Visceral Larva Migrans Research Articles

Ocular toxocariasis masquerading as toxoplasmosis: a case report and literature review

Background: False-negative and false-positive results in Toxoplasma serology are possible, and this could be misleading. Here, we report the case of a boy with Toxocara-associated panuveitis who was initially treated for toxoplasmosis owing to false-positive Toxoplasma immunoglobulin M (IgM) serology. Case Presentation: A nine-year-old boy presented with intermittent headaches and blurred vision in the left eye. Close contact with domesticated animals was remarkable in the patient’s history. Upon examination, vision was 20/400 in the left eye. Slit-lamp examination revealed anterior chamber cells and flare without keratic precipitates, with vitreous cells and veils, optic disc edema, and a blurred fundus appearance. A systemic investigation revealed the presence of anti-Toxoplasma IgM antibodies. Treatment was initiated using topical cycloplegic and corticosteroid eye drops, in addition to oral trimethoprim/sulfamethoxazole. Oral corticosteroids were also administered. As the inflammation resolved, an inferior tractional detachment was detected on fundus examination, leading to the ultimate diagnosis of ocular toxocariasis. An enzyme-linked immunosorbent assay was positive for serum Toxocara antibodies. A fourteen-day course of oral albendazole was ordered by the pediatric infectious disease service because of the concern for visceral larva migrans, while topical eye drops were continued and oral prednisone was tapered. One month later, visual acuity in the left eye had improved to 20/70. The anterior chamber inflammation resolved; however, some vitreous cells and optic disc edema persisted. The inferior tractional detachment was much better visualized, and a peripheral granuloma was observed. Four months later, without any oral or topical medications, the patient’s visual acuity had improved to 20/30 and his eye had no active inflammation. The patient has been followed up for two years and has never developed any other lesions. Conclusions: False-positive results on Toxoplasma serology and diffuse vitritis from toxocariasis that limited retinal visualization complicated the initial diagnosis in this case. In diagnosing the etiology of uveitis, ocular examination and detailed history taking should be emphasized, as laboratory results may be misleading.

Fatal Hymenolepis nana-associated visceral larva migrans in captive juvenile white-tailed antsangies (Brachytarsomysalbicauda)

White-tailed antsangies (Brachytarsomys albicauda) are Madagascan rodents uncommonly kept in captivity. Hymenolepis nana is a cestode with an unusual life cycle, incorporating direct, indirect and autoinfective stages. This case series represents the first reported outbreak of H. nana cestodiasis in white-tailed antsangies, summarizing macroscopic and histological findings in four cases. On post-mortem examination (PME), numerous cysticerci were detected consistently throughout the intestinal serosa, liver, mesenteric lymphatic vasculature and mesenteric lymph nodes. Pancreatic cysticerci were observed in one case. Adult tapeworms, larvae and eggs were found only in the small intestine, and faecal egg shedding was a feature. Histopathological examination identified adult, larval and encysted cestodes within the respective gross lesions, with pulmonary, pancreatic and splenic involvement detected in a single case. The cestodes sampled on PME were identified by polymerase chain reaction and DNA sequencing, with H. nana confirmed in all cases. Visceral larva migrans was consistent throughout all specimens, in contrast with the natural infections of standard rodent hosts, and may be considered a likely pathological feature of H. nana infection in white-tailed antsangies.

Alterations of plasma circulating microRNAs in BALB/c mice with Toxocara canis visceral and cerebral larva migrans

