Exposure to Toxoplasma gondii Through Consumption of Raw or Undercooked Meat: A Systematic Review and Meta-Analysis

Correlation between toxoplasmosis and schizophrenia in Egyptian patients and its impact on dopamine serum levels

Toxoplasma gondii, a parasite infecting around one-third of the global population, has been linked to neurological disorders like schizophrenia. Abnormal dopamine levels are linked to the pathophysiology of schizophrenia, but their association remains unclear. This study aimed to investigate the relationship between T. gondii seroprevalence and dopamine serum levels in schizophrenic patients in Egypt. This case-control study included 93 patients diagnosed with schizophrenia and 93 individuals as controls. T. gondii seroprevalence was determined using an enzyme-linked immunosorbent assay (ELISA). Dopamine serum levels were measured using ELISA. Sociodemographic and clinical characteristics were also collected. The study found a higher prevalence of T. gondii IgG antibodies in patients with schizophrenia (68 %) compared to controls (46.2 %). Contact with cats, sausage consumption, and undercooked meat were identified as possible risk factors associated with T. gondii infection. The mean level of serum dopamine was significantly (P < 0.001) higher in patients with schizophrenia (115.3 Pg/ml ±31.8) compared to the control group (75.02 Pg/ml ±26.5). The study found that schizophrenic patients with T. gondii seropositivity had significantly higher dopamine serum levels (mean=145.2 ± 32.1 pg/ml) than those without T. gondii seropositivity (mean=122.5 ± 29.7 pg/ml) (p = 0.001). Logistic regression analysis revealed that T. gondii seropositivity was a significant predictor of increased dopamine serum levels in schizophrenic patients (odds ratio=3.4, 95 % confidence interval=1.8-6.4, p < 0.001). The study suggests that T. gondii seroprevalence may increase dopamine serum levels in Egyptian schizophrenic patients, potentially contributing to dopamine dysregulation in schizophrenia, but further research is needed to confirm these findings and investigate the underlying mechanisms.

Ongoing Healthcare Disparities in neuroHIV: Addressing Gaps in the Care Continuum

PURPOSE OF REVIEW

We aim to review the neurological complications of HIV and the social, cultural, and economic inequalities that contribute to disparities in neuroHIV care.

RECENT FINDINGS

Disparities in diagnostics and care of patients with neurological infections and non-infectious conditions associated with HIV in both high-income and low-to-middle-income countries (LMIC) are common. The COVID-19 pandemic has exacerbated these disparities. Factors, such as HIV-related stigma, may deter people from accessing HIV treatment. First-line recommended treatments for neurological infections are not available in many LMICs, leading to inadequate treatment and exposure to agents with more harmful side effect profiles. Access-related factors, such as lack of transportation, lack of health insurance, and inadequate telehealth access, may increase the risk of HIV-related neurological complications. Further research is needed to increase awareness of neurological complications among providers and PWH, and regional guidelines should be considered to better address these complications.

Seroprevalence of Toxoplasma infection in individuals occupationally exposed to livestock and raw meat: A case-control study

BACKGROUND

The expectancy of Toxoplasma gondii transmitted from livestock and raw meat to humans is a public health problem and is an example of the One Health theory.

OBJECTIVES

This survey aimed to determine the seroprevalence and risk factors related to this common infection in individuals occupationally exposed (IOE) to livestock, raw meat and viscera in industrial slaughterhouses and livestock fields in Isfahan province, central Iran.

METHODS

This study is a case-control survey carried out on the 401 serum samples of IOE (including slaughterhouse workers, butchers, veterinarians, veterinary technicians, livestock farmers and farm workers) compared to 401 archived samples of the general population (that all matched with cases by region, age and gender). All 802 samples were investigated for anti-T. gondii IgM and anti-T. gondii IgG using enzyme-linked immunosorbent assay.

RESULTS

A statistically significant higher anti-T. gondii IgG occurrence (p < 0.001) was observed in IOE compared to the control group (46.1% vs. 31.4%). According to our knowledge, this is the first case-control study on the seroprevalence of anti-T. gondii in IOE to livestock in central Iran.

CONCLUSIONS

These findings show a potentially significant association between T. gondii seropositivity and occupational exposure to livestock. Therefore, it is essential to develop guidelines for preventing disease transmission among IOE to livestock, raw meat and viscera in industrial slaughterhouses and livestock fields.

