Atypical Toxocara canis-Induced Hepatic Visceral Larva Migrans: Diagnostic Challenges and Literature Review.

Toxocariasis, a zoonotic infection transmitted by Toxocara canis (from dogs) and Toxocara cati (from cats) larvae, poses rare but severe risks to humans. We present a case of hepatic visceral larva migrans (VLM) caused by Toxocara canis in a 21-year-old male with a history of close contact with a pet dog. Initial symptoms and imaging findings mimicked a pyogenic liver abscess. The initial laboratory investigations revealed neutrophilia and elevated levels of IgE. Despite broad-spectrum antibiotics, persistent fever prompted further investigation. Subsequent serological testing for Toxocara antibodies and histopathological analysis of liver tissue demonstrating eosinophil infiltrates and Charcot-Leyden crystals led to a confirmed diagnosis of a liver abscess caused by Toxocara canis. Serological testing for Toxocara antibodies and histopathological analysis of liver tissue confirmed a Toxocara canis-induced liver abscess. Albendazole treatment yielded significant clinical improvement. This case highlights the necessity of considering toxocariasis in liver abscess differentials, particularly in high-seroprevalence regions like Vietnam. Relying solely on serological tests may be insufficient, emphasizing the need for corroborative evidence, including invasive procedures like liver biopsy, for accurate hepatic toxocariasis diagnosis.

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

BACKGROUND: Human 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. METHODS: Small 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. RESULTS: This 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. CONCLUSIONS: Our 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.

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

BACKGROUND: The 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. METHODS: We prospectively followed a young patient presenting with FHLH in the Tuscany region of Italy. RESULTS: The 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. CONCLUSIONS: Parasitic 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.

Liver abscesses caused by visceral larva migrans: Aimless wanderer separated from the host.

Visceral larva migrans (VLM) is a systemic zoonotic parasitic disease caused by migration of the second stage larva through viscera of humans. Despite being a foremost public health problem in low- and middle-income countries (LMICs) such as India, larva migrans remains an untended zoonosis. Here, we report two cases of VLM who presented with fever and abdominal pain for a prolonged duration. On further investigation, marked peripheral eosinophilia with multiple confluent necrotizing eosinophilic granulomas were identified on histopathological examination of the liver.

Eosinophilic Granuloma of the Liver Mimicking Metastatic Liver Tumor.

We herein report a case of coagulation necrosis with granulation and eosinophilic infiltration of the liver. A 37-year-old woman was diagnosed with a new mass lesion in the liver 1 month after breast cancer surgery and admitted for a further examination. Because the tumor occurred immediately after surgery, it was considered essential to determine whether or not it was a metastatic liver tumor from breast cancer. A percutaneous liver tumor biopsy revealed eosinophilic granuloma of the liver, which is considered to have a high possibility of visceral larva migrans with suspected gnathostomiasis infection. A detailed medical history and histological diagnosis are important for making a differential diagnosis.

Toxocariasis en niños: análisis de 85 casos en un hospital pediátrico de Argentina / Toxocariasis in children: analysis of 85 cases in a paediatric hospital in Argentina

INTRODUCCIÓN: La toxocariasis es una enfermedad parasitaria ampliamente distribuida. Las formas clínicas descritas son la asintomática (TA), larva migrans visceral (LMV), larva migrans ocular (LMO) y encubierta (TE). OBJETIVOS: Describir las características clínicas, de laboratorio, evolución y tratamiento de los casos y comparar las diversas formas clínicas de presentación. PACIENTES Y MÉTODOS: Análisis retrospectivo de todos los pacientes pediátricos con diagnóstico de toxocariasis atendidos en el Servicio de Infectología del Hospital General de Niños Pedro de Elizalde entre 2012 y 2019. RESULTADOS: Se incluyeron 85 pacientes. El 63,5 % fueron varones y la mediana de edad fue de 60 meses. Cuarenta y nueve pacientes presentaron TA, 14 LMV, 15 LMO y 7 TE. Los pacientes con LMV presentaron menor edad y recuento de eosinófilos más altos. Todos los casos de LMO presentaron mal pronóstico visual. Se indicó tratamiento con albendazol en todos los casos de LMV, en los casos activos de LMO, en 4 TE y en 3 TA. CONCLUSIÓN: Este estudio representa uno de los más grandes llevados a cabo en el país. Todas las formas clínicas excepto las LMO tuvieron buena evolución. Resulta fundamental enfatizar en la prevención y en el diagnóstico precoz de la enfermedad para instaurar de manera oportuna el tratamiento y evitar secuelas.

