Ocular toxocariasis

Toxocara canis infection in multiple types of animals: ophthalmological and pathological observations

Human ocular toxocariasis (OT), caused by pet roundworm Toxocara canis (Nematoda Ascaridoidea), is a worldwide ocular parasitic infection that poses a severe threat to eyesight, especially in school-aged children. However, the infection process and pathological mechanism of Toxocara are difficult to study in the human body. This study was designed to explore long-term ocular manifestations in different rodents infected with Toxocara canis, uncovering the specific pathological mechanism and migration pathway of larvae after infection. The three types of experimental animals we selected were C57BL/6 mice, Mongolian gerbils and Brown Norway rats. Mice were randomly divided into five groups and infected orally with 1000, 2000, 4000, 8000 and 10,000 T. canis eggs; gerbils were randomly divided into four groups and infected orally with 1000, 2000, 4000 and 10,000 T. canis eggs; rats were randomly divided into three groups and infected orally with 2000, 6000 and 10,000 T. canis eggs. Their ocular changes were closely observed and recorded for at least 2 months. We also enucleated the eyeballs of some animals to perform pathological sectioning and hematoxylin-eosin staining. After 3 dpi (days post-infection), hemorrhagic lesions, mechanical injury of the retina and larval migration could be observed in some infected animals. The ocular infection and mortality rates tended to be stable at 7 dpi. Larval tissue, structure disorder and inflammation could be observed in the pathological sections. In conclusion, the mice infected with 2000 T. canis eggs and gerbils infected with 1000, 2000 and 4000 T. canis eggs showing obvious ocular lesions and lower mortality rates could provide a basis for long-term observation.

Pediatric Posterior Infectious Uveitis

PURPOSE

To describe the most important cause of infectious posterior uveitis in pediatric patients.

METHODS

Review of the literature.

RESULTS

The most important causes of infectious uveitis in pediatric patients are: cat-scratch disease, toxocariasis, tuberculosis, viral diseases and toxoplasmosis. Ocular manifestations include retinitis, neuroretinitis, choroidal granulomas, peripheral granulomas and posterior pole granulomas.

CONCLUSION

Infectious posterior uveitis is a challenging subject and should be considered in the differential diagnosis of any posterior uveitis in children. Infectious uveitis must be excluded before initiating immunosuppressive therapy.

Recurrent vitreous opacity caused by intraocular Toxocara larva: a case report and literature review

BACKGROUND

Toxocara larva entity has seldom been reported on the surface of the retina. We report on an unusual case of recurrent vitreous opacity caused by intraocular Toxocara larva after vitrectomy.

CASE PRESENTATION

A 34-year-old male was referred to our clinic with a 6-month history of decreased visual acuity in the right eye characterized as red, painless, and progressive. Optos fundus photograph showed optic disc elevation with granuloma, and proliferative membrane starting from the optic disc and running towards the superior temporal retina due to the movement of a Toxocara larva, which was covered by the proliferative membrane in the superior temporal retina. Since it adhered closely to the retina, the lesion in the superior temporal retina was not removed to avoid induction of an iatrogenic retinal break and the larva was not found during the first diagnostic pars plana vitrectomy. Intraocular Anti-Toxocara IgG was 45.53U (< 3, enzyme-linked immunosorbent assay (ELISA)), and the Goldmann-Witmer coefficient was 8.55, confirming the diagnosis of ocular toxocariasis. After this operation, visual acuity improved to 20/200. However, vitreous opacity worsened again, and the proliferative membrane expanded around the Toxocara larva three weeks after the operation. Toxocara larva was found and removed in the superior temporal region during the second operation. His visual acuity improved to 20/100, vitreous opacity disappeared, and the retina was stable two months after the second operation.

CONCLUSION

It is advisable to remove suspected Toxocara larva to prevent the reoccurrence of ocular toxocariasis.

The Value of the Antibody Detection in the Diagnosis of Ocular Toxocariasis and the Aqueous Cytokine Profile Associated With the Condition

Introduction

To evaluate and compare the specificity of Toxocara canis-specific antibody detection in the serum and aqueous samples for the diagnosis of ocular toxocariasis (OT) and explore the cytokine profiles associated with the condition in children.

