OBJECTIVE: Toxoplasma gondii is one of the most widespread parasites in the human population globally. Several modes of its transmission have been proposed: some are well-researched and confirmed, others remain unconfirmed. One unconfirmed hypothesis pertains to potential transmission of Toxoplasma gondii via oral sex (fellatio) in humans. A recent study found tissue cysts in the semen of men with latent toxoplasmosis. Therefore, we aimed to test the hypothesis of Toxoplasma gondii transmission through oral sex experimentally.
METHODS: Eighty-two laboratory mice were orally administered semen samples from 41 men with latent toxoplasmosis. These semen samples were examined for the presence of Toxoplasma gondii DNA using PCR.
RESULTS: We detected Toxoplasma gondii DNA in three of the 41 semen samples from men with latent toxoplasmosis. Oral administration of semen samples to laboratory mice did not result in parasite transmission.
CONCLUSIONS: We have not demonstrated the transmission of Toxoplasma to mice by oral exposure to semen from infected men. While this does not conclusively rule out the possibility of such transmission in humans, the results suggest that, if it does occur, this mode of transmission is likely infrequent.

Toxoplasma (T.) gondii is an obligate intracellular parasite with felids, including domestic cats, as definitive hosts. In immunocompetent individuals, T. gondii infection is usually asymptomatic. However, under immunosuppression, it may have severe pathological impacts, which often result from the reactivation of a chronic infection. In this case study, a 21-month-old female domestic shorthair cat-diagnosed with primary immune-mediated hemolytic anemia three months prior and treated with cyclosporine and prednisolone-presented with acute tachypnea, dyspnea, diarrhea, and anorexia. Thoracic radiography suggested severe pneumonia. Testing for Mycoplasma spp., Anaplasma spp., Ehrlichia spp., and lungworm infection was negative. Serology for T. gondii revealed seroconversion of IgG, but not of IgM, indicating previous exposure to T. gondii. The cat remained stable but tachypneic for three days, followed by an acute onset of dyspnea and clinical deterioration, after which euthanasia was elected. Numerous protozoa were present in a postmortem transtracheal bronchoalveolar lavage and fine-needle aspiration of the lung. Microsatellite typing classified the extracted DNA as T. gondii type II variant TgM-A. This case demonstrates that T. gondii reactivation, leading to fulminant pneumonia, can be a sequela of immunosuppressive treatment in cats and should, therefore, be considered as a differential diagnosis in immunosuppressed cats with acute-onset respiratory signs. Rapid diagnosis may prevent fatal consequences.

BACKGROUND: Some evidence reveled that chronic infection with Toxoplasma gondii (T. gondii) has recently been associated with infertility in human and experimental model. This baseline study aimed to investigate serological evidence of Toxoplasma infection among infertile women who admitted to the in vitro fertilization (IVF) clinic at Imam Khomeini Hospital, Mazandaran province, Sari, northern Iran.
METHODS: In this retrospective (descriptive-analytical) study, all infertile women referred to the IVF clinic during 2010-2019 (10 years), constitute the study population. All data including demographic and some related characteristics were collected into a questionnaire and registered at the Iranian National Registry Center for Toxoplasmosis (INRCT) at the Mazandaran University of Medical Sciences, northern Iran. The existence of anti-Toxoplasma antibodies (IgG and IgM) was explored using a commercially available enzyme-linked immune sorbent assay (ELISA) kit (PishtazTeb, Iran), based on the manufacturer\'s protocol.
RESULTS: Of 520 infertile women, anti-T. gondii IgG, IgM and both IgG and IgM antibodies were detected among 342/520 (65.77%), 1/520 (0.19) and 4/520 (0.77) infertile women, respectively. Primary and secondary infertility was detected in 74.56% and 25.44% of IgG seropositive infertile women, respectively. Also, most of the IgG seropositive subjects had no history of abortion, polycystic ovary syndrome (PCO), fibroma, contraceptive use and varicocele in spouse as primary cause of infertility. Furthermore, serum levels of prolactin and antimullerian (AMH) hormones were normal in 81.29 and 80.12% of infertile women with anti- T. gondii IgG, respectively. There was also a statistically significant difference between the seroprevalence of Toxoplasma infection and these variables associated to primary infertility (P < 0.05).
CONCLUSIONS: According to the high prevalence (about two thirds) of chronic T. gondii infection among infertile women, particularly those with a history of abortion and primary infertility, it can be concluded that latent Toxoplasma infection pose a risk to infertile woman in the study area. Therefore, we advise that screening and treatment of Toxoplasma infection among infertile women must be favorably considered.

