• Parasites, Hosts and Diseases
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• v.42 no.3
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• pp.137-140
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• 2004

Ocular toxocariasis named also ocular larva migrans is caused by larvae of the roundworm Toxocara spp. The purpose of this study was to find out the seroprevalence of Toxocara antibodies in patients suspected of ocular toxocariasis. Between January 2001 and December 2003, sera from 239 ocular patients, aged 3 to 80 years, were examined by ELISA and confirmed by Western blot test. Out of the 239 patients, 172 (72%) were seronegative and 67 (28%) were Toxocara seropositive; 95% CI (22-34%). The median age of Toxocara seropositive patients was 37.6 years. There was no significant difference in the number of Toxocara positive sera between the younger age group (${\leq}14$ years) and the older age group (＞14 years), p＞0.05. A high rate of Toxocara seropositivity in ocular patients should alert the ophthalmologists in Slovenia to include toxocariasis in the differential diagnosis of eye diseases more frequently.

• Parasites, Hosts and Diseases
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• v.52 no.5
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• pp.537-540
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• 2014

We present a case of ocular toxocariasis treated successfully with oral albendazole in combination with steroids. A 26-year-old male visited the authors' clinic with the chief complaint of flying flies in his right eye. The fundus photograph showed a whitish epiretinal scar, and the fluorescein angiography revealed a hypofluorescein lesion of the scar and late leakage at the margin. An elevated retinal surface and posterior acoustic shadowing of the scar were observed in the optical coherence tomography, and Toxocara IgG was positive. The patient was diagnosed with toxocariasis, and the condition was treated with albendazole (400 mg twice a day) for a month and oral triamcinolone (16 mg for 2 weeks, once a day, and then 8 mg for 1 week, once a day) from day 13 of the albendazole treatment. The lesions decreased after the treatment. Based on this study, oral albendazole combined with steroids can be a simple and effective regimen for treating ocular toxocariasis.

• Parasites, Hosts and Diseases
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• v.60 no.2
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• pp.133-137
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• 2022

Toxocariasis is one of the most common geohelminth infections in several parts of the world. We describe a rare case of ocular toxocariasis with secondary exudative retinal detachment treated with albendazole and an intravitreal dexamethasone implant. A 13-year-old boy with counting finger vision was diagnosed with retinal vasculitis and exudative retinal detachment in his right eye. Fundoscopic examination revealed retinal hemorrhage, retinal vasculitis, and exudative retinal detachment. Serological test using serum and intraocular aqueous humor were positive for anti-Toxocara specific IgG antibodies. He received repeated doses of intravitreal dexamethasone implants combined with oral albendazole. A sequential follow-up optical coherence tomography revealed that the retina was successfully reattached. His visual acuity subsequently improved to 20/400.

• Parasites, Hosts and Diseases
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• v.39 no.1
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• pp.1-11
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• 2001

Human toxocariasis is a helminthozoonosis due to the migration of Toxocara species larvae through human organism. Humans become infected by ingesting either embryonated eggs from soil (geophagia, pica), dirty hands or raw vegetables, or larvae from undercooked giblets. The diagnosis relies upon sensitive immunological methods (ELISA or western-blot) which use Toxocara excretory-secretory antigens . Seroprevalence is high in developed countries, especially in rural areas, and also in some tropical islands. The clinical spectrum of the disease comprises four syndromes, namely visceral larva migrans, ocular larva migrans, and the more recently recognized "common" (in adults) and "covert"(in children) pictures. Therapy of ocular toxocariasis is primarily based upon corticosteroids use, when visceral larva migrans and few cases of common or covert toxocariasis can be treated by anthelmintics whose the most efficient appeared to be diethylcarbamazine. When diagnosed , all of these syndromes require thorough prevention of recontamination (especially by deworming pets) and sanitary education.

• Parasites, Hosts and Diseases
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• v.38 no.4
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• pp.267-273
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• 2000

We report 5 cases of ocular toxocariasis in Korean adults complaining of visual impairment along with floating or bubbling sensation. Fundoscopic examination revealed a retinal detachment along with exudate in 4 cases. They all showed typical reaction by ELISA and immunoblot against Toxocra excretory-secretory antigen. One case showed high level of anti-Toxocara IgE antibodies (34.000 Toxocara units/L) as well as increased level of serum total IgE antibodies and the specific IgE antibodies for 3 inhalant antigens, suggesting that high level of anti-Toxocara IgE antibodies was associated with an atopic status. Clinical manifestations were improved after the sequential use of steroids then mebendazole. We also suggest that ocular toxocariasis should be thoroughly investigated even when an evocative uniocular inflammatory lesion is encountered in peripheral retina without a systematic disease.

