Seroepidemiology of human Toxoplasma gondii infection in China

Seroprevalence and Associated Risk Factors of Toxoplasma gondii in Patients Diagnosed with Schizophrenia: A Case-Control Cross Sectional Study

The protozoan parasite, Toxoplasma gondii, has been linked to several psychiatric disorders, including schizophrenia. The aim of this study was to assess the prevalence of T. gondii IgG antibodies and risk factors associated with seroprevalence in patients diagnosed with schizophrenia. This seroepidemiological study assessed 196 participants, divided into two groups. The study group consisted of 98 schizophrenic patients and was matched with 98 healthy blood donors. A questionnaire was used to gather information regarding potential risk factors associated with T. gondii seroprevalence. Results revealed a higher seroprevalence of T. gondii IgG antibodies in schizophrenic patients (69.39%, 68/98) when compared to healthy controls (51.02%, 50/98) (OR: 2.18; 95% CI: 1.21-3.9; p = 0.01). Patients with schizophrenia who consumed raw or undercooked meat (80.65%, 25/31) (OR: 3.75; 95% CI: 1.25-11.21, p = 0.02) and those with a lower educational level (77.59%, 45/58) (OR: 3.5; 95% CI: 1.59-7.54, p = 0.002) presented increased T. gondii seropositivity rates versus their control counterparts. Our findings indicate a high T. gondii IgG seroprevalence in patients diagnosed with schizophrenia compared to healthy blood donors. Factors associated with T. gondii seroprevalence were consumption of raw or uncooked meat and a lower educational attainment. This study provided the first data regarding the potential risk factors for toxoplasmosis in Romanian patients diagnosed with schizophrenia and may serve as a foundation for future research and the development of preventive strategies.

Risk Factors Associated with Toxoplasma gondii in Patients with Cardiovascular Diseases from Western Romania

BACKGROUND

Limited data are available in the existing literature regarding the seroepidemiology of T. gondii infection among cardiovascular patients. We aimed to comprehensively assess the prevalence of T. gondii infection and associated risk factors among Romanian cardiovascular patients.

METHODS

Serologic testing was conducted in 1205 patients with cardiovascular diseases to demonstrate the presence of T. gondii antibodies. An avidity test was performed in patients with detectable IgG and IgM antibodies. A structured questionnaire was designed to identify the potential risk factors associated with T. gondii. Results: The overall seroprevalence of T. gondii antibodies was 52.1%, with the highest value observed in patients diagnosed with dilated cardiomyopathy (66.66%) and the lowest in patients with myopericarditis (30.0%). The 11 patients found with detectable IgM and IgG antibodies had a high avidity test result. A patient's area of residence, gender, educational level, owning dogs, owning any pet, and toxoplasmosis awareness were significantly associated with T. gondii seropositivity in multiple logistic regression analyses.

CONCLUSIONS

This study provides novel and valuable insights into the seroprevalence and risk factors associated with T. gondii among Romanian cardiovascular patients. Our findings reiterate the importance of toxoplasmosis awareness and health education for better control and prevention of infection with T. gondii.

Parasites as potential targets for cancer immunotherapy

Parasites and cancers have some common antigens. Much scientific evidence in the human population, animal models, and in vitro experiments exhibit that parasites have significant anti-cancer effects. The larval stage of the tapeworm Echinococcus granulosus, Toxoplasma gondii, Trypanosoma cruzy, Plasmodium's, and Trichinella spiralis are among the parasites that have been subjects of anti-cancer research in the last decades. Anti-tumor effects of parasites may be due to the direct impact of the parasites per se or indirectly due to the immune response raised against common antigens between malignant cells and parasites. This manuscript reviews the anti-cancer effects of parasites and possible mechanisms of these effects. Options for using parasites or their antigens for cancer treatment in the future have been discussed.

Protein kinases on carbon metabolism: potential targets for alternative chemotherapies against toxoplasmosis

The apicomplexan parasite Toxoplasma gondii is the causative agent of toxoplasmosis, a global disease that significantly impacts human health. The clinical manifestations are mainly observed in immunocompromised patients, including ocular damage and neuronal alterations leading to psychiatric disorders. The congenital infection leads to miscarriage or severe alterations in the development of newborns. The conventional treatment is limited to the acute phase of illness, without effects in latent parasites; consequently, a cure is not available yet. Furthermore, considerable toxic effects and long-term therapy contribute to high treatment abandonment rates. The investigation of exclusive parasite pathways would provide new drug targets for more effective therapies, eliminating or reducing the side effects of conventional pharmacological approaches. Protein kinases (PKs) have emerged as promising targets for developing specific inhibitors with high selectivity and efficiency against diseases. Studies in T. gondii have indicated the presence of exclusive PKs without homologs in human cells, which could become important targets for developing new drugs. Knockout of specific kinases linked to energy metabolism have shown to impair the parasite development, reinforcing the essentiality of these enzymes in parasite metabolism. In addition, the specificities found in the PKs that regulate the energy metabolism in this parasite could bring new perspectives for safer and more efficient therapies for treating toxoplasmosis. Therefore, this review provides an overview of the limitations for reaching an efficient treatment and explores the role of PKs in regulating carbon metabolism in Toxoplasma, discussing their potential as targets for more applied and efficient pharmacological approaches.

Seeing Neurodegeneration in a New Light Using Genetically Encoded Fluorescent Biosensors and iPSCs

Neurodegenerative diseases present a progressive loss of neuronal structure and function, leading to cell death and irrecoverable brain atrophy. Most have disease-modifying therapies, in part because the mechanisms of neurodegeneration are yet to be defined, preventing the development of targeted therapies. To overcome this, there is a need for tools that enable a quantitative assessment of how cellular mechanisms and diverse environmental conditions contribute to disease. One such tool is genetically encodable fluorescent biosensors (GEFBs), engineered constructs encoding proteins with novel functions capable of sensing spatiotemporal changes in specific pathways, enzyme functions, or metabolite levels. GEFB technology therefore presents a plethora of unique sensing capabilities that, when coupled with induced pluripotent stem cells (iPSCs), present a powerful tool for exploring disease mechanisms and identifying novel therapeutics. In this review, we discuss different GEFBs relevant to neurodegenerative disease and how they can be used with iPSCs to illuminate unresolved questions about causes and risks for neurodegenerative disease.

Assessment of Geographical Distribution of Emerging Zoonotic Toxoplasma gondii Infection in Women Patients Using Geographical Information System (GIS) in Various Regions of Khyber Pakhtunkhwa (KP) Province, Pakistan

