-
Turkiye Parazitolojii Dergisi Dec 2023The "One Health" concept is a universal approach to sustainably balancing and optimizing the health of humans, animals, and ecosystems. This approach is based on the...
The "One Health" concept is a universal approach to sustainably balancing and optimizing the health of humans, animals, and ecosystems. This approach is based on the health of humans, domestic and wild animals, and plants in a wider environment in which self-renewable ecosystems exist, with essential characteristics of integration, unifying and holistic perspective. Toxoplasmosis, one of the most common zoonotic infections in both terrestrial and oceanic ecosystems in the world, is an ideal model disease for the "One Health" approach. Toxoplasmosis is a zoonotic disease caused by the obligate intracellular pathogen protozoan . In the life cycle of , the definitive host is domestic cats and felines, and the intermediate hosts are all mammals (including humans), birds and reptiles. The infected cats have primary importance and play a crucial role in the contamination of habitats in the ecosystems with oocysts. Thus, ecosystems with domestic cats and stray cats are contaminated with cat feces infected with oocytes. positivity has been scientifically demonstrated in all warm-blooded animals in terrestrial and aquatic habitats. The disease causes deaths and abortions in farm animals, resulting in great economic losses. However, the disease causes great problems in humans, especially pregnant women. During pregnancy, it may have effects such as congenital infections, lesions in the eye and brain of the fetus, premature birth, intrauterine growth retardation, fever, pneumonia, thrombocytopenia, ocular lesions, encephalitis, and abortion. The mechanism of death and abortion of the fetus in a pregnant woman infected with occurs as a result of complete disruption of the maternal immune mechanism. The struggle against toxoplasmosis requires the universal collaboration and coordination of the World Organization for Animal Health, the World Health Organization and the World Food Organization in the "One Health" concept and integrative approaches of all responsible disciplines. Establishing universal environmental safety with the prevention and control of toxoplasmosis requires the annihilation of the feces of the infected cats using suitable techniques firstly. Then routinely, the monitoring and treatment of positivity in cats, avoiding contact with contaminated foods and materials, and development of modern treatment and vaccine options. Particularly, mandatory monitoring or screening of positivity during the pregnancy period in humans should be done. It would be beneficial to replace the French model, especially in the monitoring of disease in humans. In this article, the ecology of toxoplasmosis was reviewed at the base of the "One Health" concept.
Topics: Female; Humans; Animals; Pregnancy; Cats; One Health; Ecosystem; Toxoplasmosis; Toxoplasma; Zoonoses; Animals, Domestic; Toxoplasmosis, Animal; Cat Diseases; Mammals
PubMed: 38149449
DOI: 10.4274/tpd.galenos.2023.38039 -
PLoS Neglected Tropical Diseases Jun 2024Ocular toxoplasmosis (OT) is the most common cause of infectious uveitis worldwide, including Thailand. This study describes the clinical presentation, visual acuity...
Clinical characteristics, visual acuity outcomes, and factors associated with loss of vision among patients with active ocular toxoplasmosis: A retrospective study in a Thai tertiary center.
BACKGROUND
Ocular toxoplasmosis (OT) is the most common cause of infectious uveitis worldwide, including Thailand. This study describes the clinical presentation, visual acuity (VA) outcomes, and factors associated with VA loss in patients with active OT following antiparasitic treatment.
METHODOLOGY/PRINCIPAL FINDINGS
A retrospective chart review of patients with active OT treated with antiparasitic drugs between 2010 and 2020 was performed. Outcome measures included clinical characteristics, interval VA, and predictive factors associated with loss of VA ≤ 20/50 at 6 months post-treatment. Ninety-two patients (95 eyes) were enrolled. The median follow-up time was 10.9 months (IQR 4.9-31.8 months). The median age at presentation was 35.9 years, 51% were male, and 92.4% had unilateral OT. Eleven patients (12%) were immunocompromised (HIV infection, eight patients; receiving immunosuppressive agents, three patients). Patients mainly presented with primary retinitis without previous scar (62%), posterior pole lesion (56%), and lesion size of ≤ 2-disc area (75%). Immunocompromised patients showed a significantly larger size of retinitis than immunocompetent patients. Oral trimethoprim/sulfamethoxazole monotherapy was the primary short-term antiparasitic drug prescribed (85%). At the final visit, 21% of all affected eyes suffered VA ≤ 20/200. The cumulative incidence of recurrent OT at three years was 33.9% (95% CI, 19.7%-54.2%). Immunocompromised patients [adjusted odds ratio (aOR) 4.9, p = 0.041], macular lesion (aOR 5.4, p = 0.032), and initial VA ≤ 20/200 (aOR 9.1, p = 0.014) were predictive of having VA ≤ 20/50 at 6 months post-treatment.