BACKGROUND: Toxoplasma gondii (TG), a zoonotic protozoan parasite, belongs to a group of TORCH infectious agents, which can cause severe damage to the fetus if a primary infection occurs during pregnancy. After primary infection, TG rests lifelong in human organisms causing a latent infection. Most studies have analyzed the consequences of acute, but not latent, TG infection. This study analyzed the impact of latent toxoplasmosis on spontaneous abortion history, pregnancy complication rate and neonatal outcome.
METHODS: IgG and IgM anti-TG antibodies were tested in 806 pregnant women who were consulted at the Timisoara Clinical Emergency Hospital between 2008 and 2010. Demographic data, obstetrical history, and data about the pregnancy complications, birth and neonate were collected for each woman and comparisons between the groups, with and without latent TG infection, were made.
RESULTS: This study did not show differences between groups regarding the history of spontaneous abortion (OR = 1.288, p = 0.333), cesarean section (OR = 1.021, p = 0.884), placental abruption (OR 0.995, p = 0.266), pregnancy-induced hypertension rate (OR 1.083, p = 0.846), secondary sex ratio (1.043, p = 0.776), 1\' APGAR score at birth (p = 0.544), gestational age at birth (p = 0.491) or birth weight (p = 0.257).
CONCLUSIONS: The observed differences between the rate of pregnancy complications in the two groups of pregnant women with and without latent infection with TG, did not reach a statistical significance.

OBJECTIVE: This study aimed to determine the possible association between Toxoplasma gondii infection and COVID-19 outcomes among 133 patients with an RT-PCR-positive test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), hospitalized at Imam Khomeini Hospital, Sari, Mazandaran Province, northern Iran, during August to November 2020.
METHODS: A questionnaire was used to collect baseline data from the patients who were registered to the Iranian National Registry Center for Toxoplasmosis (INRCT). Also, blood samples were taken from each patient for detecting anti-T. gondii antibodies and T. gondii DNA using enzyme-linked immunosorbent assay (ELISA) and conventional-PCR methods, respectively. Variables related to the COVID-19 severity and outcomes were indicated based on multiple multinomial logistic regression models.
RESULTS: Of 133 patients enrolled in the INRCT with COVID-19 through RT-PCR, 50 (37.59%), 52 (39.1%), and 31 (23%) suffered from mild, moderate, and severe COVID-19, respectively. 57.1% of the patients who died had severe COVID-19, while among those with other outcomes, only 18.60% had severe COVID-19 (P < 0.05). Anti-T. gondii IgG was detected in 109/133 (81.95%) patients, which was not statistically significant (P > 0.05). Among those with negative and positive anti-T. gondii IgG, 2 (8.30%) and 29 (26.60%) had severe COVID-19, respectively (P > 0.05). T. gondii DNA and anti-T. gondii IgM were not found in any of the patients. Moreover, all deaths occurred in those with moderate or severe COVID-19 and a positive anti-T. gondii IgG.
CONCLUSIONS: To our knowledge, this is the first registry-based study concerning T. gondii infection among patients with COVID-19. Our data show the high rate of latent T. gondii infection among COVID-19 with different severity. However, there is no significant relationship between latent T. gondii infection and COVID-19 severity and outcomes. Thus, conducting multicenter studies in different geographic regions of the world could offer a better understanding of this relationship.