Materials and Methods

This is a prospective cohort study. The inclusion criteria were the clinical presentations of OT, which included unilateral vision reduction, typical peripheral or posterior pole granuloma with variable degrees of vitritis, and exclusion of other diagnoses. The titer of antibody against the excretory-secretory antigen of Toxocara canis [T-immunoglobulin G (IgG)] was measured in serum and aqueous samples that were taken from the affected eyes. The diagnosis of OT was made upon positive detection of T-IgG either in the serum or aqueous. The rest with typical clinical presentations as described above but a positive serum or aqueous T-IgG could not be confirmed were diagnosed as suspected OT. Cytokines were measured using multiplexed cytometric bead array system.

Results

Two hundred and eleven eyes of 211 patients had participated in the study. One hundred and twenty-eight eyes were diagnosed as OT. The median age of the cohort was 7.7 years with a male to female ratio of 2.5:1. Major initial symptoms were decreased vision (74%) and strabismus (22%). The percentages of eyes with peripheral granuloma, posterior granuloma, and endophthalmitis were 40, 18, and 41%, respectively. Vitritis (100%), vitreous strands (64%), retinal fibrotic bands (57%), and retinal detachment (42%) were the most common signs. T-IgG was positive in 66.7% of the aqueous and 57.2% of the serum samples. Forty-four patients were diagnosed T-IgG negative in both serum and aqueous of the affected eyes. Interleukin (IL)-6, monocyte chemoattractant protein (MCP)-1, IL-8, eosinophil chemotactic protein (Eotaxin), MCP-1β, and vascular endothelial growth factor (VEGF) were higher in T-IgG negative eyes when compared to controls and further increased in T-IgG positive eyes. However, only T-IgG positive eyes showed increased IL-5, IL-13, and IL-10. IL-1β, tumor necrosis factor-alpha (TNF-α), IL-12, IL-2, interferon-gamma (IFN-γ), and IL-4 were undetectable in all eyes.

Conclusions

Pediatric OT is often present with severe retinal complications. Polarized intraocular Th2 response was only found in aqueous T-IgG positive eyes. Our results supported an aqueous sample-based antibody test for the more specific diagnosis of OT.

Frequency of Toxocara Antibodies in Patients Clinically Suspected to Ocular Toxocariasis, Northeast of Iran

Background:

Human toxocariasis is a neglected parasitic disease in most countries including Iran. Among different clinical forms of toxocariasis, ocular toxocariasis (OT) is an important disease resulting in severe vision loss. However, the prevalence and incidence of OT are currently unclear in Iran. This study aimed to determine the prevalence of ocular toxocariasis among patients with uveitis in the Northeast of Iran.

Methods:

From 2015 to 2017, 510 patients with uveitis referred to Khatam-al-Anbia, a tertiary eye hospital at Mashhad, Iran were examined for OT. Serum samples of the suspected patients were obtained and evaluated for IgG against Toxocara canis using ELISA test. Anti-Toxocara IgG positive serums were further investigated using confirmatory Western blotting (WB) analysis.

Results:

Twenty patients had pathologic changes and clinical presentations in the anterior and posterior segments of their eyes and they were clinically diagnosed ocular toxocariasis. Among the 20 patients, 2 (10%) patients showed IgG antibody against Toxocara canis on ELISA as well as on WB test. The calculated prevalence of ocular toxocariasis was about 0.4%.

Conclusion:

Ocular toxocariasis can be diagnosed both clinically and serologically in Mashhad, northeastern Iran. Although OT is a rare pathologic eye disease, it should be considered as one of the important cause of infectious posterior uveitis.

As the worm turns: An infant with exotropia

A two-year-old full-term boy with a history of an intermittent exotropia presented to the pediatric ophthalmology clinic for routine follow-up. He was found to have a stable sensorimotor examination however dilated funduscopic examination of the right eye was significant for a dim foveal reflex with a new discrete, white, elevated retinal lesion superotemporal to the fovea with surrounding subretinal exudates. An examination under anesthesia (EUA) was performed two days later that revealed a subretinal posterior pole granuloma with hyperfluorescence and late leakage from the lesion without telangiectatic vessels on fluorescein angiography. A repeat EUA one month later demonstrated an increase in surrounding subretinal and overlying intraretinal fluid. The patient was started on topical 1% prednisolone with a presumed diagnosis of Toxocara granuloma. At EUA, three months later, the subretinal and intraretinal fluid had resolved. The topical steroids were tapered, and the patient continues to be followed closely.

