found in 868/2990 (32.5%), 112/300 (36.1%), 111/375 (25.7%), 3/157 (1.9%) and 96/362 (20.1%) of women who tested positive for Toxoplasma gondii antibodies.

CONCLUSION

The study found a high proportion of Toxoplasma gondii seroprevalence in pregnant women in the WHO Eastern Mediterranean Region, which may be linked to poor outcomes for mothers and their babies. Thus, pregnant women require monitoring and comprehensive prevention strategies for Toxoplasma gondii infection.

Adverse pregnancy outcomes in Toxoplasma gondii seropositive Hispanic women

AIMS

Chronic Toxoplasma gondii infection is not thought to affect pregnancy or birth outcomes, but there are few prospective studies. The study aims were T. gondii immunoglobulin G measurement and relationship of chronic T. gondii infection with gestational age at birth and adverse pregnancy outcomes in 690 Hispanic women in Tampa, Florida.

METHODS

Hispanic women, born either in the United States or in Latin America or the Caribbean had a venous blood sample drawn to measure T. gondii IgG and T. gondii serotype at the first prenatal visit, along with collection of demographic and health-related measures. Seropositive and seronegative women were followed throughout their pregnancy. Gestational age, infant weights, and adverse pregnancy outcomes (miscarriages, preterm births) were compared in the two groups.

RESULTS

There were 740 women of self-reported Hispanic ethnicity screened and enrolled in Tampa, Florida, with 690 having birth data extracted from the electronic health record (538 T. gondii negative and 152 T. gondii seropositive). T. gondii seropositivity was 22.4% and the majority (83%) had high avidity titers, indicating chronic infection. Compared to T. gondii seronegative Hispanic women, seroseropositive women had more smaller for gestational age infants and higher prevalences of miscarriages and preterm birth.

CONCLUSION

This is one of the largest longitudinal cohort studies of women with chronic T. gondii infection followed through pregnancy. There was a higher percentages of adverse pregnancy outcomes in this group compared to T. gondii seronegative controls. The mechanism for this is unknown and warrants reexamination of the dogma that chronic T. gondii infection in pregnant women has no significant clinical consequences.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

The Impact of Latent Toxoplasma gondii Infection on Spontaneous Abortion History and Pregnancy Outcomes: A Large-Scale Study

BACKGROUND

Toxoplasma gondii (TG), a zoonotic protozoan parasite, belongs to a group of TORCH infectious agents, which can cause severe damage to the fetus if a primary infection occurs during pregnancy. After primary infection, TG rests lifelong in human organisms causing a latent infection. Most studies have analyzed the consequences of acute, but not latent, TG infection. This study analyzed the impact of latent toxoplasmosis on spontaneous abortion history, pregnancy complication rate and neonatal outcome.

METHODS

IgG and IgM anti-TG antibodies were tested in 806 pregnant women who were consulted at the Timisoara Clinical Emergency Hospital between 2008 and 2010. Demographic data, obstetrical history, and data about the pregnancy complications, birth and neonate were collected for each woman and comparisons between the groups, with and without latent TG infection, were made.

RESULTS

This study did not show differences between groups regarding the history of spontaneous abortion (OR = 1.288, p = 0.333), cesarean section (OR = 1.021, p = 0.884), placental abruption (OR 0.995, p = 0.266), pregnancy-induced hypertension rate (OR 1.083, p = 0.846), secondary sex ratio (1.043, p = 0.776), 1' APGAR score at birth (p = 0.544), gestational age at birth (p = 0.491) or birth weight (p = 0.257).

CONCLUSIONS

The observed differences between the rate of pregnancy complications in the two groups of pregnant women with and without latent infection with TG, did not reach a statistical significance.

Toxoplasma gondii Infection Is Associated with Low Birth Weight: Findings from an Observational Study among Rural Bangladeshi Women

Gestational Toxoplasma gondii (T. gondii) infection may cause substantial adverse effects on developing fetuses, newborns and also mothers. This study aims to estimate the seroprevalence of T. gondii among rural Bangladeshi pregnant women and determine the risk of a low birth weight (LBW). We followed a longitudinal design where 208 pregnant women were followed until the birth of their infants. Levels of IgG and IgM of T. gondii were assessed using chemiluminescent immunoassay. Modified Poisson regression was used to estimate crude and adjusted associations and multiple regression analysis was performed to understand the confounding and modifying effects of the variables. Thirty-nine (19%) children were born with LBW, among whom 15 (39%) mothers were positive for T. gondii IgG during pregnancy. After adjusting for several confounders and modifiers, pregnant women with T. gondii IgG or IgM seropositivity were significantly associated with LBW of infants (aRR: 2.00, 95% CI: 1.17–3.42). The strength of this association increased after adjusting for maternal education (aRR: 4.88, 95% CI: 1.74–13.69). The final model had an AROC of 0.84 with a sensitivity of 36% and specificity of 97%. Although causality is yet to be established, the study observed an association between T. gondii infection during pregnancy among rural Bangladeshi women and LBW of newborns.