Toxoplasmosis is a zoonotic parasitic disease caused by T. gondii, an obligate intracellular apcomplexan zoonotic parasite that is geographically worldwide in distribution. The parasite infects humans and all warm-blooded animals and is highly prevalent in various geographical regions of the world, including Pakistan. The current study addressee prevalence of Toxoplasma infection in women in various geographical regions, mapping of endemic division and t district of Khyber Pakhtunkhwa province through geographical information system (GIS) in order to locate endemic regions, monitor seasonal and annual increase in prevalence of infection in women patients. Setting: Tertiary hospitals and basic health care centers located in 7 divisions and 24 districts of Khyber Pakhtunkhwa (KP) province of Pakistan. During the current study, 3586 women patients from 7 divisions and 24 districts were clinically examined and screened for prevalence of T. gondii infection. Participants were screened for Toxoplasma infection using ICT and latex agglutination test (LAT) as initial screening assay, while iELISA (IgM, IgG) was used as confirmatory assay. Mapping of the studied region was developed by using ArcGIS 10.5. Spatial analyst tools were applied by using Kriging/Co-kriging techniques, followed by IDW (Inverse Distance Weight) techniques. Overall prevalence of T. gondii infection was found in 881 (24.56%) patients. A significant (<0.05) variation was found in prevalence of infection in different divisions and districts of the province. Prevalence of infection was significantly (<0.05) high 129 (30.07%) in Kohat Division, followed by 177 (29.06%), 80 (27.87%), 287 (26.72%), 81 (21.21%), 47 (21.07%), and 80 (13.71%) cases in Hazara Division, D.I Khan Division, Malakand Division, Mardan Division, Bannu Division, and Peshawar Division. Among various districts, a significant variation (<0.05) was found in prevalence of infection. Prevalence of infection was significantly (<0.05) high 49 (44.95%) in district Karak, while low (16 (10.81%) in district Nowshera. No significant (>0.05) seasonal and annual variation was found in prevalence of Toxoplasma infection. LAT, ICT and ELISA assays were evaluated for prevalence of infection, which significantly (<0.05) detected T. gondii antibodies. LAT, ICT and ELISA assays significantly (<0.05) detected infection, while no significant (>0.05) difference was found between positivity of LAT and ICT assays. A significant difference (<0.05) was found in positivity of Toxoplasma-specific (IgM), (IgG) and (IgM, IgG) immunoglobulin by ICT and ELISA assay. The current study provides comprehensive information about geographical distribution, seasonal and annual variation of Toxoplasmosis infection in various regions of Khyber Pakhtunkhwa province of Pakistan. Infection of T. gondii in women shows an alarming situation of disease transmission from infected animals in the studied region, which is not only a serious and potential threat for adverse pregnancy outcomes, but also cause socioeconomic burden and challenges for various public and animal health organizations in Pakistan and across the country.

Association between toxoplasmosis and bipolar disorder: A systematic review and meta-analysis

BACKGROUND

The relationship between toxoplasma gondii (T. gondii) infection and bipolar disorder (BD) is poorly understood. This review explores this relationship by estimating the strength of the association between the two conditions using data from published studies.

METHODS

Following PRISMA guidelines, we performed a review and meta-analysis of published articles obtained from a systematic search of PubMed, PsycINFO, EMBASE and the Cochrane library up to January 10th, 2021. We included observational studies that compared seroprevalence of IgG class antibodies against T. gondii in patients with a diagnosis of BD with healthy controls. We excluded studies that included <10 participants in each study arm and patients with a serious concomitant medical illness. Discrepancies between the two independent researchers were resolved by consulting a third experienced researcher. Summary data were extracted from published reports. Analysis was conducted using both fixed-effects and random-effects models. The study is registered with PROSPERO number CRD42021237809.

FINDINGS

The search yielded 23 independent studies with a total of 12690 participants (4021 with BD and 8669 controls). Persons with BD had a greater odd of seropositivity with toxoplasmosis than controls, both in the fixed-effects model (OR = 1.34 [95%CI: 1.19 to 1.51]) and the random-effects model (OR = 1.69 [95%CI: 1.21 to 2.36]). No publication bias was detected but reported results showed a high heterogeneity (I2 = 84% [95%CI:77%-89%]).

INTERPRETATION

The findings support the relationship between toxoplasmosis infection and BD and suggests a need for studies designed to explore possible causal relationship. Such studies may also improve our understanding of the pathophysiology of BD and open other avenues for its treatment.

FUNDING

P.O.R. Sardegna F.S.E. 2014-2020.

Is latent Toxoplasma gondii infection associated with the occurrence of schizophrenia? A case-control study

Introduction

Neurotropic pathogens such as Toxoplasma gondii (T. gondii) which result in chronic infections in the brain are associated with mental illnesses. In view of this, a growing body of literature has revealed the possible interaction of schizophrenia and T. gondii infection.

Method

A case-control study was conducted from February 2018 to January 2019 among 47 Schizophrenia patients and 47 age and sex-matched controls. Data was collected using a structured questionnaire. Serum was used for serological analysis of anti-T. gondii IgG and IgM antibodies through chemiluminescent immunoassay. Proportions and mean with standard deviations (SD) were used as descriptive measures and variables with p-values <0.05 were considered as statistically significant and independently associated with schizophrenia.

Result

The mean ages of schizophrenia patients and controls were 29.64 ± 5.8 yrs and 30.98 ± 7.3 yrs, respectively. We found that 81.9% (77/94) of the study subjects had a positive anti-T. gondii IgG antibody. While the difference is statistically insignificant, schizophrenic patients have a marginally higher seroprevalence of toxoplasmosis than controls (87.2% vs 80.9%; p = 0.398). Schizophrenia cases who live in homes with soil floors have a significantly higher T. gondii infection as compared to those who live in homes with cement/ceramic floors (90.9% vs 33.3%; p = 0.004). Furthermore, there was a significantly lower T. gondii infection among schizophrenic cases who were taking antipsychotic medication for more than three yrs (79.3% vs 100.0%, p = 0.039). On the other hand, among all study subjects who have T. gondii infection, subjects who are addicted to khat and alcohol were about seven times more likely to develop schizophrenia (71.4% vs 47.7%, OR = 7.13, p = 0.024).

Conclusion

Our data is not sufficient to show a significant positive correlation between T. gondii infection and schizophrenia. For study subjects with T. gondii infection, addiction to khat and alcohol is one of the risk factors for schizophrenia.

Sero-prevalence of 19 infectious pathogens and associated factors among middle-aged and elderly Chinese adults: a cross-sectional study

OBJECTIVES

To systematically assess the sero-prevalence and associated factors of major infectious pathogens in China, where there are high incidence rates of certain infection-related cancers.

DESIGN

Cross-sectional study.

SETTING

10 (5 urban, 5 rural) geographically diverse areas in China.

PARTICIPANTS

A subcohort of 2000 participants from the China Kadoorie Biobank.

PRIMARY MEASURES

Sero-prevalence of 19 pathogens using a custom-designed multiplex serology panel and associated factors.

RESULTS

Of the 19 pathogens investigated, the mean number of sero-positive pathogens was 9.4 (SD 1.7), with 24.4% of participants being sero-positive for >10 pathogens. For individual pathogens, the sero-prevalence varied, being for example, 0.05% for HIV, 6.4% for human papillomavirus (HPV)-16, 53.5% for Helicobacter pylori (H. pylori) and 99.8% for Epstein-Barr virus . The sero-prevalence of human herpesviruses (HHV)-6, HHV-7 and HPV-16 was higher in women than men. Several pathogens showed a decreasing trend in sero-prevalence by birth cohort, including hepatitis B virus (HBV) (51.6% vs 38.7% in those born <1940 vs >1970), HPV-16 (11.4% vs 5.4%), HHV-2 (15.1% vs 8.1%), Chlamydia trachomatis (65.6% vs 28.8%) and Toxoplasma gondii (22.0% vs 9.0%). Across the 10 study areas, sero-prevalence varied twofold to fourfold for HBV (22.5% to 60.7%), HPV-16 (3.4% to 10.9%), H. pylori (16.2% to 71.1%) and C. trachomatis (32.5% to 66.5%). Participants with chronic liver diseases had >7-fold higher sero-positivity for HBV (OR=7.51; 95% CI 2.55 to 22.13).

CONCLUSIONS

Among Chinese adults, previous and current infections with certain pathogens were common and varied by area, sex and birth cohort. These infections may contribute to the burden of certain cancers and other non-communicable chronic diseases.

