Prevalence, clinical features, and causes of vision loss among patients with ocular toxocariasis

Ocular Toxocariasis in Adult Caucasian Patients: Clinical Presentations and Treatment Outcomes

PURPOSE

To report the clinical features and treatment outcomes in adult Caucasians with ocular toxocariasis (OT) and investigate their prognosis depending on their serological status.

METHODS

Retrospective observational cohort study (2016-2021) including consecutive adults with uveitis and positive western blot (WB) in the aqueous humor or vitreous. The presence of serum antibodies was not necessary for inclusion, allowing to compare the outcomes depending on the serological status.

RESULTS

Seventeen eyes of 15 patients were included. Mean age at diagnosis was 51.9 years. Vitreous inflammation was the most frequent sign (100%). Vitreoretinal tractions (41.2%) and chorioretinal granulomas (58.8%) were less prevalent. Atypical features were: spontaneous intravitreal hemorrhage (23.5%), exudative retinal detachment (11.8%), isolated macular edema (17.6%), papillitis (29.4%) and vasculitis (47.1%). Twenty percent of patients had a positive serum serology. Baseline clinical features did not differ statistically depending on the serological status; however, the degree of inflammation was numerically higher in patients with negative serology. Overall, macular thickness, anterior and posterior segment inflammation improved significantly after treatment with oral albendazole, systemic ± local corticosteroids. Vitrectomy (47.1%) was performed in case of persistent vitritis (62.5%), retinal detachment (12.5%) and intravitreous hemorrhage (25%).

CONCLUSION

OT has no pathognomonic sign and atypical presentations were not infrequent in this adult Caucasian cohort. Serum antibodies were rarely positive, stressing on the importance of ocular sample analysis, especially in case of atypical features. Serum antibodies may prove useful in forecasting the rapidity of inflammation clearance. Antiparasitic and anti-inflammatory treatment was safe and efficient in most cases.

Intravitreal Dexamethasone Implant (Ozurdex) for Ocular Toxocariasis

This study aimed to evaluate the efficacy and safety of intravitreal dexamethasone implants in the treatment of ocular toxocariasis (OT). A retrospective analysis was performed on 6 cases in which laboratory tests diagnosed OT. All patients were administered with intravitreal dexamethasone implants with or without vitrectomy. The average follow-up time was 19.7 months. All operated eyes achieved anatomic success, and all patients' visual acuity was improved. Five of these six had a visual acuity of 20/100, and three had final acuity of 20/40 or even better. Intravitreal dexamethasone implants can be used to treat different types of OT, which not only effectively control inflammation and improve the patient's vision but also reduce the use of systemic glucocorticoids.

The application of dexamethasone implants in uveitis treatment

Uveitis refers to a group of ocular inflammatory diseases that can significantly impair vision. Although systemic corticosteroid therapy has shown substantial efficacy in treating uveitis, extensive use of corticosteroids is associated with significant adverse effects. Recently, a biodegradable, sustained-release implant, namely dexamethasone intravitreal implant (Ozurdex), has been reported for treating non-infectious and infectious uveitis. This review aims to summarize the experiences with Ozurdex treatment across various forms of uveitis and to assist readers in understanding the appropriate timing and potential side effects of Ozurdex in uveitis treatment, thereby maximizing patient benefits in uveitis management.

The Consistency of Anti-Toxocara IgG Between the Aqueous Humor and Vitreous of Patients With Clinically Suspected Ocular Toxocariasis

PURPOSE

To assess the consistencies of anti-Toxocara IgG (T-IgG) and Goldmann-Witmer coefficient (GWC) between paired aqueous humor (AH) and vitreous samples from patients with clinically suspected ocular toxocariasis (OT).

DESIGN

Inter-test reliability assessment.

METHODS

A total of 47 patients with clinically suspected OT who underwent vitrectomy were included. AH, vitreous, and serum samples from each patient were collected, and levels of specific T-IgG in them were detected. The association and agreement of T-IgG and GWC between AH and vitreous were evaluated. The area under the receiver operating characteristic curve was generated to assess the diagnostic performance of AH.

