Toxoplasmosis outbreak in São Paulo, Brazil: Epidemiology and visual outcome.

PURPOSE: To describe a 2019 acute toxoplasmosis outbreak in the city of São Paulo, Brazil, and to evaluate the laboratory serological profile for toxoplasmosis for three consecutive years. The ophthalmological manifestations of the patients involved in the outbreak were also studied. METHODS: A cross-sectional descriptive study of a toxoplasmosis outbreak in São Paulo, Brazil, between February and May 2019. Epidemiological data were described, as were the observed ocular manifestations. As part of this study the number of patients with positive IgM toxoplasmosis serology was obtained from a large laboratory network (DASA) for three consecutive years, including the year of the outbreak (2018, 2019, 2020). RESULTS: Eighty-three individuals were identified in the outbreak and two clusters were studied. The clinical picture of at least 77% of the patients, the epidemiological analysis, and the short incubation period (5-8 days) suggested contamination by oocysts. Serological laboratory data analysis revealed an increase of positive toxoplasmosis IgM in 2019 of 73% compared to the previous year. Ophthalmological examination revealed that at least 4.8% of the patients developed toxoplasmic retinochoroiditis, none of whom had been treated during the acute systemic disease. CONCLUSION: Our findings indicate vegetable contamination as the possible source of this outbreak, a high prevalence of toxoplasmosis in São Paulo during the outbreak period, and a drop in the number of tests during the COVID-19 pandemic. Retinochoroiditis was observed in at least 4.8% of the cases. We confirm the need to implement effective means for the prevention, diagnosis, and treatment of the disease. This may involve raising awareness among the population of the importance of vegetable hygiene, and improved quality control of food and water.

Long-term Ocular Outcomes in Congenital Toxoplasmosis Treated Perinatally.

BACKGROUND: Congenital toxoplasmosis (CT) can be accompanied by serious organ manifestations, particularly retinochoroiditis, and may occur throughout life. We aimed to monitor long-term ocular prognosis in a large French cohort of patients with CT and its changes over time in the context of mandatory prenatal screening (since 1992) and incidence decrease since 2008. METHODS: Patients with CT diagnosed between 1987 and 2021 were prospectively included and followed for up to 35 years. The effect of the period of conception on the risk of first retinochoroiditis has been tested using a flexible extension of the Cox model. Incidence rates of retinochoroiditis were estimated. RESULTS: A total of 646 infected live born children were followed for a median of 12 years (range, 0.5-35); 187 patients (29%) had at least 1 ocular lesion (first at a median age of 5 years; range, 0-26 years) with peaks at 7 and 12 years. Early maternal infection and the presence of nonocular signs at birth were associated with a higher risk of retinochoroiditis, whereas delayed diagnosis of CT (after birth versus before or at birth) was associated with a lower risk (13% decrease for each additional month after birth; P = .01). A period effect for the risk of developing retinochoroiditis in patients born after 2008 was not detected. CONCLUSIONS: Despite prenatal screening and prolonged perinatal treatment, retinochoroiditis is not a rare event in French patients with CT and can occur well into adulthood, with peak incidences at 7 and 12 years of age. It rarely causes severe damage but warrants regular follow-up into adulthood.

An alternative method to establish an early acute ocular toxoplasmosis model for experimental tests.

PURPOSE: To provide a simple alternative acute ocular toxoplasmosis model with great reproducibility for experimental tests that demand monitoring of the ocular lesion. METHODS: ME49-wt and ME49-GFP tachyzoites from cell culture were used to infect male C57BL6 mice by intraperitoneal injection. B1 expression by real-time polymerase chain reaction (qPCR) assay was used to detect the presence of T. gondii in ocular tissue at the beginning of the infection. Fluorescence microscopy and histopathology analysis were carried out to assess the evolution of the acute infection up to 20 days in both eyes of infected mice. RESULTS: All mice infected with the 104 tachyzoites showed B1 expression in the retina of both eyes, in the RPE (retinal pigment epithelium), and choroid structures, after 5 days of infection. Tachyzoites of the ME49-GFP strain were easily detected by fluorescence microscopy in the retina tissue of mice after 5 days post-infection. After 20 days, mice inflammatory cell infiltrates and a disorganized morphology of the retinal laminar architecture were observed. CONCLUSION: Infection of C57BL6 mice via intraperitoneal with 104 tachyzoites of the ME49-GFP strain from cell culture is a suitable model for acute ocular toxoplasmosis. This model has great reproducibility in establishing the ocular lesion since day 5 post-infection. This model can be suitable for experimental tests of chemotherapy and the investigation of the role of the immune response on the development of uveitis.