The Role of Type II Fatty Acid Synthesis Enzymes FabZ, ODSCI, and ODSCII in the Pathogenesis of Toxoplasma gondii Infection

Toxoplasma gondii is an obligate intracellular protozoan parasite, which has a worldwide distribution and can infect a large number of warm-blooded animals and humans. T. gondii must colonize and proliferate inside the host cells in order to maintain its own survival by securing essential nutrients for the development of the newly generated tachyzoites. The type II fatty acid biosynthesis pathway (FASII) in the apicoplast is essential for the growth and survival of T. gondii. We investigated whether deletion of genes in the FASII pathway influences the in vitro growth and in vivo virulence of T. gondii. We focused on beta-hydroxyacyl-acyl carrier protein dehydratase (FabZ) and oxidoreductase, short chain dehydrogenase/reductase family proteins ODSCI and ODSCII. We constructed T. gondii strains deficient in FabZ, ODSCI, and ODSCII using CRISPR-Cas9 gene editing technology. The results of immunofluorescence assay, plaque assay, proliferation assay and egress assay showed that in RHΔFabZ strain the apicoplast was partly lost and the growth ability of the parasite in vitro was significantly inhibited, while for RHΔODSCI and RHΔODSCII mutant strains no similar changes were detected. RHΔFabZ exhibited reduced virulence for mice compared with RHΔODSCI and RHΔODSCII, as shown by the improved survival rate. Deletion of FabZ in the PRU strain significantly decreased the brain cyst burden in mice compared with PRUΔODSCI and PRUΔODSCII. Collectively, these findings suggest that FabZ contributes to the growth and virulence of T. gondii, while ODSCI and ODSCII do not contribute to these traits.

Global seroprevalence of Toxoplasma gondii in Camelidae: A systematic review and meta-analysis

PURPOSE

The present study aimed to analyze data available of the seroprevalence of Toxoplasma gondii (T. gondii) among camelids around the world.

METHODS

The search was performed using seven international databases including Scopus, PubMed, Google Scholar, ProQuest, ScienceDirect, Web of Science, and EMBASE up to 11 October 2018. Random effects model was used to determine the pooled seroprevalence of T. gondii infection with 95% confidence intervals (CI) and analyzed data from four continents. Subgroup and meta-regression analyses were also performed according to continent and gender.

RESULTS

In total, 42 studies out of 3517 published articles involving 14,542 camels from 17 countries were included for the final analyses. The global pooled seroprevalence of T. gondii infection in the Camelidae family was 28.16% (95% CI 23.64-32.68%). Besides, the highest seroprevalence rate was in Europe (49.64%) followed by Africa (37.63%), America (21.76%), and Asia (17.58%). Moreover, the overall seroprevalence rates of T. gondii infection were 22% (95% CI 10-33%) and 15% (95% CI 9-22%) for the females and males, respectively.

CONCLUSION

This meta-analysis showed a high seroprevalence of T. gondii infection in camelids as these animals play an important role in the transmission cycle of this zoonotic disease.

Potential linkage between Toxoplasma gondii infection and physical education scores of college students

Objective

Toxoplasma gondii is a worldwide protozoan parasite that could infect virtually all warm-blooded animals, including humans. Our study aimed to investigate the prevalence of T. gondii infection in college students at Anhui province, China and to assess risk factors for T. gondii infection in college students. Moreover, growing studies demonstrated the association between T. gondii infection and host behavioral changes. We also studied the linkage between T. gondii and physical education (PE) scores of college students.

Methods

A total of 2704 serum samples of medical school students attending physical education lessons were collected from September 2017 to September 2019 and evaluated for T. gondii IgG antibodies using an enzyme-linked immunosorbent assay (ELISA). Questionnaires and statistical analysis were used to determine the risk factors for T. gondii infection. We also analysed PE scores of T. gondii -infected students and T. gondii-uninfected students.

Results

The overall seroprevalence of T. gondii was 11.5%. The main risk factors related to T. gondii infection in college students were cat in the household and gardening or agriculture activity. Furthermore, in the basketball group and the soccer group, scores of T. gondii seropositive students were significantly higher than those of seronegative students, while in other sports there was no difference between scores of T. gondii-infected students and T. gondii uninfected students.

Conclusion

This is the first report of T. gondii seroprevalence in college students in Anhui province, China.

Expression of TIGIT in splenic and circulatory T cells from mice acutely infected with Toxoplasma gondii

The surface protein TIGIT (T cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif (ITIM) domain) has been characterized as an important regulator of cell-mediated immune responses in various infections. However, TIGIT expression in immune cells of mice infected with Toxoplasma gondii has not been investigated. Here, we detected TIGIT expression and related phenotypes by flow cytometry and real-time PCR in splenic and circulatory T cells of mice infected with the T. gondii RH strain. We found that the expression of TIGIT on the surface of CD4⁺ T cells and CD8⁺ T cells from the spleen and peripheral blood mononuclear cells decreased in the early stage, but increased significantly in the late stage of acute T. gondii infection in mice. Importantly, TIGIT expression was positively correlated with lesions in the murine spleen. In addition, T. gondii-specific TIGIT⁺T_CM cells in the spleen were activated and transformed into TIGIT⁺ T_EM cells. Hematoxylin and eosin staining of spleen sections and real-time PCR showed that the severity of splenic lesions was positively correlated with the T. gondii load. This study demonstrates that acute T. gondii infection can regulate the expression of TIGIT in T cells and affect immune cell function.

Ocular Toxoplasmosis in Africa: A Narrative Review of the Literature

PURPOSE

To present a narrative review about ocular toxoplasmosis epidemiology, disease burden and prevalent African parasitic strains.

METHODS

An initial search for MeSH terms was conducted with a posterior advanced search in two electronic databases. Full text reading was performed.

RESULTS

Animal African studies have identified Toxoplasma gondii type II, type III, Africa 1, and Africa 3 strains. Seroprevalence varies from 6.4% to 74.5%. Nevertheless, there is a scarcity of epidemiology and serotyping information about ocular toxoplasmosis. African studies have demonstrated that uveitis patients present high frequencies of ocular toxoplasmosis. There is a lack of studies describing specific clinical characteristics, which can be related, to environmental and socioeconomic factors, parasite serotype and genotype, and genetic susceptibility of the host.

CONCLUSION

As Toxoplasma gondii has more virulent strains in the Southern hemisphere, it is relevant to determine African strain types and the correlation between the infecting strains and the clinical manifestations.

Low Prevalence of Antibodies Against Toxoplasma gondii in Chinese Populations

Toxoplasma gondii has been found to infect almost all warm-blooded animals, including humans. In this study, a total of 3,275 human serum samples were collected from hospitals in five provinces of China. About 5.13% (168/3,275) (95% CI, 4.42–5.94) of the serum samples tested positive for T. gondii IgG antibody by a modified agglutination test (MAT) (cut-off: 1:20). Significant associations were detected between geographic location (OR = 1.763), age (OR = 3.072), infertility in women (OR = 2.4409) and T. gondii infection in humans (p < 0.05). To minimize infection, citizens need to be informed about the best practices for toxoplasmosis prevention, including eating well-cooked meat, drinking boiled water, washing vegetables and fruits, and being careful during contact with cats.

Human Toxoplasma gondii infection in Nigeria: a systematic review and meta-analysis of data published between 1960 and 2019

BACKGROUND

Over 70% of the worlds' population is infected by Toxoplasma gondii; a pathogen capable of causing cerebral toxoplasmosis in HIV patients and neonatal complications like miscarriage, chorioretinitis, hydrocephalus, cerebral calcification and foetal death in the third trimester of pregnancy. In spite of this, the burden of this zoonotic pathogen is poorly understood in Nigeria. The aim of the present study therefore, is to determine the burden of T. gondii among normal individuals, HIV patients and pregnant women as well as the distribution of the infection across Nigeria.

METHODS

Using the PRISMA guidelines, we conducted a systematic review and meta-analysis of data retrieved from six electronic databases (AJOL, Google Scholar, PubMed, Scopus, Science Direct and Web of Science). Pooled prevalence (PP) and heterogeneity were determined by the random-effects model and the Cochran's Q-test respectively. The quality of each study and publication bias were assessed by the 9 point Joanna Briggs Institute Critical Appraisal Instrument and the Egger's regression asymmetry test respectively, while the robustness of a pooled estimate was tested by the single study omission analysis.