BackgroundHuman toxocariasis is a neglected parasitic disease characterised by the syndromes visceral, cerebral, and ocular larva migrans. This disease is caused by the migrating larvae of Toxocara roundworms from dogs and cats, affecting 1.4 billion people globally. Via extracellular vesicles (EVs), microRNAs have been demonstrated to play roles in host–parasite interactions and proposed as circulating biomarkers for the diagnosis and follow-up of parasitic diseases.MethodsSmall RNA-seq was conducted to identify miRNAs in the infective larvae of T. canis and plasma EV-containing preparations of infected BALB/c mice. Differential expression analysis and target prediction were performed to indicate miRNAs involved in host–parasite interactions and miRNAs associated with visceral and/or cerebral larva migrans in the infected mice. Quantitative real-time polymerase chain reaction (PCR) was used to amplify circulating miRNAs from the infected mice.ResultsThis study reports host and parasite miRNAs in the plasma of BALB/c mice with visceral and cerebral larva migrans and demonstrates the alterations of these miRNAs during the migration of larvae from the livers through the lungs and to the brains of infected mice. After filtering unspecific changes in an irrelevant control, T. canis-derived miRNAs and T. canis infection-induced differential miRNAs are predicted to modulate genes consistently involved in mitogen-activated protein kinase (MAPK) signalling and pathways regulating axon guidance and pluripotency of stem in the infected mice with visceral and cerebral larva migrans. For these plasma circulating miRNAs predicted to be involved in host-parasite crosstalk, two murine miRNAs (miR-26b-5p and miR-122-5p) are experimentally verified to be responsive to larva migrans and represent circulating biomarker candidates for visceral and cerebral toxocariasis in BALB/c mice.ConclusionsOur findings provide novel insights into the crosstalk of T. canis and the mammalian host via plasma circulating miRNAs, and prime agents and indicators for visceral and cerebral larva migrans. A deep understanding of these aspects will underpin the diagnosis and control of toxocariasis in humans and animals.Graphical

Olecranon apophysitis on MR images

An 11-year-old water-polo male player with no previous history of trauma presented to the emergency department with right elbow pain for the past 3 months. X-ray showed olecranon fragmentation and irregularity (arrow on a). Sagittal and axial T1W (c-d) and PDFS

SEROPREVALENCE OF IgG ANTIBODIES OF HUMAN TOXOCARIASIS AND ASOCIATED RISK FACTORS IN KHANH HOA PROVINCE

Background: Human toxocariasis is a zoonotic parasitic disease caused by Toxocara canis and T. cati roundworm larvae. While many studies have shown that dog and cat owners are at a higher risk of acquiring Toxocara spp. infection, there is no available evidence regarding the seroprevalence of Toxocara spp. infection among dog and cat owners in Khanh Hoa. Therefore, this study aims to investigate the prevalence of anti-IgG of Toxocara spp. infection and associated risk factors for visceral larval migrans among dog owners in three different areas of Khanh Hoa province..Subjects and methods: A descriptive cross-sectional study was conducted from 2022 to 2024 in three localities representing different socio-geographic areas (urban, rural, and mountainous) of Khanh Hoa province. A total of 1502 blood samples were collected from local individuals aged 5 to 75 for this study. Serum anti-T.canis IgG antibodies were detected using a commercial enzyme-linked immunosorbent assay (ELISA) kit: NovaLisaTM, Toxocara canis IgG ELISA. Simultaneously, a survey using structured questionnaire about information on risk factors associated with Toxocariasis was conducted among 720 people (aged 18 and over) from 1,502 individuals whose bloods were taken for testing.Results and conclusions: A total of 1,502 blood samples were examined for the presence of antibodies to dog and cat roundworm larval infection. Results revealed an overall positive rate of 57.66% across the three localities, with variations depending on geography. In Khanh Vinh, a mountainous district, the infection rate was 75.44%, and in its commune Khanh Trung, it was 81.20%. For the two urban wards, the rates were significantly lower (Phuoc Long Ward: 44.40% and Van Thanh Ward: 54.18%). A structured questionnaire was used to investigate risk factors among 720 individuals (aged 18 years old and over) out of the 1,502 individuals whose bloods were tested. Results indicated that 389 of them tested positive for the ELISA test. Infection rates varied among age groups: under 25 years old (6.94%), 25-50 years old (66.78%), and over 50 years old (37.28%). Notably, 49.87% of infected individuals owned dogs or cats, 93.32% regularly consumed raw vegetables, and 25.71% frequently handled dogs or cats. The high infection rate of dog and cat roundworm larvae in Khanh Hoa underscores the presence of several identified high-risk factors.