RESULTS

The T-IgG levels and GWC values in vitreous were higher than those in AH (P = .023 and P = .029, respectively), but similar positivity rates in the T-IgG (P = 1.000) and GWC >3 (P = 1.000) were apparent between vitreous and AH. In addition, there was a positive correlation between the AH and vitreous T-IgG levels (rs = 0.944, P < .001) and the GWC values (rs = 0.455, P = .022). Moreover, the consistencies between AH and vitreous samples in their T-IgG and GWC positivity rates were almost perfect (both, κ = 0.915, 95% CI = 0.799-1.000) in both. The area under the receiver operating characteristic curve reached 0.991, with a 95% confidence interval of 0.971 to 1.000. The best cut-off value for accurate OT diagnosis was found at 1.434, yielding 96% sensitivity and 100% specificity.

CONCLUSIONS

Our findings demonstrate that AH and vitreous samples had significant correlations and perfect agreements for both T-IgG and GWC, suggesting that the AH may serve as a proxy for vitreous to provide a safer, earlier, and more convenient screening of OT.

[Atypical ocular toxocariasis in a child: A case report]

INTRODUCTION

Ocular toxocariasis is a rare disease, predominantly affecting children and young adolescents, and usually presenting as unilateral posterior uveitis. We report the case of a child with toxocariasis associated with serous retinal detachment.

OBSERVATION

A 8-year-old child with no previous history of toxocariasis was referred for a 1-year decline in visual acuity, unimproved by optical correction, with vitreous condensation on examination, without central or peripheral granulomas, and serous retinal detachment on OCT. The diagnosis was made after extensive questioning, with evidence of contact with dogs and positive serology. Medical treatment combining corticosteroid therapy and antiparasitic therapy was initiated, and the clinical picture improved.

DISCUSSION

Ocular toxocariasis is a rare infection, unilateral in 90% of cases. Its clinical manifestation in children is pars planitis, posterior uveitis with a posterior pole chorioretinal focus associated with vitreoretinal traction and/or peripheral granuloma. In our case, the patient presented with vitreous condensation only, with OCT serous retinal detachment and no peripheral or central granulomas. Positive plasma serology or ocular samples confirmed the diagnosis.

CONCLUSION

Ocular toxocariasis should not be ruled out in the absence of a typical clinical picture, and seropositivity enables confirmation of the diagnosis when clinical suspicion arises.

Safety and effectiveness of intravitreal dexamethasone implant in patients with ocular toxocariasis

AIMS

To evaluate the safety and effectiveness of intravitreal dexamethasone (DEX) implant in patients with active uveitis due to ocular toxocariasis (OT).

METHODS

Seventy-eight patients with OT were recruited in this retrospective study, including 51 patients in DEX group treated with intravitreal DEX implant and 27 patients in control group without intervention. The reduction of vitreous haze scores (VHS), the best-corrected visual acuity (BCVA) changes, intraocular pressure (IOP) and cataract progression and formation were recorded at baseline (V0), 1 (V1), 3 (V3) and 6 months (V6) after treatment in DEX group, and V0 and V6 in control group.

RESULTS

There was no change in VHS and BCVA in control group between V0 and V6. Better VHS (p=0.001) and BCVA (p=0.022) was achieved in DEX group; the rate of VHS=0 was 0%, 67.4%, 42.9% and 44.9% at V0, V1, V3 and V6, respectively (p＜0.001), and the mean BCVA was improved from logMAR 1.5±0.9 to 1.2±0.9 at V1, 1.4±1.0 at V3 and 1.4±1.2 at V6. A favourable BCVA at V1 was associated with older age (p=0.038) and uninvolved macula (p=0.000) in DEX group. No significant difference in IOP elevation ≥10 mm Hg, cataract progression and formation between groups. More eyes needed retinal surgery in control group (p<0.001).

CONCLUSIONS

This was the first study to investigate use of intravitreal DEX implant in OT patients, which can efficiently reduce ocular inflammation and improve BCVA in macular uninvolved patients.

