Incidence of congenital toxoplasmosis among infants born to HIV-coinfected mothers: case series and literature review

Toxoplasma gondii infections in pediatric neurosurgery

Toxoplasma gondii is a parasite that is estimated to infect one-third of the world's population. It is acquired by ingesting contaminated water and food specially undercooked meat, contact with domestic or wild feline feces, and during pregnancy by transplacental transmission.Immunocompetent hosts are usually asymptomatic, and infection will be self-limited, while those patients whose immune system is debilitated by HIV infection, immunosuppressive therapy, long-term steroid treatment, and fetuses infected during gestation will show evidence of systemic activity which is more severe in the central nervous system and eyes due to insufficient immune response caused by their respective blood barriers. Congenital toxoplasmosis has an estimated incidence of 8% in mothers who were seronegative at the beginning of their pregnancy. Infection in the first trimester may result in spontaneous abortion or stillbirth; however, it is estimated that the highest risk for vertical transmission is during the second and third trimesters when blood flow and placenta thickness favor parasitic transmission.Congenital toxoplasmosis can be detected with periodic surveillance in endemic areas, and with appropriate treatment, the risk of vertical transmission can be reduced, and the severity of the disease can be reversed in infected fetuses.While most infected newborns will show no evidence of the disease, those who suffer active intrauterine complications will present with cerebral calcifications in 8-12% of cases, hydrocephalus in 4-30%, and chorioretinitis in 12-15%. Also, seizure disorders, spasticity, and varying degrees of neurocognitive deficits can be found in 12%.Four distinct patterns of hydrocephalus have been described: aqueductal stenosis with lateral and third ventricle dilatation, periforaminal calcifications leading to foramen of Monro stenosis with associated asymmetrical ventricle dilatation, a mix of aqueductal and foramen of Monro stenosis, and overt hydrocephalus without clear evidence of obstruction with predominant dilatation of occipital horns (colpocephaly).While all patients diagnosed with congenital toxoplasmosis should undergo pharmacological treatment, those presenting with hydrocephalus have traditionally been managed with CSF shunting; however, there are reports of at least 50% success when selected cases are treated with endoscopic third ventriculostomy. Successful hydrocephalus management with appropriate treatment leads to better intellectual outcomes.

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

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

Congenital Co-infections Among HIV-Exposed Infants Born to Mothers on Antiretroviral Treatment in the United States

BACKGROUND

Many women living with HIV (WLHIV) are co-infected with cytomegalovirus (CMV), Toxoplasma gondii (T gondii), and/or hepatitis C virus (HCV). The rates of congenital or perinatal transmission of these co-infections are not well defined in the current era, when most WLHIV receive antiretroviral therapy (ART) during pregnancy.

METHODS

Retrospective review of infants of WLHIV born between 2009-2019. Mothers were screened for antibodies to CMV, T. gondii, and HCV; chronic HCV infection was confirmed using plasma RNA PCR. Infants whose mothers had positive/unknown serostatus were screened for CMV using urine or saliva DNA PCR or culture at ≤3 weeks of life; T. gondii using serology at ≤1 month; and HCV using plasma RNA PCR at ≤6 months and serology at ≥12 months.

RESULTS

The study included 264 infants from 255 pregnancies in 191 mothers. At delivery, the median (IQR) CD4 count was 569 (406-748) cells/mm³ and plasma HIV load was 0 (0-24) RNA copies/mL. Among 243 infants born to CMV-seropositive (209) or CMV-missed serostatus (25) mothers, 163 (67.1%) were tested for CMV. Four infants had CMV detected, resulting in a rate of congenital infection of 2.5%. Among 65 infants from 54 (21.2%) pregnancies in T. gondii-seropositive women and 8 in women with unknown T. gondii-serostatus, one acquired congenital toxoplasmosis in the setting of acute maternal T. gondii infection. There were no episodes of vertical transmission from mothers with latent toxoplasmosis. Among 18 infants from 13 (5.1%) pregnancies in HCV RNA PCR-positive women and 4 in women with unknown HCV serostatus, there were no congenital or perinatal HCV transmissions.

