Toxoplasmic encephalitis with high 201Tl uptake and retention mimicking malignant lymphoma in a patient with human immunodeficiency virus infection.

Various opportunistic infections develop during immunodeficiency due to human immunodeficiency virus (HIV) infection. The treatment options for malignant lymphoma (ML) and toxoplasmic encephalitis (TE) are completely different; therefore, their discrimination is critical. A 25-year-old female of foreign nationality had been experiencing headaches for several weeks and suddenly developed convulsions. Brain computed tomography revealed multiple intracranial lesions; therefore, the patient was referred to the neurosurgery department. Brain magnetic resonance imaging (MRI) revealed multiple masses with surrounding edema, accompanied by enhanced contrast. The largest mass (2 cm) in the left occipital lobe exhibited ringed contrast enhancement. Her blood test results showed a CD4 count of 40/µL, positive HIV Ag/Ab, HIV-RNA level of 56 × 104 copies/mL, positive anti-Toxoplasma IgG (63 IU/mL), and negative anti-Toxoplasma IgM. 201Tl- single photon emission computed tomography (201Tl-SPECT) revealed abnormal accumulation only in the tumor in the left occipital lobe (early T/N ratio, 3.034; delayed T/N ratio, 2.738; retention index, 0.9), which was suspected to be a ML. Both tumors, with or without high accumulation of 201Tl, were subjected to craniotomy biopsy. Pathological examination revealed infiltration of small lymphocytes with a necrotic background. The patient was diagnosed with TE based on a positive result of a tissue polymerase chain reaction test for Toxoplasma gondii. Two weeks after sulfamethoxazole and trimethoprim combination therapy, MRI imaging showed dramatic improvement in multiple brain tumors. This case is atypical because ML was ruled out despite high 201Tl-SPECT uptake and retention. Careful diagnosis through pathological examination and DNA testing is important.

[Cerebral toxoplasmosis developed after unrelated bone marrow transplantation for acute myeloid leukemia].

A 16-year-old boy received an unrelated bone marrow transplant while in second remission of acute myeloid leukemia. He suffered from severe oral mucosal complications and had difficulty taking oral drugs such as sulfamethoxazole/trimethoprim (ST). Engraftment was obtained on transplant day 35, and blurred vision and headache appeared around transplant day 60. Funduscopy revealed retinal hemorrhage and macular edema, and an MRI scan of the head revealed a nodular lesion in the left putamen. Toxoplasma gondii was detected by CSF PCR, and cerebral toxoplasmosis was diagnosed. Following therapy with ST and clindamycin, the patient was administered pyrimethamine, sulfadiazine, and leucovorin. Symptoms improved promptly, and CSF PCR was negative 45 days after the start of treatment. Since the prevalence of toxoplasma antibodies increases with age, it is crucial to avoid toxoplasma reactivation by ST after hematopoietic cell transplantation in postpubescent patients.

Assessment of tissue levels of miR-146a and proinflammatory cytokines in experimental cerebral toxoplasmosis following atovaquone and clindamycin treatment: An in vivo study.

BACKGROUND: Despite recent advances for treating cerebral toxoplasmosis (CT), monitoring the parasite burden and treatment response is still challenging. miRNAs are small non-coding RNAs with regulatory functions that can be used in diagnosis and treatment monitoring. We investigated the changes in miR-146a, BAG-1 gene, IL-6, and IL-10 tissue levels in the brain of BALB/c mice with chronic CT caused by the PRU strain of T. gondii following anti-parasitic and antibiotic treatment. METHOD: Fifty-three 6-to 8-week-old BALB/c mice were infected using intraperitoneal inoculation of cerebral cysts of T. gondii PRU strain and then divided into five groups as follows: group 1 included mice treated with 100 mg/kg/d Atovaquone (AT), group 2 included mice treated with 400 mg/kg/d clindamycin (CL), group 3 included mice treated with combination therapy (AT + CL), group 4 included infected untreated mice as a positive control (PC), and; group 5 included uninfected untreated mice as negative control (NC). After the completion of the treatment course, tissue level of mir-146a, miR-155, BAG-1 gene, IL-6, and IL-10 was investigated with real-time polymerase chain reaction. The IL-6/IL-10 ratio was calculated as an indicator of immune response. Moreover, brain cyst numbers were counted on autopsy samples. RESULTS: miR-146a, IL-6, IL-10, and BAG-1 genes were expressed in PC, but not in the NC group; miR-146a, IL-6, IL-10, and BAG-1 gene expression were significantly lower in AT, CL, and AT + CL compared with PC. MiR-146a and BAG-1 levels in AT and CL were not different statistically, however, they both had lower levels compared to AT + CL (P < 0.01). There was no difference in the expression of IL-6 and IL-10 between treatment groups. BAG-1 expression was significantly lower in AT, than in CL and AT + CL (P < 0.0089 and < 0.002, respectively). The PC group showed a higher ratio of IL-6/IL-10, although this increase was not statistically significant. It is noteworthy that the treatment with AT reduced this ratio; in the inter-group comparison, this ratio showed a decrease in the AT and AT + CL compared to the PC. The number of brain tissue cysts was significantly lower in AT, CL, and AT + CL, than in PC (p < 0.0001). AT had significantly lower brain cysts than CL and AT + CL (P < 0.0001). CONCLUSION: It seems that the factors studied in the current research (microRNA and cytokines) are a suitable index for evaluating the response to antiparasitic and antibiotic treatment. However, more studies should be conducted in the future to confirm our findings.