Clinical features of ocular toxocariasis: a comparison between ultra-wide-field and conventional camera imaging

PURPOSE

The purpose of this study is to compare the lesion detection rates of ocular toxocariasis (OT) between ultra-wide-field scanning laser ophthalmoscopy (UWF-SLO) and conventional fundus photography (CFP), and to evaluate the potential diagnostic ability of UWF-SLO in OT.

METHODS

A total of 56 patients with serological/immunological confirmed unilateral OT were enrolled. The presence of OT characteristic features included the posterior granuloma (postG), peripheral granuloma (periG), tractional retinal detachment (TRD), retinal folds (RF), and vitreous strands (VS) and was analyzed in 36 patients with UWF-SLO and 56 patients with CFP. Diagnostic tests were employed using the clinical examination as gold standard.

RESULTS

In total of the 56 OT eyes, granulomas were identified in 91.1% (51/56) of eyes, including postG in 46.4% (26/56) of eyes, periG in 41.1% (23/56) of eyes, and combined granulomas in 3.6% (2/56) of eyes. TRD, RF, and VS were found in 28.6% (16/56), 51.8% (29/56), and 83.9% (47/56) of patients, respectively. Although the specificities of the diagnosis in clinical features were similar by the diagnostic tests, the sensitivities of postG, periG, TRD, RF, and VS using UWF-SLO were 100%, 100%, 66.7%, 95%, and 81.8%, respectively, which were significantly higher those of CFP (72.2%, 31.3%, 11.1%, 55%, and 48.5%). Additionally, the extent of vitreous haze was milder graded by UWF-SLO compared to CFP (p = 0.0099).

CONCLUSIONS

The diagnostic ability of UWF-SLO was superior to CFP using clinical examination as gold standard for the ascertainment of the characteristic manifestations of OT, especially for granulomas and RF.

Ocular Toxocariasis: Beyond Typical Patterns through the New Imaging Technologies

PURPOSE

To report five cases of ocular Toxocariasis (OT) in which ultrawide-field (UWF) imaging was helpful in diagnosis and assessment. OT is an underdiagnosed condition triggered by the ocular invasion of Toxocara larvae. Typical features are peripheral granuloma or endophthalmitis.Methods: A retrospective case series of 10 outpatients were studied by complete ophthalmologic examination and complementary tests. UWF retinal imaging, fundus autofluorescence (FAF) and spectral-domain optical coherence tomography (SDOCT) were retrospectively analyzed. Five patients with suspected OT were included.Results: UWF imaging and FAF was able to detect all retinal lesions in a single rapid capture. Two patients showed positive serology for Toxocara. An image suggesting the larva in the vitreous cavity was shown in one patient. Antihelmintic 15 treatment along with steroids was prescribed in two patients.Conclusion: UWF imaging and SDOCT provide a more efficient approach and follow-up in OT, raising final standards of care.

Imaging of toxocariasis

Several imaging modalities have now been employed to visualize the manifestations of larval Toxocara infection in hepatic, neurologic, ocular, renal, and other anatomical sites. This report reviews the usefulness and value of these individual imaging methods in diagnosis and follow-up of the different cases causing eosinophilic (granulomatous) infiltrations the liver, lungs, brain, heart, and eyes. Imaging provides a means of assisting in diagnosis and management in this infection where diagnosis by biopsy is often unlikely to capture an actual larva for the purpose of making a definitive diagnosis on the basis of larval morphology or DNA detection.

Toxocara Optic Disc Granuloma: Deep Range Imaging Optical Coherence Tomography Findings

We aimed to present a unique case of a child with an optic disc granuloma with exudative retinal detachment as a manifestation of ocular toxocariasis. The response to systemic therapy was assessed using deep range imaging optical coherence tomography. This imaging technique was the most accurate for identification of retinal, macular and vitreous changes associated with this intraocular pathology.