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.

Visceral larva Migrans in a Young Italian Patient: A Diagnostic Dilemma

BackgroundThe association of fever, focal hepatic lesions and peripheral hyper-eosinophilia (FHLH) can be observed in both infectious and non-infectious conditions. Fascioliasis, capillariasis, toxocariasis, all causes of visceral larva migrans (VLM), represent most of the former, whilst lymphomas, eosinophilic leukemias and mastocytosis belong in the non-infectious conditions.MethodsWe prospectively followed a young patient presenting with FHLH in the Tuscany region of Italy.ResultsThe patient was subject to serological and parasitological examination in an attempt to clarify the origin of the lesions. Serologies for both Fasciola hepatica and Toxocara spp. were positive, with the latter presenting a higher index. We opted for treatment with a prolonged course of albendazole due to the serological results and being toxocariasis more frequent in our setting. The patient was then subject to radiological follow-up. The patient responded to treatment with albendazole as shown by a decrease in eosinophils, seronegativization for Toxocara spp., clinical and radiological improvement. Toxocariasis was hence considered the most likely diagnosis.ConclusionsParasitic infections cannot be disregarded in the presence of FHLH. Differential diagnosis between these parasitic infections can be challenging due to the presence of similar clinical presentations and serological cross-reactions, and follow-up of the patient is needed to ensure optimal treatment outcomes.

Toxocara Optic Neuropathy: About 02 Cases

Ocular toxocariasis is recognized to be a cause of childhood blindness. It usually results as a sequel of systemic infestation with the second or third stage larva of T. cani (visceral larval migrans). It is an uncommon cause of uveitis that mainly affects younger patients. Inflammation is typically unilateral and presents as either a granuloma in the peripheral or posterior retina or a moderate to severe vitreous inflammation mimicking endophthalmitis. We report two cases of children with ocular toxocariasis with posterior granuloma, negative for specific serodiagnosis. An anterior chamber puncture of the anterior chamber and an ELISA test with homologous antigens of Toxocara canis on the acqueous humor made the diagnosis diagnosis.

Soluble thiabendazolium salts with anthelminthic properties

Thiabendazole is an anthelmintic drug used to treat strongyloidiasis (threadworm), cutaneous and visceral larva migrans, trichinosis, and other parasites. The active pharmaceutical ingredient is typically administered orally as tablets that should be chewed before swallowing. Current formulations combine the active ingredient with excipients, including sodium saccharinate as a sweetener. Thiabendazole’s low aqueous solubility hinders fast dissolution and absorption through the mucous membranes. We sought to reformulate this medicine to improve both solubility and palatability. We utilized the possibility of protonation of the azole nitrogen atom and selected four different hydrogen donors: saccharin, fumaric, maleic, and oxalic acids. Solvothermal synthesis resulted in salts with each co-former, whereas neat and liquid-assisted grinding enabled the synthesis of additional formulations. Product formation was observed by powder X-ray diffraction. To better understand the structural basis of the proton transfer, we solved the crystal structures of the salts with saccharin, maleic acid, and oxalic acid using single-crystal X-ray diffraction. The structure of the salt with fumaric acid was solved by powder X-ray diffraction. We further characterized the salts with vibrational spectroscopic and thermoanalytical methods. We report a broad tunability of the aqueous solubility of thiabendazole by salt formation. Reformulation with maleic acid provided a 60-fold increase in solubility, while saccharin and oxalic acid gave a modest improvement. Fumaric acid resulted in a solid with only slightly higher solubility. Furthermore, saccharin is a sweetener, while the acids taste sour. Therefore, the salts formed also result in an intrinsic improvement of palatability. These results can inform new strategies for oral and chewable tablet formulations for treating helminthic infections.