CONCLUSIONS
Ocular toxoplasmosis mainly presents as unilateral primary retinitis within the posterior pole. Severe VA loss was observed in one-fifth of eyes following treatment with lesion resolution. Immunocompromised patients, eyes with macular lesions, and poor initial VA were associated with poor VA outcomes.
Topics: Humans; Toxoplasmosis, Ocular; Male; Retrospective Studies; Adult; Female; Thailand; Visual Acuity; Middle Aged; Tertiary Care Centers; Young Adult; Immunocompromised Host; Antiparasitic Agents; Trimethoprim, Sulfamethoxazole Drug Combination; Adolescent; Treatment Outcome; Southeast Asian People
PubMed: 38843299
DOI: 10.1371/journal.pntd.0012232 -
International Ophthalmology Oct 2023To analyse the demography, etiology, and classification of uveitis at a tertiary academic referral center. (Observational Study)
Observational Study
PURPOSE
To analyse the demography, etiology, and classification of uveitis at a tertiary academic referral center.
METHODS
An observational study was conducted on the archives of uveitic patients at the Ocular Inflammation Service of the Department of Ophthalmology at the University Hospital of Ioannina (Greece) from 1991 to 2020. This study aimed to investigate the epidemiological profile of patients, including their demographics and the main etiologic factors of uveitis.
RESULTS
Out of 6191 cases with uveitis, 1925 were infectious, 4125 were non-infectious, and an overall of 141 masquerade syndromes were recorded. Among these cases, 5950 patients were adults, with a slight female predominance, while 241 were children (< 18 years old). Interestingly, 24.2% of cases (1500 patients) were associated with 4 specific microorganisms. Herpetic uveitis (HSV-1 and VZV/HZV) was the most common cause of infectious uveitis (14.87%), followed by toxoplasmosis (6.6%) and tuberculosis (2.74%). In 49.2% of non-infectious uveitis cases, no systematic correlation was found. The most frequent causes of non-infectious uveitis included sarcoidosis, white dot syndromes, ankylosing spondylitis, lens-induced uveitis, Adamantiades-Behçet disease, and idiopathic juvenile arthritis. Infectious uveitis was more common in the rural population, whereas non-infectious uveitis was more frequently recorded in the urban population CONCLUSIONS: Although our study was conducted on a predominantly white Caucasian population, it also reflects the effect of increasing immigration, improvements of diagnostic techniques, changes in referral patterns, and various actual changes in disease incidence.
Topics: Adult; Child; Humans; Female; Adolescent; Male; Uveitis; Behcet Syndrome; Tertiary Care Centers; Morbidity; Referral and Consultation; Retrospective Studies
PubMed: 37428299
DOI: 10.1007/s10792-023-02772-5 -
Outcomes of trimethoprim/ sulfamethoxazole treatment for ocular toxoplasmosis in Congolese patients.BMC Ophthalmology Oct 2023Ocular toxoplasmosis (OT) is the leading cause of infectious posterior uveitis in several areas worldwide. The combination of Trimethoprim/Sulfamethoxazole (TMP/SMX) has...
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.
Topics: Humans; Male; Female; Young Adult; Adult; Middle Aged; Trimethoprim, Sulfamethoxazole Drug Combination; Toxoplasmosis, Ocular; Pyrimethamine; Prospective Studies; Democratic Republic of the Congo
PubMed: 37907920
DOI: 10.1186/s12886-023-03183-x -
PloS One 2023Toxoplasmosis, caused by the obligate intracellular parasite Toxoplasma gondii, affects about one-third of the world's population and can cause severe congenital,...
Repurposing the Medicines for Malaria Venture's COVID Box to discover potent inhibitors of Toxoplasma gondii, and in vivo efficacy evaluation of almitrine bismesylate (MMV1804175) in chronically infected mice.