Past and present seroprevalence and disease burden estimates of Toxoplasma gondii infections in Germany: An appreciation of the role of serodiagnostics

Toxoplasmosis is one of the major foodborne parasitic diseases in Germany, with 49% of its population chronically infected with its causative agent, Toxoplasma gondii. Although the acute disease is usually benign in immunocompetent individuals, it is a threat for immunocompromised patients as well as for fetuses of seronegative mothers. As a result of infection, congenital and ocular toxoplasmosis can have serious lifelong consequences. Here I will highlight the epidemiologic situation, from its past in the two separate parts of Germany, to its unification 30 years ago and up to the present day. The main identified risk factor for infection in Germany is thought to be the consumption of undercooked or raw meat or sausages. However, the relative impact of this risky eating habit as well as that of other risk factors are changing and are discussed and compared to the situation in the Netherlands. Finally, the importance of robust and efficient high-throughput serological assays for obtaining reliable epidemiological data, on which public health decisions can be made, is highlighted. The potential of bead-based multiplex assays, which allow the incorporation of multiple antigens with different analytical properties and thus yield additional information, are described in this context. It illustrates the interdependence of new analytic assay developments and sound epidemiology, a foundation that decades-old data from Germany did not have.

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.

Seroprevalence of Toxoplasma gondii and associated risk factors for infection in the Netherlands: third cross-sectional national study

A third nationally representative serosurvey was performed to study the changes in Toxoplasma gondii (T. gondii) seroprevalence in the Netherlands over a 20-year time span and to identify and confirm risk factors for acquired toxoplasmosis. This cross-sectional study (conducted in 2016/2017) was designed similarly to the previous two studies (1995/1996 and 2006/2007) and included a questionnaire and serum sampling among Dutch residents. Factors associated with seropositivity for T. gondii were determined using multivariable analysis of the questionnaire-derived data. The earlier observed decrease in T. gondii seroprevalence between 1995/1996 and 2006/2007 (from 40.5% to 26.0%) did not continue into 2016/2017 (29.9%). Similarly to the previous studies, the seroprevalence increased with age and varied among regions. In all studies, higher T. gondii seropositivity was associated with increasing age, lower educational level, not living in the Southeast, and eating raw or semi-cooked pork. The incidence of congenital toxoplasmosis was estimated at 1.3/1000 (95% CI 0.9-1.8) live-born children in 2017. As the seroprevalence of T. gondii in the Netherlands did not decrease over the last decade, an increase in public health awareness is needed and prevention measures may need to be taken to achieve a further reduction in T. gondii infections in the Netherlands.

Toxoplasma gondii exposure in Brazilian indigenous populations, their dogs, environment, and healthcare professionals

Although Toxoplasma gondii exposure has been reported in indigenous populations worldwide, a One Health approach has not been applied to date. This study concurrently assessed T. gondii exposure in indigenous populations, and their dogs, environment, and indigenous or non-indigenous healthcare professionals (HPs). Human and dog serum samples from 9 indigenous communities in Brazil were assessed by indirect immunofluorescence antibody test for anti-T. gondii antibodies. Soil samples (30 per community) were processed with PCR to amplify T. gondii DNA. Associated risk factors and seroprevalence were analyzed using logistic regression models. Human seropositivity and type of water source were assessed by generalized linear mixed model (GLMM) with binomial error distribution, and game meat consumption with chi-squared test. Overall, 225/463 (49%) indigenous persons were seropositive for anti-T. gondii antibodies. Of all the HPs, 67/168 (40%) were positive, and included 54/147 (37%) positive non-indigenous HPs. Indigenous persons more likely to be seropositive compared with non-indigenous HPs (OR: 1.63; 95% CI: 1.11-2.39). A total of 97/253 (38%) dogs were seropositive and highly associated with seropositive owners (p < 0.001). Based on univariate analysis for indigenous individuals, state location of community (p < 0.001), ethnicity (p < 0.001), consumption of game meat (p < 0.001), type of water source (p < 0.001), and educational level (p = 0.026) were associated with seropositivity. Logistic regression showed that indigenous seropositivity was associated with eating game meat (p = 0.002), drinking water from rivers (p < 0.001), and inversely proportional to the educational level. According to univariate analysis for non-indigenous HP, age (p = 0.005), frequency of visits to the indigenous populations (p < 0.001), consumption of water at the indigenous communities (p < 0.001), and ingestion of raw meat (p = 0.023) were associated with T. gondii seropositivity. Logistic regression revealed living outdoors (p = 0.042), habit of hunting (p = 0.008), and drinking river water (p = 0.007) as risk factors associated to seropositivity in dogs. In addition, indigenous communities lacking water treatment had higher seroprevalence for all groups including indigenous persons (GLMM; z = -7.153; p < 0.001), their dogs (GLMM; z = -2.405; p = 0.0162), and all HPs (GLMM; z = -2.420; p = 0.0155). Human seropositivity was associated with that of their dogs (p < 0.001). A single soil sample, out of 270 (0.37%), was positive for T. gondii by PCR. Our results indicate water source is a risk for human and dog toxoplasmosis in indigenous communities; both share similar exposure. Moreover, quality water access was shown to be crucial to prevent toxoplasmosis in both total and non-indigenous HPs who work in these indigenous communities.

