A systematic review and meta-analysis of the prevalence of toxoplasmosis in hemodialysis patients in Iran

Latent Toxoplasma gondii infection and associated risk factors among patients with chronic kidney disease: a registry-based study

BACKGROUND

Patients with chronic kidney disease (CKD) are susceptible to acquiring opportunistic parasites due to acquired immunodeficiency caused by uremia. Therefore, the present case-control study attempted to determine the prevalence of T. gondii infection and also associated risk factors among patients with CKD under hemodialysis and healthy controls who were registered at the Iranian National Registry Center for Toxoplasmosis (INRCT) in Mazandaran Province, northern Iran.

METHODS

212 cases with CKD and 200 healthy controls were enrolled in this study. Informed consent as well as a questionnaire were obtained from all subjects. Blood samples were collected from each participant and the serum was screened for anti-Toxoplasma antibodies (IgG and IgM). PCR assay was performed to detect circulating T. gondii in the blood samples of patients and controls using the primer pair targeting the RE gene.

RESULTS

Out of 412 participants, 67.92% of patients and 15.5% of control subjects were positive for anti-Toxoplasma IgG, but all participants were negative for anti-Toxoplasma IgM. Also, considering PCR assays with RE target, the prevalence of T. gondii infection was 24.1% in case subjects, while none of the control subjects tested positive. Among the PCR positive, 34 (66.7%) had Toxoplasma IgG positivity. The results from the multiple multinomial logistic regression revealed that the seroprevalence of anti-T. gondii IgG antibodies in patients with CKD was 3.12 times higher than in healthy controls (OR = 3.12; 95% CI = 0.43, 14.8; P < 0.001). Also, there was a significant association between seroprevalence of T. gondii infection and age, having a cat at home, and level of glomerular filtration rate (GFR) in these patients.

CONCLUSION

Our findings demonstrate a highly significant association between latent T. gondii infection and CKD, mostly in the late stages. Thus, regular screening for T. gondii infection in these patients is strongly recommended to prevent the reactivation of latent infections. A combination of serological screening, chemoprophylaxis, and PCR follow-up for patients at risk of reactivation should effectively reduce the likelihood of latent infection reactivation.

CLINICAL TRIAL NUMBER

Not applicable.

Bacillus subtilis spores displaying Toxoplasma gondii GRA12 induce immunity against acute toxoplasmosis

Background

Toxoplasma gondii (T. gondii) is a widely prevalent intracellular parasite that infects almost all warm-blooded animals and causes serious public health problems. The drugs currently used to treat toxoplasmosis have the disadvantage of being toxic and prone to the development of resistance, and the only licensed vaccine entails a risk of virulence restoration. The development of a safe and effective vaccine against T. gondii is urgently needed. Bacillus subtilis (B. subtilis) has been used as a potential vaccine expression vector for the treatment and prevention of various diseases. T. gondii GRA12 is a key virulence factor that resists host innate immunity and exhibits good antigenicity with several excellent B and T cell epitopes.

Methods

A recombinant spore named rBS-GRA12 was constructed by fusing the T. gondii GRA12 protein to the B. subtilis coat protein B (CotB). rBS-GRA12 spores were identified by PCR, western blotting, immunofluorescence assays, amylase activity, and ultrastructural analysis. Immunological experiments were then conducted to assess the immunoprotective effects of rBS-GRA12. Groups of mice immunized with rBS-GRA12 (106, 108, or 1010 colony-forming units), GRA12 protein emulsified with Freund's adjuvant (FA+GRA12), Freund's adjuvant alone (FA), phosphate buffered saline (PBS), or wild-type B. subtilis spores (WT). Splenocyte proliferation, antibodies, and cytokine expression levels were used to assess immune responses induced by the immunizations. All groups were inoculated with T. gondii RH strain, and survival times and parasite loads in tissues were used to assess protective effects against T. gondii infection.

Results

Amylase activity assays confirmed the generation of recombinant B. subtilis. PCR, western blotting and immunofluorescence assays confirmed that the rBS-GRA12 spores expressed GRA12. Observation of rBS-GRA12 spores via transmission and scanning electron microscopy indicated that GRA12 expression had no effect on spore morphology or structure. Splenocyte proliferation was significantly greater in all three rBS-GRA12 groups than in the FA+GRA12 group, and IgG and IgG2a subclass titers were higher. Substantial production of interferon gamma (IFN-γ), interleukin (IL)-12, and an increase in IL-4 production were evident in the rBS-GRA12-108 group. Secretory sIgA levels were significantly elevated in all three rBS-GRA12 groups than in the FA+GRA12 group and the control groups. Brain and liver tissues parasite loads were significantly lower in the three rBS-GRA12 groups than in any other group. Compared to all other groups, mice in the three rBS-GRA12 groups exhibited longer survival times when challenged with acute T. gondii infection.

Conclusion

Mice immunized with rBS-GRA12 exhibited higher levels of cellular, humoral, and mucosal immune responses than control mice. These results provide a new perspective for the development of T. gondii vaccines.

Sero-molecular prevalence of toxoplasmosis in hemodialysis and peritoneal dialysis patients in Markazi Province, Iran

BACKGROUND

Infectious diseases, particularly parasitic infections such as toxoplasmosis, contribute significantly to the morbidity and mortality of hemodialysis patients. Toxoplasma gondii infection poses serious risks, especially to immunocompromised individuals. This study aimed to assess the prevalence of latent toxoplasmosis in dialysis patients in Markazi Province, Iran.

METHODS

A total of 181 patients (168 hemodialysis and 13 peritoneal dialysis) were included in this cross-sectional study. Blood samples were collected and tested for anti-Toxoplasma IgG and IgM antibodies using ELISA, while PCR was used to detect T. gondii DNA. Data were analyzed using SPSS, with P < 0.05 considered significant.

RESULTS

Out of 181 patients, 123 (67.95%) were seropositive for IgG antibodies, with the highest prevalence in those aged over 60 years. No cases tested positive for IgM antibodies or T. gondii DNA. Age was significantly associated with higher seroprevalence (P < 0.05), but there were no significant differences regarding gender, dialysis type, or duration of dialysis.

CONCLUSION

The high prevalence of latent toxoplasmosis in dialysis patients underscores the need for regular screening to prevent serious complications. Given the limitations of serological tests, molecular diagnostics like PCR should be considered for better detection in immunocompromised patients.