Comparison of immunological and molecular methods for laboratory diagnosis of ocular toxoplasmosis in blood, serum and tears in Brazil.

Ocular toxoplasmosis (OT) is caused by protozoan T. gondii. Ophthalmological examination is considered the gold standard for OT diagnosis, and laboratory tests are used for diagnostic confirmation. However, these tests can present different results, which change depending on their basis, on sample type and on patients' clinical alteration. Thus, the aim of the present study is to assess immunodiagnostic and molecular techniques applied in blood, serum and tear fluid to diagnose T. gondii infection in patients seen at an Ophthalmology Clinic. In total, 160 patients were included in the study, 40 of them had OT with active lesions (G1); 40 had OT with healed lesions (G2), 40 had non-toxoplasmic uveitis (G3) and 40 had no ocular alterations (G4). Serum samples were subjected to Immunoenzymatic Assay (ELISA) and to Indirect Immunofluorescence Reaction (IFAT) to search for anti-T. gondii IgM and IgG. Tear fluid samples were analyzed through ELISA for IgA research. All blood and tear fluid samples were subjected to conventional polymerase chain reaction (cPCR) and in a Nested PCR model for T. gondii DNA amplification with targets B1, GRA7 and REP 529. IgG and IgM anti-T. gondii was detected in serum samples from 106 and 15 patients, respectively, when combining ELISA and IFAT results. Anti-T.gondii IgA antibodies were detected in 9.2% of the tear material. Nested PCR with GRA7 target showed higher positivity in blood samples (24.4%); Nested PCR with B1 target showed a higher frequency of positivity in tears (15%). Biological samples of patients with active lesions showed the highest positivity frequencies in all immunodiagnostic assays, as well as in most PCR models. The present results highlighted the need of associating techniques with different fundamentals to confirm OT diagnosis. Furthermore, further tear fluid analyses should be performed to validate this biological material as lesser invasive alternative for the more accurate OT diagnosis.

Metagenomic analysis of the ocular toxoplasmosis in children uveitis from Fayoum governorate, Egypt.

Granulomatous anterior uveitis with single or numerous gelatinous nodules was found in children living in rural Egypt. All ocular diseases were originally thought to be water-born and related to digenic flukes. The current study sought to learn more about the causes of anterior granulomatous uveitis in Egyptian youngsters who used to swim in rural water canals. 50 children with eye lesions that had not responded to medical treatment were recruited. Four samples were surgically extracted and examined using real-time PCR, transmission electron microscopy (TEM), and shotgun metagenomic sequencing (SMS). Toxoplasma gondii was detected free within the syncytium's distal section, while the proximal part exhibited active synthesis of a presumably extra-polymeric material, possibly released by the microbial population. Toxoplasma gondii was found in 30 samples. Serologically, distinct anti-Toxoplasma antibodies were not found in 91.6% of patients. SMS showed that the T. gondii ME 49 strain had the greatest percentage (29-25%) in all samples within an Acinetobacter-containing microbial community. These findings suggested that these bacteria entered the body via the exterior route rather than the circulatory route. The lack of genetic evidence for subsequent parasite stages invalidates the prior findings about the assumed trematode stage.

Crystalline Retinopathy Following Intravitreal Clindamycin.

This case report describes a 74-year-old woman who developed a crystalline retinopathy following intravitreal injection of clindamycin. The patient presented with ocular toxoplasmosis in the left eye but was allergic to sulfa medications, so she was treated with intravitreal clindamycin. Subsequently, fine refractile yellow-white crystals were observed on examination of the left macula. Optical coherence tomography localized the crystals to the posterior hyaloid. Intravitreal clindamycin should be considered in the differential diagnosis of crystalline retinopathy. [Ophthalmic Surg Lasers Imaging Retina 2024;55:168-170.].

Serous macular detachment in ocular toxoplasmosis: A review.

