Search Results (37)

Ocular toxoplasmosis is a relapsing infectious eye disease that carries an increasing risk of vision loss with each reactivation episode. Antimicrobial drug prophylaxis has been used to reduce the rate of recurrence. This review aims to summarize the current literature regarding expert clinician preferences, as well as the effectiveness and safety of prophylaxis. A literature search was conducted using the PubMed platform of the National Library of Medicine of the National Center for Biotechnology Information and relevant pre-specified search terms. Four professional surveys indicated that approximately three-quarters of experts gave antimicrobial drug prophylaxis for recurrent ocular toxoplasmosis, and that trimethoprim-sulfamethoxazole was the most popular approach. Clinical studies of prophylaxis varied in multiple parameters, including drug, dosing and duration, plus time of follow-up. Considering the four studies with at least 50 participants, the rate of recurrence of ocular toxoplasmosis within 5 years was up to 9.1% of patients taking prophylaxis, and treatment-limiting side effects occurred in up to 7.9% of patients. The available literature demonstrates that antimicrobial drug prophylaxis can reduce the recurrence rate of ocular toxoplasmosis; however, further research on drug dosing and duration of treatment is required to assist decision-making in clinical practice. Full article

Uveitis constitutes a heterogeneous group of intraocular inflammatory pathologies, including both infectious and non-infectious aetiologies, often leading to substantial morbidity and permanent loss of vision in up to 20% of the affected cases. Visual impairment is most prominent in intermediate, posterior, or panuveitis and is commonly associated with cystoid macular oedema, epiretinal membranes, macular holes, and retinal detachment. In the context of uveitis, these complications arise as a result of recurrent flare-ups or chronic inflammation, contributing to cumulative ocular damage. Pars plana vitrectomy (PPV) has an evolving role in the diagnostic and therapeutic approach to uveitis. Diagnostic PPV allows for the analysis of vitreous fluid and tissue using techniques such as PCR, flow cytometry, cytology, and cultures, providing further insights into intraocular immune responses. Therapeutic PPV can be employed for the management of structural complications associated with uveitis, in a wide spectrum of inflammatory clinical entities such as Adamantiades–Behçet disease, juvenile idiopathic arthritis, acute retinal necrosis, or ocular toxoplasmosis. Modern small-gauge and minimally invasive techniques improve visual outcomes, reduce intraocular inflammation, and may decrease reliance on systemic immunosuppression. Emerging technologies, including robot-assisted systems, are expected to enhance surgical precision and safety in the future. Despite these advances, PPV outcomes remain variable due to heterogeneity in indications, surgical techniques, and postoperative management. Prospective studies with standardized protocols, detailed subgroup analyses, and the integration of immunological profiling are needed to define which patients benefit most, optimize therapeutic strategies, and establish predictive biomarkers in uveitis management. Full article

Toxoplasmosis is a parasitic disease associated with significant morbidity and mortality. This cross-sectional study aimed to determine the prevalence, associated risk factors, and ocular health outcomes related to Toxoplasma gondii seropositivity in 161 residents from four Quilombolas communities in the northern region of Tocantins, Brazilian Legal Amazon. Peripheral blood samples were collected and tested by Enzyme-Linked Immunosorbent Assay (ELISA) for Immunoglobulin G (IgG) and/or Immunoglobulin M (IgM) and Polymerase Chain Reaction (PCR), while a standardized form was used to collect sociodemographic, health, and behavioral data. Statistical analysis, conducted using Epi-Info 3.3.2, considered T. gondii seropositivity as the primary outcome, with a significance level less than 5% (p ≤ 0.05). An overall seroprevalence of 62.11% (100/161) was observed. Key risk factors significantly, as measured by the Odds Ratio (OR), associated with T. gondii seropositivity included being elderly (OR: 4.07, CI: 2.05–8.06, p < 0.01), having cats (OR: 5.56, CI: 2.74–22.27, p < 0.01), a low parental education level (OR: 2.97, CI: 1.46–6.02, p < 0.01), children playing on the ground (OR: 2.50, CI: 1.30–4.82, p < 0.01), and having a home vegetable garden (OR: 3.80, CI: 1.94–7.47, p < 0.01). Regarding ocular health, no conclusive direct association was established between T. gondii seropositivity and specific ocular manifestations when analyzed for children and the elderly separately. Observed ocular problems in the grouped population were primarily linked to age-related comorbidities rather than parasitic infection. High rates of T. gondii seropositivity, driven by specific environmental and socioeconomic factors, highlight the vulnerability of these communities, emphasizing the need for targeted preventive strategies. Full article