Ocular Toxocariasis: Long-Term Follow-Up and Prognosis of Patients following Vitrectomy

Purpose: To investigate the outcomes of surgical treatment in patients with ocular toxocariasis and identify prognostic factors.Methods: We retrospectively reviewed the medical records of 56 consecutive patients who underwent vitrectomy.Results: The mean follow-up was 20.7 months. Visual acuity (VA) improved in 70.4% of patients by the final visit, but VA was better than Snellen 20/70 in only 31.5% of patients. Preoperative VA was closely correlated with final VA (P = 0.001). Macular involvement was associated with final VA worse than 20/70 (P = 0.03). The most common postoperative complications were ocular hypertension (19.6%) and retinal detachment (12.5%). Seven patients (12.5%) experienced recurrent inflammation postoperatively, but no preoperative factors were associated with recurrent inflammation.Conclusion: Surgical treatment could rescue visual function in patients with ocular toxocariasis but their prognosis was unfavorable. Preoperative VA was associated with final VA, whereas macular involvement was associated with poor visual outcomes.

Multiple Granulomas of Ocular Toxocariasis in an Immunocompetent Male

A 25-year-old male presented with unilateral panuveitis with multiple voluminous elevated retinal lesions along with subretinal fluid and exudation. An extensive laboratory work-up was done, and a clinical suspicion of viral retinitis was considered. The patient was initiated on antiviral therapy and, subsequently, oral corticosteroids. As the corticosteroids were tapered, the patient developed worsening lesions and vitreous inflammation. Pars plana vitrectomy (diagnostic and therapeutic) was performed and cytology sample revealed a highly eosinophilic infiltrate suggestive of parasitic infection. The real-time polymerase chain reaction was positive for Toxocara cati. The diagnosis of ocular toxocariasis was made. This case highlights a highly unusual presentation where multiple retinal granulomas of ocular toxocariasis were observed in an immunocompetent male.

Toxocariasis: a silent threat with a progressive public health impact

Background

Toxocariasis is a neglected parasitic zoonosis that afflicts millions of the pediatric and adolescent populations worldwide, especially in impoverished communities. This disease is caused by infection with the larvae of Toxocara canis and T. cati, the most ubiquitous intestinal nematode parasite in dogs and cats, respectively. In this article, recent advances in the epidemiology, clinical presentation, diagnosis and pharmacotherapies that have been used in the treatment of toxocariasis are reviewed.

Main text

Over the past two decades, we have come far in our understanding of the biology and epidemiology of toxocariasis. However, lack of laboratory infrastructure in some countries, lack of uniform case definitions and limited surveillance infrastructure are some of the challenges that hindered the estimation of global disease burden. Toxocariasis encompasses four clinical forms: visceral, ocular, covert and neural. Incorrect or misdiagnosis of any of these disabling conditions can result in severe health consequences and considerable medical care spending. Fortunately, multiple diagnostic modalities are available, which if effectively used together with the administration of appropriate pharmacologic therapies, can minimize any unnecessary patient morbidity.

Conclusions

Although progress has been made in the management of toxocariasis patients, there remains much work to be done. Implementation of new technologies and better understanding of the pathogenesis of toxocariasis can identify new diagnostic biomarkers, which may help in increasing diagnostic accuracy. Also, further clinical research breakthroughs are needed to develop better ways to effectively control and prevent this serious disease.

Electronic supplementary material

The online version of this article (10.1186/s40249-018-0437-0) contains supplementary material, which is available to authorized users.

Soil-Transmitted Helminths in Tropical Australia and Asia

Soil-transmitted helminths (STH) infect 2 billion people worldwide including significant numbers in South-East Asia (SEA). In Australia, STH are of less concern; however, indigenous communities are endemic for STH, including Strongyloides stercoralis, as well as for serious clinical infections due to other helminths such as Toxocara spp. The zoonotic hookworm Ancylostoma ceylanicum is also present in Australia and SEA, and may contribute to human infections particularly among pet owners. High human immigration rates to Australia from SEA, which is highly endemic for STH Strongyloides and Toxocara, has resulted in a high prevalence of these helminthic infections in immigrant communities, particularly since such individuals are not screened for worm infections upon entry. In this review, we consider the current state of STH infections in Australia and SEA.