Iron-overload-induced ferroptosis in mouse cerebral toxoplasmosis promotes brain injury and could be inhibited by Deferiprone.

Iron is a trace metal element that is essential for the survival of cells and parasites. The role of iron in cerebral toxoplasmosis (CT) is still unclear. Deferiprone (DFP) is the orally active iron chelator that binds iron in a molar ratio of 3:1 (ligand:iron) and promotes urinary iron excretion to remove excess iron from the body. The aims of this experiment were to observe the alterations in iron in brains with Toxoplasma gondii (T. gondii) acute infections and to investigate the mechanism of ferroptosis in CT using DFP. We established a cerebral toxoplasmosis model in vivo using TgCtwh3, the dominant strains of which are prevalent in China, and treated the mice with DFP at a dose of 75 mg/kg/d. Meanwhile, we treated the HT-22 cells with 100 µM DFP for half an hour and then infected cells with TgCtwh3 in vitro. A qRT-PCR assay of TgSAG1 levels showed a response to the T. gondii burden. We used inductively coupled plasma mass spectrometry, an iron ion assay kit, Western blot analysis, glutathione and glutathione disulfide assay kits, a malonaldehyde assay kit, and immunofluorescence to detect the ferroptosis-related indexes in the mouse hippocampus and HT-22 cells. The inflammatory factors interferon-γ, tumor necrosis factor-α, transforming growth factor-ß, and arginase 1 in the hippocampus and cells were detected using the Western blot assay. Hematoxylin and eosin staining, electron microscopy, and the Morris water maze experiment were used to evaluate the brain injuries of the mice. The results showed that TgCtwh3 infection is followed by the activation of ferroptosis-related signaling pathways and hippocampal pathological damage in mice. The use of DFP led to ferroptosis resistance and attenuated pathological changes, inflammatory reactions and T. gondii burden of the mice, prolonging their survival time. The HT-22 cells with TgCtwh3 activated the ferroptosis pathway and was inhibit by DFP in vitro. In TgCtwh3-infected cells, inflammatory response and mitochondrial damage were severe, but these effects could be reduced by DFP. Our study elucidates the mechanism by which T. gondii interferes with the host's iron metabolism and activates ferroptosis, complementing the pathogenic mechanism of CT and further demonstrating the potential value of DFP for the treatment of CT.

A Case of Cerebral Toxoplasmosis and Cryptococcosis Preferred Therapy Associated Adverse Drug Reactions in a Patient Newly Co-diagnosed with Acquired Immune Deficiency Syndrome.