RESULTS

Exactly 5834 of the 16,230 individuals examined for T. gondii infection by 50 studies across 17 Nigerian States were positive for the infection. Overall PP was 32.92% (95% CI: 27.89, 38.37), with a range of 14.41% (95% CI: 5.32, 33.54) to 86.82% (95% CI: 66.13, 95.69) across sub-groups. Pooled prevalence was significantly higher (p < 0.001) among pregnant women (40.25%; 95% CI: 33.19, 47.73) and HIV patients (31.68, 95% CI: 20.53, 45.41) than normal individuals (23.32, 95% CI: 17.25, 30.75). T. gondii prevalence declined by over 58% during the 59 years reviewed.

CONCLUSION

Toxoplasma gondii infection is moderately prevalent in Nigeria. Highest prevalence estimates were observed among pregnant women and in the south-south region. For effective control of the disease in Nigeria, a holistic approach involving on-farm, environmental, public health and animal components are suggested.

Seroprevalence and risk factors of Toxoplasma gondii infection in primary school children in Henan province, central China

Toxoplasma gondii is an obligate intracellular protozoan parasite with global distribution. However, data on T. gondii infection among children in primary school in Henan province, central China were lacking. In this study, 2451 serum samples of primary school children in this province were collected from September 2015 to October 2018 and evaluated for T. gondii antibodies using an enzyme-linked immunosorbent assay (ELISA). The overall seroprevalence was 9.51% (233/2451), of which 7.59% (186/2451) showed IgG positivity, 0.73% (18/2451) IgM and 1.18% (29/2451) both. The main risk factors related to T. gondii infections were the age of children, residence area, contact with cats, and exposure to soil. Moreover, hand washing before eating was considered a protective factor. Seroprevalence of T. gondii infection among the study population was common, emphasizing the need to prevent and control this infection. This is the first report of T. gondii seroprevalence in primary school children in Henan province, central China.

Seroprevalence of hepatitis E virus among different age groups in Tehran, Iran

Hepatitis E virus (HEV) is considered to be a public health problem on a global scale, especially in developing countries. This study aims to investigate the seroprevalence of HEV in the Tehrani population. This descriptive-analytical study was carried out between the years 2017 and 2018 in Tehran, Iran. A total of 493 individuals whose blood samples and demographic data were collected via questionnaires through random cluster sampling were selected. To determine the presence of specific IgG antibody against HEV, commercial kits were used through ELISA. Chi-squared tests, logistic regression and t test were also required to conduct the statistical analysis. Of the 493 participants, with a mean age of 40.98 ± 17.10 years, included in this study, 180 were men and 313 were women. Of these, 48 (9.7%) had IgG antibodies against HEV. No significant difference was observed between the sexes (or different age groups) and positive antibody. It has been reported that the prevalence rate of this infection is high in Tehran, which is indicative of the endemic nature of this infection in society. The results of this study are similar to those obtained from the east of Golestan province, Iran but different from those obtained from Isfahan province, Iran. As a high percentage of people are susceptible to the infection in society, it is likely to have the prevalence of an epidemic.

A Transcriptome Analysis: Various Reasons of Adverse Pregnancy Outcomes Caused by Acute Toxoplasma gondii Infection

Background

Toxoplasma gondii (T. gondii) is an obligate intracellular parasite, which can affect the pregnancy outcomes in infected females by damaging the uterus, and the intrauterine environment as well as and the hypothalamus resulting in hormonal imbalance. However, the molecular mechanisms underlying the parasite-induced poor pregnancy outcomes and the key genes regulating these mechanisms remain unclear. Therefore, this study aimed to analyze the gene expression in the mouse’s uterus following experimentally-induced acute infection with T. gondii RH strain. Three groups of female mice were intraperitoneally injected with tachyzoites as follow; 3 days before pregnancy (FBD6), after pregnancy (FAD6), and after implantation (FID8) as the experimental groups. Another corresponding three groups served as control, were injected with normal saline at the same time. Transcriptome analysis of the total RNA extracted from both infected and non-infected mouse uterus samples was performed using RNA sequencing (RNA-Seq).

Results

The three experimental groups (FBD6, FAD6, and FID8) had a total of 4,561, 2,345, and 2,997 differentially expressed genes (DEGs) compared to the controls. The significantly upregulated and downregulated DEGs were 2,571 and 1,990 genes in FBD6, 1,042 and 1,303 genes in FAD6 and 1,162 and 1,835 genes in FID8 group, respectively. The analysis of GO annotation, and KEGG pathway showed that DEGs were mainly involved in anatomical structure development, transport, cell differentiation, embryo development, hormone biosynthetic process, signal transduction, immune system process, phagosome, pathways in cancer, and cytokine-cytokine receptor interaction pathways.

Conclusion

T. gondii infection can induce global transcriptomic changes in the uterus that may cause pregnancy hypertension, destruct the intrauterine environment, and hinder the normal development of placenta and embryo. Our results may help to understand the molecular mechanisms of the acute T. gondii infection, which could promote the development of new therapeutics or prophylactics for toxoplasmosis in pregnancy.

Identification of Host Proteins Interacting with Toxoplasma gondii SAG1 by Yeast Two-Hybrid Assay

Toxoplasma gondii is one of the most successful human pathogens. To eliminate the infection, identification of receptors or binding partners from humans is indeed urgent. T. gondii surface antigen is the ultimate component involved during the attachment of parasite into host cell. However, mechanism of invasion between SAG and host-cell membrane remains unclear. Yeast two-hybrid experiment was used to identify the binding partners from cDNA human library by using T. gondii SAG1 as bait. Mated yeast cells were plated on DDO/X plates to confirm only prey plasmid that expressing interacting protein was selected. We detected 39 clones interacted with SAG1 based on a series of the selection procedures. After colony PCR, only 29 clones were positive and subsequently sent for sequencing. The yeast plasmids for true positive clones were rescued by transformation into E. coli TOP 10F' cells. Twenty-two clones were further examined by small-scale Y2H experiment. The results indicated that a strong interaction existed between Homo sapiens lysine-rich coil-coiled and SAG1 protein, which could activate the expressions of the reporter genes in diploid yeast. Co-immunoprecipitation experiment result indicated the binding between this prey and SAG1 protein was significant (Mann-Whitney U test, Z = - 1.964, P = 0.05). H. sapiens lysine-rich coil-coiled protein was found to be interacted with SAG1. This prey protein may serve as the potential drug target in vaccination study.

Toxoplasma Serology Status and Risk of Miscarriage, A Case-Control Study among Women with A History of Spontaneous Abortion

Background

Toxoplasma gondii is one of the major causes of abortion in pregnant women. Most cases of abortion occur in the acute phase of infection and early pregnancy. The purpose of this study was to investigate the association between spontaneous abortion and seropositive status of toxoplasmosis in women with first-time spontaneous abortion.

Materials and Methods

This research is a case-control study on 240 serum samples from women experiencing spontaneous abortion for the first time as the case group, and 240 serum samples from women who had a normal delivery with no history of abortion as the control group. The level of anti-Toxoplasma gondii IgM and IgG antibodies were assessed in serum samples using ELISA. To separate the acute and chronic infections, all IgM-positive samples in both groups and IgG-positive samples of the case group were examined using IgG avidity.

Results

The toxoplasmosis IgM antibody was detected in 3.3% (8/240) of the case group and 0.4% (1/240) of the control group, which was a statistically significant difference between the two groups [P=0.019, odds ratio (OR)=10.266]. Of all samples 47.5% and 46.3% of the case and control groups were positive for toxoplasmosis IgG antibody, respectively. Seven out of 8 (87.5%) IgM-positive serum samples from the case group had low IgG avidity, indicating acute infections, whereas all IgG-positive sera and 1 IgM-positive serum, which was related to the control group, showed a high IgG avidity, indicating chronic infections.

Conclusion

Maternal acute toxoplasmosis during pregnancy is raised as one of the factors that increase the chance of spontaneous abortion. The necessary health training, especially on the parasite transmission ways to women before marriage, as well as the serological test in women before and during pregnancy is recommended. Polymerase chain reaction (PCR) and IgG avidity assays should be performed in the medical diagnostic laboratories for accurate distinguishing of the initial infection of toxoplasmosis in the pregnant women.