EXPERIMENTAL TOXOCARIASIS IN RABBITS

Toxocariasis as a zoonosis represents a medical and veterinary problem. In the structure of human larval helminthiases, toxocariasis accounts for more than 60%. In non-specific hosts, including humans, toxocara larvae undergo visceral larva migrans, primarily damaging the liver, lungs, and other organs and tissues. Constant reinvasion accumulates second and third-stage larvae in the bodies of nonspecific (paratenic) hosts. In our research, we considered the problem of soil parasitological contamination on rabbit farms and the risks of rabbit infection, emphasising the need to study the involvement of rabbits as paratenic hosts in toxocariasis. We selected rabbits of the Soviet chinchilla breed as experimental animals. Toxocara eggs were administered orally to the animals. Hematological studies were conducted using commonly accepted methods. To detect specific IgG class antibodies, rabbit serum was analysed by enzyme-linked immunosorbent assay (ELISA). The presence of IgG class antibodies in the blood serum of rabbits at a positive titer (1:100) in ELISA allows us to conclude that rabbits, along with other animals, serve as paratenic hosts for Toxocara canis. Haematological research results indicated the absence of significant differences and remained within the physiological norm throughout the entire experiment.

Toxocariasis as a cause of multiple pulmonary and liver nodules in an immunocompetent adult

Human toxocariasis is a cosmopolite parasitic infection due to an helminth Toxocara canis (T.canis) and Toxocara catis(T.catis). Visceral larva migrans constitutes a rare and doubtful form. We reported the case of a visceral larva migrans with a concomitant localization in lung and liver.

Hepatic Visceral Larva Migrans: A Case Series

AbstractVisceral larva migrans is an uncommon systemic parasitic infection of liver caused by second-stage larva of Toxocara canis or Toxocara catis. The liver is the most common visceral organ to be involved. The diagnosis is usually delayed because of a lack of awareness about visceral larva migrans in adults, with most patients confused with either an abscess or neoplastic nodules. Heterogenous solid cystic, multiple hypodense, and hypovascular lesions on imaging with peripheral eosinophilia make the diagnosis in most cases. We present four adult patients with 2 to 4 weeks of fever and very high peripheral eosinophilia. The liver biopsy in three cases revealed an eosinophilic abscess. All cases on treatment with albendazole showed a good response. Visceral larva migrans must be considered in patients with heterogenous, hypovascular space-occupying liver lesions presenting with fever and peripheral eosinophilia.

Hepatic visceral larva migrans: A case series.

Hepatic visceral larva migrans: A case series.

English

Toxocara canis is one of the most prevalent gastrointestinal parasites of dogs and other canids worldwide. The closeness shared between humans and their companion animals (dogs) exposes humans to high risk of T. canis eggs, which leads to Visceral Larva Migrans (VLM) and Ocular Larval Migrans (OLM). This cross-sectional study was design to determine the prevalence and intensity of Toxocara canis eggs on the hair of dogs in Saki town, Oyo State.  Six hundred and twenty seven (627) hair samples were collected from three regions (neck, dorsum, and peri-anal regions) of 209 dogs between July 2019 and January 2020. Socio-demographic data, associated risk factors and knowledge about the T. canis were obtained from dog owners using a structured questionnaire. Hair samples from 84 dogs were infected with eggs of T. canis giving an overall prevalence of 40.2%. Generally, a significantly higher (p?0.05) prevalence of T. canis eggs was recorded among female dogs (47.4%) than male dogs (34.2%), also among the adult dogs (48.8%) than puppies (41.6%) and the juveniles (21.3%). Higher prevalence of infection was recorded among stray (67.4%) than kenneled (20.0%). A generally low knowledge of T. canis was observed among dog owners. A bivariate logistic regression analysis showed a significant association between the age, sex and mode of life of the dogs examined. The study concluded that dogs in the study area harbour T. canis eggs on their body especially the stray dogs and puppies hence direct contact with infected dogs could be a potential risk factor for the transmission of T. canis eggs to humans Key words: Prevalence, Eggs, Toxocara canis, Nigeria, Dogs, Saki, Zoonoses, Intensity.