Toxoplasmosis, caused by the obligate intracellular parasite Toxoplasma gondii, affects about one-third of the world's population and can cause severe congenital, neurological and ocular issues. Current treatment options are limited, and there are no human vaccines available to prevent transmission. Drug repurposing has been effective in identifying anti-T. gondii drugs. In this study, the screening of the COVID Box, a compilation of 160 compounds provided by the "Medicines for Malaria Venture" organization, was conducted to explore its potential for repurposing drugs to combat toxoplasmosis. The objective of the present work was to evaluate the compounds' ability to inhibit T. gondii tachyzoite growth, assess their cytotoxicity against human cells, examine their absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties, and investigate the potential of one candidate drug through an experimental chronic model of toxoplasmosis. Early screening identified 29 compounds that could inhibit T. gondii survival by over 80% while keeping human cell survival up to 50% at a concentration of 1 μM. The Half Effective Concentrations (EC50) of these compounds ranged from 0.04 to 0.92 μM, while the Half Cytotoxic Concentrations (CC50) ranged from 2.48 to over 50 μM. Almitrine was chosen for further evaluation due to its favorable characteristics, including anti-T. gondii activity at nanomolar concentrations, low cytotoxicity, and ADMET properties. Administering almitrine bismesylate (Vectarion®) orally at dose of 25 mg/kg/day for ten consecutive days resulted in a statistically significant (p < 0.001) reduction in parasite burden in the brains of mice chronically infected with T. gondii (ME49 strain). This was determined by quantifying the RNA of living parasites using real-time PCR. The presented results suggest that almitrine may be a promising drug candidate for additional experimental studies on toxoplasmosis and provide further evidence of the potential of the MMV collections as a valuable source of drugs to be repositioned for infectious diseases.
Topics: Animals; Mice; Toxoplasma; Almitrine; Drug Repositioning; COVID-19; Toxoplasmosis; Malaria
PubMed: 37418497
DOI: 10.1371/journal.pone.0288335 -
Microorganisms Oct 2023Ocular toxoplasmosis (OT) is characterized by inflammation within the eye and is the most recognized clinical manifestation of toxoplasmosis. The objective of this study...
Ocular toxoplasmosis (OT) is characterized by inflammation within the eye and is the most recognized clinical manifestation of toxoplasmosis. The objective of this study was to identify new single-nucleotide polymorphisms (SNPs) in the gene that may have significance in the immune response to OT in Colombian patients. A case-control study was conducted to investigate the associations between SNPs (rs1718119 and rs2230912) in the gene and OT in 64 Colombian patients with OT and 64 controls. Capillary electrophoresis was used to analyze the amplification products, and in silico algorithms were employed to predict deleterious SNPs. Stability analysis of amino acid changes indicated that both mutations could lead to decreased protein structure stability. A nonsynonymous SNP, Gln460Arg, located in the long cytoplasmic tail of the receptor, showed a significant association with OT (Bonferroni correction (BONF) = 0.029; odds ratio OR = 3.46; confidence interval CI: 1.05 to 11.39), while no significant association between rs1718119 and OT risk was observed. Based on the 3D structure analysis of the protein trimer, it is hypothesized that an increase in the flexibility of the cytoplasmic domain of this receptor could alter its function. This SNP could potentially serve as a biomarker for identifying Colombian patients at risk of OT.
PubMed: 37894166
DOI: 10.3390/microorganisms11102508 -
Life Science Alliance Jul 2024Toxoplasmosis is the most prevalent parasitic zoonosis worldwide, causing ocular and neurological diseases. No vaccine has been approved for human use. We evaluated the...
Toxoplasmosis is the most prevalent parasitic zoonosis worldwide, causing ocular and neurological diseases. No vaccine has been approved for human use. We evaluated the response of peripheral blood mononuclear cells (PBMCs) to a novel construct of total antigen in maltodextrin nanoparticles (NP/TE) in individuals with varying infectious statuses (uninfected, chronic asymptomatic, or ocular toxoplasmosis). We analyzed the concentration of IFN-γ after NP/TE ex vivo stimulation using ELISA and the immunophenotypes of CD4 and CD8 cell populations using flow cytometry. In addition, serotyping of individuals with toxoplasmosis was performed by ELISA using GRA6-derived polypeptides. Low doses of NP/TE stimulation (0.9 μg NP/0.3 μg TE) achieved IFN-γ-specific production in previously exposed human PBMCs without significant differences in the infecting serotype. Increased IFN-γ expression in CD4 effector memory cell subsets was found in patients with ocular toxoplasmosis with NP/TE but not with TE alone. This is the first study to show how T-cell subsets respond to ex vivo stimulation with a vaccine candidate for human toxoplasmosis, providing crucial insights for future clinical trials.