Is there any association between Toxoplasma gondii infection and depression? A systematic review and meta-analysis

BACKGROUND

Toxoplasma gondii (T. gondii) is an obligate intracellular opportunistic parasite that is the causative agent of toxoplasmosis. This parasite accounts for mental disorders; however, the relationship between T. gondii infection and depressive disorder is unclear. Regarding this, the present systematic review and meta-analysis was conducted to investigate the scientific evidence regarding the potential association between major depression disorder (MDD) and Toxoplasma infection.

METHODS

For the purpose of the study, the articles related to the subject of interest were systematically searched in seven electronic databases. Special attention was given to the studies examining T. gondii seropositivity level in depressed patients and controls.

RESULTS

The search process resulted in the identification of a total of 30 publications meeting the inclusion criteria and published up to April 2018 for the systematic review. Furthermore, 29 studies met the inclusion criteria to be entered into meta-analysis. Our meta-analysis involved the review of cross-sectional studies including 1657 depressed patients and 19565 individuals as controls and case-control studies entailing 1311 depressed cases and 6015 controls without depression. 1582 depressed people participated in cross-sectional studies whose results were reported as odds ratio (OR). In addition, the total number of participants was 15068 in this type of studies. Statistical analysis indicated that the pooled OR of the risk of anti-T. gondii IgG antibody in depressed individuals in case-control and cross-sectional studies was 1.15 (95% confidence interval (CI): 0.95-1.39).

CONCLUSIONS

As the findings of the reviewed articles indicated, toxoplasmosis is not a risk factor for MDD. However, it is necessary to perform further research to clarify the detailed association between T. gondii and dysthymia or mild and moderate depression. Furthermore, it is recommended to better investigate the effect of antibody titers on the relationship between depression and T. gondii infection.

Relationship between toxoplasmosis and obsessive compulsive disorder: A systematic review and meta-analysis

Background

A few studies investigated the relationship between toxoplasmosis and mental disorders, such as obsessive compulsive disorder (OCD). However, the specific nature of the association between Toxoplasma gondii (T. gondii) infection and OCD is not yet clear. The aim of this study was to collect information on the relationship between OCD and toxoplasmosis and assess whether patients with toxoplasmosis are prone to OCD.

Methods

For the purpose of this study, 6 major electronic databases and the Internet search engine Google Scholar were searched for the published articles up to July 30^th, 2018 with no restriction of language. The inverse variance method and the random effect model were used to combine the data. The values of odds ratio (OR) were estimated at 95% confidence interval (CI).

Results

A total of 9 case-control and 3 cross-sectional studies were included in our systematic review. However, 11 of these 12 articles were entered into the meta-analysis containing 9873 participants, out of whom 389 were with OCD (25.96% positive for toxoplasmosis) and 9484 were without OCD (17.12% positive for toxoplasmosis). The estimation of the random effect model indicated a significant common OR of 1.96 [95% CI: 1.32–2.90].

Conclusion

This systematic review and meta-analysis revealed that toxoplasmosis could be as an associated factor for OCD (OR = 1.96). However, further prospective investigations are highly recommended to illuminate the underlying pathophysiological mechanisms of T. gondii infection in OCD and to better investigate the relationship between OCD and T. gondii infection.

Toxoplasma gondii (T. gondii) is an obligate neurotropic parasite that infected about 25–30% of the total human population in the developed and developing countries. The obsessive compulsive disorder (OCD) is a psychiatric disease that affects the income and quality of life. Some studies confirmed an association between infectious agents as the associated or protective factors specifying the development of psychiatry diseases. Among various pathogens associated with psychological disorders, most of the attention is on T. gondii, which has a life-long asymptomatic latent phase after a short acute stage in healthy individuals. The detrimental effect of T. gondii on immunocompromised people and pregnant women is an important concern for public health. The correlation between toxoplasmosis and OCD is still relatively understudied with a paucity of documented findings. The previous meta-analysis reviewed only two studies and reported a 3.4-fold greater chance of OCD. The results of our study presented stronger evidence of a positive relationship between toxoplasmosis and OCD. Eventually, our research team hopes to present an overview of what is known and encourage more intensive research to determine the real impact of this parasite on the occurrence of OCD that may contribute to the prevention of OCD worldwide.

Negative Effects of Latent Toxoplasmosis on Mental Health

Infection by the parasite Toxoplasma, which affects about 33% of world population, is associated with an increased risk of several mental health disorders, the most strongly with schizophrenia. It is unknown whether schizophrenia is associated with this infection the most strongly, or whether this association has just been the most intensively studied for historical reasons. We used the data from 6,367 subjects tested for toxoplasmosis who took part in an internet survey to search for associations of these infections with 24 mental health disorders and evidence of otherwise impaired mental health. The typical symptom associated with toxoplasmosis was anxiety, and the typical toxoplasmosis-associated disorders were autism (OR = 4.78), schizophrenia (OR = 3.33), attention deficit hyperactivity disorder (OR = 2.50), obsessive compulsive disorder (OR = 1.86), antisocial personality disorder (OR = 1.63), learning disabilities (OR = 1.59), and anxiety disorder (OR = 1.48). Toxoplasmosis could play a substantial role in the etiopathogenesis of mental health disorders and its association with schizophrenia is the second strongest association, after autism.

Toxoplasma gondii Exposure and the Risk of Attention Deficit Hyperactivity Disorder in Children and Adolescents

BACKGROUND

Evidence suggests that Toxoplasma gondii, which causes toxoplasmosis, changes the metabolism of neurotransmitters, especially dopamine, resulting in both neurologic and psychiatric disorders. On the other hand, the dysregulation of catecholamines, especially of both norepinephrine and dopamine, has been proposed in the pathophysiology of attention deficit hyperactivity disorder (ADHD). The aim of the present study was to investigate anti-toxoplasma antibodies in children and adolescents with ADHD and compare it with a control group, to determine whether toxoplasmosis is a risk factor for ADHD.

METHODS

A total of 200 children and adolescents (117 patients with ADHD and 83 individuals without ADHD) participated in the study. Participants were tested for the presence of anti-T. gondii antibodies by enzyme-linked immunosorbent assay. A Parent ADHD Rating Scale and Clinical Global Impression-severity Scale were also completed. Data were analyzed using a χ test and Fisher exact test.

RESULTS

Anti-toxoplasma antibodies were detected in 18.1% of patients with ADHD disorder and 24% of individuals without ADHD. There was no significant difference in seropositivity between the 2 groups (P > 0.05). The number of patients with T. gondii infection in the 3 subgroups was 0, 9 and 12, respectively. The differences in infection rate among subgroups were not statistically significant (P > 0.05).

CONCLUSION

Although not conclusive, the present study does not support the theory that T. gondii is a risk factor for ADHD.

Functional Characterization of Dense Granule Proteins in Toxoplasma gondii RH Strain Using CRISPR-Cas9 System

Infection with the apicomplexan protozoan parasite Toxoplasma gondii is an ongoing public health problem. The parasite's ability to invade and replicate within the host cell is dependent on many effectors, such as dense granule proteins (GRAs) released from the specialized organelle dense granules, into host cells. GRAs have emerged as important determinants of T. gondii pathogenesis. However, the functions of some GRAs remain undefined. In this study, we used CRISPR-Cas9 technique to disrupt 17 GRA genes (GRA11, GRA12 bis, GRA13, GRA14, GRA20, GRA21, GRA28-31, GRA33-38, and GRA40) in the virulent T. gondii RH strain. The CRISPR-Cas9 constructs abolished the expression of the 17 GRA genes. Functional characterization of single ΔGRA mutants was achieved in vitro using cell-based plaque assay and egress assay, and in vivo in BALB/c mice. Targeted deletion of these 17 GRA genes had no significant effect neither on the in vitro growth and egress of the mutant strains from the host cells nor on the parasite virulence in the mouse model of infection. Comparative analysis of the transcriptomics data of the 17 GRA genes suggest that GRAs may serve different functions in different genotypes and life cycle stages of the parasite. In sum, although these 17 GRAs might not be essential for RH strain growth in vitro or virulence in mice, they may have roles in other strains or parasite stages, which warrants further investigations.