Potential Association Between Latent Toxoplasma gondii Infection and Suicide Attempts: A Case-Control Registry-Based Study

Toxoplasma gondii is a ubiquitous parasitic protozoan that may be an important cause of neurological and psychiatric diseases. The purpose of this case-control registry-based study was to evaluate the prevalence of T. gondii infection and related risk factors among subjects who attempted suicide by drug use and a control group at the Iranian National Registry Center for Toxoplasmosis in Mazandaran Province, northern Iran. Baseline data were collected from participants using a questionnaire, and a blood sample was taken from each individual. The plasma was prepared for serological analysis, whereas the buffy coat was used for molecular analysis. Out of 282 individuals (147 cases with suicide attempters [SA] and 135 controls), 42.9% of patients and 16.3% of control subjects were positive for anti-Toxoplasma immunoglobin G (IgG), but all participants were negative for T. gondii DNA and anti-Toxoplasma immunoglobin M. Based on multiple logistic regressions, IgG seropositivity in SA in the age group of 20-30 years was 3.22 times higher than that in the control group (p < 0.001). These findings suggest that latent T. gondii infection among SA is significantly higher than that in healthy individuals, indicating a potential association between latent toxoplasmosis and SA at least in the studied area. Further research is needed to shed light on the potential association between T. gondii and suicide among different populations and areas of the world.

Toxoplasma gondii seroprevalence in the Iranian blood donors: A systematic review and meta-analysis

Background

The present systematic review and meta-analysis was done to assess the rate of Toxoplasma gondii (T. gondii) exposure among Iranian healthy blood donors.

Methods

We searched four English (PubMed, Scopus, Web of Science, and Science Direct) and two Persian databases (Magiran and SID) as well as Google Scholar as a specialized article search engine using specific keywords for relevant papers from the inception up to November 30, 2023.

Results

In total, 19 studies enrolling 8226 apparently healthy blood donors were examined regarding T. gondii-specific IgG and/or IgM antibodies, among which 2666 [32.9% (95% CI: 25.3%-41.6%)], 168 [1.4% (95% CI: 0.9%-2.1%)], and 83 [1.7% (95% CI: 1.3%-2.1%)] subjects were seropositive regarding IgG, IgM, and both IgG/IgM antibodies, respectively. Five risk factors were significantly associated with T. gondii seroprevalence, including gender (OR = 1.98; 95% CI: 1.52-2.58; P < 0.001), contact with cat (OR = 2.41; 95% CI: 1.70-3.41; P < 0.001), contact with soil (OR = 2.83; 95% CI: 1.07-7.45; P = 0.035), consuming raw/undercooked meat (OR = 1.95; 95% CI: 1.03-3.70; P = 0.039), and raw/unwashed vegetables (OR = 1.70; 95% CI: 1.25-2.31; P = 0.001).

Conclusion

A moderate rate of T. gondii exposure was found in the Iranian blood donors, with the association of several risk factors, including gender, contact with cat, contact with soil, consumption of unwashed vegetables and/or undercooked meat. Still, more studies are recommended regarding T. gondii exposure among blood donors in Iran.

Toxoplasma gondii molecular detection and phylogenetic analysis in hemodialysis patients from Khuzestan, Southwest Iran

BACKGROUND

The diagnosis and genetic characterization of Toxoplasma gondii (T. gondii) infection can make a significant influence to the prevention of the dangerous consequences of toxoplasmosis, particularly in immunocompromised people.

OBJECTIVE

The aim of this investigation was to assess the frequency and genotyping of T. gondii in blood samples of patients with hemodialysis.

MATERIALS AND METHODS

In the current investigation, a total of 379 blood samples were taken from subjects with hemodialysis who were referred to teaching hospital of Ahvaz in the southwest of Iran. The samples were evaluated using the Nested PCR by targeting the B1 gene, and then, sequencing and phylogenetic tree were constructed.

RESULTS

T. gondii DNA was found in 112 (29.55%) of the blood samples by Nested PCR. Amplicons from T. gondii revealed high identity with GenBank sequences. The phylogenetic analysis revealed that all sequences were closely related to Type I of T. gondii.

CONCLUSION

Because of the high incidence of toxoplasmosis with type I prevalent in hemodialysis patients, we recommend a systematic screening for toxoplasmosis to carry out for monitoring the possible dissemination of toxoplasmosis during hemodialysis.

Aggravation of cognitive impairments in the valproic acid-induced animal model of autism in BALB/c mice infected with Toxoplasma gondii

PURPOSE

Toxoplasmosis is a disease caused by infection with a type of coccidial protozoan parasite called Toxoplasma gondii. The relationship between toxoplasmosis and cognitive disorders in neurodegenerative diseases has been proven. There is also evidence that children born to Toxoplasma-infected mothers are more likely to develop autism.

METHODS

In the present study, Toxoplasma-infected pregnant BALB/c mice were given valproic acid to induce autism in their male offspring, and their social behaviors, learning, and memory were examined. Chronic toxoplasmosis was established in BALB/c mice by intraperitoneal injection of cyst form of T. gondii. To induce autism, 600 mg/kg of valproic acid was injected intraperitoneally into mice on the 12.5th day of pregnancy. The behavioral experiments, such as social interaction, novel object recognition, and passive avoidance tasks, were performed on male offspring at 50 days.

RESULTS

Toxoplasma and valproic acid during the embryonic period caused social communication deficits and disrupted recognition memory and avoidance memory in offspring. Our findings showed that administering valproic acid to Toxoplasma-infected mothers exacerbates cognitive disorders in their offspring.

Newly optimized ELISA kit and LAT reveal significantly higher seroprevalence in sheep raised in agro-ecological zone as against range-ecological zone, with a significant association of meteorological parameters

BACKGROUND

Toxoplasma gondii is a zoonotic and foodborne intracellular parasite capable of inducing congenital infections, stillbirths and abortions in humans and animals, globally. The consumption of undercooked or raw mutton is "one of the vital risks" for acquiring toxoplasmosis: an asymptomatic condition in healthy persons, while life-threatening in immunodeficient individuals like "HIV/AIDS" patients.

OBJECTIVES

The current study has multiple objectives: to optimize a newly ELISA kit for Sheep, to find out the seroprevalence of ovine toxoplasmosis of two ecological zones of the Punjab, Pakistan through LAT and newly Optimized Sheep ELISA kit, to do the comparison of efficacies of various tests (LAT with newly Optimized ELISA kit and newly Optimized ELISA kit with commercial ELISA kit) and to determine the different meteorological parameters as the risk factors for T. gondii infection in sheep.

METHODS

A cross-sectional study was conducted on 400 sheep sera, 200 were collected from sheep raised on open grazing system by local farmers in the adjoining areas of Civil Veterinary Dispensaries (CVDs) of range-ecological zone i.e. tehsil Kot Chutta (Dera Ghazi khan). Similarly, the remaining 200 were collected from agro-ecological zone i.e. tehsil Sharaqpur (Sheikhupura), to evaluate the comparative efficacy of LAT with optimized ELISA kit and newly optimized ELISA kit with commercial ELISA kit.