PURPOSE: The simultaneous occurrence of cerebral toxoplasmosis and cryptococcosis is rare. The infections continue to be treated with sulfadiazine and amphotericin-B-based regimens (preferred therapy), respectively. Both these drugs are linked to some serious adverse drug reactions (ADRs). We report such a unique instance of both; the CNS co-infections and adverse drug reactions to the preferred therapy. CASE PRESENTATION: A 44-year-old Asian-Indian female was diagnosed with cerebral toxoplasmosis, impending cryptococcal meningoencephalitis, and acquired immune deficiency syndrome (AIDS). The preferred therapy of opportunistic CNS co-infections commenced. Within a week, she had an occurrence of fall in hemoglobin concentrations (11.3 g/dL to 5.6 g/dL; grade IV), reticulocytosis (1% to 3.2%), and indirect hyperbilirubinemia (0.5 mg/dL to 2.8 mg/dL; grade IV) after sulfadiazine administration. The drug was discontinued and the patient was treated with hematocrit transfusions. After amphotericin-B deoxycholate (AmBd) administration, the patient developed hypokalemia (serum potassium; 4.5 mmol/L to 2.7 mmol/L) and increased serum creatinine (1.0 to 2.2 mg/dL; stage-I) levels. Hence, AmBd was discontinued and potassium correction was given. The patient got diagnosed with sulfadiazine induced hemolytic anemia and AmBd induced acute renal failure. He was switched to alternative therapy regimens for the treatment of cerebral toxoplasmosis and cryptococcosis. Radiological investigations were followed up to confirm the clinical outcomes of alternative therapy. Complete recovery from the ADRs and opportunistic infections was observed. CONCLUSION: The preferred therapy regimens for toxoplasmosis and cryptococcosis are accompanied by potential adverse drug reactions, thus continuous monitoring is vital, especially in the initial phases of therapy. Discontinuation of the treatment should be the preliminary intervention in the management. Having said that, alternative therapy regimens had an optimal clinical response in the present case.

Cerebral toxoplasmosis in HIV-infected patients: a review.

Toxoplasma gondii infection in the central nervous system commonly occurs among immunodeficient patients. Its prevalence is high in countries with a high burden of HIV and low coverage of antiretroviral drugs. The brain is one of the predilections for T. gondii infection due to its low inflammatory reaction, and cerebral toxoplasmosis occurs solely due to the reactivation of a latent infection rather than a new infection. Several immune elements have recently been recognized to have an essential role in the immunopathogenesis of cerebral toxoplasmosis. Although real-time isothermal amplification, next-generation sequencing, and enzyme-linked aptamer assays from blood samples have been the recommended diagnostic tools in some in-vivo studies, a combination of clinical symptoms, serology examination, and neuroimaging are still the daily standard for the presumptive diagnosis of cerebral toxoplasmosis and early anti-toxoplasma administration. Clinical trials are needed to find a new therapy that is less likely to affect folate synthesis, have neuroprotective properties, or cure the latent phase of infection. The development of a vaccine is being extensively tested in animals, but its efficacy and safety for humans are still not proven.

Revisiting the Evidence Base for Modern-Day Practice of the Treatment of Toxoplasmic Encephalitis: A Systematic Review and Meta-Analysis.

BACKGROUND: Toxoplasmic encephalitis (TE) is an opportunistic infection of people with human immunodeficiency virus (HIV) or other causes of immunosuppression. Guideline-recommended treatments for TE are pyrimethamine and sulfadiazine (P-S) or pyrimethamine and clindamycin (P-C); however, a substantial price increase has limited access to pyrimethamine. Consequently, some centers have transitioned to trimethoprim-sulfamethoxazole (TMP-SMX), an inexpensive alternative treatment. We aimed to review the evidence on the efficacy and safety of pyrimethamine-containing therapies vs TMP-SMX. METHODS: We searched for and included randomized controlled trials (RCTs) and observational studies of TE treatments, regardless of HIV status. Data for each therapy were pooled by meta-analysis to assess the proportions of patients who experienced clinical and radiologic responses to treatment, all-cause mortality, and discontinuation due to toxicity. Sensitivity analyses limited to RCTs directly compared therapies. RESULTS: We identified 6 RCTs/dose-escalation studies and 26 single-arm/observational studies. Identified studies included only persons with HIV, and most predated modern antiretroviral treatment. Pooled proportions of clinical and radiologic response and mortality were not significantly different between TMP-SMX and pyrimethamine-containing regimens (P > .05). Treatment discontinuation due to toxicity was significantly lower in TMP-SMX (7.3%; 95% confidence interval [CI], 4.7-11.4; I2 = 0.0%) vs P-S (30.5%; 95% CI, 27.1-34.2; I2 = 0.0%; P < .01) or P-C (13.7%; 95% CI, 9.8-18.8; I2 = 32.0%; P = .031). These results were consistent in analyses restricted to RCT data. CONCLUSIONS: TMP-SMX appears to be as effective and safer than pyrimethamine-containing regimens for TE. These findings support modern RCTs comparing TMP-SMX to pyrimethamine-based therapies and a revisiting of the guidelines.

Synergistic sulfonamides plus clindamycin as an alternative therapeutic regimen for HIV-associated Toxoplasma encephalitis: a randomized controlled trial.