Seroprevalence of Toxoplasma gondii infection in blood donors in mainland China: a systematic review and meta-analysis

Toxoplasma gondii transmitted from blood donors to receiving patients has become a concern as numerous articles about the epidemiology of T. gondii infection in blood donors from different provinces have been published in China. This study aimed to evaluate the seroprevalence of T. gondii infection in Chinese blood donors using a meta-analysis. A total of 40 eligible studies, published from 1986 to 2017 and covering 18 provinces and municipalities were included. Among a total of 49,784 Chinese blood donors, the overall IgG seroprevalence of T. gondii infection was 6.26% (95% CI: 4.62%–8.13%). The highest prevalence was in the Northeast of China and the lowest in Central China. The infection rate increased slowly over the years, but not significantly. A statistically significant correlation was found between the seroprevalence of T. gondii infection and the detection method and educational level (p < 0.01). There was no relationship between age, gender, occupation and blood type and seroprevalence of T. gondii (p > 0.05). The prevalence of antibodies to T. gondii in Chinese blood donors was lower than in other countries, but the risk of transfusion-transmitted toxoplasmosis still exits. More concise methods are still needed to evaluate the possibility of transfusion-transmitted toxoplasmosis from blood donors.

The association between Toxoplasma gondii infection and hypertensive disorders in T2DM patients: a case-control study in the Han Chinese population

Type 2 diabetes mellitus (T2DM) is a major global health problem. The rate of infection with Toxoplasma gondii (T. gondii) is more than one-third of the total world population. The effects of T. gondii infection on the risk of diabetic complications and comorbidities are unclear. This study aims to determine the relationship between T. gondii infection and complications of T2DM in the Han Chinese population. We collected 1580 blood samples from T2DM patients and measured the levels of specific IgG antibodies against T. gondii in the sera of these patients using an ELISA assay. A logistic regression analysis was performed to estimate the effect of T. gondii infection on the complications of T2DM, while adjusting for age, gender, and triglyceride level (TG). We applied the multifactor dimensionality reduction (MDR) method to detect the interactions between T. gondii infections, demographic indexes and biochemical indicators among the different complications. Gender (the odds ratio (OR) = 0.63, 95%CI =0.45-0.89, P = 0.008) and TG level (OR = 0.64, 95%CI =0.45-0.89, P = 0.009) were influencing factors in T. gondii infections. T2DM patients who were infected with T. gondii had a 2.34 times risk of developing hypertension than those patients without T. gondii infection (OR = 2.34, 95%CI = 1.12-4.88, P = 0.024). The multiplicative interaction analysis and the additive interaction analysis did not reveal any evidence of interactive effects on diabetic complications and comorbidities. T. gondii might be a factor associated with hypertension in T2DM patients.

Seroprevalence and Manifestations of Ocular Toxoplasmosis in Patients with Schizophrenia

PURPOSE

Recent studies have linked infectious agents such as Toxoplasma gondii to schizophrenia. We investigated the seroprevalence of T. gondii and conducted ophthalmologic examinations in schizophrenia patients and controls to identify lesions suggestive of ocular toxoplasmosis.

METHODS

During 2015 and 2016, 34 schizophrenia patients and 85 healthy controls underwent ophthalmologic examination and anti-T. gondii IgG and IgM antibody measurements by chemiluminescence.

RESULTS

Schizophrenia patients had a higher prevalence of anti-T. gondii IgG positivity than controls (91.18% [95% confidence interval (CI), 77.04%-96.95%] vs. 70.59% [95% CI, 60.18%-79.21%]; p = 0.017). Anti-T. gondii IgM antibodies (acute form) were not detected in any patient. One (3%) schizophrenic patient and two (2.4%) control patients presented fundoscopic scarring.

CONCLUSION

The seropositivity rate was significantly higher among schizophrenia patients than among controls (p = 0.017). There was no association between the presence of fundoscopic scarring and schizophrenia (p = 1.000).

Seroepidemiology and Risk Factors of Toxoplasma gondii Infection among the Newly Enrolled Undergraduates and Postgraduate Students in China

Toxoplasma gondii is an obligate intracellular zoonotic parasite, infecting warm-blood animals including humans. Previous serological surveys of T. gondii infection have focused on people of different occupations and special groups, such as slaughterhouse workers, AIDS patients and pregnant women. To investigate the potential impact of T. gondii infection on the health of young students, the prevalence of T. gondii infection and associated risk factors among the newly enrolled undergraduates and postgraduate students were investigated. A total of 3,569 newly enrolled students (age range: 15- to 37-years-old, median 26 years) from various regions of China were recruited in this study. The serum samples were tested for the presence of T. gondii specific IgG by the modified agglutination test (MAT). Questionnaires were used to collect information on risk factors for T. gondii infection. Sixty-five (1.82%) out of 3,569 participants were seropositive for IgG antibodies to T. gondii by MAT (titer≥1:20). Four variables were found to be positively associated with T. gondii infection, including primary geographical location, living in rural areas, gardening or agriculture, and drinking unboiled water by the univariate logistic regression, and only gardening or agriculture was the independent risk factor for T. gondii positivity by using multivariate logistic regression in this study, which may provide information to guide future research and control policies.

Epidemiology of Toxoplasma gondii infection in native Tibetans in Tibet, China

Toxoplasma gondii (T. gondii) is one of the most common and widespread protozoan parasite which caused toxoplasma infection in animals and humans. Toxoplasma infection in healthy people is usually asymptomatic and it can lead to serious pathological effects in congenital cases and immunodeficient patients. The aim of the study is to investigate the prevalence of T. gondii infection in native Tibetans in Tibet as scarce information is available on such a high plateau. A total of 600 blood samples were collected from Tibetans people who visited the hospital in Nyingchi city with the history of flu, swollen lymph glands, muscle pain, and neurological or eyes complications (showing single or more signs). The serum of collected samples were tested for IgG antibody by ELISA. The result showed that the prevalence in men and women were 11.3% and 11.0%, respectively, the prevalence in different ages were 9.8% in < 7 years, 6.2% in ≥7-17 years, 10.1% in ≥18-40 years, 14.8% in ≥41-65 years and 11.6% in ≥66 years. The current study indicates the first report of this zoonotic parasite infection in Tibetan people.

Sixty Years (1957-2017) of Research on Toxoplasmosis in China-An Overview

Toxoplasma gondii is a ubiquitous zoonotic pathogen belonging to apicomplexan parasites. Infection in humans and animals may cause abortion and other severe symptoms under certain circumstances, leading to great economical losses and public health problems. T. gondii was first discovered in China in 1955 and the corresponding work was published in 1957. Since then, a lot of work has been done on this parasite and the diseases it causes. This review summarizes the major progress made by Chinese scientists over the last 60 years, and gives our perspectives on what should be done in the near future. A wide variety of diagnostic approaches were designed, including the ones to detect T. gondii specific antibodies in host sera, and T. gondii specific antigens or DNA in tissue and environmental samples. Further work will be needed to translate some of the laboratory assays into reliable products for clinic uses. Epidemiological studies were extensively done in China and the sero-prevalence in humans increased over the years, but is still below the world average, likely due to the unique eating and cooking habits. Infection rates were shown to be fairly high in meat producing animals such as, pigs, sheep, and chickens, as well as in the definitive host cats. Numerous subunit vaccines in the form of recombinant proteins or DNA vaccines were developed, but none of them is satisfactory in the current form. Live attenuated parasites using genetically modified strains may be a better option for vaccine design. The strains isolated from China are dominated by the ToxoDB #9 genotype, but it likely contains multiple subtypes since different ToxoDB #9 strains exhibited phenotypic differences. Further studies are needed to understand the general biology, as well as the unique features of strains prevalent in China.

