Effects of Toxoplasma gondii infection and schizophrenia comorbidity on serum lipid profile: A population retrospective study from Eastern China

Application of gold immunochromatographic assay strip combined with digital evaluation for early detection of Toxoplasma gondii infection in multiple species

BACKGROUND

Timely diagnosis of Toxoplasma gondii infection is necessary to prevent and control toxoplasmosis transmission. The gold immunochromatographic assay (GICA) is a means of rapidly detecting pathogen in samples. GICA-based diagnostic methods have been developed to accurately detect pathogens with high sensitivity and specificity, and their application in T. gondii diagnosis is expected to yield good results.

METHODS

Colloidal gold test strips were produced using T. gondii C-terminal truncated apical membrane antigen 1 (AMA1C). Colloidal gold-AMA1C and colloidal gold-murine protein conjugate were synthesized under optimal conditions. A nitrocellulose membrane was treated with AMA1C and goat anti-mouse antibody as the test line and control line, respectively. In total, 90 cat serum samples were tested using AMA1C-GICA and a commercial enzyme linked immunosorbent assay (ELISA) kit. The GICA results were digitally displayed using a portable colloidal gold immunochromatographic test strip analyzer (HMREADER). The sensitivity, specificity, and stability of AMA1C-GICA were assessed, and this was then used to examine clinical samples, including 203 human sera, 266 cat sera, and 81 dog sera.

RESULTS

AMA1C-GICA had a detection threshold of 1:32 for T. gondii-positive serum. The GICA strips specifically detected T. gondii antibodies and exhibited no reactivity with Plasmodium vivax, Paragonimus kellicotti, Schistosoma japonicum, Clonorchis sinensis, and Schistosoma mansoni. Consequently, 15 (16.7%) positive samples were detected using the AMA1C-GICA and commercial ELISA kits for each of the assays. The receiver-operating characteristic curve showed that GICA had a relative sensitivity of 85.3% and specificity of 92%, with an area under the curve of 98%. After analyzing clinical samples using HMREADER, 1.2%-23.4% of these samples were found to be positive for T. gondii.

CONCLUSIONS

This study presents a novel assay that enables timely and efficient detection of serum antibodies against T. gondii, thereby allowing for its early clinical diagnosis. Furthermore, the integration of digital detection using HMREADER can enhance the implementation of GICA.

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.