Topics: Humans; Nanoparticles; Polysaccharides; Toxoplasma; Antigens, Protozoan; Toxoplasmosis; Interferon-gamma; Lymphocyte Activation; Female; Adult; Leukocytes, Mononuclear; CD4-Positive T-Lymphocytes; Male; CD8-Positive T-Lymphocytes; T-Lymphocytes; Middle Aged
PubMed: 38724195
DOI: 10.26508/lsa.202302486 -
Cureus Oct 2023A 45-year-old immunocompetent man with a two-week history of unilateral painful red eye was referred to the university hospital for further investigation. High...
A 45-year-old immunocompetent man with a two-week history of unilateral painful red eye was referred to the university hospital for further investigation. High intraocular pressure, corneal edema, large pigmented keratic precipitates, cells and flares in the anterior chamber, patches of iris transillumination with atrophy, multifocal segmental retinal arteritis (SRA) or Kyrieleis arteritis, and peripheral choroidal elevation with overlying vitritis without adjacent old scars were observed. Toxoplasmosis, varicella-zoster virus, herpes simplex, and cytomegalovirus serologies (IgG) were positive. More detailed history-taking revealed that the patient consumed grilled rats in Ghana where rats are eaten more regularly. Toxoplasmosis diagnosis was assumed. The patient was successfully treated according to local guidelines with azithromycin 500 mg/day for five weeks. No recurrence or new lesion was observed during the six-month follow-up period.
PubMed: 38022132
DOI: 10.7759/cureus.47060 -
Research Square Aug 2023Studies on uveitis in Sierra Leone were conducted prior to the Ebola Virus Disease epidemic of 2013-16, which was associated with uveitis in 20% of survivors. They did...
BACKGROUND/OBJECTIVES
Studies on uveitis in Sierra Leone were conducted prior to the Ebola Virus Disease epidemic of 2013-16, which was associated with uveitis in 20% of survivors. They did not include imaging or investigation of tuberculosis and used laboratory services outside the country. We performed a cross-sectional study on patients presenting with uveitis to establish their clinical characteristics and identify the impact of in-country laboratory diagnoses.
METHODS
We invited uveitis cases presenting to Eye Clinics in Sierra Leone from March to September 2022 to participate in the study. They underwent a diagnostic work-up, including fundus and ocular coherence tomography imaging. Active uveitis cases underwent further investigations including serology and immunological tests for syphilis, tuberculosis and herpetic viruses and HIV, and chest radiographs.
RESULTS
We recruited 128 patients. The mean age was 36 ± 14 years and there was an equal gender split. Panuveitis was the predominant anatomical uveitis type (n=51, 40%), followed by posterior uveitis (n=36, 28%). Bilateral disease affected 40 patients (31%). Active uveitis was identified in 75 (59%) cases. ICD 11 definition of blindness with VA<3/60 occurred in 55 (33%) uveitis eyes. Aetiology of uveitis from clinical and laboratory assessment demonstrated that most cases were of undifferentiated aetiology (n=66, 52%), followed by toxoplasmosis (n=46, 36%). Trauma contributed to eight (6%) cases, syphilis to 5 (4%) cases and Ebola to 2 (2%).
CONCLUSIONS
Uveitis was associated with high levels of visual impairment. Posterior and panuveitis contributed to the highest proportion of uveitis cases. Laboratory studies helped differentiate syphilis as a significant aetiology of uveitis.
PubMed: 37609303
DOI: 10.21203/rs.3.rs-3222203/v1 -
PloS One 2024Ocular toxoplasmosis (OT) is caused by protozoan T. gondii. Ophthalmological examination is considered the gold standard for OT diagnosis, and laboratory tests are used...
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.
Topics: Humans; Toxoplasmosis, Ocular; Toxoplasma; Brazil; Antibodies, Protozoan; Immunologic Tests; Immunoglobulin G; Immunoglobulin M; Immunoglobulin A
PubMed: 38319921
DOI: 10.1371/journal.pone.0298393