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

Anti-Toxoplasma gondii IgG seroprevalence in the general population in Iran: A systematic review and meta-analysis, 2000-2023

Toxoplasmosis ranks among the most prevalent parasitic diseases globally. It seems that chronic toxoplasmosis is associated with several neuropsychiatric and other harmful effects in infected people, therefore, there is a need to investigate the prevalence of toxoplasmosis across various world regions. In this study, we conducted a meticulous meta-analysis to estimate the seroprevalence of anti-Toxoplasma gondii IgG antibodies within the general population in Iran (GPI). International and national scientific databases for studies published between January 1, 2000, and September 30, 2023, were searched. Observational studies reporting anti-T. gondii IgG seroprevalence in the GPI was selected/included. The data were synthesized using a random-effects model to calculate with a 95% confidence interval (95% CI) the national and regional anti-T. gondii IgG seroprevalence rates in Iran. Additionally, subgroup analyses were conducted to investigate the frequency of exposition to T. gondii in different socio-demographic, climatic, and geographical scenarios. From 18661 identified studies, 327 were included in the present meta-analysis, encompassing 122,882 individuals across the 31 Iranian provinces. The pooled nationwide anti-T. gondii IgG seroprevalence among the GPI was determined to be 32.9% (95% CI: 30.9-35.1%). The highest anti-T. gondii IgG seroprevalence was observed in Mazandaran province (North of Iran) (61%), whereas the lowest was in Semnan province (12.5%).Anti-T. gondii IgG seroprevalence demonstrated a higher occurrence in provinces characterized by moderate temperatures of 16-21°C, high relative humidity, and annual precipitation. Additionally, a higher anti-T. gondii IgG seroprevalence was identified among individuals with a habit of consumption of undercooked meat, raw fruits or vegetables, and untreated water. Moreover, those reporting direct contact with cats, possessing a lower level of education, residing in rural areas, being engaged in farming occupations, or playing the role of housewives exhibited higher anti-T. gondii IgG seroprevalence figures.The anti-T. gondii IgG seroprevalence within GPI closely aligns with the estimated worldwide average exposition rates. This underscores the imperative for public health policymakers to prioritize educational efforts regarding toxoplasmosis transmission pathways and its link to harmful effects.

Sero-prevalence of Toxoplasma gondii before and during the COVID-19 pandemic in Northwestern Iran

BACKGROUND

Toxoplasma gondii (T. gondii) is a ubiquitous protozoan parasite on our planet that causes toxoplasmosis. This study evaluated the seroprevalence and related risk factors for T. gondii infection in a population referred to healthcare centers in Meshkin-Shahr, Northwest Iran.

METHODS

A total of 400 blood samples were randomly collected from the general population and assessed using the anti-Toxoplasma antibodies, Immunoglobulin G and M (IgG and IgM) Enzyme-linked immunosorbent assay (ELISA) Kits in two steps before and during the coronavirus disease 2019 (COVID-19) pandemic, 2019-2020. The results were analyzed through logistic regression via SPSS 26 software.

RESULTS

Before the COVID-19 pandemic, anti-toxoplasma antibodies were detected in 39% of individuals (IgG: 38%, IgM: 0.5%, and IgG-IgM: 0.5%). Among the eleven risk factors evaluated, contact with soil and people awareness were significantly associated with T. gondii infection (p < 0.05). However, factors such as females, 20-39 age groups, junior high schools, housewives, rural areas, raw meat or vegetable consumption, vegetable or fruits washed by water, not detergent, and cat owners did not show a significant relationship with seropositivity (p > 0.05). After the outbreak of the COVID-19 pandemic, the overall seroprevalence for anti-T. gondii antibody increased to 49.7% (IgG: 47.7%, IgM: 0.5%, and IgG and IgM: 1.5%). Among these patients, 26% were positive for COVID-19. Additionally, before the COVID-19 pandemic, 40 samples were negative for anti-T. gondii antibodies but later became positive. The crude and adjusted models suggested that toxoplasmosis may be a possible risk factor for increased susceptibility to COVID-19, with an odds ratio (OR) of 1.28 (95% confidence interval (CI), 0.82-1.99; P < 0.05). Conversely, a non-significant protective effect against latent toxoplasmosis was observed in COVID-19-positive individuals (OR = 0.99; 95% CI, 0.51-1.92; P > 0.05), and COVID-19 positivity did not increase the levels of anti-T. gondii IgG antibodies.

CONCLUSIONS

The general population in this region had a moderate seroprevalence of T. gondii. The increased number of COVID-19-positive patients with latent toxoplasmosis highlights the need to pay attention to the early diagnosis and proper treatment of toxoplasmosis in these patients and implement preventive programs in these areas for future possible viral infections.

Seroprevalence and Potential Risk Factors of Toxocariasis among General Population in Southwest Iran: Implications on the One Health Approach

Toxocariasis is one of the most common zoonotic diseases distributed worldwide. This study aimed to estimate the seroprevalence of anti-Toxocara immunoglobulin G (IgG) antibodies and the associated risk factors among general populations living in urban and rural areas of Abadan and Khorramshahr cities in Khuzestan Province, Southwest Iran. This cross-sectional study was conducted between March and September 2022. There were 363 participants (190 females and 173 males) aged from <20 to ≥60 years old. Anti-Toxocara IgG antibodies in serum samples were measured using a commercially available enzyme-linked immunosorbent assay (ELISA). A structured questionnaire was employed to collect information regarding sociodemographic status and probable risk factors associated with toxocariasis. It was found that the seroprevalence rate in males (15.0%, 95% CI = 10.47-21.11) was higher than in females (10.5%, 95% CI = 6.92-15.70). Moreover, we observed that the seroprevalence was higher in participants at younger ages compared to other age ranges (COR = 2.55, 95% CI = 0.92-7.12, p =0.073). The findings of the univariate analysis revealed that residency in rural areas (p  < 0.001), using unpurified water (p  < 0.001), contact with dog (p =0.002), contact with soil (p  < 0.001), consumption of improperly washed vegetables (p  < 0.001), and history of drinking untreated water (p  < 0.001) were risk factors associated with toxocariasis. Further comprehensive studies with a focus on humans and animals should be designed in different areas of the Province. The data represented by the current study are useful to health policymakers to consider precise surveillance and effective prevention measures to control this zoonotic infection among general populations.