Cerebro-Ocular Toxocariasis Revealed by Bilateral Cystoid Macular Edema

DESIGN

Case Report Case description: This report describes the case of a female patient diagnosed with oculo-cerebral toxocariasis manifesting initially in the form of isolated bilateral cystoid macular edema. Diagnosis was made by means of positive anterior chamber and lumbar puncture western blots. The unusual presentation, ancillary findings and treatment are discussed. The control of intraocular inflammation that was only partially responsive to steroids was eventually achieved with pegylated interferon alfa-2a.

CONCLUSION

Isolated macular edema is a rare presentation of ocular toxocariasis. Interferon alfa-2a may prove useful in case of insufficient control of inflammation.

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.

Who Let the Dogs Out? Unmasking the Neglected: A Semi-Systematic Review on the Enduring Impact of Toxocariasis, a Prevalent Zoonotic Infection

Toxocariasis remains an important neglected parasitic infection representing one of the most common zoonotic infections caused by the parasite Toxocara canis or, less frequently, by Toxocara cati. The epidemiology of the disease is complex due to its transmission route by accidental ingestion of embryonated Toxocara eggs or larvae from tissues from domestic or wild paratenic hosts. Even though the World Health Organization and Centers for Disease Control classified toxocariasis amongst the top six parasitic infections of priority to public health, global epidemiological data regarding the relationship between seropositivity and toxocariasis is limited. Although the vast majority of the infected individuals remain asymptomatic or experience a mild disease, the infection is associated with important health and socioeconomic consequences, particularly in underprivileged, tropical, and subtropical areas. Toxocariasis is a disease with multiple clinical presentations, which are classified into five distinct forms: the classical visceral larva migrans, ocular toxocariasis, common toxocariasis, covert toxocariasis, and cerebral toxocariasis or neurotoxocariasis. Anthelmintic agents, for example, albendazole or mebendazole, are the recommended treatment, whereas a combination with topical or systemic corticosteroids for specific forms is suggested. Prevention strategies include educational programs, behavioral and hygienic changes, enhancement of the role of veterinarians, and anthelmintic regimens to control active infections.

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.

Cytokine Profile in Aqueous Humor of Patients With Ocular Toxocariasis

Purpose

Ocular toxocariasis (OT) is a vision-threatening disease with a largely unknown intraocular pathogenesis. Herein, we determined the cytokine expression profile in aqueous humor (AH) of patients with OT.

Methods

This is a retrospective case-control study of cytokine levels in AH of patients with OT and uveitis and control subjects. Thirty samples from eyes with OT, 23 from eyes with non-OT uveitis, and 25 from eyes with age-related cataract were analyzed using a multiplexed magnetic bead immunoassay. Thirty-one cytokines were detected and classified into 5 categories: T-helper type 1 (Th1) -associated cytokines, Th2-associated cytokines, Th17 cytokine, proinflammatory mediators, and growth factors.

Results

In the 31 cytokines, 9 cytokines were undetectable, including IL-1a, IL-1b, IL-2, IL-3, IL-12p70, IL-17A, TGF-a, TNF-β, and IFN-g. From the 22 cytokines, 13 exhibited significantly increased expression in the OT group than in the control group, including TNF-a, IFN-a2, IL-4, IL-5, IL-6, IL-9, IL-10, IL-13, sCD40L, PDGF-AA, PDGF-AB/BB, FLT3l, and EGF. There were 5 cytokines exhibited significantly increased expression in the OT group than in non-OT group, including IL-5, IL-9, IL-10, IL-13, and PDGF-AA. There was no significantly decreased expression in any cytokines in the OT group when compared with control or non-OT groups. To the 5 cytokines that showed significant difference in OT group alone, IL-10 and IL-13 exhibited more than 13-fold increase, and IL-5 showed the most obvious as 27-fold increase in OT patients, when compared with that in control group.