BACKGROUND: Toxocariasis is a widely spread parasitic disease. The most frequent clinical form is asymptomatic (AT) although it may present with visceral larva migrans (VLM), ocular larva migrans (OLM) or covert (TE) involvement. Aims: To describe the clinical presentation, laboratory, evolution and treatment characteristics of the cases and to compare the various clinical forms of presentation. PATIENTS AND METHODS: Retrospective analysis of all children diagnosed with toxocariasis attended at the Infectology Service of the Pedro de Elizalde Children's General Hospital between 2012-2019. RESULTS: We included 85 patients. 63.5% were males and the median age was 60 months. 49 patients presented AT, 14 VLM, 15 OLM and 7 TE. Children with LMV had lower age and higher eosinophil count. All the cases of OLM evolved with a poor visual prognosis. Treatment with albendazole was indicated in all cases of LMV, in active cases of LMO, in 4 TE and in 3 AT. CONCLUSION: This study represents one of the largest conducted in our country. The ocular forms had bad prognosis, while the visceral and covert forms had good evolution. It is essential to emphasize the prevention and early diagnosis of the disease in order to establish timely treatment and avoid sequelae.

Clinico-radiologic Characteristics of Pulmonary Visceral Larva Migrans Caused by Ascaris suum.

Objective Visceral larva migrans (VLM) caused by Ascaris suum is a major health problem in pig farming regions. The clinical characteristics of pulmonary VLM caused by A. suum, however, are unclear. We assessed the clinico-radiologic features of this disease. Methods Medical records, including the results of chest radiography and high-resolution computed tomography (HRCT), were retrospectively reviewed from January 2000 through June 2019, at the University of Miyazaki Hospital and Kyoritsuiin Hospital in Miyazaki Prefecture, Japan. Results Seven patients with VLM caused by A. suum were identified. All seven patients had a unique habit of consuming raw foods, such as organic vegetables, chicken, turkey, wild boar, and venison. All but one patient, who had eosinophilic pneumonia with a fever and severe fatigue, had only mild or no respiratory symptoms. All 7 patients had remarkable eosinophilia (median, 1,960/µL) and high serum IgE levels (median, 1,346 IU/mL). Chest HRCT revealed multiple nodules and multiple nodular ground-glass opacities in 57% and 29% of the patients, respectively. The pulmonary lesions were located predominantly in subpleural areas. All seven patients were treated with albendazole, which led to improvement within two to three months. Neither eggs nor parasites were detected in the feces or sputum of any patient. Conclusion Consumption of raw organic vegetables or raw meat is a possible route of A. suum infection. Infected patients exhibit mild respiratory symptoms, and multiple nodules with a halo in the subpleural area are a common finding on chest HRCT. Treatment with albendazole was effective in these cases.

[Toxocariasis in children: analysis of 85 cases in a paediatric hospital in Argentina]. / Toxocariasis en niños: análisis de 85 casos en un hospital pediátrico de Argentina.