CONCLUSIONS

In a US cohort of pregnant WLHIV on ART, we identified high maternal CMV seroprevalence and a high rate of congenital CMV infection. We did not identify any congenital or perinatal transmissions of T. gondii or HCV among mothers who had latent or chronic infections. Our data support screening pregnant WLHIV and their infants for CMV and suggest that the rates of congenital and perinatal T. gondii and HCV infections among infants born to WLHIV on ART may be lower in the era of effective ART.

Neurological development of children who are HIV-exposed and uninfected

Widespread use of antiretroviral drugs for pregnant/breastfeeding females with human immunodeficiency virus (HIV) has led to declining vertical transmission. Despite being HIV-uninfected, the increasing number of children who are HIV-exposed and uninfected (CHEU) often present with developmental alterations. We review seminal and recent evidence on the neurological development of CHEU and associations with early life HIV/antiretroviral exposure. Our conceptual model highlights the numerous exposures and universal risk factors for CHEU developmental disorders. Early studies suggest a significant association between HIV exposure and neurological abnormalities, varying according to the burden of HIV-specific exposures and other risk factors. More recent observations from the modern era are inconsistent, although some studies suggest specific antiretrovirals may adversely affect neurological development of CHEU. As the CHEU population continues to grow, alongside simultaneous increases in types and combinations of antiretrovirals used in pregnancy, long-term monitoring of CHEU is necessary for understanding the effects of HIV/antiretroviral exposure on CHEU developmental outcomes. What this paper adds Evidence on the neurological development of children who are human immunodeficiency virus (HIV)-exposed and uninfected (CHEU) is synthesized. Comparisons are made to children who are HIV-unexposed, across treatment eras and settings, and by antiretroviral drug regimens and drug classes. CHEU exposures are complex and include HIV-specific and universal risk factors which may affect development during the early years of life.

Anti-Toxoplasmic Immunoglobulin G Quantitation Correlates with Immunovirological Parameters of HIV-Infected Cameroonians

BACKGROUND

Toxoplasmosis is still a neglected common opportunistic infection in immunocompromised individuals, who are mainly people living with HIV (PLHIV) in whom reactivation of toxoplasmosis may occur with advanced HIV conditions in resource-limited settings (RLS).

OBJECTIVE

The objective was to assess the correlation between anti-toxoplasmic immunoglobulin G (anti-Toxo IgG) concentration and the immuno-virological status of PLHIV.

METHODS

A cross-sectional study was conducted in the year 2018 among 100 PLHIV aged ≥18 years in Yaounde-Cameroon. For each participant, anti-Toxo IgG, CD4-T lymphocytes, and plasma viral load (PVL) were measured using ELISA, flow cytometry, and real-time PCR, respectively.

RESULTS

Overall, 56% of the participants were seropositive for anti-Toxo IgG, while 33% were negative and 11% were equivocal. All (n=19) those with PVL>1000 copies/mL were seropositive to anti-Toxo IgG versus 52.85% (37/70) with PVL<1000 copies/mL; p<0.0001. Interestingly, all (n=11) those with severe immunodeficiency (T-CD4<200 cells/μL) were positive to anti-Toxo IgG versus 57.69% (45/78) with T-CD4>200 cells/μL; p<0.0001. Most importantly, PVL and anti- Toxo IgG concentration were positively correlated (r = 0.54; p<0.0001), while T-CD4 and anti- Toxo IgG concentration were negatively correlated (r = - 0.70; p<0.0001). Adjusting age, gender, immune status, and virological profile in logistic regression shows that only immune status was independently associated with the serological status of toxoplasmosis (p=0.0004).

CONCLUSION

In Cameroon, about half of PLHIV might be seropositive to anti-Toxo IgG, with decreasing immunity appearing as a risk of toxoplasmosis relapse. Thus, in the context of immunodeficiency, routine quantification of anti-Toxo IgG would alleviate the programmatic burden of this opportunistic infection in RLS with the generalized HIV epidemic.

The prevalence of latent and acute toxoplasmosis in HIV-infected pregnant women: A systematic review and meta-analysis

OBJECTIVE

HIV in pregnancy is not only important for mother-to-child HIV transmission, but also it assumes additional importance because HIV increases susceptibility to opportunistic infections, leading to increased morbidity and mortality in mothers and neonates. Toxoplasmosis is one of the most important opportunistic infections in HIV-infected pregnant women. The present study was undertaken to assess the prevalence of latent toxoplasmosis (LT) and acute toxoplasmosis (AT) infection in HIV-infected pregnant women.