Conclusion

The cytokine profile expression in aqueous humor from patients with ocular toxocariasis was investigated, and our findings suggest that Th1 and Th17 cytokine responses are not enhanced, whereas the cytokine status was polarized toward a Th2 response. Our findings also suggest the involvement of IL-5, IL-10, and IL-13 in the immunopathogenesis of ocular toxocariasis.

A Case Report of Intravitreal Dexamethasone Implant with Exudative Retinal Detachment for Ocular Toxocariasis Treatment

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.

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.

Hypopyon and White Cataract Due to an Intraocular Helminth

We describe a case of a 29-year-old man with a history of intravenous drug use and vague history of eye trauma who presented with a hypopyon and white cataract in the right eye. He underwent pars plana vitrectomy and lensectomy; his anterior chamber aspirate revealed a single helminth on calcofluor stain. We suspect that his helminth infection may be secondary to unsanitary eating and drinking practices. As overall hygiene and dietary habits have improved during the years, parasitic helminth infections are relatively rare in nonendemic areas, especially in the nonpediatric population. [Ophthalmic Surg Lasers Imaging Retina. 2022;53:168-171.].

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.

Diagnosis of Ocular Toxocariasis by Serum and Aqueous Humor IgG ELISA

Purpose

Ocular toxocariasis (OT) is a worldwide ocular parasitic infection and is especially sight-threatening in children. Because of the clinical manifestation diversity, OT has frequently been misdiagnosed. The purpose of this study was to evaluate the diagnostic value of anti-toxocara immunoglobulin G (IgG) in intraocular fluid (IF) and serum in OT.

Methods

IF and serum were collected from patients with clinically diagnosed OT and non-OT uveitis. The level of anti-toxocara IgG was detected by enzyme-linked immunosorbent assay. The data were statistically analyzed in anti-toxocara IgG and the Goldmann–Witmer coefficient (GWC) between groups. The area under the receiver operating characteristic curve (AUC ROC) was performed to assess the diagnostic value of serum and IF anti-toxocara IgG and the GWC.

Results

A total of 290 participants, 128 (44.1%) with OT and 162 (55.9%) with non-OT uveitis, were included in this study. The default serum anti-toxocara IgG cutoff value of 11 U had 72.1% sensitivity and 95.5% specificity. With the optimized cutoff value of 8.2 U, the AUC was 0.886 (95% confidence interval [CI] = 0.830–0.929, P < 0.0001), sensitivity increased to 80.2%, and specificity was 94.0%. With an IF anti-toxocara IgG cutoff value of 1.8 U, the AUC was 0.934 (95% CI = 0.892–0.963, P < 0.0001), sensitivity was as high as 88.4%, and specificity was 96.4%.

Conclusions

Our study proposes novel diagnostic cutoff values of serum and IF anti-toxocara IgG for OT, which are 8.2 U and 1.8 U, respectively.

Translational Relevance

This study will improve the accuracy of diagnosis in patients with OT.

Clinical Features and Prognostic Factors in Northern Chinese Patients with Peripheral Granuloma Type of Ocular Toxocariasis: A Retrospective Cohort Study

PURPOSE

To summarize the clinical features and probable factors associated with recurrence within 6 months in northern Chinese ocular toxocariasis (OT) patients.

METHODS

A retrospective cohort study (38 OT eyes) was conducted. Clinical features, aqueous inflammatory cytokines, complications, and parameters associated with recurrence after treatment were analyzed.

RESULTS

The initial best-corrected visual acuity (BCVA) was related to the anterior inflammation grade at the onset (P = .028). The mean BCVA and anterior inflammation improved significantly (P < .05) after treatment. The OT eyes had higher aqueous humor cytokine levels (IL-6, IL-8, and IL-10) compared with the normal eyes (P < .001). More severe anterior inflammation grade or longer duration of uveitis were more likely to increase the probability of recurrence (P = .008 and P = .025), TA injection during/after vitreous surgery can reduce the probability of recurrence (P = .031).