Ocular toxoplasmosis, a disease of the eye caused by the protozoan parasite Toxoplasma gondii, represents a common cause of posterior uveitis. The Authors review the current Literature regarding the uncommon presentation of ocular toxoplasmosis as macular serous retinal detachment (SRD). It is imperative to keep in mind that inflammatory SRD is a possible presentation of toxoplasmic retinochoroiditis. Underestimation of this clinical scenario and treatment with steroids alone without appropriate antiparasitic drugs, could lead to devastating consequences.

Ocular toxoplasmosis following anti-tumour necrosis factor-α therapy combined with oral methotrexate therapy: A case report and review of literature.

Purpose: To report a case of ocular toxoplasmosis following long-term treatment with adalimumab and review the literature on ocular toxoplasmosis following anti-Tumour necrosis factor-α therapy. Method: A retrospective chart review of A 21-year-old male who developed retinochoroiditis in his left eye following adalimumab therapy combined with oral methotrexate. Result: A known patient of juvenile idiopathic arthritis (JIA) on adalimumab and oral methotrexate for the last four years presented to us with a blurring of vision for the last 15 days. Fundus examination of the left eye revealed severe vitritis and two patches of retinochoroiditis in the inferior part of the fundus. Subsequent investigations confirmed it to be a case of toxoplasma retinochoroiditis, and he responded to anti-toxoplasma treatment. A review of literature on a similar topic revealed five such cases, and the index case was the first such report in patients with JIA. Conclusion: The index case highlights the importance of early recognition and management of opportunistic infections in patients receiving biologicals.

Bacillary layer detachment as an inflammatory biomarker in toxoplasmosis retinochoroiditis: serial evolution on optical coherence tomography.

We describe the clinical course and serial evolution of bacillary layer detachment (BALAD) on optical coherence tomography (OCT) in toxoplasmosis retinochoroiditis and its importance as an inflammatory biomarker. Colour fundus photography and swept-source OCT of the BALAD were done at the time of presentation and subsequently at 1 week, 2 weeks, 4 weeks and at 11 weeks. Treatment involved oral trimethoprim (160 mg) + sulphamethoxazole (800 mg) two times per day, started at presentation for 2 months. Oral prednisolone was started after 1 week at a dose of 50 mg a day and tapered weekly over the next 5 weeks. The BALAD initially increased after starting treatment with trimethoprim-sulphamethoxazole and regressed within 1 week after initiation of oral prednisolone. Best corrected visual acuity improved to 20/40 from 20/160 at presentation (Snellen equivalent). This suggests that BALAD is an indicator of an acute inflammatory event and the accumulated fluid is secondary to retinal and choroidal inflammation.

Outcomes of trimethoprim/ sulfamethoxazole treatment for ocular toxoplasmosis in Congolese patients.

BACKGROUND: Ocular toxoplasmosis (OT) is the leading cause of infectious posterior uveitis in several areas worldwide. The combination of Trimethoprim/Sulfamethoxazole (TMP/SMX) has been presented as an attractive alternative to the "classic' treatment therapy (Pyrimethamine/Sulfadiazine). METHODS: A prospective study was carried out between February 2020 and September 2021 in 2 ophthalmic centers in Kinshasa. This study aimed to describe TMP/SMX treatment outcomes for OT in a cohort of immunocompetent Congolese patients. RESULTS: 54 patients were included, with a mean age at presentation of 37.5 ± 13.6 years old and a Male-Female ratio of 1.45:1. Three patients (5.6%) presented a recurrence during the follow-up period. At the end of the follow-up, improvement in VA and resolution of inflammation concerned 75.9% and 77.5% of patients, respectively. Cataracts (3.7%), macular scars (3.7%), and vitreous opacities (3.7%) were the principal causes of non-improvement in VA. Treatment-related adverse events were present in 10 patients (18.5%); gastrointestinal (14.8%) and dermatological (3.7%) adverse events were the most frequent. Dermatological adverse events led to discontinuation of treatment. CONCLUSION: TMP/SMX regimen appears to be a safe and effective treatment for OT in Congolese patients. The low cost and the accessibility of the molecules make this regimen an option for treating OT in resource-limited countries.

Animal Models for Toxoplasma gondii Infection.