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.

Comparison of Toxoplasmosis in Narcotic Drug-addicted and Healthy Persons in the Southwest of Iran; A Case-control Study

INTRODUCTION

Toxoplasmosis and narcotic drug addiction are endemic in various regions of Iran. These drugs can provide situations for infections by disrupting the immune system. The current case-control study was designed to determine the prevalence of toxoplasmosis in narcotic drugaddicted persons in comparison with healthy subjects using serology and molecular techniques in the southwest of Iran.

METHODS

A total of 201 subjects (including 101 individuals with drug addiction and 100 control participants) were randomly selected. Chronic and acute toxoplasmosis was detected using the enzymelinked immunosorbent assay (ELISA) IgG avidity. T. gondii immunoglobulin G (IgG) and immunoglobulin M (IgM) were also determined by the ELISA. Moreover, the presence of T. gondii in blood samples was diagnosed using the nested-polymerase chain reaction (Nested-PCR).

RESULTS

For T. gondii IgG, 17 (17.0%) of 100 and 39 (38.6%) of 101 cases were diagnosed in the control participants and drug-addicted people, respectively [P=0.001, OR=3.071, CI= (1.591-5.929)]. Moreover, 16 (15.8) and 5 (5.0%) cases were positive for the B1 gene in the drug-addicted patients and controls by the nested-PCR technique, respectively [P=0.019, OR=3.576, CI= (1.257-10.179)]. However, no significant differences were found between the opium (n=64) and crystal methamphetamine (n=37) groups in terms of T. gondii IgG and IgM antibodies and the presence of the parasite in the blood (P>0.05).

CONCLUSION

The present results demonstrated that the outbreak of the infection was more frequent in narcotic drug-addicted persons than the controls using serology and molecular techniques.

A Systematic Review and Meta-Analysis on the Occurrence of Toxoplasmosis in Animals Slaughtered in Brazilian Abattoirs

Toxoplasmosis is mainly transmitted to human beings through the consumption of contaminated food, and several outbreaks caused by infected meat consumption have been reported in Brazil. We performed a systematic literature review on the prevalence and risk factors for toxoplasmosis in slaughtered animals and performed a meta-analysis of its prevalence for different species and regions. Furthermore, we also discussed the infectivity of seropositive animals, risk factors, and preventive strategies. In the meta-analysis, the overall prevalence estimates for poultry, ostrich, goats, swine, equids, sheep, and bovines were 42.4, 40.4, 23.0, 19.9, 19.1, 17.3, and 16.2%, respectively. Regarding the Brazilian regions, the highest prevalence values were detected for bovines and equids in the South (32.3 and 34.4%, respectively) and swine, goats, sheep, and poultry in the Northeast (29.3, 23.0, 22.9, and 69.8%%, respectively). High proportions of Toxoplasma gondii viability in bioassay conducted on seropositive animals were seen for sheep (34/40 = 85%) and swine (12/15 = 80%). Toxoplasma gondii infections are widespread on Brazilian farms, and the summarized data allow the establishment of high-priority areas and/or species for the adoption of preventive strategies to control this parasite at different levels of the food chain.