BACKGROUND: The preferred therapeutic regimen for Toxoplasma encephalitis (TE) is a combination of pyrimethamine and sulfadiazine, and trimethoprim-sulfamethoxazole (TMP-SMX) plus azithromycin is the widespread alternative therapeutic regimen. The synergistic sulfonamides tablet contains TMP, sulfadiazine, and SMX and hypothetically could be used for TE treatment. This study aimed to compare the efficacy and safety of synergistic sulfonamides plus clindamycin (regimen B) with TMP-SMX plus azithromycin (regimen A) for the treatment of human immunodeficiency virus (HIV) associated TE. METHODS: This was an open-labeled, multi-center randomized controlled trial recruited from 11 centers. Each recruited patient was randomly assigned to receive regimen A or regimen B for at least 6 weeks. The overall response was evaluated by assessment of the clinical response of TE-associated clinical features and the radiological response of TE-associated radiological findings. The overall response rate, clinical response rate, radiological response rate, and adverse events were assessed at 2, 6, and 12 weeks. Death events were compared between the two regimens at 6, 12, and 24 weeks. RESULTS: A total of 91 acquired immunodeficiency syndrome (AIDS)/TE patients were included in the final analysis (44 in regimen A vs . 47 in regimen B). The overall response rate, which refers to the combined clinical and radiological response, was 18.2% (8/44) for regimen A and 21.3% (10/47) for regimen B at week 6. The results of clinical response showed that, in comparison with regimen A, regimen B may perform better with regards to its effect on the relief of clinical manifestations (50.0% [22/44] vs . 70.2% [33/47], P = 0.049). However, no significant differences in radiological response, mortality events, and adverse events were found between the two regimens at week 6. CONCLUSIONS: Synergistic sulfonamides plus clindamycin, as a novel treatment regimen, showed no significantly different efficacy and comparable safety in comparison with the TMP-SMX plus azithromycin regimen. In addition, the regimen containing synergistic sulfonamides may exhibit advantages in terms of clinical symptom alleviation. TRIAL REGISTRATION: ChiCTR.org.cn, ChiCTR1900021195.

Brief Report: Financial Burden of Toxoplasmosis Encephalitis Treatment at a Safety Net Hospital.

BACKGROUND: Although the price increase of pyrimethamine in 2015 received heavy media coverage, there are little data regarding specific implications to hospitals and the total costs of treating inpatients with toxoplasmosis encephalitis (TE). METHODS: Using average drug wholesale costs, we estimated the inpatient drug costs of TE drugs 3 years prepyrimethamine and postpyrimethamine price increase in August 2015. The drug regimens and total doses were determined through retrospective chart review of patients living with HIV who received treatment for TE while inpatient during this period. RESULTS: The 3-year pre-increase TE drug costs for 66 admissions were estimated at $50,310 compared with a total drug cost of $1,026,006 for 61 admissions postincrease. Pyrimethamine made up 98% of the drug costs postincrease, compared with 57% pre-increase. Pyrimethamine-based regimens were the most frequently used throughout the study period. CONCLUSIONS: The price increase of pyrimethamine in 2015 led to a substantial and unnecessary financial burden to hospitals. This required health care systems to shift valuable resources to continue to provide medications to a vulnerable patient population. There has been more focus on providing high-value care in recent years. Our study highlights the need for further examination of pharmaceutical companies' arbitrary determination of medication costs and how they contribute to patient care.

Central nervous system aspergillosis misdiagnosed as Toxoplasma gondii encephalitis in a patient with AIDS: a case report.

BACKGROUND: Patients with acquired immunodeficiency syndrome (AIDS) tend to suffer from several central nervous system (CNS) infections due to hypoimmunity. However, CNS aspergillosis (CNSAG) is extremely rare and difficult to diagnose. Thus, it is easily misdiagnosed. CASE PRESENTATION: We reported a 47-year-old male AIDS patient with ghosting vision and anhidrosis on the left head and face. He was accordingly diagnosed with Toxoplasma gondii encephalitis (TE) at other hospitals, for which he received regular anti-Toxoplasma gondii and anti-human immunodeficiency virus (anti-HIV) treatment. Then, the patient was transferred to our hospital due to a lack of any improvement with the prescribed treatment. The patient's neurological examination revealed no abnormalities at admission, only a slight change in the cerebrospinal fluid. His cranial magnetic resonance imaging (MRI) revealed multiple abnormal signals in the brain parenchyma, and his blood was positive for Toxoplasma gondii IgG antibody. The initial diagnosis at our hospital was also TE. Considering the poor efficacy of anti-TE treatment, cerebrospinal fluid metagenomics next-generation sequencing (mNGS) was performed, but no pathogenic bacteria were detected. However, Aspergillus fumigatus was detected in the cerebrospinal fluid via targeted next-generation sequencing (tNGS) and bronchoalveolar alveolar lavage fluid via mNGS. The diagnosis was accordingly revised to CNSAG combined with his other clinical manifestations. After administering voriconazole antifungal therapy, the patient's symptoms were relieved, with improved absorption of the intracranial lesions. CONCLUSIONS: The present case experience indicates the need for clinicians to strengthen their understanding of CNSAG. Moreover, for patients with diagnostic difficulties, early mNGS and tNGS (using biological samples with only a few pathogens) are helpful for early diagnosis and treatment, potentially allowing patients to achieve favorable outcomes.