FINDINGS

The newly ELISA kit optimized against a commercial ELISA kit was found to have 100% sensitivity, 97.6% specificity with 98% Positive Predictive Value, 100% Negative Predictive Value, Cut off value = 0.505, 28.28 LR+, 0.0104 LR-, and 2719.23 DOR. Seroprevalence of toxoplasmosis was detected significantly (P < 0.01; χ2) higher in Sharaqpur (44.5% by LAT; 35.5% by ELISA) as compared to that in Kot Chutta (39.5% by LAT; 31% by ELISA). The highest seroprevalence was seen in the sheep of the 1-2 years age group (P < 0.01; χ2), whereas the lowest in the oldest animals (≥ 4 years). Investigation of meteorological data of both the regions reveals that the zone with higher seroprevalence has relatively higher rainfall, higher humidity, lower environmental temperatures, and higher altitude as the critical factors, potentially behind the significant difference seen in seroprevalence level. The partial correlation of both tests (newly optimized ELISA kit and LAT) was 0.991 at maximum temperature in Sharaqpur while it was 0.981 in Kot Chutta.

INTERPRETATION

A novel significant correlation was found between the meteorological parameters (relative humidity, minimum, maximum, and average temperatures) divided into yearly units of both the ecological zones, and year-wise seroprevalence (birth years of age-wise groups) of the corresponding regions. We hypothesize that such environmental conditions increase the risk of toxoplasmosis in grazing sheep, owing to a more favorable environment for coccidian oocyst survival. The ELISA kit optimized in this study will be helpful for the detection of seroprevalence of ovine toxoplasmosis in other ecological zones of Pakistan as well as of any other country in the world. More studies are recommended involving regions from other ecological zones of Pakistan to further explore the seroprevalence of ovine toxoplasmosis and to ratify the novel correlation of meteorological parameters with seroprevalence.

A Case-Control Seroprevalence Survey of Toxoplasmosis in Hemodialysis Patients and Healthy Subjects in Kazeroon and Jahrom Districts in Fars Province, Southern Iran

Opportunistic parasites such as Toxoplasma gondii (T. gondii) are capable of causing neurological and ocular manifestations in patients undergoing hemodialysis. By designing a matched case-control study, we conducted a seromolecular survey of T. gondii in hemodialysis patients compared to a healthy group from Jahrom and Kazeroon cities in Fars Province, Iran. For this purpose, 75 hemodialysis patients from Kazeroon city, 75 hemodialysis patients from Jahrom city, and 75 healthy individuals were recruited for the study. The serum levels of specific immunoglobulins (IgG/IgM) in the case and control groups were evaluated using the enzyme-linked immunosorbent assay (ELISA) method. Also, buffy coat samples were used to extract genomic DNA. Then, Polymerase Chain Reaction (PCR) was accomplished using the RE and GRA6 genes of T. gondii. A standard questionnaire containing demographic factors was administered. Although the seroprevalence of the anti-T. gondii IgG antibody in hemodialysis patients from Kazeroon (18.66% (14/75)) and Jahrom (25.33% (19/75)) was higher than that in the control group (13.33% (10/75)), no statistically significant difference was observed between the case and control groups (P value = 0.373 from Kazeroon and P value = 0.354 from Jahrom). Among the studied variables, only residence (urban) was significantly associated with the anti-T. gondii IgG antibody in the case group from Kazeroon. Also, no IgM antibody titers and DNA of T. gondii were detected in the case and control groups from both cities. Although high seroprevalence of anti-T. gondii IgG antibody was seen in hemodialysis patients, further epidemiological studies with larger samples need to be done in Jahrom and Kazeroon cities and in other parts of Iran. It is also necessary for health officials to establish programs for the prevention and control of T. gondii infection in hemodialysis patients.

In Vitro and In Vivo Anti-parasitic Activity of Sambucus ebulus and Feijoa sellowiana Extracts Silver Nanoparticles on Toxoplasma gondii Tachyzoites

BACKGROUND

Current chemical treatments for toxoplasmosis have side effects, researchers are looking for herbal remedies with minimal side effects and the best effectiveness. This study aimed to evaluate the anti-toxoplasmic effects of silver nanoparticles based on Sambucus ebulus (Ag-NPs-S. ebulus) and Feijoa sellowiana (Ag-NPs-F. sellowiana) fruit extracts, in vitro and in vivo.

METHODS

Vero cells were treated with different concentrations (0.5, 1, 2, 5, 10, 20, 40 μg/mL) of extracts and pyrimethamine as a positive control. Vero cells were infected with T. gondii and treated with extracts. The infection index and intracellular proliferation of T. gondii were evaluated. The survival rate of infected mice with tachyzoites of T. gondii was examined after intraperitoneal injection of the extracts at a dose of 40 mg/kg/day for 5 days after infection.

RESULTS

The Ag-NPs-S. ebulus and Ag-NPs-F. sellowiana, almost similar to pyrimethamine, reduced proliferation index when compared to untreated group. Also, high toxoplasmicidal activity was observed with Ag-NPs-S. ebulus extract. Mice in the treatment groups of Ag-NPs-S. ebulus and pyrimethamine achieved better results in terms of survival than the others.

CONCLUSION

The results indicated that Ag-NPs-F. sellowiana and S. ebulus have a significant growth effect on T. gondii in vitro and in vivo. Ag-NPs-S. ebulus extract has a more lethal effect on the parasite than Ag-NPs-F. sellowiana. It is suggested that in future investigate the induction of Toxoplasma-infected cell apoptosis using nanoparticles.

Toxoplasmosis and cytomegalovirus infection and their role in Egyptian autistic children

Autism is a neurodevelopmental disorder with a significantly increased incidence rate across the world over the past few years. Toxoplasmosis and cytomegalovirus (CMV) infection are globally prevalent and have been associated with diverse neurological and psychiatric disorders. A few studies have demonstrated the role of toxoplasmosis and CMV as potential etiological factors for autism. Accordingly, this study was performed to estimate the relationship between toxoplasmosis and CMV infection in children with autism as well as to assess their impact on the Childhood Autism Rating Scale (CARS) score. A total of 45 autistic children (6 girls, 39 boys) and 45 (21 girls, 24 boys) healthy control children were enrolled in our study. Their blood samples were collected and tested for the presence of Toxoplasma and CMV (IgG and IgM) antibodies and DNA by ELISA and real-time PCR (RT-PCR), respectively. Toxoplasmosis was detected in 11 (24.4%) autistic children through the ELISA [10 (22.2%) IgG + /IgM - and 1 (2.2%) IgG + /IgM +]; however, RT-PCR assay recorded only 1 positive case (2.2%), while it was detected in 10 (22.2%) control children through ELISA [9 (20%) IgG + /IgM - and 1 (2.2%) IgG + /IgM +] and 1 (2.2%) by RT-PCR. On the other hand, CMV infection was detected in all autistic children with 44 (97.8%) testing positive by ELISA [24 (53.3%) IgG + /IgM - , 18 (40%) IgG + /IgM + and 2 (4.4%) IgG - /IgM +] and 25 (55.6%) testing positive by RT-PCR assay. In addition, ELISA assay recorded 43 (95.6%) [19 (42.2%) IgG + /IgM + and 22 (48.9%) IgG + /IgM - and 2 (4.4%) IgG-/IgM +] and RT-PCR recorded 21 (46.7%) positive samples in control children with CMV. No significant difference was noted between autistic and control children for the overall prevalence of Toxoplasma or/and CMV infection. Similarly, the CARS score indicated a non-significant difference with Toxoplasma or/and CMV infection. Our data does not show an association between autism and toxoplasmosis or/and CMV infection. Nevertheless, considering that autistic children are at a high risk of contracting these infections, further studies with a larger sample size are recommended.