CONCLUSIONS

The combination therapy of vitreoretinal surgery, steroids, and albendazole therapy may reduce inflammation and recurrence of OT effectively.Abbreviations: BCVA: best-corrected visual acuity; BFGF: basic fibroblast growth factor; CFT: central foveal thickness; CI: confidence interval; ELISA: Enzyme-linked immunosorbent assay; ERM: epiretinal membrane; IOP: intraocular pressure; IQR: interquartile range; IL: interleukin; LFM: laser flare meter; MH: macular hole; OCT: optical coherence tomography; OR: odds ratio; OT: ocular toxocariasis; RD: retinal detachment; TA: triamcinolone acetonide; TCLA: Toxocara canis larva crude antigen; TGF: transforming growth factor; VCAM: vascular cell adhesion molecule; VEGF: vascular endothelial growth factor.

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.

Study of toxoplasmosis and toxocariasis in patients suffering from ophthalmic disorders using serological and molecular methods

Introduction

Toxoplasma gondii is an intracellular protozoan parasite that can cause ocular toxoplasmosis with most complications such as retinal detachment. Toxocara parasite, round worm, found in dogs and cats appears as larva migrans in humans can cause serious ocular complications such as debilitating vision loss.In Khuzestan province, southwest of Iran, T. gondii infection has been reported to be significant but toxocariasis was rare. However, the frequency of ocular toxoplasmosis and toxocariasis has not been studied in this area. The aim of this study was to evaluate the ocular toxoplasmosis and ocular toxocariasis using serological and molecular methods.

Method

In this case control study, 310 patients were identified by ophthalmologist as ocular toxoplasmosis and then 5 cc of venous blood samples were taken from each of them. Serum samples and buffy coat were prepared and ELISA was used to detect IgG and IgM anti-Toxoplasma antibodies and the molecular PCR was used to detect Toxoplasma DNA parasite in buffy coats. ELISA test was used to detect of IgG anti-Toxocara antibodies.

Results

Totally, for ocular toxoplasmosis, 130 (41.93%) of 310 patients were positive by ELISA, of them 121 (39%) IgG positive and nine (2.9%) IgM positive were diagnosed. Of 121 cases with IgG⁺, 119 (98.35%) were diagnosed with high IgG avidity indicating chronic phase of the infection. For ocular toxocariasis evaluation, antibodies against Toxocara were not detected in any of the samples. By PCR molecular method, 11 out of 310 patients (3.54%) had T. gondii DNA in the blood. In control, in total, 21 cases were detected positive by serology method, which showed a significant difference with the results of the case group(P < 0.05).By PCR method, only three cases showed positive which also indicated significant difference with result of case group (3 vs 9) (P < 0.05). In the control group, also no anti-toxocara antibodies were found.

Conclusion

It can be concluded that T. gondii in Khuzestan province as the etiologic agent of ocular toxoplasmosis and physicians should consider diagnostic methods for identifying the infection when they visit the patients.

Toxocariasis and the clinical spectrum

Toxocara canis and T. cati are among the most widely distributed helminthic species in the world with a high zoonotic impact. Millions of people are infected^a and hundreds of thousands are suffering from toxocarosis, a disease encompassing four different entities: larva migrans visceralis (VLM) syndrome, ocular larva migrans (OLM) syndrome, covert toxocarosis (covT), common toxocarosis (comT) and neurotoxocarosis (NT). Toxocara infections in humans may remain clinically inapparent but may also induce severe diseases. This contribution gives a synoptic overview of the most important historical, clinical, diagnostic and therapeutical aspects of toxocarosis in humans.

Case Report: Ocular Toxocariasis: A Report of Three Cases from the Mississippi Delta

Ocular toxocariasis can be vision threatening, and is commonly reported from tropical or subtropical regions. Knowledge of clinical manifestations from the United States, particularly in underserved areas such as the American South, is lacking. We report three cases of ocular toxocariasis in individuals from the Mississippi Delta, a rural community with prevalent poverty. Visual acuity was severely affected in two of the three cases. Increased awareness of ocular toxocariasis, which may have under-recognized frequency, will contribute to prompt diagnosis and treatment, which will ultimately improve patient health in the region.