Role of ultrasound biomicroscopy in diagnosis of ocular toxocariasis

Purpose

To investigate ultrasound biomicroscopy (UBM) characteristics of patients with ocular toxocariasis (OT) and to explore the role of UBM in the diagnosis and differential diagnosis of OT.

Design

Cross-sectional study.

Methods

78 eyes of 77 patients clinically consistent with OT and confirmed by serum and/or intraocular antibodies in a single tertiary centre (Fudan University Eye and ENT Hospital, Shanghai) between July 2009 and July 2016 were included in the study. UBM was performed, and the outcomes were analysed.

Results

Mean age of the patients included was 12.8±10.3 years. Positive UBM findings were observed in 72 of 78 eyes (92.3%). The primary imaging feature was peripheral granulomas (66 eyes; 84.6%), of which 78.5% were adjacent to the nasal or temporal side of horizontal meridian and 79.7% located on the surface of the ciliary body, presenting as olivary foci on radical section and botuliform foci on coronal section. Moreover, 12 of the peripherally involved eyes were accompanied with posterior pole granulomas, which could be termed ‘combined type’. Other UBM findings included vitreous strands (53 eyes; 67.9%), peripheral tractional retinal detachment (41 eyes; 52.6%) and tractional cyclodialysis (32 eyes; 41.0%).

Conclusions

The utilisation of UBM verifies the existence of the combined subtype (with both peripheral and posterior pole granulomas) and improves the detection rate of peripheral granulomas, which is of great importance to the diagnosis and differential diagnosis of OT.

Infectious uveitis: An enigma

Infectious uveitis accounts for majority of the cases of uveitis in developing countries. It also encompasses an array of various microorganisms and their clinical presentations. Some of these infectious uveitic entities are familiar, while others are newly emerging in the global ophthalmic world. Many of these entities are also a major cause of morbidity and mortality, and appropriate, timely management is required to save not the eye, but life of the patient. This review highlights the ocular manifestations of various infectious uveitic entities, relevant to the ophthalmologist.

Evaluation of the Goldmann-Witmer coefficient in the immunological diagnosis of ocular toxocariasis

Ocular toxocariasis (OT) is a zoonotic parasitic infection mainly caused by the intraocular tissue invasion of second-stage Toxocara canis or Toxocara cati larva. Measuring specific anti-T. canis antibodies in the intraocular fluid (IF) can increase OT diagnosis accuracy using Goldmann-Witmer coefficient (GWC). However, there is no systemic evaluation of GWC application in the immunological diagnosis of OT. To assess GWC for the immunodiagnosis of ocular toxocariasis, paired IF and serum samples from 72 patients diagnosed with OT were retrospectively analyzed for specific anti-T. canis IgG by enzyme linked immunosorbent assay (ELISA). GWC values were calculated to determine intraocular specific IgG production. Clinical features and other laboratory data were recorded, and their correlations with GWC evaluated. Of the 72 OT patients, 60 (83.33%) showed intraocular specific IgG production confirmed by GWC, while intraocular nonspecific IgE production was found in 64/69 (92.75%) cases. No significant correlation was found among clinical features and IF specific IgG production. Values for peripheral blood samples were lower than those of intraocular fluid regarding OT screening, and vitreous humor samples showed increased local specific IgG and nonspecific IgE production compared with aqueous humor samples. Overall, our results indicate that GWC and intraocular IgE production have referential values in diagnosing ocular toxocariasis.

Ocular Toxocariasis: Clinical Features and Long-term Visual Outcomes in Adult Patients

PURPOSE

To investigate clinical characteristics and treatment outcomes of proven ocular toxocariasis (OT) in adult patients.

DESIGN

Retrospective, consecutive, interventional case series.

METHODS

setting: Institutional.

STUDY POPULATION

Consecutive OT patients with positive serum serology and positive western blot (WB) on ocular sample.

OBSERVATION PROCEDURES

Clinical features, optical coherence tomography (OCT), and treatment outcomes.

MAIN OUTCOME MEASURES

Best-corrected visual acuity (BCVA) and OCT central foveal thickness (CFT).