Four Chemotherapeutic Compounds That Limit Blood-Brain-Barrier Invasion by Toxoplasma gondii.

BACKGROUND: Toxoplasma gondii, an intracellular protozoan parasite, exists in the host brain as cysts, which can result in Toxoplasmic Encephalitis (TE) and neurological diseases. However, few studies have been conducted on TE, particularly on how to prevent it. Previous proteomics studies have showed that the expression of C3 in rat brains was up-regulated after T. gondii infection. METHODS: In this study, we used T. gondii to infect mice and bEnd 3 cells to confirm the relation between T. gondii and the expression of C3. BEnd3 cells membrane proteins which directly interacted with C3a were screened by pull down. Finally, animal behavior experiments were conducted to compare the differences in the inhibitory ability of TE by four chemotherapeutic compounds (SB290157, CVF, NSC23766, and Anxa1). RESULTS: All chemotherapeutic compounds in this study can inhibit TE and cognitive behavior in the host. However, Anxa 1 is the most suitable material to inhibit mice TE. CONCLUSION: T. gondii infection promotes TE by promoting host C3 production. Anxa1 was selected as the most appropriate material to prevent TE among four chemotherapeutic compounds closely related to C3.

Delayed Cerebral Toxoplasmosis in a Kidney Transplant Patient: a Case Report.

Cerebral toxoplasmosis is often life-threatening in an immunocompromised patient due to delayed diagnosis and treatment. Several differential diagnoses could be possible only with preoperative brain images of cerebral toxoplasmosis which show multiple rim-enhancing lesions. Due to the rarity of cerebral toxoplasmosis cases in Korea, the diagnosis and treatment are often delayed. This paper concerns a male patient whose cerebral toxoplasmosis was activated 21 years post kidney transplantation. Brain open biopsy was decided to make an exact diagnosis. Cerebral toxoplasmosis was confirmed by immunohistochemistry and PCR analyses of the tissue samples. Although cerebral toxoplasmosis was under control with medication, the patient did not recover clinically and died due to sepsis and recurrent gastrointestinal bleeding.

Cerebral toxoplasmosis complicating lymphoplasmacytic lymphoma in partial remission.

Toxoplasma gondii can develop toxoplasmic encephalitis (TE) in immunodeficient conditions such as AIDS and after organ transplantation. While some cases of TE with malignant lymphoma were reported, these cases occurred immediately after chemotherapy or when their diseases were active. Here we report the first Case of TE that occurred in patient who was in partial remission (PR) of lymphoplasmacytic lymphoma (LPL) for two years. A 76-year-old man was referred to our institute because of disturbance of consciousness, right arm weakness and paresthesia. A computed tomography (CT) scan detected multiple nodules in his brain. Magnetic resonance imaging (MRI) of the head detected multiple gadolinium-enhancing parenchymal lesions with hyperintense signals on T2-and diffusion-weighted images, located in both cerebral and cerebellar hemispheres. Blood test and cerebrospinal fluid (CSF) findings were unremarkable. His rapidly deteriorating consciousness precluded a chance of brain biopsy. Considering the limited efficacy of antimicrobials and the imaging findings that could be compatible with the diagnosis of malignant lymphoma, we suspected central nerve system (CNS) recurrence of LPL. Although chemotherapy was initiated, he died of respiratory failure just after chemotherapy. A pathological autopsy showed his cause of death was TE. To our knowledge, this is the first case of TE in long-term PR of malignant lymphoma. TE should be suspected when patients with malignant lymphoma present unexplained neurologic symptoms regardless of their treatment efficacy of lymphoma. (226/250 words).

Effect of HIV aspartyl protease inhibitors on experimental infection with a cystogenic Me49 strain of Toxoplasma gondii.

