Treatment of ocular toxocariasis with albendezole: a case report

Global Seroprevalence of Toxocara spp. in Children: A Systematic Review and Meta-analysis

BACKGROUND

In the present study, we performed a systematic review and meta-analysis to assess the global and regional seroprevalence of Toxocara spp. and associated risk factors among children.

METHODS

The present systematic review and meta-analysis was followed based on the Preferred Reporting. Items for Systematic Reviews and Meta-analyses (PRISMA) protocol. We searched the online databases (PubMed, Scopus, and Web of Science) and Google Scholar search engine for studies that measured seroprevalence of Toxocara spp. among children, published between 1 January 2000 and 15 January 2022. Accordingly, the pooled seroprevalence and 95% confidence intervals (CI) were estimated using a random-effects meta-analysis model.

RESULTS

A total of 65 articles from 22 countries met the inclusion criteria. The global seroprevalence of Toxocara spp. infection among children was estimated as 25% (95% CI 22-29). Meta-regression analysis showed that the type of population studied (p = 0.002) and year of publication (p = 0.044) it may be the source of heterogeneity. The highest and lowest pooled seroprevalence of Toxocara spp. infection were estimated in Thailand and Colombia as 58.2% (95% CI 50.9-65.5) and 7.04% (95% CI 3.05-11.3), respectively. Male gender was associated with a higher risk of Toxocara spp. compared to females, and this association was statistically significant (OR = 1.24; 95% CI 1.09-1.41, p = 0.001). However, residing in rural areas did not show a statistically significant increase in risk compared to living in urban areas (OR = 1.39; 95% CI 0.88-2.21, p = 0.143).

CONCLUSION

Toxocariasis is common among children, hence, prevention and control scheme of this helminth in children should be considered by health officials and health policymakers, especially in developing countries, where seroprevalence is highest.

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.

Infections and glaucoma

Glaucoma is an intraocular pressure-related ophthalmic disease with multiple causes that results in an optic neuropathy and vision loss. Intraocular pressure elevation is among its strongest risk factors. While glaucoma is mostly primary in etiology, secondary glaucoma is not infrequent. Recognizing its cause is imperative, since treatment is often different depending on the pathophysiologic mechanism. Numerous clinically relevant ophthalmic infections can result in robust inflammatory responses that may result in pressure elevation or intraocular anatomic configurations that predispose to pressure elevation. Knowing the mechanisms by which these infections can lead to glaucoma is critical in treating, and we consolidate what is currently known in regards to how infectious diseases lead to glaucoma.

Protective effect of the probiotic Lactobacillus acidophilus ATCC 4356 in BALB/c mice infected with Toxocara canis

Human toxocariasis consists of chronic tissue parasitosis that is difficult to treat and control. This study aimed to evaluate the action of the probiotic Lactobacillus acidophilus ATCC 4356 on larvae of Toxocara canis and the effect of IFN-γ cytokine on parasite-host in vivo (1.10⁹ CFU) and in vitro (1.10⁶, 1.10⁷, 1.10⁸, 1.10⁹ CFU) interactions. Four groups of six BALB/c mice were formed: G1 - L. acidophilus supplementation and T. canis infection; G2 - T. canis infection; G3 - L. acidophilus supplementation; and G4 - PBS administration. Mice were intragastrically suplemented with probiotics for 15 days before inoculation and 48 h after inoculation with 100 T. canis eggs. The inoculation of T. canis was also perfomed intragastrically. The recovery of larvae took place through digestion of liver and lung tissues; the evaluation of IFN-γ gene transcription in leukocytes was performed by qPCR. The in vitro test consisted of incubating the probiotic with T. canis larvae. The supplementation of probiotics produced a reduction of 57.7% (p = 0.025) in the intensity of infection of T. canis larvae in mice, whereas in the in vitro test, there was no larvicidal effect. In addition, a decrease in the IFN-γ gene transcription was observed in both, T. canis-infected and uninfected mice, regardless of whether or not they received supplementation. The probiotic L. acidophilus ATCC 4356 reduced T. canis infection intensity in mice, however, the probiotic did not have a direct effect on larvae, demonstrating the need of interaction with the host for the beneficial effect of the probiotic to occur. Yet, the proinflammatory cytokine IFN-γ did not apparently contributed to the observed beneficial effect of probiotics.