Advances and Challenges in Diagnostics of Toxoplasmosis in HIV-Infected Patients

Toxoplasma gondii is a worldwide distributed protozoan parasite. This apicomplexan parasite infects one-third of the population worldwide, causing toxoplasmosis, considered one of the neglected parasitic infections. In healthy humans, most infections are asymptomatic. However, in immunocompromised patients, the course of the disease can be life-threatening. Human immunodeficiency virus (HIV)-infected patients have a very high burden of Toxoplasma gondii co-infection. Thus, it is essential to use modern, sensitive, and specific methods to properly monitor the course of toxoplasmosis in immunodeficient patients.

Comparison of volatile/inhalational and IV anesthesia in long-term survival of patients with breast cancer: a retrospective study

OBJECTIVE

Breast cancer is a worldwide health concern, and surgical removal has remained the preferred therapeutic option in most patients. Furthermore, the current study was designed to investigate the disease-free survival and overall survival in breast cancer patients, who receive either propofol or isoflurane during operation.

METHOD

This retrospective study was conducted on 994 patients (IV group, n = 530; volatile/inhalational group, n = 464) who underwent breast cancer operation from January 2006 to December 2016 at Faghihi Hospital, Shiraz, Iran. All studied patients were followed up till 2020. Patients are classified into two groups, IV and volatile/inhalational, according to the received anesthesia. For statistical analysis, The Cox regression test was conducted to investigate the association between factors affecting the recurrence of the disease and the Log Rank test was utilized to assess the patients' survival. Finally, to reduce the effect of confounding factors, all patients were matched according to age, tumor size and tumor grade.

RESULTS

Based on results from the log-rank test, the volatile/inhalational group had a better recurrence-free survival (P = 0.039) compared to the total IV group. However, the overall survival was not considerably different (P = 0.520).

CONCLUSION

The current study showed that although 2-year disease-free survival is higher in the volatile/inhalational group, there is no meaningful association between the 5-year overall survival and anesthesia technique.

Does latent Toxoplasma infection have a protective effect against developing multiple sclerosis? Evidence from an updated meta-analysis

Previous epidemiologic evidence suggests a protective effect of Toxoplasma gondii infection against multiple sclerosis (MS) development; however, inconsistent findings have been reported in this regard. Therefore, we performed an updated meta-analysis of observational studies to investigate the association of To. gondii infection with MS development. We searched all articles published in PubMed, Scopus, Embase and Web of Science databases as of 20 December 2021. A random effects meta-analysis model was used to generate the pooled OR at 95% CIs. The heterogeneity between studies was assessed using I2 and Cochran's Q statistics. Moreover, the likelihood of publication bias was determined by Egger's regression test. A total of 11 studies were eligible for meta-analysis, including 1172 MS cases and 1802 controls. Our findings indicated that 29.8% (95% CI 22.8 to 37.2%) of MS patients were seropositive for To. gondii infection, compared with 34.2% (95% CI 21.9 to 47.6%) of control subjects. The estimated pooled OR was 0.79 (95% CI 0.49 to 1.26), suggesting a non-significant negative association between To. gondii infection and MS development (p>0.05). The current study does not support the significant protective role of To. gondii infection on MS development. Our findings imply that further well-designed epidemiological and mechanistic studies are warranted to ascertain the possible association between To. gondii infection and MS and to exclude the potential confounders.

Epitope vaccine design for Toxoplasma gondii based on a genome-wide database of membrane proteins

Background

There is presently no effective and safe vaccine for Toxoplasma gondii for humans. The study described here was designed to search for a novel group of optimal B cell and T cell epitopes from Toxoplasma membrane proteins using genome-wide comprehensive screening.

Methods

The amino acid sequences of membrane proteins of T. gondii were obtained from the UniProt database. The ABCPred and BepiPred servers were employed to predict the linear B cell epitopes. The Immune Epitope Database (IEDB) online service was utilized to forecast T cell epitopes within T. gondii membrane proteins that bind to human leukocyte antigen (HLA) class I (HLA-I) or HLA-II molecules.

Results

From the 314 membrane proteins of T. gondii, a total of 14 linear B cell epitopes embedded in 12 membrane proteins were identified. Eight epitopes for major histocompatibility complex (MHC) class I (MHC-I) molecules and 18 epitopes for MHC-II molecules were ultimately selected, for which world population coverage percentiles were 71.94% and 99.76%, respectively. The top rated combinations of linear B cell epitopes and T cell epitopes covering both BALB/c mice and a majority of the human population were identified for the development of a protective vaccine.

Conclusions

The ultimate vaccine construct described here, which comprises B cells, MHC-I and MHC-II epitopes, might protect individuals against T. gondii infection by inducing humoral and cellular immune responses.

Graphic abstract

Supplementary Information

The online version contains supplementary material and is available at 10.1186/s13071-022-05497-z.

Serological Investigation of Bovine Toxoplasmosis Using Commercial and Indigenous ELISA Kits While Validating Cattle Toxo IgG ELISA Kit

Simple Summary

Toxoplasmosis is a zoonotic disease caused by T. gondii infection. The main aims of this study were to assess the seropositivity to toxoplasmosis of an exotic breed of cattle (n = 400) from different farms using the Latex Agglutination Test, validate the Cattle Toxo IgG ELISA kit with the help of the commercially available ELISA kit and compare the efficacy of the LAT and Cattle Toxo IgG ELISA kit for assessing seropositivity of cattle to toxoplasmosis. Four hundred cattle sera were collected from an exotic breed of cattle in Pakistan. These sera were evaluated through an LAT and Cattle Toxo IgG ELISA kit. Of 400 samples, 90 were elected and screened through a commercially available ELISA kit. The sensitivity and specificity of the Cattle Toxo IgG ELISA kit came out to be 100% and 96.15%, and in LAT, it was found as 26.31% and 61.53%, respectively. The Cattle Toxo IgG ELISA kit revealed 29.75% (119/400) seropositivity, 6% less than that found through LAT. The results of this study show that Cattle Toxo IgG ELISA kit is a highly accurate and reliable serodiagnostic tool to diagnose bovine toxoplasmosis.