Toxoplasma gondii is an obligate intracellular protozoan parasite that commonly infects mammals and birds throughout the world. This protocol describes murine models of acute T. gondii infection, toxoplasmic encephalitis and toxoplasma retinochoroiditis. T. gondii infection in severe combined immunodeficient (SCID) mice, deficient in T and B cells, has allowed for the study of T cell-independent mechanisms of defense against intracellular organisms, as described here. The uracil auxotroph strain cps1-1 and temperature-sensitive mutant strains of T. gondii induce protection against challenge with virulent strains of the parasite. They have allowed studies of immunization and adoptive-transfer experiments. A protocol is provided for infection with these mutant strains. The EGS strain of T. gondii has the unique feature of spontaneously forming tissue cysts in cell culture. Dual fluorescent reporter stains of this strain have allowed the study of tachyzoite to bradyzoite transitions in vitro and in vivo. A protocol for in vitro and in vivo growth of this strain and tissue cyst isolation is provided. Genetic manipulation of T. gondii and mice has led to the development of parasites that express fluorescent proteins as well as mice with fluorescently labeled leukocytes. This together with the use of T. gondii that express model antigens and transgenic mice that express the appropriate T cell receptor have facilitated the in vivo study of parasite host-interaction. In addition, parasites that express bioluminescent markers have made it possible to study the dynamics of infection in real time using bioluminescence imaging. Support protocols present methodology for evaluation of progression of infection and immune response to the parasite that includes these newer methodologies. In addition, support protocols address the maintenance of T. gondii tissue cysts and tachyzoites, as well as preparation of T. gondii lysate antigens. © 2023 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Induction of acute T. gondii infection in mice Basic Protocol 2: Model of toxoplasmic encephalitis and toxoplasma retinochoroiditis in chronically infected mice Basic Protocol 3: Assessment of T. gondii invasion into neural tissue Basic Protocol 4: T. gondii infection in scid/scid (SCID) mice Basic Protocol 5: Infection with the uracil auxotroph strain CPS1-1 or the temperature-sensitive TS-4 strain of T. gondii Basic Protocol 6: In vivo and in vitro maintenance of the EGS strain of T. gondii Support Protocol 1: Assessment of progression of infection and immune response to T. gondii Support Protocol 2: Maintenance of a bank of T. gondii cysts of the ME49 strain Support Protocol 3: Maintenance of T. gondii tachyzoites using human foreskin fibroblasts Support Protocol 4: Maintenance of T. gondii tachyzoites in mice Support Protocol 5: Preparation of T. gondii lysate antigens Support Protocol 6: Isolation of T. gondii tissue cysts from brain.

Retinal ferroptosis as a critical mechanism for the induction of retinochoroiditis during ocular toxoplasmosis.

Toxoplasmosis is a major infectious disease, affecting approximately one-third of the world's population; its main clinical manifestation, ocular toxoplasmosis (OT), is a severe sight-threatening disease. Nevertheless, the diagnosis of OT is based on clinical findings, which needs improvement, even with biochemical tests, such as polymerase chain reaction and antibody detections. Furthermore, the efficacy of OT-targeted treatment is limited; thus, additional measures for diagnosis and treatments are needed. Here, we for the first time report a significantly reduced iron concentration in the vitreous humor (VH) of human patients infected with OT. To obtain further insights into molecular mechanisms, we established a mouse model of T. gondii infection, in which intravitreally injected tracer 57Fe, was accumulated in the neurosensory retina. T. gondii-infected eyes showed increased lipid peroxidation, reduction of glutathione peroxidase-4 expression and mitochondrial deformity in the photoreceptor as cristae loss. These findings strongly suggest the involvement of ferroptotic process in the photoreceptor of OT. In addition, deferiprone, an FDA-approved iron chelator, reduced the iron uptake but also ameliorated toxoplasma-induced retinochoroiditis by reducing retinal inflammation. In conclusion, the iron levels in the VH could serve as diagnostic markers and iron chelators as potential treatments for OT.

Elevated interleukin-10 levels in patients with ocular toxoplasmosis.

In elderly patients, ocular toxoplasmosis is one of the most common etiologies of uveitis, which should be differentially diagnosed from ocular lymphoma, another common pathology of uveitis in older adults. The high level of interleukin (IL)-10 and an IL-10/IL-6 ratio higher than 1 (>1.0) are helpful parameters to diagnose ocular lymphoma. In this study, we used aqueous humor samples to detect 4 cases of ocular toxoplasmosis in patients with high levels of IL-10 and an IL-10/IL-6 ratio higher than 1. Our results show that ocular toxoplasmosis may be associated with increased cytokine levels in aqueous humor.