Retinal vasculitis with Chronic Recurrent Multifocal Osteomyelitis: a case report and review of the literature

Background

Concurrent presentation of retinal vasculitis with mixed sclerotic and lytic bone lesions is rare.

Case presentation

We present the case of a 37-year old woman with a several year history of episodic sternoclavicular pain who presented for rheumatologic evaluation due to a recent diagnosis of retinal vasculitis. We review the differential diagnosis of retinal vasculitis, along with the differential diagnosis of mixed sclerotic and lytic bone lesions. Ultimately, bone marrow biopsy confirmed diagnosis of chronic recurrent multifocal osteomyelitis (CRMO). Concurrent presentation of CRMO with retinal vasculitis is extremely rare but important to recognize. The patient demonstrated clinical response to prednisone and tumor necrosis factor-alpha inhibition (TNF-i).

Conclusion

This case reports and unusual presentation of CRMO spectrum disease involving the sternum and sternoclavicular joint with concurrent retinal vasculitis.

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.

Toxocara Neuroretinitis Associated with Raw Meat Consumption

Neuroretinitis characterized by optic disc edema and star-like exudates in the macula was detected in a patient who presented with sudden unilateral painless vision loss and had a history of raw meat consumption. The patient tested seropositive for Toxocara. Combination therapy with steroid and albendazole resulted in an increase in visual acuity and complete resolution of clinical signs.

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.

Toxocara optic neuropathy: clinical features and ocular findings

We evaluated thirteen eyes of twelve patients diagnosed clinically and serologically with Toxocara optic neuropathy. Eleven patients had unilateral involvement and one patient had bilateral optic neuropathy. Eight patients (66.7%) had a possible infection source to Toxocara. Six patients (50%) had painless acute optic neuropathy. Ten eyes had asymmetric, sectorial optic disc edema with peripapillary infiltration and three eyes had diffuse optic disc edema. Eosinophilia was noted in five patients (41.7%) and optic nerve enhancement was observed in eight of eleven eyes (72.7%) with available orbit magnetic resonance imaging (MRI). Mean visual acuity significantly improved following treatment [mean logarithmic of the minimum angle of resolution (logMAR) 0.94±0.56 at baseline and 0.47±0.59 at the final (P=0.02)]. Asymmetric optic disc edema with a peripapillary lesion and a history of raw meat ingestion were important clues for diagnosing Toxocara optic neuropathy. Additionally, Toxocara IgG enzyme-linked immunosorbent assay (ELISA) test and evaluating eosinophil may be helpful for diagnosis.

Toxocariasis: critical analysis of serology in patients attending a public referral center for ophthalmology in Brazil

PURPOSE

To analyze the contribution of IgG anti-Toxocara antibodies in the diagnosis of ocular toxocariasis (OT) in serum samples of patients attending a public referral center for ophthalmology in Brazil and to determine the most frequent ocular signs and symptoms.

STUDY DESIGN

This was a retrospective descriptive study of a cohort of outpatients followed from December 1989 to May 2006.

METHODS

IgG anti-Toxocara antibody titers were determined by enzyme-linked immunosorbent assay. The results were correlated with the clinical and funduscopic findings.

RESULTS

Of the diagnoses for the 126 patients, 42 were considered as probable OT, 48 as negative, and 36 as inconclusive. The median IgG anti-Toxocara antibody titers of the patients with probable OT were significantly higher than those of the patients in the negative or inconclusive groups (P = 0.0001). Higher titers were observed more frequently in patients in the probable OT group (P = 0.01) than in the negative group, in which titers were absent or lower in most patients (P < 0.0001). The right eye was affected more in the OT group than in the negative group (P = 0.01), and inflammation was located mostly in the intermediate and posterior poles. The mean age of the patients diagnosed with probable OT was significantly lower (mean, 8 years) than that of the negative patients (mean, 14.5 years) (P = 0.006).