Abstract

Toxoplasma gondii is a protozoan parasite that causes toxoplasmosis in warm-blooded vertebrates, globally. The main aims of this study were to assess the seropositivity to toxoplasmosis of an exotic breed of cattle (n = 400) from different farms using the Latex Agglutination Test and validate Cattle Toxo IgG ELISA kit. Of a total of 400 cattle sera that were evaluated by LAT, 143 (35.75%) were found positive. Based on these data, 90 samples (n = 60 seronegative by LAT; n = 30 seropositive by LAT) were elected for screening through a commercially available ELISA kit. The same 90 samples were screened through a Cattle Toxo IgG ELISA kit for validation purposes. Of 90 samples, 40 were seropositive in the Cattle Toxo IgG ELISA kit (100% sensitivity), and 38 were seropositive in a commercially available ELISA kit. All 50 samples in the Cattle Toxo IgG ELISA kit (96.15% specificity) were also seronegative in the commercially available ELISA kit. Hence, the sensitivity and specificity of the Cattle Toxo IgG ELISA kit came out to be 100% and 96.15%, and in LAT, it was found as 26.31% and 61.53%, respectively. Therefore, the Cattle Toxo IgG ELISA kit is a highly reliable serodiagnostic tool to diagnose bovine toxoplasmosis.

Expression of Interleukin-33 Gene in Hemodialysis Patients with Chronic Toxoplasmosis in Baghdad, Iraq

Toxoplasmosis is a protozoan parasite with high distribution, leading to different abnormalities in hosts. The present study aimed to determine the distribution of toxoplasmosis in hemodialysis patients and the expression of the Interleukin (IL)-33 gene in chronic Toxoplasmosis. The present study evaluated 120 subjects, including 60 patients who were undergoing dialysis and 60 healthy samples as the control group, from the 1^st February to 1^st November 2021. Anti-Toxoplasma gondii IgG was detected by using the enzyme-linked immunosorbent assay (ELISA) technique and the real-time polymerase-chain-reaction (PCR) was used to perform IL-33. The results demonstrated that the highest anti-toxoplasmosis IgG antibody rate was observed in the age group 51-70 years who were undergoing dialysis, in comparison with that in the control group (P<0.05). The male patients who had anti-toxoplasmosis IgG antibodies outnumbered the healthy people (P<0.05), while the female patients did not significantly differ from the healthy group. Chronic toxoplasmosis showed a higher number according to residency (the urban and rural patients), compared to healthy people. The frequency of dialysis times per week in chronic Toxoplasmosis patients was significantly higher among the infected patients. The findings were displayed to be positive in dialysis at 2 weeks (P<0.05). The expression of the IL-33 gene was investigated in patients who were undergoing hemodialysis and in healthy controls by using real-time PCR. The findings demonstrated that there was a high Ct value for patients and controls with a high Ct value of templates, preoperational to the gene concentration. The high prevalence of toxoplasmosis in dialysis patients and the role of IL-33 in cellular immunity in these patients highlight the need to investigate the mechanisms limiting infection with intracellular protozoa.

Toxoplasma infection and risk of epilepsy: A case-control study of incident patients

We performed an age matched case-control study of incident epileptic patients to assess the relationship between Toxoplasma gondii seropositivity and epilepsy. Cases were 94 newly diagnosed patients (mean age, 36.7 ± 15.9) with unprovoked convulsive epilepsy of unknown etiology and controls were 88 healthy individuals (mean age, 37.5 ± 17.1) with no history of epilepsy or neurological disorders. Sera of all subjects were examined for anti-Toxoplasma IgG antibodies using commercially enzyme-linked immunoassays. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) using univariate analysis and logistic regression, adjusted for potential confounders. The prevalence of anti-Toxoplasma IgG antibodies in epileptic patients (68.1%; 95%CI, 57.6-77.3%) was significantly higher than healthy controls (47.7%; 95%CI, 36.9-58.6%), indicating a significant relationship between Toxoplasma infection seropositivity and epilepsy (adjusted OR, 2.58; 95%CI, 1.16-5.72; P value < 0.05). The univariate analyses showed more than two-fold higher Toxoplasma seropositivity in patients with focal (OR, 2.31; 95%CI, 0.94-5.67) and generalized (OR, 2.35; 95%CI, 1.215-4.57) seizures versus healthy controls. Our findings support hypothesis that Toxoplasma infection/exposure may play an important role in development of epilepsy. Preventive measures to control of Toxoplasma infection especially in north of Iran and early treatment might be effective to reduce the occurrence of epilepsy in this region.

Seroprevalence Estimates of Latent and Acute Toxoplasma Infections in HIV+ People-Call for Action in Underprivileged Communities

We undertook a comprehensive, systematic review of observational studies to estimate respective seroprevalences of latent and acute Toxoplasma gondii infections in HIV⁺ people at the global, regional and country levels; related seroprevalence to socio-economic variables and CD4+ cell counts; and assessed temporal changes in prevalence and risk factors for this group. We systematically searched international databases for seroepidemiological surveys between 1 January 1980 and 31 July 2020. We used a random effects model to calculate pooled seroprevalences with 95% confidence intervals (CI), and estimated the numbers of HIV⁺ people inferred to harbour latent and acute T. gondii infections (LT or AT). We grouped seroprevalence data according to the geographic regions defined by the World Health Organization (WHO) and conducted subgroup and meta-regression analyses of the data. Of a total of 4024 studies identified, 150 and 65 of them met the inclusion criteria for LT and AT in HIV⁺ people, respectively. The overall, pooled seroprevalences of LT and AT were 37.4% (95% CI, 33.4–41.4) and 1.3% (95% CI, 0.9–1.8%), equating to ~14.2 and 0.5 million HIV⁺ people, respectively. Most HIV⁺ people with T. gondii infections originated from Africa, and the highest seroprevalences were in low-income countries with low human development indices. Significant risk factors for toxoplasmosis in HIV⁺ patients included the consumption of raw/undercooked meat, frequent contact with soil, a low CD4+ T lymphocyte number (<200 cells per μL) and age. Overall, the finding of high seroprevalences of particularly latent T. gondii infection in HIV⁺ people in underprivileged regions of the world, such as parts of Africa, calls for preventative action. Programs that include routine serological monitoring, counselling, care, animal control and/or prophylactic treatment measures are needed to prevent severe toxoplasmosis from developing in people living with HIV infection. Our study highlights the potential importance of parasite chemoprophylaxis in resource-poor settings, particularly in low-income countries.

Toxoplasma gondii seroprevalence among tuberculosis patients: A systematic review and meta-analysis

Toxoplasma gondii and Mycobacterium tuberculosis are intracellular pathogens, both infecting a substantial proportion of human population. We conducted a systematic review and meta-analysis to estimate the pooled T. gondii seroprevalence in tuberculosis patients. Three international databases were systematically searched for literature on prevalence of T. gondii in tuberculosis patients. A total of 1389 documents were identified, and eight papers were eligible to be included in the systematic review and meta-analysis. Geographical data gaps were evident, as no studies were identified from many countries where both infections are important. The pooled seroprevalence of IgG, IgM, and both IgG and IgM antibodies against T. gondii in tuberculosis patients were estimated to be 35.9% (95% confidence interval [CI], 19.3-56.7%), 35.0% (95% CI, 3.0-90.3%), and 13.4% (95% CI, 2.4-49.0%), respectively. In the included case-control studies, the pooled T. gondii seroprevalence (proportion anti- T. gondii IgG antibody positive) was higher in tuberculosis patients than in their controls, with an odds ratio by random effects model of 1.63 (95% CI, 1.28-2.08). The results of our work suggest an association between T. gondii seropositivity and being a tuberculosis patient, which should however be interpreted with caution because the timeline of the infections and the disease process are not accounted for. Our work showed that T. gondii seropositivity, indicating chronic infection with the zoonotic parasite, was relatively common among tuberculosis patients.