A pilot study on screening for gestational/congenital toxoplasmosis of pregnant women at delivery in the Eastern Province of Saudi Arabia

BACKGROUND

Globally, congenital toxoplasmosis remains a significant cause of morbidity and mortality, and outbreaks of T. gondii infection represent a major public health threat, especially in developing countries. Evidence in the literature indicates that only a few studies have been conducted on the incidence of maternal and congenital toxoplasmosis in Saudi Arabia. This prospective study aims to measure the overall incidence of congenital toxoplasmosis, both patent and 'silent' infection, among pregnant women in the Eastern Province of Saudi Arabia. The study would attempt to relate the cord blood results with the time of seroconversion in the mother, underlining the importance of early intervention in such cases.

METHODS

Five hundred paired maternal/cord blood samples were tested for anti-Toxoplasma IgG or IgM antibodies. Samples were collected during delivery from mother and newborn (cord blood) from November 2011 to May 2012. Only positive for anti-Toxoplasma IgG or/and IgM cord blood was processed for real-time PCR for confirmation. The age of mothers ranged from 16 to 45 years.

RESULTS

The sample subjects were tested during child delivery for specific IgG and IgM antibodies against Toxoplasmosis, of which 21.0% (n = 105) mother/baby pairs were found serologically positive for anti-Toxoplasma IgG antibodies. The rate of maternal seropositivity for anti-Toxoplasma IgM antibodies was found among 4 participants (0.8%), who were also seropositive for anti-Toxoplasma IgG antibodies. None of the children tested positive for anti-Toxoplasma IgM antibodies, even those born to mothers with IgM positive. All 105 cord blood tests in the study sample were confirmed negative by real-time PCR. The seroprevalence of Toxoplasma IgG antibodies increased with maternal age, parity, and was significantly higher in women who gave birth to children with congenital anomalies (p = 0.008).

CONCLUSION

The findings of the current study indicate a dire need to develop and implement preventive programs against Toxoplasma gondii infection, as well as a health education program on how to avoid toxoplasmosis for all seronegative women during pregnancy.

Duffy blood group system and ocular toxoplasmosis

Duffy blood group phenotypes [Fy(a + b-), Fy(a-b+), Fy(a + b+), Fy(a-b-)], characterized by the expression of Fy^a, and Fy^b antigens, are present in red blood cells. Therefore, we hypothesize that the non-hematopoietic expression of these antigens might influence cell invasion by T. gondii. 576 consecutive patients from both genders were enrolled. The presumed OT clinical diagnosis was performed. Duffy phenotyping was performed by hemagglutination in gel columns and for the correct molecular characterization Fy(a-b-) phenotype, using PCR-RFLP. Anti-T. gondii IgG antibodies were detected by ELISA. Chi-square, Fisher's exact tests were used to compare the proportions. OT was present in 22.9% (n = 132) and absent in 77.1% (n = 444) of patients. The frequencies of anti-T. gondii IgG antibodies were higher in OT (127/132, 96.2%) than those without this disease (321/444, 72.3%) (p < .0001). None of the Duffy antigens or phenotypes were associated with T. gondii infection (χ2: 2.222, GL: 3, p = .5276) as well as the risk of OT (χ2: 0.771, GL: 3, p = .8566). Duffy blood group system phenotypes and their antigens do not constitute risk factors for infection by T. gondii infection and the development of OT.

Evaluation of Toxoplasma gondii B1 gene in Placental Tissues of Pregnant Women with Acute Toxoplasmosis

Background:

One of the consequences of toxoplasmosis is the risk of passing it from mother to fetus and the onset of congenital toxoplasmosis during pregnancy. The purpose of this study was to evaluate the B1 gene of Toxoplasma gondii in the placental tissues of pregnant women with acute toxoplasmosis.

Materials and Methods:

The study was a cross-sectional study. Serum samples of pregnant women who attended to Fatemieh Hospital of Hamadan University of Medical Sciences were tested for immunoglobulin G (IgG) antibodies against T. gondii by enzyme-linked immunosorbent assay. Then, polymerase chain reaction was used to identify the specific B1 gene of T. gondii in IgG seropositive women. The placental tissues of the pregnant women with positive serum B1 gene examined for this gene. Anti-Toxoplasma immunoglobulin M (IgM) was performed on the umbilical cord and neonate blood.

Results:

Anti-Toxoplasma IgG was detected in 167 out of 653 (25.6%) pregnant women. T. gondii B1 gene was identified in 36 out of 167 (21.6%) of IgG seropositive women. After delivery, the B1 gene was evaluated in 15 out of 36 (41.7%) patients’ placental tissues, 13 of which were positive for this gene (86.7%). Anti-Toxoplasma IgM was detected neither in any umbilical cord nor in neonatal blood samples. All newborns, with the exception of one case, were born with normal birth weight and in term birth.

Conclusion:

The B1 gene was detected in 86.7% of the placental tissue of women who were involved in acute toxoplasmosis during pregnancy.

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.