Ocular Toxoplasmosis (OT), a leading cause of infectious posterior uveitis, presents significant diagnostic challenges in atypical cases due to phenotypic overlap with other retinochoroiditides and a reliance on expert interpretation of multimodal imaging. This scoping review systematically maps the burgeoning application of artificial intelligence (AI), particularly deep learning, in automating OT diagnosis. We synthesized 22 studies to characterize the current evidence, data landscape, and clinical translation readiness. Findings reveal a field in its nascent yet rapidly accelerating phase, dominated by convolutional neural networks (CNNs) applied to fundus photography for binary classification tasks, often reporting high accuracy (87–99.2%). However, development is critically constrained by small, imbalanced, single-center datasets, a near-universal lack of external validation, and insufficient explainable AI (XAI), creating a significant gap between technical promise and clinical utility. While AI demonstrates strong potential to standardize diagnosis and reduce subjectivity, its path to integration is hampered by over-reliance on internal validation, the “black box” nature of models, and an absence of implementation strategies. Future progress hinges on collaborative multi-center data curation, mandatory external and prospective validation, the integration of XAI for transparency, and a focused shift towards developing AI tools that assist in the complex differential diagnosis of posterior uveitis, ultimately bridging the translational chasm to clinical practice. Full article

Background: Ocular toxoplasmosis remains the leading cause of posterior uveitis worldwide. Optical coherence tomography (OCT) provides valuable insights into the structural alterations associated with this condition. The present study aimed to characterize the vitreous, retinal, and choroidal morphological changes observed during both the active and scarred stages of ocular toxoplasmosis using OCT imaging. A secondary objective was to evaluate the added value of three-dimensional reconstruction in the assessment of retinal lesions. Methods: A retrospective study was conducted on 12 eyes belonging to 12 patients diagnosed with toxoplasmosis retinochoroiditis (TRC). Optical coherence tomography (OCT) scans centered on the active lesions were qualitatively analyzed at baseline and follow-up. Additionally, a ResUNet model was trained to generate a full volumetric reconstruction of the retinochoroidal lesions in selected cases. Results: Twelve eyes were analyzed at a mean of 16.2 days from symptom onset. The mean follow-up duration was 144 days (range: 12–490 days). OCT imaging revealed characteristic alterations in the retina, choroid, and vitreous body, which were documented both at baseline and at follow-up. Representative cases were selected for three-dimensional reconstruction to illustrate the extent of retinal architectural involvement. Conclusions: OCT analysis refines our understanding of the structural damage associated with ocular toxoplasmosis, while three-dimensional reconstruction enhances our ability to visualize and interpret these alterations on a larger scale. Full article

Toxoplasma gondii is the most common infectious cause of posterior uveitis in immunocompetent adults. While the parasite is typically acquired through ingestion of undercooked meat or contaminated food and water, unpasteurized goat milk has been identified as a less frequent but plausible source of infection. Coinfections in ocular toxoplasmosis are rare, and the role of Epstein–Barr virus (EBV) in these coinfections remains poorly understood. We report the case of a 70-year-old immunocompetent male presenting with severe, refractory panuveitis in the left eye. Initial serologic testing confirmed acquired Toxoplasma gondii infection, and treatment was initiated with systemic antimicrobials and corticosteroids. Intraocular inflammation persisted despite sequential therapy with trimethoprim–sulfamethoxazole, clindamycin, and azithromycin, eventually requiring pars plana vitrectomy with intravitreal clindamycin and dexamethasone due to non-clearing vitreous hemorrhage. Vitreous PCR testing revealed intraocular concurrent detection of EBV DNA, prompting combined antimicrobial and antiviral therapy. Epidemiological history revealed recent consumption of unpasteurized goat milk, suggesting a potential oral transmission route for Toxoplasma gondii. Although visual acuity improved following surgical intervention and targeted therapy, it remained markedly compromised due to the severity of the disease. This case illustrates the diagnostic value of multiplex PCR in refractory uveitis, enabling the detection of Toxoplasma gondii and the concurrent detection of EBV DNA in an immunocompetent patient. It highlights the importance of early molecular testing and detailed epidemiological assessment, including atypical transmission routes such as unpasteurized goat milk. Full article