• Journal of agricultural medicine and community health
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• v.23 no.2
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• pp.295-303
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• 1998

Toxocariasis is a parasitic zoonosis caused by infestation of humans with larvae of Toxocara canis, the common roundworm in dogs. Two syndromes have been identified : visceral larva migrans and ocular toxocariasis. In this study we were characterized proteinase activity in crude extracts from liver, lung, kidney and heart of mice infected with Toxocara canis and the dynamics of their changes in different stages of disease. The optimal pH was 5.5. In liver of mice infected with Toxocara canis, the maximun activity of proteinase was observed in 5 day post infection. In lung, the activity reached its maximun on 5th day in A group (infected with 100 embryonated eggs), and on 5th week in B group (infected with 50 embryonated eggs). In kidney, the maximum activity was shown at 6th week in A group, and in B group was shown at 10th day. In early infection, the activity reached its maximun in heart of mice infected with Toxocara canis. As we could see, the dynamics of the changes of proteinase activity in mice is similar in the case of the disease with other biochemical and immunological indices observed in toxocariasis.

• Journal of Korean Ophthalmic Optics Society
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• v.9 no.2
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• pp.447-453
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• 2004

The prevalence of Toxocara canis eggs in the public places in the city of Gwangju were studied through examination of 800 soil and 123 fecal specimens. Toxocara canis eggs were found in 15% of soil samples. In 25% parks and 17% residential quarters, these eggs were detected with higher contamination rate than other places. The soil contamination rate of playgrounds in spring and autumn was higher than that of summer and winter, and the variation range of the rate was high in parks and residential quarters. The contamination rate of eggs in 123 samples of dogs' feces was 31%, it was higher than that of soil samples(21%).

• Parasites, Hosts and Diseases
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• v.51 no.5
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• pp.563-567
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• 2013

An ocular Toxocara canis infection is reported for the first time in Vietnam. A 34-year-old man residing in a village of Son La Province, North Vietnam, visited the National Eye Hospital (NEH) in August 2011. He felt a bulge-sticking pain in his left eye and loss of vision occurred over 3 months before visiting the hospital. The eye examination in the hospital showed damage of the left eye, red eye, retinal fibrosis, retinal detachment, inflammation of the eye tissues, retinal granulomas, and a parasitic cyst inside. A larva of Toxocara was collected with the cyst by a medical doctor by surgery. Comparison of 264 nucleotides of internal transcribed spacer 2 (ITS2) of ribosomal DNA was done between our Vietnamese Toxocara canis and other Toxocara geographical isolates, including Chinese T. canis, Japanese T. canis, Sri Lankan T. canis, and Iranian T. canis. The nucleotide homology was 97-99%, when our T. canis was compared with geographical isolates. Identification of a T. canis infection in the eye by a molecular method was performed for the first time in Vietnam.

• Parasites, Hosts and Diseases
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• v.62 no.2
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• pp.243-250
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• 2024

We investigated organ specific Toxocara canis larval migration in mice infected with T. canis larvae. We observed the worm burden and systemic immune responses. Three groups of BALB/c mice (n=5 each) were orally administered 1,000 T. canis 2nd stage larvae to induce larva migrans. Mice were sacrificed at 1, 3, and 5 weeks post-infection. Liver, lung, brain, and eye tissues were collected. Tissue from 2 mice per group was digested for larval count, while the remaining 3 mice underwent histological analysis. Blood hematology and serology were evaluated and compared to that in a control uninfected group (n=5) to assess the immune response. Cytokine levels in bronchoalveolar lavage (BAL) fluid were also analyzed. We found that, 1 week post-infection, the mean parasite load in the liver (72±7.1), brain (31±4.2), lungs (20±5.7), and eyes (2±0) peaked and stayed constant until the 3 weeks. By 5-week post-infection, the worm burden in the liver and lungs significantly decreased to 10±4.2 and 9±5.7, respectively, while they remained relatively stable in the brain and eyes (18±4.2 and 1±0, respectively). Interestingly, ocular larvae resided in all retinal layers, without notable inflammation in outer retina. Mice infected with T. canis exhibited elevated levels of neutrophils, monocytes, eosinophils, and immunoglobulin E. At 5 weeks post-infection, interleukin (IL)-5 and IL-13 levels were elevated in BAL fluid. Whereas IL-4, IL-10, IL-17, and interferon-γ levels in BAL fluid were similar to that in controls. Our findings demonstrate that a small portion of T. canis larvae migrate to the eyes and brain within the first week of infection. Minimal tissue inflammation was observed, probably due to increase of anti-inflammatory cytokines. This study contributes to our understanding of the histological and immunological responses to T. canis infection in mice, which may have implications to further understand human toxocariasis.