The Therapeutic Efficacy of Zinc Oxide Nanoparticles on Acute Toxoplasmosis in BALB/c Mice

Background

Toxoplasma gondii infects nearly one-third of the world's population. Due to the significant side effects of current treatment options, identifying safe and effective therapies seems crucial. Nanoparticles (NPs) are new promising compounds in treating pathogenic organisms. Currently, no research has investigated the effects of zinc oxide NPs (ZnO-NPs) on Toxoplasma parasite. We aimed to investigate the therapeutic efficacy of ZnO-NPs against tachyzoite forms of T. gondii, RH strain in BALB/c mice.

Methods

In an experiment with 35 female BALB/c mice infected with T. gondii tachyzoites, colloidal ZnO-NPs at concentrations of 10, 20, and 50 ppm, as well as a 50 ppm ZnO solution and a control group, were orally administered four hours after inoculation and continued daily until the mices' death. Survival rates were calculated and tachyzoite counts were evaluated in the peritoneal fluids of infected mice.

Results

The administration of ZnO-NPs resulted in the reduction of tachyzoite counts in infected mice compared to both the ZnO-treated and control group (P<0.001). Intervention with ZnO-NPs significantly increased the survival time compared to the control group (6.2±0.28 days, P-value <0.05), additionally, the highest dose of ZnO-NPs (50 ppm) showed the highest mice survival time (8.7±0.42 days).

Conclusion

ZnO-NPs were effective in decreasing the number of tachyzoites and increasing mice survival time in vivo. Moreover, there were no significant differences in survival time between the untreated control group and the group treated with zinc oxide, suggesting that, bulk ZnO is not significantly effective in comparison with ZnONPs.

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.

Detection of Anti-Toxoplasma gondii IgG and IgM Antibodies and Associated Risk Factors during Pregnancy in Southwest Iran

Background

This research was aimed at evaluating the seroprevalence of acute and chronic Toxoplasma gondii (T. gondii) infection in pregnant women and related risk factors in southwest Iran.

Methods

In this cross-sectional study, eighty-eight pregnant women were included from October 2019 to December 2019. The presence of anti-T. gondii IgM and IgG antibodies was measured using the enzyme-linked immunosorbent assay (ELISA). In addition, a questionnaire consisting of demographic information was completed for each subject.

Results

The overall seroprevalence of T. gondii infection was estimated to be 34.09% (30/88). Of these, 1 (1.13%) and 29 (32.95%) samples were found positive for IgM and IgG, respectively. Regarding the risk factors, the consumption of raw/undercooked meat (P value = 0.007) and history of abortion (P value = 0.017) were significantly associated with IgG seroprevalence in pregnant women.

Conclusion

The results showed that the pregnant women of southwest Iran might be moderately exposed to T. gondii. Since the risk of acute T. gondii infection in this susceptible group is very important, regular screening tests to diagnose the infection are recommended before pregnancy.

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.

Rhomboid antigens are promising targets in the vaccine development against Toxoplasma gondii

Toxoplasma gondii (T. gondii) is an obligate intracellular parasite with worldwide distribution. It is estimated that near one-third of the people around the globe are latently seropositive for the parasite. Since the current common drugs are incapable in the elimination of parasites within tissue cysts, the development of an effective vaccine has high priority for researchers to limit the infection. During recent years, non-stop efforts of scientists have made great progress in the identification and development of T. gondii candidate vaccines. However, there is a lack of a commercially licensed vaccine for human application yet. Rhomboid proteases (ROMs) are a class of serine proteases that have an important role in the invasion of the parasites that can be considered as a new target for vaccine strategy. They also play critical roles in mitochondrial fusion and growth factor signaling, allowing the parasite to completely enter into the host cell. In the current review, we have summarized the recent progress regarding the development of ROM-based vaccines against acute and chronic T. gondii infection in animal models.

Cutaneous leishmaniasis: an epidemiological study in southwest of Iran

The current study was aimed to evaluate the frequency and epidemiological aspects of cutaneous leishmaniasis (CL) in the southwest of Iran, an endemic focus for the leishmaniasis from 2014 to 2017. In the present retrospective cross-sectional study, all suspicious CL persons who were referred to health centers affiliated to Abadan School of Medical Sciences (Abadan and Khorramshahr cities) were tested. In this regard, both clinical and parasitological (staining with Giemsa) verifications were performed to diagnose a case. Furthermore, a structured questionnaire containing some demographic details was applied for each positive patient. In total, 151 and 132 positive CL cases were identified in Abadan and Khorramshahr cities, respectively. More frequency of CL was observed during the Winter season, among male subjects, and in urban inhabitants in both cities. The incidence of CL based on age distribution was higher in the age range of 20-30 years than others. Besides, the hands and feet were the most involved organs. Although the frequency of CL has declined in the region, CL is still a public health problem. More appropriate control strategies are required to limit and eliminate the infection in the future.