UNASSIGNED: Today, a suitable vaccine has not yet been discovered to prevent Toxoplasma gondii infection. Therefore, prophylaxis can be suggested as the preferred approach to prevent toxoplasmosis. This study aims to evaluate the prophylactic effects of synthesized zinc nanoparticles (ZnNPs) using Lavandula angustifolia Vera., by microwave method on chronic toxoplasmosis in mice.
UNASSIGNED: BALB/c Mice orally administrated with ZnNPs the doses of 32.5, 75, 150 mg/kg/day for two weeks. On the 15th day, the mice were intraperitoneally infected with the Tehran strain of T. gondii (25 tissue cysts). The mean diameter and the numbers of brain tissue cysts, as well as the mRNA levels of inducible nitric oxide synthesize (iNOs), and interferon-gamma (IFN-γ) in mice of each experimental group were evaluated.
UNASSIGNED: The synthesized ZnNPs represent a spherical form with a size ranging from 30 to 80 nm. The results revealed that oral administration of Zn NPs at the doses of 32.5 (p < 0.001) and 75 mg/kg/day (p < 0.001) for 14 days significantly reduced the mean number and diameter of the brain tissue cysts in tested mice. No T. gondii tissue cyst was observed after oral administration of Zn NPs at the doses of 150 mg/kg. Based on the results of Real-time PCR analysis, the expression level of IFN-γ and iNOs was significantly increased (p < 0.001) in mice treated with 32.5, 75, 150 mg/kg/day for two weeks.
UNASSIGNED: The obtained findings of the current investigation exhibit the significant prophylactic effects of ZnNPs against chronic toxoplasmosis in mice; so that oral administration of ZnNPs the doses 32.5, 75, 150 mg/kg reduced the parasite load and even completely controlled the infection in mice. The results show that the ZnNPs had strengthened the innate immune system which could be the reason for its strong prophylactic effects. However, further in vivo and clinical investigations are required to confirm these results as well as other possible mechanisms that can trigger these pharmacological properties.

UNASSIGNED: Neuroinflammation is implicated in the pathophysiology of depression. Toxoplasma gondii (T. gondii) causes chronic brain inflammatory process and may thus contribute to both depression and its most serious complication, suicidal behavior. In this study, we hypothesized that latent toxoplasmosis may underlie current depression and/or suicidal behavior.
UNASSIGNED: Currently depressed individuals (N = 384) and age, sex, and residence-matched healthy controls (HC) (N = 400) were tested for latent toxoplasmosis (i.e., positive serum T. gondii IgG antibodies). Exclusions included positive IgM and negative IgG antibodies indicating acute T. gondii infection and history of cognitive problems. Depression severity and history of lifetime suicide attempts were assessed using Beck Depression Inventory (BDI) and Columbia Suicide Severity Rating Scale, respectively.
UNASSIGNED: Participants with seropositive anti-T. gondii IgG antibody had a significantly higher odds of being depressed compared with seronegative participants (OR = 2.9, 95% CI: 1.9-4.3; p < 0.001). BDI score was significantly different between depressed seropositive and depressed seronegative individuals (IgG＋: mean (SD)= 39.65 (11.83) vs. IgG-: mean (SD)= 33.44(9.80); t = 5.03, p < 0.001). Further, seropositive depressed participants were more likely to have prior history of actual suicide attempts compared with seronegative participants (OR= 6.2, 95% CI: 3.4-11.2, p < 0.001).
UNASSIGNED: Latent toxoplasmosis may represent be a risk factor for depression and suicidal behavior. Screening for, and treatment of, underlying T. gondii infection may help improve depression and curb the increasing suicide rates. Future studies should prospectively test these hypotheses to be adequately implemented.HIGHLIGHTSLatent toxoplasmosis has been linked to history of psychiatric disorders.Depressed individuals have higher positivity rate of T. gondii IgG antibody than healthy controls.Depressed T. gondii seropositive individuals have increased likelihood to have history of suicidal behavior.

OBJECTIVE: HIV in pregnancy is not only important for mother-to-child HIV transmission, but also it assumes additional importance because HIV increases susceptibility to opportunistic infections, leading to increased morbidity and mortality in mothers and neonates. Toxoplasmosis is one of the most important opportunistic infections in HIV-infected pregnant women. The present study was undertaken to assess the prevalence of latent toxoplasmosis (LT) and acute toxoplasmosis (AT) infection in HIV-infected pregnant women.
METHODS: PubMed/MEDLINE, Scopus, Web of Science, EMBASE and SciELO were searched to identify relevant studies. A random-effects model was used to estimate the overall and subgroup-pooled prevalences across studies. Heterogeneity between studies was assessed via the I2 test.
RESULTS: A total of 14 articles that included 3256 subjects in nine countries met the inclusion criteria. The overall prevalence rates of LT and AT in HIV-infected pregnant women were 45.7% (95% CI, 32.3-59.7%) and 1.1% (95% CI, 0.4-3.2%), respectively. The findings indicate that, worldwide, approximately 559,000 and 13,450 HIV-infected pregnant women are affected by LT and AT, respectively. From this review, it is estimated that approximately 3432 babies annually could be born with congenital toxoplasmosis (CT) from HIV-infected pregnant mothers.
CONCLUSIONS: The present study indicates that a large number of HIV-infected mothers are affected by LT and AT. This can lead to adverse complications such toxoplasmic encephalitis in mothers and CT in neonates. Our results suggest a need for screening programs using well-validated diagnostic platforms for both LT and AT for all HIV-infected pregnant women.