A systematic review of toxoplasmosis cases in patients receiving targeted immunotherapy with biologics or small molecules was performed. This systematic review searched for case reports, case series and observational studies in PubMed; last search was on 19 July 2025. The review identified 46 toxoplasmosis cases among patients receiving biologics (including CAR T-Cell Therapies) or small molecules for diverse autoimmune, oncologic and transplant conditions. These cases were reported from 18 countries, including the United States and several European countries. Most patients developed severe disease. Fifty percent (23/46) presented with cerebral toxoplasmosis, 33% (15/46) with ocular toxoplasmosis, 7% (3/46) with lymphadenopathy, 4% (2/46) with disseminated disease, 2% (1/46) with both cerebral and ocular disease, 2% (1/46) with pneumonic toxoplasmosis, and 2% (1/46) with severe fetal congenital toxoplasmosis. Among those were also four cases with fatal outcomes due to toxoplasmosis and eight cases with permanent ocular or neurological deficits. In addition, there was a case of fetal congenital toxoplasmosis that occurred despite maternal discontinuation of adalimumab five months before conception, resulting in elective pregnancy termination due to severe fetal cerebral disease. Overall, 44% (20/46) of cases were due to reactivation of chronic latent Toxoplasma infections and 39% (18/46) due to acute primary infections; 17% did not report this information. One case of disseminated acute toxoplasmosis was also identified after eating wild boar sausages, and two cases of severe acute ocular toxoplasmosis after eating undercooked venison meat, and undercooked unspecified type of meat respectively, while on small molecules or biologics. Details on the clinical presentations, management and clinical outcomes of these cases were reported. Recommendations for the management of toxoplasmosis in patients with targeted immunotherapies were also provided. Health care providers should consider toxoplasmosis in patients on biologics or small molecules who present with compatible clinical syndromes. Prompt diagnosis and treatment can be lifesaving. Full article

Toxoplasma gondii is responsible for the disease toxoplasmosis and has the broadest host range among apicomplexan parasites, as it infects virtually all warm-blooded vertebrates. Toxoplasmosis is a zoonotic and emerging public health concern with considerable morbidity and mortality, especially in the developing world, affecting approximately one-third of the world’s human population. Clinical presentation varies among species, and the infection establishes lifelong chronicity in hosts. Most of the host species (including healthy humans) are asymptomatic on the one hand, it is fatal to marsupials, neotropical primates and some marine mammals on the other hand. In immunocompetent humans, infection is typically asymptomatic, whereas immunocompromised individuals may develop disseminated disease affecting virtually any organ system—most commonly reproductive, cerebral, and ocular systems. Toxoplasmosis spreads by ingestion of food or water contaminated with T. gondii oocysts, consumption of undercooked/raw meat containing tissue cysts, transplacental transmission from mother to fetus, or by receiving infected organ/blood from the infected individual. Toxoplasmosis is mainly diagnosed by serologic tests and polymerase chain reaction (PCR). It is treated with pyrimethamine combined with sulfadiazine or clindamycin, often supplemented with leucovorin, atovaquone, and dexamethasone. Despite having many potent anti-T. gondii antigenic candidates, there is no commercially available vaccine for humans due to many factors, including the complex life cycle of the parasite and its evasion strategies. To date, the only commercially available anti-T. gondii vaccine is for sheep, licensed for veterinary use to prevent ovine abortions. In this review, we have summarized the current understanding of toxoplasmosis. Full article