The Probable Association between Chronic Toxoplasma gondii Infection and Type 1 and Type 2 Diabetes Mellitus: A Case-Control Study

Purpose

The probable association between Toxoplasma gondii (T. gondii) infection and diabetes mellitus (DM) is still controversial, and there are several studies with conflicting results. Thus, this study was performed to assess the possible association between chronic T. gondii infection and type 1 diabetes mellitus (T1DM) and T2DM.

Methods

In this case-control study, a total of 105 diabetic subjects including 36 patients with T1DM and 69 patients with T2DM were recruited. In addition, 150 nondiabetic subjects were enrolled as controls. Each case group had its own control group. Each participant completed a structured questionnaire obtaining demographic information. Serum samples were examined for T. gondii-specific IgG antibody using enzyme-linked immunosorbent assay (ELISA) method.

Results

Analysis revealed that 69.4% and 34.0% of patients with T1DM and control subjects were serologically positive for T. gondii, respectively (odds ratio (OR): 4.41; 95% confidence interval (CI): 1.75–11.06; P=0.001). Moreover, 72.5% of T2DM patients and 29.0% of healthy individuals were seropositive for T. gondii (OR: 6.44; 95% CI: 3.25–12.74; P < 0.001). Among risk factors, only contact with cats was significantly associated with IgG seroprevalence in both T2DM patients (P < 0.001) and control subjects (P=0.045).

Conclusion

Although the results showed that chronic T. gondii infection is significantly associated with T1DM and T2DM, there remain many questions regarding the exact mechanisms of T. gondii in the pathogenesis of DM.

Seroprevalence and associated risk factors of Toxoplasma gondii infection in patients undergoing hemodialysis and healthy group

Objectives

In this study, the seroprevalence of anti-Toxoplasma gondii (T. gondii) specific antibodies in patients undergoing hemodialysis compared to the control group were evaluated. In this case–control study, 200 hemodialysis patients (HDP) and 100 healthy controls were participated. The specific antibodies (IgG/IgM) in both groups were tested using enzyme-linked immunosorbent assay (ELISA) method. A structured questionnaire containing some demographic information was completed for each person in case and control groups.

Results

The overall seroprevalence of T. gondii infection was 49.5% (99/200) and 23.0% (23/100) in the case and control groups, respectively. There was a significant association between seroprevalence of T. gondii infection and contact with cats (P < 0.001), consumption of raw/undercooked meat (P = 0.01), and source of drinking water (P = 0.001) in the hemodialysis patients. Also, in the control subjects, there were a significant association between consumption of raw/undercooked meat (P = 0.04) and source of drinking water (P = 0.001) with T. gondii infection. The findings showed a high seroprevalence of T. gondii infection in HDP compared with healthy controls; thus, we recommend the regular screening programs for T. gondii infection in this susceptible group.

Seroepidemiology and Associated Risk Factors of Toxoplasma gondii in Hemodialysis Patients

PURPOSE

Immunocompromised patients may be at risk for reactivation of the toxoplasmosis infection, because of defection in cell-mediated immunity. Therefore, early diagnosis would be highly desirable in these individuals. This case-control study was designed to increase information about toxoplasmosis in hemodialysis (HD) patients in Guilan province, Iran.

METHODS

The study was performed among 150 patients and 150 controls referred to hospitals of Guilan University of Medical Sciences during 2018-2019. Questionnaire forms, including demographic and epidemiological information, were completed. Peripheral blood samples were taken for serum separation and were collected into tubes and then kept at - 20 °C until use. IgG and IgM antibodies to Toxoplasma gondii were detected by a commercial ELISA kit. Accordingly, IgG absorbance levels < 9 were considered negative, 9-11 was considered borderline, and > 11 was positive; IgM absorbance levels < 0.9 were considered negative, 0.9-1.1 was assumed to be borderline, and > 1.1 was positive.

RESULTS

Throughout the study, 72.0% of HD patients and 64.7% of the control group were positive for anti-Toxoplasma IgG antibody subsequently. 2% of HD patients and 0.7% of the control group were positive for anti-Toxoplasma IgM antibody and these difference weren't significant between control and ones with HD (P > 0.05). There was no significant difference between dialysis duration factor and the seropositivity rate. Seroprevalence of T. gondii infection did not vary significantly with age, educational level, residence and presence of a cat at home. On the contrary, seroprevalence varied significantly with gender and consumption of raw vegetables.

CONCLUSION

Because of the high percentage of positivity for Toxoplasma IgG antibodies in hemodialysis patients, we suggest a periodically screening program to carry out for monitoring and evaluating the possible dissemination of toxoplasmosis during hemodialysis.

Relationship between toxoplasmosis and autism: A systematic review and meta-analysis

Toxoplasma gondii (T. gondii) is a foodborne parasite that is investigated in many psychiatric diseases, such as autism spectrum disorders (ASD). Therefore, a systematic literature review was conducted searching seven electronic databases on the prevalence of T. gondii antibodies among autism patients. The current study involved sensitivity analysis, meta-regression, subgroup analysis, publication bias test, and quality assessment of studies. On the basis of the findings, the odds ratio (OR) of latent Toxoplasma infection 1.93 (95% confidence intervals (CI): 1.01-3.66) was associated with ASD risk. However, there was no relationship between acute infection and ASD 0.39 (95% CI: 0.18-0.87). The obtained results of Begg's and Egger's tests showed no publication bias (P = 0.851 and P = 0.297, respectively). The sensitivity analysis confirmed robust and stable estimates with a significant level of heterogeneity (I2 = 78.1%, P < 0.000). Of the investigated patients' characteristics, only the gender variable was analyzed, indicating the combined ORs of 2.63 (95% CI: 0.29-23.63) in females and 2.62 (95% CI: 0.94-7.30) in male participants. This study showed that toxoplasmosis plays an important role as a risk factor for autism. However, further prospective investigations are highly recommended to illuminate the developmental pathways to this disorder and provide new strategies for the prevention and treatment of this disease.

Seroprevalence of toxoplasma gondii infection: An umbrella review of updated systematic reviews and meta-analyses

Objectives:

Toxoplasmosis is one of the neglected parasitic disease in humans and animals that produced via toxoplasma gondii. This study we implemented an umbrella review of all existing systematic reviews, meta-analyzing studies to apprise, and summarize seroprevalence of human toxoplasmosis in worldwide.