Evaluation and Treatment of a Severe Case of Pediatric Idiopathic Hypereosinophilic Syndrome

BackgroundHypereosinophilic syndromes (HES) are a group of rare disorders characterized by marked peripheral eosinophilia resulting in end organ damage. When evaluating a patient with persistent hypereosinophilia, it is important to screen for the more common secondary causes of eosinophilia and assess for primary, myeloid HES. When no clear etiology is determined, a diagnosis of idiopathic HES is made. While this evaluation can be clinically challenging, making an accurate diagnosis can help guide effective treatment. CaseA 3-year-old Caucasian female with profound peripheral eosinophilia (70,100 cells/mL) and lymphocytosis (24,900 cells/mL) presented for immunologic evaluation following a two year history of persistent eosinophilia (1,450–27,700 cells/mL), presumably secondary to recurrent toxocariasis. The patient had been treated with albendazole three times for Toxocara after having positive serology and imaging consistent with visceral larva migrans in the context of an otherwise negative extensive infectious evaluation. Intermittent oral steroids and daily medium-dose inhaled steroids had also been started for wheezing. A bone marrow biopsy (BMbx) demonstrated increased numbers of eosinophils with cytoplasmic vacuoles, areas of hypogranulation, and subtle segmentation abnormalities, but genetic rearrangements for PDGFRA, PDGFRB, FIP1L1, and JAK2 were negative. An abnormal population of lymphocytes (CD3-CD4+) making up 1.7% of total lymphocytes was noted; however, this was not reproducible on repeat BMbx. Positron emission tomography redemonstrated bilateral pulmonary nodules and mild hilar lymphadenopathy, and bronchoalveolar lavage was normal other than an eosinophilia. The remainder of her immunologic evaluation was normal other than a pan-hypergammaglobulinemia without evidence ofT or B cell clonality. A 429 gene primary immunodeficiency panel was not felt to be clinically significant.Given the patient's persistent eosinophilia, oral steroids at 2 mg/kg were started with only a partial response (2,600 eosinophils/mL). Ultimately, mepolizumab 100 mg injected subcutaneously every 4 weeks was started as steroid sparing therapy with an excellent clinical response (780 eosinophils/mL) even after weaning off of oral steroids. ConclusionThis unique case illustrates the importance of a thorough evaluation of patients with persistent eosinophilia and the efficacy of mepolizumab in a child with marked idiopathic HES.

Forms of Ocular Larval Toxocariasis in Childhood. A Review

The aim of this paper is to present an outline of forms of ocular manifestations of visceral larva migrans in children, as illustrated by the extensive photographic documentation. Ocular larval toxocariasis (OLT) has various clinical manifestations even in childhood age, in which age representation has an influence. The most common is presence of peripheral granuloma of the eye, frequently with a tractional vitreal streak leading from the retinal periphery to the optic nerve papilla. This is followed by granuloma of the posterior pole of the eye, usually reaching from the macular landscape to the central retinal periphery, always with vitritis. In children OLT may be manifested also in affliction of the optic nerve (cystic granuloma of the head of the optic nerve or neuropathy with vitreal reaction), fulminant endophthalmitis and in rare cases also diffuse chorioretinitis. The diagnosis rests upon a clinical ophthalmological finding, as well as laboratory examination of the levels of antibodies with potential eosinophilia. Histological examination may demonstrate spherical polypoid ossification in the choroid at the posterior pole of the eye as a consequence of fibrotisation and calcification, proceeding from the surrounding area of the absorbed larva. General combined treatment with antihelminthics and corticosteroids is arduous and does not always produce the desired effect in the sense of a satisfactory improvement of visual acuity. In differential diagnostics, manifestations of OLT in small children are still associated with retinoblastoma and a clinical picture of other intraocular diseases.