Toxoplasmosis is a zoonotic disease of major significant perspectives in public health and veterinary medicine. So far, the available drugs control only the active infection, once the parasite encysts in the tissues, they lose their efficacy. Cytokines; IFN-γ and IL-10, play a critical role in the modulation of toxoplasmic encephalitis and neuro-inflammation in chronic toxoplasmosis. Antiretroviral protease inhibitors applied in the treatment of acquired immunodeficiency syndrome, revealed activity against multiple parasites. Aluvia (lopinavir/ritonavir) (L/R); an aspartyl protease inhibitor, had efficiently treated T. gondii RH strain infection. We investigated the potential activity of L/R against experimental T. gondii infection with a cystogenic Me49 strain in mice, considering the role of IFN-γ and IL-10 in the neuropathology versus pyrimethamine-sulfadiazine combination therapy. Three aluvia regimens were applied; starting on the day of infection (acute phase), 2-week PI (early chronic phase) and eight weeks PI (late chronic phase). L/R reduced the brain-tissue cyst burden significantly in all treatment regimens. It impaired the parasite infectivity markedly in the late chronic phase. Ultrastructural changes were detected in Toxoplasma cyst membrane and wall, bradyzoite membrane and nuclear envelope. The signs of bradyzoite paraptosis and cytoplasmic lipid droplets were observed. L/R had significantly reduced the brain-homogenate levels of IFN-γ and IL-10 in its three regimens however, they could not reach the normal level in chronic phases. Cerebral hypercellularity, perivascular inflammatory response, lymphoplasmacytic infiltrates and glial cellular reaction were ameliorated by L/R treatment. Herein, L/R was proved to possess promising preventive and therapeutic perspectives in chronic cerebral toxoplasmosis.

Detection and treatment of cerebral toxoplasmosis in an aplastic pediatric post-allogeneic hematopoietic cell transplant patient: a case report.

BACKGROUND: Cerebral toxoplasmosis infection presents with non-specific neurologic symptoms in immunocompromised patients. With lack of measurable adaptive immune responses and reluctance to sample affected brain tissue, expedient diagnosis to guide directed treatment is often delayed. CASE PRESENTATION: We describe the use of cerebrospinal fluid polymerase chain reaction and plasma cell-free DNA technologies to supplement neuroimaging in the diagnosis of cerebral toxoplasmosis in an immunocompromised pediatric patient following allogeneic hematopoietic cell transplantation for idiopathic severe aplastic anemia. Successful cerebral toxoplasmosis treatment included antibiotic therapy for 1 year following restoration of cellular immunity with an allogeneic stem cell boost. CONCLUSIONS: Plasma cell-free DNA technology provides a non-invasive method of rapid diagnosis, improving the likelihood of survival from often lethal opportunistic infection in a high risk, immunocompromised patient population.

Determination of parasitic burden in the brain tissue of infected mice in acute toxoplasmosis after treatment by fluconazole combined with sulfadiazine and pyrimethamine.

BACKGROUND/AIMS: One of the opportunistic pathogens which cause serious problems in the human immune system is Toxoplasma gondii, with toxoplasma encephalitis (TE) seen in patients affected by it. The treatment of these patients is limited, and if not treated on time, death will be possible. METHODS: In this study, the effects of the treatment with different doses of fluconazole (FLZ) in combination with the current treatment of acute toxoplasmosis on reducing the mortality rate and the parasitic load in the murine model in vivo were studied. The mice were treated with different doses of fluconazole alone, sulfadiazine, and pyrimethamine plus fluconazole. A day after the end of the treatment and 1 day before death, the mice's brains were collected, and after DNA extraction and molecular tests, the parasite burden was detected. RESULTS: This study showed that a 10-day treatment with 20 mg/kg of fluconazole combined with sulfadiazine and pyrimethamine 1.40 mg/kg per day affected acute toxoplasmosis and reduced the parasitic load significantly in brain tissues and also increased the survival rate of all mice in this group until the last day of the study, in contrast to other treatment groups. These results also indicate the positive effects of combined therapy on Toxoplasma gondii and the prevention of relapse. CONCLUSIONS: Reducing the parasitic burden and increasing the survival rate were more effective against acute toxoplasmosis in the combined treatment of different doses of fluconazole with current treatments than current treatments without fluconazole. In other words, combination therapy with fluconazole plus pyrimethamine reduced the parasitic burden in the brain significantly, so it could be a replacement therapy in patients with intolerance sulfadiazine.