METHODS

PubMed/MEDLINE, Scopus, Web of Science, EMBASE and SciELO were searched to identify relevant studies. A random-effects model was used to estimate the overall and subgroup-pooled prevalences across studies. Heterogeneity between studies was assessed via the I² test.

RESULTS

A total of 14 articles that included 3256 subjects in nine countries met the inclusion criteria. The overall prevalence rates of LT and AT in HIV-infected pregnant women were 45.7% (95% CI, 32.3-59.7%) and 1.1% (95% CI, 0.4-3.2%), respectively. The findings indicate that, worldwide, approximately 559,000 and 13,450 HIV-infected pregnant women are affected by LT and AT, respectively. From this review, it is estimated that approximately 3432 babies annually could be born with congenital toxoplasmosis (CT) from HIV-infected pregnant mothers.

CONCLUSIONS

The present study indicates that a large number of HIV-infected mothers are affected by LT and AT. This can lead to adverse complications such toxoplasmic encephalitis in mothers and CT in neonates. Our results suggest a need for screening programs using well-validated diagnostic platforms for both LT and AT for all HIV-infected pregnant women.

Screening of compound libraries for inhibitors of Toxoplasma growth and invasion

Toxoplasma gondii can infect virtually all warm-blooded animals, including humans. It can differentiate between rapidly replicating tachyzoites that cause acute infection and slowly growing bradyzoites in tissue cysts. Treatment options for toxoplasmosis are challenging because current therapies cannot eradicate the latent T. gondii infection that is mainly caused by the bradyzoite forms. Accordingly, recurrence of infection is a problem for immunocompromised patients and congenitally infected patients. Protein kinases have been widely studied in eukaryotic cells, and while little is known about signaling in Toxoplasma infection, it is likely that protein kinases play a key role in parasite proliferation, differentiation, and probably invasion. To identify optimized new kinase inhibitors for drug development against T. gondii, we screened a library of kinase inhibitor compounds for anti-Toxoplasma activity and host cell cytotoxicity. Pyrimethamine served as a positive control and 0.5% DMSO was used as a negative control. Among the 80 compounds screened, 6 compounds demonstrated ≥ 80% parasite growth inhibition at concentrations at which 5 compounds did not suppress host cell viability, while 3 kinase inhibitors (Bay 11-7082, Tyrphostin AG 1295 and PD-98059) had suppressive effects individually on parasite growth and host cell invasion, but did not strongly induce bradyzoite formation.

Disease of the Year 2019: Ocular Toxoplasmosis in HIV-infected Patients

Ocular toxoplasmosis (OT) may be an initial manifestation of acquired immunodeficiency syndrome (AIDS) in human immunodeficiency virus (HIV)-infected patients. OT has different clinical manifestations and can mimic other intraocular infections. Clinical findings may show single or multifocal retinochoroidal lesions or panuveitis. Atypical presentations are associated with extensive uni- or bilateral areas of retinal necrosis. OT lesions not associated with preexisting retinochoroidal scars are usually due to acquired rather than congenital infection. When CD4+ T cell counts are <100 c/uL, vitritis is frequently mild. Isolated anterior uveitis has been reported in single cases. Positive immunoglobulin M (IgM) antibodies are rare but their presence can support the diagnosis. As atypical presentations of OT are common, anterior chamber puncture for multiplex polymerase chain reaction amplification of infectious DNA should be considered, as early diagnosis and treatment can prevent massive tissue destruction and preserve vision. This review provides an overview of OT in HIV-infected patients.

Unpasteurised milk consumption as a potential risk factor for toxoplasmosis in females with recurrent pregnancy loss