Objective: To report a case of ocular toxoplasmosis reactivation in a patient with neurosarcoidosis undergoing immunosuppressive therapy. Methods: Case report and literature review. Results: A 34-year-old male with neurosarcoidosis, treated with Infliximab and Mycophenolate Mofetil, presented with sudden visual decline in his left eye. Multimodal imaging revealed active chorioretinitis. Serological tests showed elevated Toxoplasma IgG levels with normal IgM levels. Treatment with oral corticosteroids and antibiotics led to significant improvements in vitreous turbidity and lesion inactivity at follow-up, despite unchanged visual acuity. Conclusions: This case highlights the risk of toxoplasmosis reactivation in immunosuppressed sarcoidosis patients. It emphasizes the importance of considering ocular toxoplasmosis even with normal IgM levels, and demonstrates the value of multimodal imaging in diagnosis and follow-up. Full article

The health burden of ocular toxoplasmosis is substantial, and there is an unmet need for safe and curative anti-microbial drugs. One major barrier to research on new therapeutics is the lack of in vitro human-based models beyond two-dimensional cultured cells and tissue explants. We aimed to address this research gap by establishing a human retinal organoid model of ocular toxoplasmosis. Retinal organoids, generated from human induced pluripotent stem cells and grown to two stages of organization, were incubated with a suspension of live or heat-killed GT-1 strain T. gondii tachyzoites, or medium without tachyzoites. Both developing (1 month post-isolation) and matured (6 months post-isolation) organoids were susceptible to infection. Spread of live parasites from the margin to the entire organoid over 1 week was indicated by immunolabelling for T. gondii surface antigen 1. This progression was accompanied by changes in the levels of selected tachyzoite transcripts—SAG1, GRA6, and ROP16—and human cytokine transcripts—CCL2, CXCL8, CXCL10, and IL6—in infected versus control conditions. Our human retinal organoid model of ocular toxoplasmosis offers the opportunity for many future lines of study, including tachyzoite interactions with retinal cell populations and leukocyte subsets, parasite stage progression, and disease processes of different T. gondii strains, as well as drug testing. Full article

Toxoplasma gondii is a protozoan parasite in cats that can be a cause of zoonotic concern due to sheding infectious and highly resistant oocysts. Clinical toxoplasmosis is rare in cats and can occur with mild to severe clinical signs or even fatal outcomes. T. gondii immunoglobulin M (IgM) or IgG is an indicator of ongoing or prior infection. Information about T. gondii occurrence in the domestic cat population, primary clinical concerns about affected cats, and potential risk factors is scarce in Germany. This retrospective study explored data from 174 feline patients (≥12 weeks old) presented to a tertiary veterinary care facility in central Germany between 2012 and 2023. T. gondii serological status, determined as part of the cats’ routine diagnostic evaluation, was assessed in relation to patient characteristics, environmental factors, medical history data, and clinical diagnosis. Neurological (57%), locomotor (25%), and ocular signs (11%) were common, and older age was associated with the presence of IgG (p = 0.008). Sex had no significant effects on T. gondii antibody positivity (p = 0.865). More outdoor cats than indoor-only cats were T. gondii IgG-positive (p = 0.021), and IgG-seropositive animals received a canned/wet diet more often than a dry kibble diet (p < 0.0001). Clinical representations aligned with previous studies, and age, choice of food, and outdoor living (p = 0.021) were significant predisposing factors. Full article

Toxoplasma gondii is an Apicomplexan parasite that is estimated to infect at least one-third of the global human population. T. gondii infection may be transmitted horizontally or vertically. The main risk factors for transmission to humans are related to diet, especially the consumption of undercooked meat, along with soil contact. In immunocompetent persons, the acute infection may go undetected as it typically produces minor, non-specific symptoms that are self-limited. After infection is established, recurrent retinochoroiditis is the most common clinical disease. In contrast, severe systemic or cerebral toxoplasmosis may be life-threatening for immunocompromised individuals. Furthermore, congenital toxoplasmosis acquired in utero may have devastating consequences if not recognized and promptly treated. A growing body of research has identified associations between latent T. gondii infection, and personality traits and risk-taking behaviors. Other studies have documented associations between latent infection and psychiatric conditions that include schizophrenia and bipolar affective disorder. With no current treatment regimens being curative of T. gondii infection, effective prevention measures at both the public health and individual levels are vitally important. Full article