Methods:

The search was carried out in databases including: Pub Med, Google Scholar, Science Direct, Scopus, Web of Science, Cochrane, and global health from their start dates until December 2018 in Persian and English language. A total of 21 systematics review and meta-analysis met the inclusion criteria of umbrella review. The Q test and the I² statistic were used to evaluate heterogeneities. Quality assessment were performed and made use of the AMSTAR tool.

Results:

The estimated pooled seroprevalence of T. gondii infection in blood donors, Immunocompromised patients, childbearing age women, general population, newborns and children, pregnant women and overall was 33% (95% CI, 29.0–38.0%), 42.0% (95 CI, 34.0–49.0%), 32.0% (CI, 26.0–38.0%), 42.0% (CI, 38.0–45.0%), 4.0% (CI, 2.0–5.0%), 40.0% (CI,37.0–44.0%), and 36% (CI, 24.0–48.0%), respectively.

Conclusion:

The results of our umbrella review show a higher seroprevalence of T. gondii infection in immunocompromised patients, general population, pregnant women, blood donors, childbearing age women, and newborn groups, respectively. Routine serologic screening test and health education by primary care physicians for Toxoplasmosis is recommended to be conducted in high-risk groups in the endemic region.

Investigation of Toxoplasma gondii Infection in Aborted Fetuses of Sheep Using PCR: A Study in North Khorasan Province, Iran

Toxoplasma gondii is a zoonotic obligate intracellular protozoan parasite that infects warm-blooded animals as well as humans worldwide. The purpose of this study was to delineate the prevalence of Toxoplasma infection in aborted fetuses of sheep in North Khorasan province, Iran. Three hundred and ninety-nine samples of the liver (133 samples), placenta (133 samples), and brain (133 samples) from 133 aborted fetuses of sheep were collected from 2015 to 2017. The ages of aborted fetuses were higher than 120 days' gestational age in this study. According to the samples, sixteen out of 133 aborted fetuses of sheep were infected with T. gondii. Toxoplasma DNA was found in the placenta (68.75%) and liver (31.25%) samples of infected fetuses using the PCR method. The highest and lowest rates of Toxoplasma infection were observed during 2016 and 2017, respectively. Shirvan and Faruj provinces were recognized as the two most infected districts among others. There was a significant difference between the year and abortion rate in sheep due to infection by the Toxoplasma parasite (P < 0.05). Furthermore, no significant difference between the prevalence of T. gondii infection and aborted fetuses was seen (P > 0.05) in different areas. According to the present study, T. gondii infection can be one of the causes of fetus abortion of sheep in North Khorasan province, Iran.

Serum IgG Anti-Toxoplasma gondii Antibody Concentrations Do Not Correlate Nested PCR Results in Blood Donors

Background:Toxoplasma gondii infects millions of individuals worldwide. This protozoan is food and water-borne transmitted but blood transfusion and organ transplantation constitute alternative forms for transmission. However, the influence of IgG anti-T. gondii antibodies in molecular analysis carried out in peripheral blood still remain unclear. This study aimed to investigate the serum IgG anti-T. gondii antibody concentrations correlate Nested PCR results in blood donors.

Methods: 750 blood donors were enrolled. IgM and IgG anti-T. gondii antibodies were assessed by ELISA (DiaSorin, Italy). Nested PCR was performed with primers JW62/JW63 (288 bp) and B22/B23 (115 bp) of the T. gondii B1 gene. The mean values of IgG concentration were compared for PCR positive and PCR Negative blood donors using the t-test or Mann-Whitney according to the normal distribution (p-value ≤ 0.05).

Results: 361 (48.1%) blood donors presented positive serology as follow: IgM⁺/IgG⁻: 5 (0.6%); IgM⁺/IgG⁺: 21 (2.8%); IgM⁻/IgG⁺: 335 (44.7%) and 389 (51.9%), negative serology. From 353 blood donors with positive serology tested, the Nested PCR was positive in 38 (10.8%) and negative in 315 (89.2%). There were no differences statistically significant between the mean values of serum IgG anti-T. gondii antibody concentrations and the Nested PCR results.

Conclusions: In conclusion, our data show that variations in the serum IgG anti-T. gondii antibody concentrations do not correlate T. gondii parasitemia detected by Nested PCR in chronically infected healthy blood donors.

Prevalence of Toxocara and Toxascaris infection among human and animals in Iran with meta-analysis approach

BACKGROUND

Toxocariasis is a worldwide zoonotic parasitic disease caused by species of Toxocara and Toxascaris, common in dogs and cats. Herein, a meta-analysis was contrived to assess the prevalence of Toxocara/Toxascaris in carnivore and human hosts in different regions of Iran from April 1969 to June 2019.

METHODS

The available online articles of English (PubMed, Science Direct, Scopus, and Ovid) and Persian (SID, Iran Medex, Magiran, and Iran Doc) databases and also the articles that presented in held parasitology congresses of Iran were involved.

RESULTS

The weighted prevalence of Toxocara/Toxascaris in dogs (Canis familiaris) and cats (Felis catus) was 24.2% (95% CI: 18.0-31.0%) and 32.6% (95% CI: 22.6-43.4%), respectively. Also, pooled prevalence in jackal (Canis aureus) and red fox (Vulpes vulpes) was 23.3% (95% CI: 7.7-43.2%) and 69.4% (95% CI: 60.3-77.8%), correspondingly. Weighted mean prevalence of human cases with overall 28 records was 9.3% (95% CI: 6.3-13.1%). The weighted prevalence of Toxocara canis, Toxocara cati, and Toxascaris leonina was represented as 13.8% (95% CI: 9.8-18.3%), 28.5% (95% CI: 20-37.7%) and 14.3% (95% CI: 8.1-22.0%), respectively.

CONCLUSION

Our meta-analysis results illustrate a considerable prevalence rate of Toxocara/Toxascaris, particularly in cats and dogs of northern parts of Iran. The presence of suitable animal hosts, optimum climate and close contact of humans and animals would have been the reason for higher seroprevalence rates of human cases in our region. Given the significance clinical outcomes of human Toxocara/Toxascaris, necessary measures should be taken.

Opportunistic parasitoses among Egyptian hemodialysis patients in relation to CD4+ T-cell counts: a comparative study

Background

Some reports are available on the prevalence of opportunistic parasitoses among hemodialysis (HD) patients, yet there is a paucity of data on the association of CD4+ T-cell counts with such infections. Therefore, this study aimed to determine the prevalence of intestinal parasites and Toxoplasma gondii in relation to CD4+ counts among HD patients in Alexandria, Egypt.

Methods

A comparative cross-sectional study was conducted on 120 HD patients and 100 apparently healthy individuals between December 2014 and January 2016. Data and samples (stool and blood) were collected from the participants after obtaining their informed consent. Stool samples were examined for parasites after concentration and staining, EDTA-blood samples were used for CD4+ counting by flow cytometry, and sera were analyzed for anti-Toxoplasma IgM and IgG antibodies.