BACKGROUND: Studies showed that biogenic selenium nanoparticles (SeNPs) have a number of pharmacological properties, such as antimicrobial ones.
OBJECTIVE: The present investigation assesses the efficacy of biogenic selenium nanoparticles (SeNPs) as a new patent against latent toxoplasmosis in a mice model.
METHODS: Male BALB/c mice were orally treated with SeNPs at the doses of 2.5, 5, 10 mg/kg once a day for 14 days. On the 15th day, the mice were infected with the intraperitoneal inoculation of 20-25 tissue cysts from the Tehran strain of Toxoplasma gondii. The mean numbers of brain tissue cysts and the mRNA levels of TNF-α, IL-12, IL-10, IFN-γ, and inducible nitric oxide synthase (iNOS) in mice of each tested group were measured. Moreover, serum clinical chemistry factors in treated mice were examined to determine the safety of SeNPs.
RESULTS: The mean number of the brain tissue cysts was significantly (P<0.001) decreased in mice treated with SeNPs at doses 2.5 (n=37), 5 (n=11), and 10 mg/kg (n=3) based on a dose dependent manner compared with the control group (n=587). The mRNA levels of IFN-γ, TNF-α, IL-12, and iNO were significantly increased in mice treated with SeNPs at the doses 10 mg/kg compared with control subgroups (p<0.05). No significant variation (p>0.05) was observed in the clinical chemistry parameters among the mice in the control subgroups compared with groups treated with SeNPs.
CONCLUSIONS: The results of the present study showed a new patent in the treatment of toxoplasmosis; so that taking the biogenic selenium nanoparticles in concentrations of 2.5-10 mg/kg for 2 weeks was able to prevent severe symptoms of the toxoplasmosis in a mice model. This indicated the prophylactic effects of SeNPs with no considerable toxicity against latent toxoplasmosis. However, more studies are required to elucidate the correct anti-Toxoplasma mechanisms of SeNPs.

BACKGROUND: Toxoplasma gondii infection, if acquired as an acute infection during pregnancy, can have substantial adverse effects on mothers, fetuses and newborns. Latent toxoplasmosis also causes a variety of pathologies and has been linked to adverse effects on pregnancy.
OBJECTIVE: Here, we present results of a comprehensive systematic review and meta-analysis of the global prevalence of latent toxoplasmosis in pregnant women.
METHODS: We searched PubMed, EMBASE, Web of Science, SciELO and Scopus databases for relevant studies that were published between 1 January 1988 and 20 July 2019.
METHODS: All population-based, cross-sectional and longitudinal studies reporting the prevalence of latent toxoplasmosis in healthy pregnant women were considered for inclusion.
METHODS: Pregnant women who were tested for prevalence of latent toxoplasmosis.
METHODS: There were no interventions.
METHODS: We used a random effects model to calculate pooled prevalence estimates with 95% confidence intervals (CIs). We grouped prevalence data according to the geographic regions defined by the World Health Organization (WHO). Multiple subgroup and meta-regression analyses were performed.
RESULTS: In total, 311 studies with 320 relevant data sets representing 1 148 677 pregnant women from 91 countries were eligible for inclusion in the meta-analysis. The global prevalence of latent toxoplasmosis in pregnant women was estimated at 33.8% (95% CI, 31.8-35.9%; 345 870/1 148 677). South America had the highest pooled prevalence (56.2%; 50.5-62.8%) of latent toxoplasmosis in pregnant women, whereas the Western Pacific region had the lowest prevalence (11.8%; 8.1-16.0%). A significantly higher prevalence of latent toxoplasmosis was associated with countries with low income and low human development indices (p < 0.001).
CONCLUSIONS: Our results indicate a high level of latent toxoplasmosis in pregnant women, especially in some low- and middle-income countries of Africa and South America, although the local prevalence varied markedly. These results suggest a need for improved prevention and control efforts to reduce the health risks to women and newborns.