The standardization of 5 immunoassays for anti-Toxoplasma immunoglobulin G(IgG)

BACKGROUND

Quantitative immunoassays to detect IgG antibodies are the most commonly used tests for diagnosing toxoplasmosis. We investigated the current state of standardization of quantitative immunoassays used to measure anti-Toxoplasma IgG levels.

METHODS

Four fully automated immunoassays (Architect i4000ISR, Immulite 2000 Xpi, Siemens; Liaison, DiaSorin; Cobas e601, Roche) and one manual immunoassay (ELISA classic Toxo IgG, Virion Serion) were performed on the following: individual patient serum samples, the WHO international standards, control samples, and calibrators provided by 5 immunoassay manufacturers. Statistical analysis was used to illustrate the results.

RESULTS

No perfect correlation (slope=1.0) was found between any 2 assays. Large differences in anti-Toxoplasma IgG titers were observed among the 5 immunoassays using serum samples from individual patients. Using IS 01/600 as a calibrator minimized the inter-assay variability of anti-Toxoplasma IgG values CONCLUSIONS: There is still significant effort needed towards standardization of anti-Toxoplasma IgG quantitative immunoassays.

Prevalence and Risk Factors for Toxoplasmosis in Middle Java, Indonesia

Toxoplasmosis is a zoonosis caused by Toxoplasma gondii. Risk factors include consumption of undercooked meat, raw vegetables, and unfiltered water. This study aims to determine the seroprevalence and spatial distribution of toxoplasmosis in Middle Java, Indonesia, using an EcoHealth approach, combined with geographic information system (GIS). A total of 630 participants were randomly selected from seven districts. Each participant completed a questionnaire and provided a blood sample. The seroprevalence of toxoplasmosis was 62.5%. Of those who were seropositive, 90.1% were IgG+, and 9.9% were IgG+ and IgM+. Several risk factors were identified, including living at elevations of ≤200 m, compared with >200 m (OR = 56.2; P < 0.001), daily contact with raw meat (OR = 1.8; P = 0.001), unfiltered water (OR = 1.7; P = 0.003), and density of cats (OR = 1.4; P = 0.045). Visualizing the spatial distribution of seropositive respondents highlighted clustering in lowland areas. This study highlighted that Middle Java has a high prevalence of toxoplasmosis and identified some important environmental, ecological, and demographic risk factors. When researching diseases, such as toxoplasmosis, where animal hosts, human lifestyle, and environmental factors are involved in transmission, an EcoHealth method is essential to ensure a fully collaborative approach to developing interventions to reduce the risk of transmission in high-risk populations.

Toxoplasmic encephalitis relapse rates with pyrimethamine-based therapy: systematic review and meta-analysis

Toxoplasmic encephalitis (TE) is caused by Toxoplasma gondii infection and can be a life-threatening disease in immunocompromised patients. This study evaluated the rate of relapse associated with pyrimethamine-based maintenance therapy (i.e. secondary prophylaxis) in patients with human immunodeficiency virus (HIV) or AIDs treated prior to and after the common use (i.e. 1996) of highly active antiretroviral therapy (HAART) (pre-HAART and post-HAART, respectively). PubMed, Google Scholar, and Cochrane databases were searched to 6 June 2016 using search terms: pyrimethamine, Daraprim, Fansidar, Metakelfin, Fansimef, 5-(4-chlorophenyl)-6-ethyl-2,4-pyrimidinediamine, encephalitis, cerebral, toxoplasmosis, toxoplasmic, and gondii. Single-arm cohort, retrospective, and randomized studies were included. Twenty-six studies with 1,596 patients were included in the analysis; twenty pre-HAART (n = 1,228) studies and six post-HAART (n = 368) were performed. Pooled proportions test for pyrimethamine-based therapy from pre-HAART studies indicated a relapse rate of 19.2% and 18.9% from the fixed-effects and random-effects models, respectively. The relapse rate in the post-HAART studies was 11.1% (fixed and random effects). Continuous therapy was suggestive of lower incidence of relapse compared with intermittent therapy in the pre-HAART era (range, 18.7 to 17.3% vs. 20.9 to 25.6%, respectively). These findings indicate that the likelihood of relapse associated with pyrimethamine-based therepy in patients with HIV and TE decreased after the introduction of HAART to approximately 11%. The findings have important implications as relapse may affect a patient’s disease severity and prognosis, increase utilization of health care resources, and result in additional health care expenditure.

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

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

Seroprevalence of Toxoplasma gondii infection and risk factors in domestic sheep in Henan province, central China

Sheep are highly susceptible to infections with Toxoplasma gondii and play a major role in the transmission of toxoplasmosis to humans. In the present study, 779 serum samples from sheep were collected from Henan province, central China from March 2015 to May 2016, and antibodies to T. gondii were detected by modified agglutination test (MAT). The overall seroprevalence of T. gondii in sheep was 12.71% (99/779). The risk factors significantly associated with T. gondii seroprevalence were the geographical origin, age, presence of cats, and the rearing system. This is the first report of T. gondii infection in sheep in Henan province, central China, and of an association of seropositivity to T. gondii with risk factors.

Seroepidemiology of toxoplasmosis in rural and urban communities from Los Rios Region, Chile

Background

Toxoplasmosis is a prevalent protozoan infection with a complex lifecycle and wide profile of risk factors. The impact of congenital infection is well documented; however, there is increasing evidence of a much broader range of potential health outcomes and the need to improve our understanding of the transmission patterns and infection sources in the overall population. This study examined the epidemiology of toxoplasmosis in distinct community types from a highly endemic area of Chile.

Methods

A cross-sectional serosurvey was carried out in households from urban slums, rural villages, and farms which included collection of blood samples, as well as data on sociodemographic, behavioral, and spatial variables. Blood samples were analyzed for the presence of T. gondii-specific IgG antibodies. Avidity index was obtained for IgG-positive samples. Mixed-effects regression modeling was used to identify associations with relevant risk factors.

Results

Crude seroprevalence was 55.9% (95% CI: 52.6–59.1%) with no difference by community type. Results are indicative of early exposure to the parasite, including 40% of 13- to 17-year olds who were already seropositive. Sociodemographic factors associated with seropositivity included age, occupations, and income. However, sex modified the effect of occupation as well as of income. Practices associated with increased seropositivity were consumption of sheep and locally produced vegetables as well as cleaning household barns or sheds. Boiling water for household use was a protective factor. Living on a sloped terrain without vegetation was a protective factor, while living in an area with high flow accumulation index was a risk factor.

Conclusions

Seroprevalence of infection was high in both rural and urban slum communities with unique risk factor profiles for each community type. Findings highlight the role of the household and the community environment as influential factors in the epidemiology of the infection. Increasing awareness is needed at the health care and public health levels to establish disease burden and options for suitable control programs.

Seroprevalence of Toxoplasma gondii Infection among HIV/AIDS Patients in Eastern China

Toxoplasmosis, a neglected tropical disease caused by the protozoan parasite Toxoplasma gondii, occurs throughout the world. Human T. gondii infection is asymptomatic in 80% of the population; however, the infection is life-threatening and causes substantial neurologic damage in immunocompromised patients such as HIV-infected persons. The major purpose of this study was to investigate the seroprevalence of T. gondii infection in subjects infected with HIV/AIDS in eastern China. Our findings showed 9.7% prevalence of anti-T. gondii IgG antibody in HIV/AIDS patients, which was higher than in intravenous drug users (2.2%) and healthy controls (4.7%), while no significant difference was observed in the seroprevalence of anti-Toxoplasma IgM antibody among all participants (P>0.05). Among all HIV/AIDS patients, 15 men (7.7%) and 10 women (15.9%) were positive for anti-T. gondii IgG antibody; however, no significant difference was detected in the seroprevalence of anti-Toxoplasma IgG antibody between males and females. The frequency of anti-Toxoplasma IgG antibody was 8.0%, 13.2%, 5.5%, and 0% in patients with normal immune function (CD4(+) T-lymphocyte count ≥500 cells/ml), immunocompromised patients (cell count ≥200 and <500 cells/ml), severely immunocompromised patients (cell count ≥50 and <200 cells/ml), and advanced AIDS patients, respectively (cell count <50 cells/ml), while only 3 immunocompromised patients were positive for anti-T. gondii IgM antibody. The results indicate a high seroprevalence of T. gondii infection in HIV/AIDS patients in eastern China, and a preventive therapy for toxoplasmosis may be given to HIV/AIDS patients based on CD4(+) T lymphocyte count.