Acquired Ocular Toxoplasmosis: a Case Report and Review of the Literature.

BACKGROUND: Toxoplasmosis is a zoonotic illness caused by Toxoplasma gondii. Ocular infection frequently manifests as acute necrotizing retinal chorioretinitis. In this paper, we describe a case of retinal chorioretinitis caused by Toxoplasma gondii infection, as well as the most recent diagnostic and treatment techniques. METHODS: Serum and vitreous fluid were collected and analyzed, and PCR for Toxoplasma gondii DNA, ELISA for Toxoplasma gondii IgG and Goldmann-Witmer coefficient, fundus fluorescein angiography (FFA), indocyanine green angiography (ICGA), and fundus autofluorescence were done (FAF). RESULTS: Toxoplasma gondii DNA (-), serum and vitreous IgG from Toxoplasma gondii (+) cells, and the Goldmann-Witmer coefficient of Toxoplasma gondii were all considerably enhanced, indicating Toxoplasma gondii infection. Antiparasitic infection in combination with an anti-inflammatory glucocorticoid were given, laser treatment of the fundus was provided, and the patient's condition has been stable with no indication of recurrence to date following conclusion of therapy. CONCLUSIONS: Toxoplasma gondii can infect the whole retina, causing variable degrees of visual impairment; thus, rapid diagnosis and tailored therapy are necessary to enhance prognosis and reduce disease recurrence.

miRNA 511_5p is a potential biomarker for ocular toxoplasmosis.

BACKGROUND: Ocular toxoplasmosis (OT) is a frequent clinical manifestation due to infection by Toxoplasma gondii. It is characterized by an inflammatory process involving macrophages activated by pro-inflammatory cytokines. The expression of microRNAs takes place during the inflammatory process and, among them, miRNA 511 regulates the activation of macrophages. This study evaluated the expression of miRNA 511_5p in patients with OT and healthy controls. METHODS: A total of 361 patients from the Hospital de Base of Fundação Faculdade de Medicina de São José do Rio Preto were enrolled and divided into four groups: G1-patients with active ocular lesions and reagent serology for T. gondii; G2-patients with scars and reagent serology for T. gondii; G3-patients without ocular lesions or scars and reagent serology for T. gondii; G4-patients without ocular lesions or scars and non-reagent serology for T. gondii. All patients underwent clinical and laboratory evaluation to confirm the diagnosis of OT. Serology tests, RNA extraction and cDNA synthesis were performed. RESULTS: The miRNA 511_5p levels were compared among the groups. The G1 group showed a high blood plasma concentration of miRNA 511_5p (mean 22.34) compared with the G2 (4.65), G3 (8.91) and G4 (3.52) groups (p<0.0001). CONCLUSION: These data suggest that miRNA 511_5p has significant potential as a biomarker for OT.

Risk factors for ocular toxoplasmosis among uveitis patients in Kinshasa, DR Congo.

OBJECTIVE: To identify the risk factors associated with ocular toxoplasmosis (OT) in a cohort of Congolese patients with uveitis. METHODS AND ANALYSIS: A cross-sectional study was conducted between March 2020 and July 2021 in two ophthalmic clinics in Kinshasa. Patients with a diagnosis of uveitis were enrolled in the study. Each patient underwent an interview, an ophthalmological examination and serology testing. Logistic regression was performed to identify risk factors for OT. RESULTS: 212 patients were included in the study with a mean age at presentation of 42.1±15.9 years (limits: 8-74 years) and a sex ratio of 1.1:1. OT concerned 96 patients (45.3%). The age of the patients below 60 years (p=0.001, OR=9.75 CI 95% 2.51 to37.80)), the consumption of cat meat (p=0.01, OR=2.65 CI 95% 1.18 to 5.96)) and undercooked meat (p=0.044, OR=2.30 CI 95% 1.02 to 5.21)) and living in rural area (p=0.021, OR=11.4 (CI 95% 1.45 to 89.84])) were identified as risk factors for OT. CONCLUSION: OT affects more young people. It is associated with dietary habits. Informing and educating the population is necessary to avoid infection.