Results

A significantly higher prevalence rate of intestinal parasitoses was found among HD patients compared to apparently healthy individuals (52.5% vs. 12.0%, respectively), with absence of helminths. Cryptosporidium species (32.5%), B. hominis(24.2%) and microsporidia (11.7%) were the most frequent parasites among HD patients, while B. hominis (13.0%), Cryptosporidium species (11.0%) and G. lamblia (4.0%) were the most frequent parasites among their counterparts. Statistically significant differences in parasite infection rates between patients and their counterparts were found for Cryptosporidium species, B. hominis and microsporidia. However, parasite species were not significantly associated with diarrhea. On the other hand, the overall T. gondii seroprevalence rate among HD patients was significantly higher than that among their counterparts (33.3% vs. 8%, respectively). HD patients with CD4+ counts < 200 cells/μl were twice more exposed to intestinal parasitoses compared to those with counts ≥200 cells/μl, but the difference was not statistically significant. However, low CD4+ counts were significantly associated with higher rates of Cryptosporidium species, microsporidia and T. gondii.

Conclusions

Intestinal parasitoses and T. gondii infection rates are significantly higher among Egyptian HD patients compared to apparently healthy individuals, with Cryptosporidium species, B. hominis, microsporidia and T. gondii being the most frequent parasites. CD4+ counts < 200 cells/μl are significantly associated with Cryptosporidium species, microsporidia and T. gondii among HD patients. Therefore, regular screening of HD patients for opportunistic parasites is recommended.

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

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

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.

Rhoptry antigens as Toxoplasma gondii vaccine target

Toxoplasmosis is a cosmopolitan zoonotic infection, caused by a unicellular protozoan parasite known as Toxoplasma gondii that belongs to the phylum Apicomplexa. It is estimated that over one-third of the world's population has been exposed and are latently infected with the parasite. In humans, toxoplasmosis is predominantly asymptomatic in immunocompetent persons, while among immunocompromised individuals may be cause severe and progressive complications with poor prognosis. Moreover, seronegative pregnant mothers are other risk groups for acquiring the infection. The life cycle of T. gondii is very complex, indicating the presence of a plurality of antigenic epitopes. Despite of great advances, recognize and construct novel vaccines for prevent and control of toxoplasmosis in both humans and animals is still remains a great challenge for researchers to select potential protein sequences as the ideal antigens. Notably, in several past years, constant efforts of researchers have made considerable advances to elucidate the different aspects of the cell and molecular biology of T. gondii mainly on microneme antigens, dense granule antigens, surface antigens, and rhoptry proteins (ROP). These attempts thereby provided great impetus to the present focus on vaccine development, according to the defined subcellular components of the parasite. Although, currently there is no commercial vaccine for use in humans. Among the main identified T. gondii antigens, ROPs appear as a putative vaccine candidate that are vital for invasion procedure as well as survival within host cells. Overall, it is estimated that they occupy about 1%–30% of the total parasite cell volume. In this review, we have summarized the recent progress of ROP-based vaccine development through various strategies from DNA vaccines, epitope or multi epitope-based vaccines, recombinant protein vaccines to vaccines based on live-attenuated vectors and prime-boost strategies in different mouse models.

Seroprevalence and molecular detection of Toxoplasma gondii in healthy blood donors in southwest Iran

BACKGROUND

Toxoplasmosis is a cosmopolitan parasitic disease caused by Toxoplasma gondii (T. gondii). Blood transfusion is a probable route of T. gondii transmission. Due to lack of information about seroprevalence of T. gondii in healthy blood donors, this study was aimed to determine the chronic and acute infection using serological and molecular methods.

MATERIAL AND METHODS

In this cross-sectional investigation, 380 samples were collected from donated bloods. Anti-Toxoplasma IgG and IgM antibodies were examined using enzyme-linked immunosorbent assay (ELISA). Also, all IgG positive samples were tested by IgG avidity test. Eventually, to detection of active infection, DNA was extracted from IgM positive and low IgG avidity samples and then tested using nested-polymerase chain reaction (PCR).

RESULTS

Among 380 blood donors, 131 (34.47%) were positive for only anti-T. gondii IgG, 2 (0.5%) were positive for only anti-T. gondii IgM, and 11 (2.9%) were positive for both IgG and IgM antibodies. Then, 142 samples (131 IgG ⁺ and 11 IgG ⁺IgM ⁺) were evaluated using IgG avidity test. Of these, 115 (81%) had high avidity IgG indicates past infection; 16 (11.26%) had low avidity IgG representing recent infection, and 11 (7.74%) were equivocal. With nested PCR, 20 samples of 50 seropositive samples were diagnosed positive.

CONCLUSION

Detected active infection using nested-PCR draws attention to the possibility of T. gondii infection via blood transfusion which emphasizes the importance of parasite DNA screening before donation of blood in high risk groups such as: multi-transfused persons, immunosuppressed patient, and pregnant women.

Seroepidemiological evaluation of Toxoplasma gondii immunity among the general population in southwest of Iran

Toxoplasmosis is a cosmopolitan zoonotic infection, caused by a unicellular protozoan parasite known as Toxoplasma gondii (T. gondii) that belongs to the phylum Apicomplexa. The present investigation was aimed to evaluate the seroprevalence of T. gondii infection in the general population of Abadan city. In this cross-sectional study, a total of 496 subjects were participated. Anti-T. gondii IgG and IgM antibodies were tested using commercially available enzyme-linked immunosorbent assay (ELISA). Moreover, a structured questionnaire was completed for each person. Out of 496 subjects, 188 (37.9%) and 30 (6.05%) samples were seropositive for IgG and IgM, respectively. The more seroprevalence was found during spring season, among female subjects, in rural inhabitants, in persons with the education level of diploma or lower, from the subjects with a history of contact with cat, in individuals who consumed raw/undercooked meat, and amongst who drink unpurified water. The results showed that inhabitants of tropical areas, may be moderately exposed to T. gondii. Increase of knowledge of people about toxoplasmosis, certainly affects in reduction of the infection.

Recent progress in microneme-based vaccines development against Toxoplasma gondii

Toxoplasmosis is a cosmopolitan zoonotic disease, which infect several warm-blooded mammals. More than one-third of the human population are seropositive worldwide. Due to the high seroprevalence of Toxoplasma gondii infection worldwide, the resulting clinical, mental, and economical complications, as well as incapability of current drugs in the elimination of parasites within tissue cysts, the development of a vaccine against T. gondii would be critical. In the past decades, valuable advances have been achieved in order to identification of vaccine candidates against T. gondii infection. Microneme proteins (MICs) secreted by the micronemes play a critical role in the initial stages of host cell invasion by parasites. In this review, we have summarized the recent progress for MIC-based vaccines development, such as DNA vaccines, recombinant protein vaccines, vaccines based on live-attenuated vectors, and prime-boost strategy in different mouse models. In conclusion, the use of live-attenuated vectors as vehicles to deliver and express the target gene and prime-boost regimens showed excellent outcomes in the development of vaccines against toxoplasmosis, which need more attention in the future studies.