RESULTS

Fourteen patients were included between 2011 and 2013. Mean age at diagnosis was 45.6 years. Mean duration between the first symptoms and diagnosis was 15.1 months. Uveitis was unilateral in all cases and all patients displayed vitreous inflammation. The main baseline findings were presence of ≥1 peripheral granulomas (57.1%), vasculitis (57.1%), vitreoretinal traction (57.1%), and chronic macular edema (ME) (71.4%). Delayed diagnosis (>8 months) seemed to be associated with higher rate of ME. All patients received albendazole. Systemic (n = 5) and/or local corticosteroids (CS) (n = 7) were administered in case of ME and/or posterior segment inflammation. Vitrectomy was performed when vitreous inflammation was severe and persistent despite CS or in case of threatening traction or visually significant epimacular membrane (28.6%). Overall, this regimen allowed significant decrease of CFT (P = .01). In the vitrectomy subgroup, mean BCVA increased (P = .01) and CFT decreased (P = .017).

CONCLUSION

While some features such as granuloma are typical signs of OT, atypical features can delay the diagnosis. In doubtful situations, WB on ocular samples seems to be more specific than serum antibodies alone. ME seems to be a common complication of longstanding OT in the adult.

Clinical Characteristics of Pediatric Patients with Ocular Toxocariasis in China

Objective: The aim of the study was to analyze the clinical characteristics of pediatric patients with ocular toxocariasis. Methods: Ocular toxocariasis was diagnosed and treated in 46 children from Shanghai and surrounding provinces. The diagnosis of ocular toxocariasis was confirmed immunologically by performing an enzyme-linked immunosorbent assay on serum and/or intraocular fluid. All pediatric patients and their guardians completed a questionnaire concerning their cases and living habits. Results: The mean age of onset was 6 ± 3 years. Most children (85%) resided in rural areas, and 91% of the children had contact with adult dogs or puppies. At the first visit, visual acuity (VA) was <20/200 in 36 cases, and we detected peripheral granuloma in 36 patients. In our study, the most common signs were vitritis, vitreous strands, and tractional retinal detachment. The Optomap 200Tx device detected granuloma with an 85% sensitivity, which is much higher than that of other techniques. We treated 40 cases (87%) with topical corticosteroids, while 28 patients (61%) were treated with systemic corticosteroids. Only 18 children (39%) required surgical intervention. All patients were examined and treated by the same ophthalmologists. Conclusions: Preschool children in China are more often affected by toxocariasis compared with other age groups. The most common signs included unilateral granuloma and ocular inflammation. In our study, clinical manifestations were severe and complicated. At the first visit, VA was <20/200 in most patients. Ocular toxocariasis was diagnosed on the basis of clinical signs and symptoms; the diagnosis was confirmed by immunological testing. Techniques using the Optomap 200Tx device can facilitate the early detection and lead to better visual prognosis.

Cerebral Toxocariasis: Silent Progression to Neurodegenerative Disorders?

Toxocara canis and T. cati are highly prevalent nematode infections of the intestines of dogs and cats. In paratenic hosts, larvae do not mature in the intestine but instead migrate through the somatic tissues and organs of the body. The presence of these migrating larvae can contribute to pathology. Toxocara larvae can invade the brains of humans, and while case descriptions of cerebral toxocariasis are historically rare, improved diagnosis and greater awareness have contributed to increased detection. Despite this, cerebral or neurological toxocariasis (NT) remains a poorly understood phenomenon. Furthermore, our understanding of cognitive deficits due to toxocariasis in human populations remains particularly deficient. Recent data describe an enhanced expression of biomarkers associated with brain injury, such as GFAP, AβPP, transforming growth factor β1 (TGF-β1), NF-L, S100B, tTG, and p-tau, in mice receiving even low doses of Toxocara ova. Finally, this review outlines a hypothesis to explore the relationship between the presence of T. canis larvae in the brain and the progression of Alzheimer's disease (AD) due to enhanced AD-associated neurodegenerative biomarker expression.