CONCLUSIONS

Higher levels of antibodies could help with the diagnosis of OT in patients with symptoms and clinical signs; however, negative results cannot exclude possible OT. Conversely, patients with negative serology or low titers make the diagnosis of OT less likely.

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.

Prevalence of Toxocara antibodies among patients clinically suspected to have ocular toxocariasis: A retrospective descriptive study in Sri Lanka

BACKGROUND

Human toxocariasis, caused by Toxocara canis, T. cati, and T. vitulorum of dogs, cats and ruminants respectively, is recognized as an important zoonotic infection worldwide. The typical clinical syndromes of toxocariasis in humans are ocular larva migrans (OLM) and visceral larva migrans (VLM). The most commonly affected sites of OLM are the peripheral retina and/or vitreous humor. In Sri Lanka, there is a dearth of information on prevalence of ocular infection in our population. Therefore, the present study was carried out to determine the prevalence of Toxocara antibodies in suspected OLM patients and to describe demographic factors and clinical manifestations of seropositive patients. A total of 250 clinically suspected ocular toxocariasis cases referred by consultant eye surgeons to the Department of Parasitology, University of Peradeniya were studied between the years 1995 to April 2015.

METHODS

Data (age, sex, fundoscopic findings) were gathered from the referral letters. Each serum sample was subjected to Toxocara excretory - secretory antigen ELISA (TES - ELISA).

RESULTS

Out of the 250 cases, 155 (62%) were seropositive. The age range of the seropositive cases was 1 to 78 years with the mean age of 27 years. The highest seropositivity (25/155) was observed within the age group of 10 to 14 years. The most frequent clinical presentation of seropositive OLM cases were unilateral reduced vision and red eye. The other symptoms include tearing, photophobia and leukokoria. A high proportion of seropositive OLM cases had uveitis (34.19%) followed by reduced vision (21.94%), vitritis (12.9%) and choroiditis (7.74%). However none of these clinical manifestations were significantly associated with TES-ELISA seropositivity except vitreits (X² = 8.557, p = 0.003).

CONCLUSION

In conclusion, the results of this study showed high seroprevalence of toxocariasis among clinically suspected OLM cases confirming the toxoplasmic etiology. This high rate of Toxocara seropositivity in ocular patients should alert ophthalmologists in Sri Lanka to include toxocariasis in the differential diagnosis of ocular diseases presented with the symptoms and signs stated above.

Association between intermediate uveitis and toxocariasis in the Korean population

The aim of the study was to investigate the characteristics of ocular toxocariasis (OT) presenting with intermediate uveitis in the Korean population.We studied intermediate uveitis patients using ocular and systemic evaluations and a Toxocara IgG serology test.Of 50 intermediate uveitis patients, 19 were seropositive for Toxocara IgG. Of the 19 OT patients, 4 presented with recurrence within 6 months and were significantly younger than nonrecurrence patients (P = 0.009). Thirteen patients had a history of eating raw cow liver.There were 14 males and 5 females in the OT group, and 11 males and 20 females in the non-OT group (P = 0.009). There was bilateral involvement in 7 out of 19 patients in the OT group, and 20 out of 31 patients in non-OT group (P = 0.033).Intermediate uveitis patients in OT were predominately male and had more unilateral presentation than non-OT patients.

Diagnostic Value of the Serum Anti-Toxocara IgG Titer for Ocular Toxocariasis in Patients with Uveitis at a Tertiary Hospital in Korea

Purpose

This study evaluated the prevalence of ocular toxocariasis (OT) in patients with uveitis of unknown etiology who visited a tertiary hospital in South Korea and assessed the success of serum anti-Toxocara immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA) as a diagnostic test for OT.

Methods

The records of consecutive patients with intraocular inflammation of unknown etiology were reviewed. All participants underwent clinical and laboratory investigations, including ELISA for serum anti-Toxocara IgG. OT was diagnosed based on typical clinical findings. Clinical characteristics, seropositivity, and IgG titers were compared between patients diagnosed with OT and non-OT uveitis. The seropositivity and the diagnostic value of anti-Toxocara IgG was investigated among patients with different types of uveitis.