EUS features of hepatic visceral larva migrans (with video).

EUS features of hepatic visceral larva migrans (with video).

Prevalence of Toxocara eggs in Latin American parks: a systematic review and meta-analysis.

Toxocariasis is an infection caused in canines, felines, humans, and other vertebrates by species of the genus Toxocara, such as T. canis and T. cati. The embryonated eggs of these parasites are the main form of acquisition of the infection both for definitive hosts, such as the dog and the cat, respectively and for paratenic hosts, such as humans and other vertebrates. Toxocariasis infection in humans causes visceral larva migrans syndrome. When deposited on park soils, environmental contamination becomes a risk for environmental, human, and animal health. To systemically estimate the prevalence of Toxocara spp. eggs in park soils in Latin America. A systematic review and meta-analysis were performed to evaluate the prevalence of Toxocara eggs in park soils in Latin America, defined by copro-parasitological, molecular and immunological techniques. We searched PubMed, Scopus, Web of Sciences, Embase, LILACS and SciELO for studies published from 1900 through 28 January 2023. A meta-analysis was performed using a random-effects model to calculate the pooled prevalence and 95% confidence intervals (95% CI). Heterogeneity was measured through I2 statistics. Forty-nine studies (2,508 parks and 12,833 samples) were included, of whom 44 had a low risk of bias. The pooled prevalence of Toxocara eggs in parks in Latin America was 50.0% (95% CI: 40.0%-60.0%). Argentina had the highest prevalence of Toxocara eggs in parks (100%), followed by Brazil (66%) and Venezuela (63%). The pooled prevalence of Toxocara eggs in soil samples was 20.0% (95% CI: 14.0%-26.0%); in faecal samples, it was 13.0% (95% CI: 6.0%-23.0%). The presence of Toxocara canis eggs in public parks in Latin America is a zoonotic and public health threat for the people who go to these places, especially if children play on the ground with dirt or contaminated objects; since many pet owners and general public are not adequately informed about the mode of transmission of this parasite.

Visceral Larva Migrans Presenting as Multiple Liver Abscesses

Visceral Larva Migrans Presenting as Multiple Liver Abscesses

Serological Evaluation of Human Toxocariasis in Patients With Hypereosinophilia Referred to Tabriz Hospitals in Iran

Introduction: Toxocariasis is a parasitic infection that causes eosinophilia in humans. Infection in humans is created by swallowing parasite eggs through contaminated soil or hands. Then, the larvae exit from eggs in the small intestine and enter the bloodstream through the perforation of the intestine, and from there, they migrate to all various organs, leading to the creation of visceral larva migrans syndrome and ocular larva migrans syndrome. Methods: In this case study, a prospective study was performed on 100 patients who referred to these centers from February 2017 to January 2018 in different hospitals in Tabriz, in Iran. After the diagnosis of 50 hypereosinophilic patients (more than 10% eosinophilia) without a history of allergic disease as a case group and 50 patients without eosinophilia as a control group, we collected blood samples from these individuals and isolated their serum or plasma. Then, anti-Toxocara antibodies were measured by the enzyme-linked immunosorbent assay (ELISA) method in these patients. The data were analyzed by SPSS software. Results: The prevalence of anti-Toxocara antibodies was observed in 20% (10 patients) and 2% (1 patient) of hyperosinophils and controls, respectively. The mean age of the case and control groups was 22–75 years and 17–79 years, respectively, and 57% and 43% of the subjects were males and females. Conclusion: Seroepidemiological studies in Iran have shown a seroprevalence of the disease between 2% and 25.6%. Due to the fact that toxocariasis is caused by worm larvae, this disease can be diagnosed only by serological methods. Therefore, it is necessary to suspect toxocariasis in people with unspecified hypereosinophilia and perform an immunoserological test by the ELISA method. The findings demonstrated that this infection exists in the city of Tabriz.