In women with a bad obstetric history, certain infections are associated with recurrent foetal loss. One of the common infectious agents is a protozoan parasite, Toxoplasma gondii. The aim of this study was to assess unpasteurised milk consumption as a potential risk factor for toxoplasmosis in females with recurrent pregnancy loss from the province of Khyber Pakhtunkhwa, Pakistan. In this study, we recruited a total of 360 females, comprising a study group of 180 females with previous history of recurrent pregnancy loss and a control group of 180 females with no such history. Blood serum from the participants was analysed for Toxoplasma gondii IgM antibodies by enzyme linked immunosorbent assay. Among the study group, 23 (12.8%) females were serologically positive for IgM antibodies against Toxoplasma gondii, whilst 157 (87.2%) were IgM negative. In the control group, only two (4.8%) females were IgM positive, whilst 178 (95.2%) were IgM negative. Bad pregnancy outcome in the study group and control group was observed to be significantly different (p < .0001). In both of these groups, unpasteurised milk consumption was found as a major risk factor for Toxoplasma gondii infection. A routine serological investigation should be carried out in pregnant women to rule out toxoplasmosis and reduce the risk of recurrent pregnancy loss as well as congenital toxoplasmosis in newborns.Impact statementWhat is already known on this subject? Seropositivity for Toxoplasma gondii antibodies ranges from 7% to 51% in different regions of the world. The prevalence rate varies because of differences in climate, culture, food habits, behaviour, personal hygiene and cooking habits of different societies and ethnic groups. Various risk factors have been identified that contribute to a high prevalence rate of the disease, including consumption of raw or poorly cooked meat, physical contact with cats or cat litter, consumption of unwashed raw vegetables and fruits, drinking of contaminated water and milk. We presumed that consuming unpasteurised milk could be a potential risk factor for developing toxoplasmosis in pregnant women.What the results of this study add? This study demonstrates high seroprevalence of Toxoplasma gondii antibodies in females of child bearing age that have consumed unpasteurised milk and is a potential risk factor for developing toxoplasmosis.What the implications are of these findings for clinical practice and/or further research? Our findings suggest that primary preventive measures (personal hygiene, frequent hand washing and consuming pasteurised milk) should be taken by health surveillance authorities to focus on families, especially pregnant women, to educate them about personal hygiene, contact with cattle or using their milk and milk products. The latter is especially important to aware them about the hazards of consuming unpasteurised and contaminated milk.

How does toxoplasmosis affect the maternal-foetal immune interface and pregnancy?

Toxoplasma gondii is a zoonotic parasite which, depending on the geographical location, can infect between 10% and 90% of humans. Infection during pregnancy may result in congenital toxoplasmosis. The effects on the foetus vary depending on the stage of gestation in which primary maternal infection arises. A large body of research has focused on understanding immune response to toxoplasmosis, although few studies have addressed how it is affected by pregnancy or the pathological consequences of infection at the maternal-foetal interface. There is a lack of knowledge about how maternal immune cells, specifically macrophages, are modulated during infection and the resulting consequences for parasite control and pathology. Herein, we discuss the potential of T. gondii infection to affect the maternal-foetal interface and the potential of pregnancy to disrupt maternal immunity to T. gondii infection.

Secondary prophylaxis of toxoplasmosis in pregnancy in an HIV-positive woman

A 39-year-old HIV-positive black African woman with previously treated cerebral toxoplasmosis experienced a foetal intra-uterine death due to congenital toxoplasmosis. This case demonstrates the complexities of screening for maternal toxoplasmosis in the context of pregnancy and HIV infection-related cell-mediated immunosuppression. Additionally, the case highlights the challenges in providing effective preventative and therapeutic drug options for congenital toxoplasmosis.

Immunodiagnosis and molecular validation of Toxoplasma gondii-recombinant dense granular (GRA) 7 protein for the detection of toxoplasmosis in patients with cancer

Serological assays for the diagnosis of toxoplasmosis mostly rely on the tachyzoite specific antigens of Toxoplasma gondii, which are difficult to produce by conventional methods. The aim of this study was to clone and express of GRA7 protein of T. gondii and evaluate its potential for immunodiagnosis of toxoplasmosis in cancer patients. As well as validate the results using a new molecular assay, LAMP technique. The GRA7 gene was successfully cloned, expressed and purified by affinity chromatography and the production was evaluated by SDS PAGE, dot blot and western blot analyses. The rGRA7 was used for developing an ELISA based on the rGRA7 using sera from patients with toxoplasmosis and healthy controls. Furthermore, 50 serum samples from leukemic children infected with toxoplasmosis and 50 seronegative controls were included to evaluate the sensitivity and specificity of rGRA7 based ELISA. Finally, the LAMP technique was used to assess the accuracy and validity of the results obtained by rGRA7 based ELISA. The consistency of the results of two tests was determined by using the Kappa coefficient of agreement. The rGRA7 showed higher and optimum immunoreactivity with 1:100 dilution of serum from Toxoplasma infected patients. The sensitivity and specificity of test were calculated as 92 and 94%, respectively. According to the Kappa coefficient of agreement, there was a significant conformance between the results obtained by ELISA based on the rGRA7 and the results of LAMP technique (≈96%, P<0.001). Findings of the present study showed that rGRA7 can be used as a potential immunogenic antigen for developing immunodiagnostic tools for immunodiagnosis of toxoplasmosis in patients including patients with cancer.