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.

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.

Recent Updates on Treatment of Ocular Microbial Infections by Stem Cell Therapy: A Review

Ocular microbial infection has emerged as a major public health crisis during the past two decades. A variety of causative agents can cause ocular microbial infections; which are characterized by persistent and destructive inflammation of the ocular tissue; progressive visual disturbance; and may result in loss of visual function in patients if early and effective treatments are not received. The conventional therapeutic approaches to treat vision impairment and blindness resulting from microbial infections involve antimicrobial therapy to eliminate the offending pathogens or in severe cases; by surgical methods and retinal prosthesis replacing of the infected area. In cases where there is concurrent inflammation, once infection is controlled, anti-inflammatory agents are indicated to reduce ocular damage from inflammation which ensues. Despite advances in medical research; progress in the control of ocular microbial infections remains slow. The varying level of ocular tissue recovery in individuals and the incomplete visual functional restoration indicate the chief limitations of current strategies. The development of a more extensive therapy is needed to help in healing to regain vision in patients. Stem cells are multipotent stromal cells that can give rise to a vast variety of cell types following proper differentiation protocol. Stem cell therapy shows promise in reducing inflammation and repairing tissue damage on the eye caused by microbial infections by its ability to modulate immune response and promote tissue regeneration. This article reviews a selected list of common infectious agents affecting the eye; which include fungi; viruses; parasites and bacteria with the aim of discussing the current antimicrobial treatments and the associated therapeutic challenges. We also provide recent updates of the advances in stem cells studies on sepsis therapy as a suggestion of optimum treatment regime for ocular microbial infections.

A case of ocular toxocariasis successfully treated with albendazole and triamcinolon

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.

Clinical characteristics of ocular toxocariasis in Eastern China

PURPOSE

To explore the clinical characteristics of patients with ocular toxocariasis in eastern China.

METHODS

The medical records of 35 cases of ocular toxocariasis in Fudan University Eye & ENT Hospital between May 2009 and April 2011 were retrospectively reviewed and analyzed. UBM, RetCam or fundus imaging, and high-frequency or conventional ultrasonography were performed in these patients.

RESULTS

The mean patient age in our series of ocular toxocariasis was 11.86 ± 8.80 years. There were 28 children and seven adults, the majority residing in a rural area (88.57%). All cases were classified into three clinical subtypes: granuloma in the peripheral retina (60% of cases); granuloma in the posterior pole (28.57% of cases); and vitreous inflammation mimicking chronic endophthalmitis (5.71% of cases). We also identified an additional subtype with unique clinical features that we termed "combined type" presenting in 5.71% of our patients. This subtype exhibited granulomas in both the posterior pole and peripheral retina. RetCam fundus imaging was able to identify granulomas in the posterior and peripheral subtypes, 100% and 80.95% of cases respectively. Moreover, UBM combined with conventional ultrasonography identified granulomas in 95% of the peripheral subtype cases and in 100% of the posterior pole subtype cases.

CONCLUSIONS

This is the first ocular toxocariasis series described in Chinese patients. Compared with reports from developed countries, the ocular features in our series were more severe and complicated, presenting with poorer visual acuity and a high rate of retinal detachment (45.7%). The application of RetCam and UBM during examination in ocular toxocariasis can provide valuable information in determining the severity of disease and features important in considering surgical procedures in such patients.

Parasitic infections and myositis

Infectious myositis may be caused by a wide variety of bacterial, fungal, viral, and parasitic agents. Parasitic myositis is most commonly a result of trichinosis, cystericercosis, or toxoplasmosis, but other parasites may be involved. A parasitic cause of myositis is suggested by history of residence or travel to endemic area and presence of eosinophilia. The diagnosis of parasitic myositis is suggested by the clinical picture and radiologic imaging, and the etiologic agent is confirmed by parasitologic, serologic, and molecular methods, together with histopathologic examination of tissue biopsies. Therapy is based on the clinical presentation and the underlying pathogen. Drug resistance should be put into consideration in different geographic areas, and it can be avoided through the proper use of anti-parasitic drugs.