Toxoplasmosis in HIV infection: An overview

Toxoplasma gondii is an obligate intracellular protozoan parasite presenting as a zoonotic infection distributed worldwide. In HIV-positive individuals, it causes severe opportunistic infections, which is of major public health concern as it results in physical and psychological disabilities. In healthy immunocompetent individuals, it causes asymptomatic chronic persistent infections, but in immunosuppressed patients, there is reactivation of the parasite if the CD4 counts fall below 200 cells/μl. The seroprevalence rates are variable in different geographic areas. The tissue cyst or oocyst is the infective form which enters by ingestion of contaminated meat and transform into tachyzoites and disseminate into blood stream. In immunocompetent persons due to cell-mediated immunity the parasite is transformed into tissue cyst resulting in life long chronic infection. In HIV-infected people opportunistic infection by T. gondii occurs due to depletion of CD4 cells, decreased production of cytokines and interferon gamma and impaired cytotoxic T-lymphocyte activity resulting in reactivation of latent infection. The diagnosis can be done by clinical, serological, radiological, histological or molecular methods, or by the combination of these. There is various treatment regimen including acute treatment, maintenance therapy should be given as the current anti T. gondii therapy cannot eradicate tissue cysts. In HIV patients, CD4 counts <100; cotrimoxazole, alternately dapsone + pyrimethamine can be given for 6 months. Hence, early diagnosis of T. gondii antibodies is important in all HIV-positive individuals to prevent complications of cerebral toxoplasmosis.

Seroprevalence of Toxoplasma gondii infection among patients with hand, foot and mouth disease in Henan, China: a hospital-based study

Background

The prevalence of infection with Toxoplasma gondii (T. gondii) in humans has been increasing in China due to the growing number of cats in the country. Hand, foot and mouth disease (HFMD) is a serious public health issue in China and still one of the leading causes of child mortality. However, little is known about the epidemiology of T. gondii infection among HFMD patients.

Methods

A case–control study of 281 HFMD patients from the First People’s Hospital of Pingdingshan in Pingdingshan city, Henan province, central China, and 222 controls from Pingdingshan city was conducted. Anti-T. gondii antibodies were serologically detected using the enzyme-linked immunosorbent assay.

Results

We found that the overall anti-T. gondii immunoglobulin G (IgG) antibody prevalence among HFMD patients was 12.46 %, which was significantly higher than that in clinically healthy children (1.80 %). The highest T. gondii seroprevalence was detected in critical cases (22.58 %), followed by severe cases (11.50 %), and the lowest was detected in mild cases (8.33 %).

Conclusion

The present study is the first survey of T. gondii seroprevalence among HFMD patients in China; 12.46 % were defined as seropositive. It is imperative that improved integrated measures are taken to prevent and control T. gondii infection among HFMD patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s40249-015-0088-3) contains supplementary material, which is available to authorized users.

Beyond the association. Toxoplasma gondii in schizophrenia, bipolar disorder, and addiction: systematic review and meta-analysis

OBJECTIVE

To perform a meta-analysis on studies reporting prevalence of Toxoplasma gondii (T. gondii) infection in any psychiatric disorder compared with healthy controls. Our secondary objective was to analyze factors possibly moderating heterogeneity.

METHOD

A systematic search was performed to identify studies into T. gondii infection for all major psychiatric disorders versus healthy controls. Methodological quality, publication bias, and possible moderators were assessed.

RESULTS

A total of 2866 citations were retrieved and 50 studies finally included. Significant odds ratios (ORs) with IgG antibodies were found in schizophrenia (OR 1.81, P < 0.00001), bipolar disorder (OR 1.52, P = 0.02), obsessive-compulsive disorder (OR 3.4, P < 0.001), and addiction (OR 1.91, P < 0.00001), but not for major depression (OR 1.21, P = 0.28). Exploration of the association between T. gondii and schizophrenia yielded a significant effect of seropositivity before onset and serointensity, but not IgM antibodies or gender. The amplitude of the OR was influenced by region and general seroprevalence. Moderators together accounted for 56% of the observed variance in study effects. After controlling for publication bias, the adjusted OR (1.43) in schizophrenia remained significant.

CONCLUSION

These findings suggest that T. gondii infection is associated with several psychiatric disorders and that in schizophrenia reactivation of latent T. gondii infection may occur.

Seroprevalence and risk factors of Toxoplasma gondii infection in humans in East Hararghe Zone, Ethiopia

A cross-sectional study was conducted from April 2013 to September 2013 to determine the seroprevalence and possible risk factors for human Toxplasma gondii infection in East Hararghe Zone, Ethiopia. Serum samples were analysed using direct agglutination test, and immunosorbent agglutination assay for detecting IgG (n = 354) and IgM (n = 167) T. gondii antibodies. The T. gondii IgG and IgM seroprevalences were 65·8% [95% confidence interval (CI) 60·62–70·75] and 8·98% (95% CI 5·11–14·38), respectively. Gender difference in IgG seroprevalence was not significant (P > 0·05), but 69·5% of adults exhibited an IgG seroresponse to T. gondii. Pregnant women showed 76·4% and 9·3% seropositivity to IgG and IgM antibodies, respectively. Multivariable logistic regression analysis identified the risk factors significantly associated with T. gondii seropositivity were district [odds ratio (OR) 2·24, 95% CI 1·25–4·01, P = 0·007], pipe water source (OR 6·70, 95% CI 2·70–16·64, P < 0·001), age, with adults (OR 4·32, 95% CI 1·91–9·75, P < 0·001), and keeping cats in the home (OR 2·01, 95% CI 1·11–3·65, P = 0·021). The high seroprevalence of toxoplasmosis in the human population in the study area and the corresponding level of IgM seropositivity may be indicative of reactivation or recent infection and further studies on the status of congenital toxoplasmosis in the study area merit consideration.

Results of the National External Quality Assessment for Toxoplasmosis Serological Testing in China

Background

Toxoplasmosis is typically diagnosed by serologic testing. External quality assessment (EQA) of clinical laboratories could ensure the accuracy and reliability of serological tests. We assessed the quality of toxoplasma serological assays in Chinese clinical laboratories by an EQA performed between 2004 and 2013 by the National Center for Clinical Laboratories.

Methodology and Findings

EQA panels were prepared and shipped at room temperature to participating laboratories that employed toxoplasma IgG and IgM serological detection. By 2013, 5,384 EQA test reports for toxoplasma-specific IgM and 2,666 reports for toxoplasma-specific IgG were collected. Enzyme-linked immunosorbent (ELISA) and chemical immunofluorescent assays were the most commonly used detection methods. The overall coincidence rates of negative samples were better than those of positive samples. The overall EQA score for toxoplasma-specific IgM detection ranged between 84.3% and 99.6%. The ratio of laboratories that achieved correct IgG detection ranged from 61.1% to 99.3%. However, the inter- and intra-assay variabilities were found to be considerable. The most common problem was failure to detect low titers of antibody.

Conclusion

The EQA scheme showed an improvement in toxoplasma serological testing in China. However, further optimization of assay sensitivity to detect challenging samples remains a future challenge.