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

Introduction

Toxoplasmosis is a parasitary disease that presents high rates of gestational and congenital infection worldwide being therefore considered a public health problem and a neglected disease.

Objective

To determine the prevalence of toxoplasmosis amongst pregnant women and vertical transmission of Toxoplasma gondii in their newborns attended in the Basic Units of Health (BUH) from the city of Gurupi, state of Tocantins, Brazil.

Methods

A prevalence study was performed, including 487 pregnant women and their newborns attended in the BUH of the urban zone of the city of Gurupi, state of Tocantins, Brazil, during the period from February 2012 to February 2014. The selection of the pregnant women occurred by convenience. In the antenatal admission they were invited to participate in this study. Three samples of peripheral blood were collected for the detection of specific anti-T. gondii IgG, IgM and IgA through ELISA, for the polimerase chain reaction (PCR) and IgG avidity during pregnancy. When IgM antibodies were detected the fetal and newborn infection investigation took place. The newborn was investigated right after birth and after one year of age through serology and PCR to confirm/exclude the vertical transmission. The analyses were performed in the Studies of the Host-Parasite Relationship Laboratory (LAERPH, IPTSP-UFG), Goiania, state of Goias, Brazil. The results were inserted in a data bank in Epi-Info 3.3.2 statistic software in which the analysis was performed with p≤5%.

Results

The toxoplasmosis infection was detected in 68.37% (333/487, CI95%: 64.62–72.86). The toxoplasmosis chronic infection prevalence was of 63.03% (307/487, CI95%: 58.74–67.32). The prevalence of maternal acute infection was of 5.33% (26/487; CI95%: 3.3–7.3) suspected by IgM antibodies detection in the peripheral blood. The prevalence of confirmed vertical transmission was of 28% (7/25; CI95%: 10.4–45.6).

Conclusions

These results show an elevated prevalence of toxoplasmosis in pregnant women and vertical transmission of T. gondii in the city of Gurupi, state of Tocantins, Brazil.

In Vitro and In Vivo Effects of the Bumped Kinase Inhibitor 1294 in the Related Cyst-Forming Apicomplexans Toxoplasma gondii and Neospora caninum

We report on the in vitro effects of the bumped kinase inhibitor 1294 (BKI-1294) in cultures of virulent Neospora caninum isolates Nc-Liverpool (Nc-Liv) and Nc-Spain7 and in two strains of Toxoplasma gondii (RH and ME49), all grown in human foreskin fibroblasts. In these parasites, BKI-1294 acted with 50% inhibitory concentrations (IC50s) ranging from 20 nM (T. gondii RH) to 360 nM (N. caninum Nc-Liv), and exposure of intracellular stages to 1294 led to the nondisjunction of newly formed tachyzoites, resulting in the formation of multinucleated complexes similar to complexes previously observed in BKI-1294-treated N. caninum beta-galactosidase-expressing parasites. However, such complexes were not seen in a transgenic T. gondii strain that expressed CDPK1 harboring a mutation (G to M) in the gatekeeper residue. In T. gondii ME49 and N. caninum Nc-Liv, exposure of cultures to BKI-1294 resulted in the elevated expression of mRNA coding for the bradyzoite marker BAG1. Unlike in bradyzoites, SAG1 expression was not repressed. Immunofluorescence also showed that these multinucleated complexes expressed SAG1 and BAG1 and the monoclonal antibody CC2, which binds to a yet unidentified bradyzoite antigen, also exhibited increased labeling. In a pregnant mouse model, BKI-1294 efficiently inhibited vertical transmission in BALB/c mice experimentally infected with one of the two virulent isolates Nc-Liv or Nc-Spain7, demonstrating proof of concept that this compound protected offspring from vertical transmission and disease. The observed deregulated antigen expression effect may enhance the immune response during BKI-1294 therapy and will be the subject of future studies.