Lack of Association between Toxocara Exposure and Suicide Attempts in Psychiatric Patients

Infection with Toxocara may affect the central nervous system. A high seroprevalence of Toxocara infection has been reported in psychiatric patients. To the best of our knowledge, there is no previous report about an association of Toxocara infection with suicide attempts. Therefore, we sought to determine whether Toxocara exposure is associated with suicide attempts in psychiatric patients. We studied 282 psychiatric outpatients (156 with suicide attempts and 126 without suicide attempts). Sera of patients were analyzed for the presence of anti-Toxocara IgG antibodies by using a commercially available enzyme immunoassay. One of the 156 (0.6%) suicide attempters and 1 (0.8%) of the 126 controls were positive for anti-Toxocara IgG antibodies (OR = 0.80; 95% CI: 0.04–13.02; P = 1.00). Toxocara seropositivity was significantly higher (P = 0.01) in male patients with consumption of raw dried goat meat than male patients without this consumption. Results suggest that Toxocara exposure is not associated with suicide attempts in psychiatric outpatients in Durango City, Mexico. However, further studies with larger samples sizes to confirm our results should be conducted. Too few patients were seropositive to assess further associations of Toxocara exposure with sociodemographic, clinical, and behavioral characteristics of the psychiatric patients.

Seroepidemiology of Toxocara infection in patients with vision impairment and blindness in durango, Mexico

Background

Toxocara infection is a cause of vision impairment and blindness. We aimed to determine the seroprevalence and correlates of Toxocara infection in patients suffering from vision impairment and blindness in Durango City, Mexico.

Methods

Through a cross-sectional seroprevalence study, 204 patients with vision impairment and 19 blind patients were studied for the presence of anti-Toxocara IgG antibodies in Durango City, Mexico. Seroprevalence association with socio-demographic, housing, clinical, and behavioral characteristics of participants was also investigated.

Results

Five (2.5%) of the 204 patients with vision impairment, and none of the 19 patients with blindness were positive for anti-Toxocara IgG antibodies. In total, five of the 223 (2.2%) patients were positive for anti-Toxocara IgG antibodies. Seropositivity to Toxocara was not associated with age, sex, educational level, socio-economic status, presence of underlying diseases or behavioral characteristics of the patients. In contrast, multivariate analysis showed that Toxocara seropositivity was associated with living in a house with soil floor (odds ratio (OR) = 11.14; 95% confidence interval (CI): 1.57 - 78.74; P = 0.01).

Conclusions

This is the first report of Toxocara exposure in patients with vision impairment and blindness in Mexico, and of an association of Toxocara exposure with living in a house with soil floors. Results suggest a low Toxocara exposure in these patients in Durango, Mexico. The risk factor associated with Toxocara exposure identified in this study warrants for further investigation.

Adult ocular toxocariasis mimicking ciliary body malignancy

Purpose. To discuss an unusual presentation of ocular toxocariasis. Methods. Case report. Results. A 40-year-old woman presented with decreased vision in the left eye with a long history of recurrent red eye from uveitis. Eosinophilia and positive ELISA titers for Toxocara canis favored the diagnosis of ocular toxocariasis. Over 3 months, an anterior scleral mass had a rapid growth raising the possibility of medulloepithelioma, which rarely can mimic uveitic syndromes. Surgical plan changed from local excision to enucleation. Histopathology demonstrated a large homogeneous mass of chronic inflammatory cells with inflammation of the overlying thinned out sclera, medial rectus insertion, and limbal cornea. The triad of peripheral granuloma, eosinophilia, and positive blood serology established the diagnosis of ocular toxocariasis. Conclusions. Ocular toxocariasis can mimic ocular malignancy such as medulloepithelioma in adults and rarely presents as an anterior scleral mass.

Toxocara cati larvae in the eye of a child: a case report

Toxocariasis is a consequence of human infection by Toxocara larvae. There are symptomatic (visceral, ocular) and asymptomatic course of toxocariasis. The ocular form is very rare. We present a 6-year-old patient who developed an ocular form of toxocariasis caused by Toxocara cati. He demonstrated lesions in the peripheral retina of the right eye. White granuloma was present in the superior peripheral retina. A positive immunological assay for toxocariasis essentially completed the outcomes. On the basis of clinical manifestations and conducted examinations, a diagnosis of ocular form of toxocariasis was established. Albendazole and corticosteroids were applied in treatment. Current results clearly highlight the usefulness of excretory-secretory antigens derived from larvae of Toxocara cati for the fine diagnosis ocular larva migrans caused by Toxocara larvae.

Molecular diagnosis of an ocular toxocariasis patient in Vietnam

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.