Results

Of 238 patients with uveitis of unknown etiology, 71 (29.8%) were diagnosed with OT, and 80 (33.6%) had positive ELISA results for serum anti-Toxocara IgG. The sensitivity and specificity of the ELISA test were 91.5% (65 / 71) and 91.0% (152 / 167), respectively. The positive predictive value of the serum anti-Toxocara IgG assay was 81.3%. Among patients with anterior, intermediate, posterior, and panuveitis, the prevalence rates of OT were 8.3%, 47.1%, 44.8%, and 7.1%, respectively; the seropositivity percentages were 18.1%, 47.1%, 43.7%, and 17.9%; and the positive predictive values were 38.5%, 95.8%, 92.1%, and 40.0%. The serum anti-Toxocara IgG titer also significantly decreased following albendazole treatment.

Conclusions

OT is a common cause of intraocular inflammation in the tertiary hospital setting. Considering that OT is more prevalent in intermediate and posterior uveitis, and that the positive predictive value of the anti-Toxocara IgG assay is high, a routine test for anti-Toxocara IgG might be necessary for Korean patients with intermediate and posterior uveitis.

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.

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.

Larva migrans in India: veterinary and public health perspectives

Despite an important public health problem in developing world like India, larva migrans remains a neglected zoonosis. Cutaneous larva migrans, Visceral larva migrans, and Ocular larva migrans are the important clinical manifestations seen in humans in India. Although many nematode parasites have the ability to cause the infection, the disease primarily occurs due to Ancylostoma caninum and Toxocara canis. Presence of the infection in dogs is an indirect indication of its incidence in humans in endemic regions. In India, sporadic cases of this neglected but important parasitic zoonosis are the main implications of lack of diagnostic methods and under-reporting of human cases. Tropical climate in addition to overcrowding, poor hygiene and sanitation problems, stray dogs, open defecation by dogs and improper faecal disposal are the important factors for persistence of this disease in the country. Sanitary and hygienic measures, improved diagnostic techniques and surveillance programme in dogs as well as humans should be adopted for its effective control. Comprehensive collaborative efforts by physicians and veterinarians are required to tackle this problem in order to attain optimal health for humans, animals and the environment. Moreover, recognition of larva migrans as an important public health problem is the most important step to combat this neglected disease in developing countries like India.

Infectious optic neuropathies: a clinical update

Different forms of optic neuropathy causing visual impairment of varying severity have been reported in association with a wide variety of infectious agents. Proper clinical diagnosis of any of these infectious conditions is based on epidemiological data, history, systemic symptoms and signs, and the pattern of ocular findings. Diagnosis is confirmed by serologic testing and polymerase chain reaction in selected cases. Treatment of infectious optic neuropathies involves the use of specific anti-infectious drugs and corticosteroids to suppress the associated inflammatory reaction. The visual prognosis is generally good, but persistent severe vision loss with optic atrophy can occur. This review presents optic neuropathies caused by specific viral, bacterial, parasitic, and fungal diseases.

Infectious Uveitis

Infectious uveitis is one of the most common and visually devastating causes of uveitis in the US and worldwide. This review provides a summary of the identification, treatment, and complications associated with certain forms of viral, bacterial, fungal, helminthic, and parasitic uveitis. In particular, this article reviews the literature on identification and treatment of acute retinal necrosis due to herpes simplex virus, varicella virus, and cytomegalovirus. While no agreed-upon treatment has been identified, the characteristics of Ebola virus panuveitis is also reviewed. In addition, forms of parasitic infection such as Toxoplasmosis and Toxocariasis are summarized, as well as spirochetal uveitis. Syphilitic retinitis is reviewed given its increase in prevalence over the last decade. The importance of early identification and treatment of infectious uveitis is emphasized. Early identification can be achieved with a combination of maintaining a high suspicion, recognizing certain clinical features, utilizing multi-modal imaging, and obtaining specimens for molecular diagnostic testing.