Sero-molecular survey on Toxoplasma gondii infection among drug addicted and non-addicted individuals: a case-control study

Background

Up to now, epidemiological studies on the prevalence of Toxoplasma gondii infection among drug addicted individuals have been rarely performed. By designing an age and sex matched case–control study, we sought to determine the prevalence and associated factors with T. gondii infection in these population using serological and molecular techniques.

Methods

One hundred and thirty-seven drug addicted individuals and 141 healthy subjects were enrolled in this study. Informed consent as well as a standard questionnaire were obtained from all subjects participating. Blood samples were collected from each participant and the serum was screened for anti-Toxoplasma antibodies (IgG and IgM). PCR assay was performed using the primer pair targeting the RE and GRA6 genes of T. gondii. Then, PCR products were sequenced to determine genotype.

Results

The seroprevalence of T. gondii infection based on IgG titer was 34.3% in case and 9.9% in the control groups, revealing a statistically significant difference (OR = 4.37; 95% CI = 2.46–9.12; P = 0.001). After analyzing the variables studied through the questionnaire, age was the only significantly factor associated with the anti-T. gondii IgG antibody in case group. Considering PCR assays with RE genomic target, the prevalence of T. gondii infection was 5.1% in the case and 3.5% in control groups which the difference was no statistically significant (OR = 1.46; 95% CI = 0.45–4.73; P = 0.521). Subsequently, all sequenced samples were genotype #1 using the GRA6 genomic target.

Conclusions

T. gondii exposure is relatively high among drug addicted individuals in Iran, and there is a need for health policymakers and researchers to establish enlightenment and prevention programs for these population at risk of infection.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06979-8.

Seroprevalence and risk factors of Toxoplasma gondii in cattle from Unai, Minas Gerais state, Brazil

Toxoplasma gondii is a widespread protozoan parasite that causes infections in animals and humans. The presence of tissue cysts in cattle musculature evidences their epidemiological significance in transmission to humans. The present study aimed to evaluate the seroprevalence of and risk factors of T. gondii seropositivity in beef cattle in the municipality of Unaí, Minas Gerais state, Brazil. Bovine blood samples (n = 612) were collected from 31 herds. Risk factors associated with the animal-level and herd-level seroprevalence were analysed using a questionnaire that investigates the epidemiological aspects of toxoplasmosis. A search for anti-T. gondii antibodies was performed by means of an indirect fluorescent antibody test (IFAT). Analysis of 612 samples showed 369 animals positive for anti-T. gondii antibodies (IFAT ≥64), with a seroprevalence of 60.29% (95% confidence interval (CI): 56.35-64.10). The herd-level seroprevalence was 96.77% (95% CI: 79.00-99.58). Applying a multivariate logistic regression analysis, a test of the association between seroprevalence of T. gondii infection and the potential predictors showed that cats (domestic or wild) with access to the drinking water of cattle were a significant (P = 0.001) predictor. The seroprevalence of T. gondii in cattle destined for human consumption is widely distributed throughout the entire study area. Thus, integrated control measures and strategies are suggested to prevent T. gondii infection in cattle.

High prevalence of anti-Toxoplasma gondii antibodies in beef cattle in Midwestern Brazil

The present study aimed to determine the seroprevalence of anti-Toxoplasma gondii antibodies using an indirect immunofluorescence assay (IFA-IgG) in 3,814 cows aged ≥ 24 months belonging to 353 beef farms in the Mato Grosso state. Additionally, we aimed to identify the possible risk factors associated with seropositivity in Mato Grosso, which encompasses three biomes (Amazon, Cerrado, and Pantanal) of Brazil. Analysis of 3,814 samples observed that 1,307 animals were positive for anti-T. gondii antibodies (IFA-IgG ≥ 64), with an animal-level seroprevalence of 34.27%. Herd-level seroprevalence was 92.07%. In the animal-level model, cows raised in the Amazon and Pantanal biomes and breed studies on European and Zebu or hybrid were found to be at risk for T. gondii seropositivity. Prevalence of anti-T. gondii antibodies in cows destined for human consumption was found to be widely distributed throughout the entire study area. Further studies are required to assess the impact of beef in the possible transmission of toxoplasmosis to humans residing in the region and establish additional control measures for this protozoan mainly on beef herds raised in the Amazon and Pantanal biomes, where the highest values of seroprevalence were observed.