BACKGROUND: Toxocariasis is a widely spread parasitic disease. The most frequent clinical form is asymptomatic (AT) although it may present with visceral larva migrans (VLM), ocular larva migrans (OLM) or covert (TE) involvement. AIMS: To describe the clinical presentation, laboratory, evolution and treatment characteristics of the cases and to compare the various clinical forms of presentation. PATIENTS AND METHODS: Retrospective analysis of all children diagnosed with toxocariasis attended at the Infectology Service of the Pedro de Elizalde Children's General Hospital between 2012-2019. RESULTS: We included 85 patients. 63.5% were males and the median age was 60 months. 49 patients presented AT, 14 VLM, 15 OLM and 7 TE. Children with LMV had lower age and higher eosinophil count. All the cases of OLM evolved with a poor visual prognosis. Treatment with albendazole was indicated in all cases of LMV, in active cases of LMO, in 4 TE and in 3 AT. CONCLUSION: This study represents one of the largest conducted in our country. The ocular forms had bad prognosis, while the visceral and covert forms had good evolution. It is essential to emphasize the prevention and early diagnosis of the disease in order to establish timely treatment and avoid sequelae.

Status of human toxocariasis, a neglected parasitic zoonosis in Iran: a systematic review from past to current.

Although human toxocariasis can lead to serious complications including neurological, ocular and visceral complications, there is a lack of comprehensive epidemiological information about the seroprevalence of Toxocara species in humans. In the present study, we analysed and reviewed the overall seroprevalence of human toxocariasis in Iran. The data collection was systematically undertaken on published articles using the PubMed, Google Scholar, ScienceDirect and Scopus databases. A total of 27 studies from the past two decades reporting seroprevalence of human toxocariasis met our eligibility criteria. The pooled proportion of Toxocara infection was estimated as 6.58% (95% confidence interval = 3.98-9.77). A wide variation between different studies was observed (Q statistic = 799.37, df = 26, P < 0.0001, and I2 = 96.7%). The seroprevalence rate of toxocariasis in the Iranian population is relatively high; contamination of the environment by eggs from the host as well as from household dogs and cats should be blamed.

Larva visceral migrans secundaria a Toxocara en paciente anciano / Visceral larva migrans due to Toxocara in elderly patient

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The visceral larva migrans caused by Toxocara canis: a case report.

Hepatic toxocarosis is caused by the dog´s roundworm, Toxocara canis. Responsible for an eosinophilic inflammatory syndrome causing liver damage that can be detected on ultrasound, computed tomography and sometimes magnetic resonance imaging. We report the case of a nine-year-old child, living in countryside, with a notion of cohabitation with canids. He presented a digestive symptomatology revealed by abdominal pain, with a hemeosinophilia in the hemogram. The etiological assessment of hyper eosinophilia objectified a positive Toxocara canisserology. The imaging assessment in search of digestive visceral lesions, found multiple heterogeneous hypoechogenic areas, poorly defined, scattered in the liver. On the abdominal CT scan, its areas appear of unenhanced density and low density and better visible after injection of contrast product. This observation reveals that imagery, although not very specific, helps in the assessment of liver damage from digestive toxocarosis.

Imaging of toxocariasis.

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

Visceral larval migrans of Toxocara canis and Toxocara cati in non-canid and non-felid hosts.

Toxocara canis and Toxocara cati are considered the most ubiquitous gastrointestinal helminths in domesticated canids and felids. Ascarid eggs passed in the faeces of canids and felids in a suitable environment may remain infective for years and are capable of infecting not only canids and felids, but a large range of other vertebrate paratenic hosts, including man. Infection with Toxocara species also occurs following the ingestion of paratenic hosts containing infective larvae. As infective larvae are incapable of completing their lifecycle in these hosts, they instead travel to different parts of the body, sometimes inducing inflammatory responses, and in some cases remaining entrapped in the body for years. Migration routes depend on the host species; however, nearly all organs may be affected with varying quantities of larval burdens.

[Visceral Larva Migrans: A pediatric case of atypical presentation with cutaneous vasculitis in the province of Buenos Aires, Argentina]. / Toxocariosis visceral: un caso pediátrico atípico con vasculitis cutánea en la provincia de Buenos Aires, Argentina.

Toxocariosis is a parasitic disease caused by the larvae from genus Toxocara sp. There are two classic syndromes described for this entity: visceral larva migrans and ocular larva migrans, depending on larvae localization. Human being behaves as an accidental host in which Toxocara sp. does not become an adult worm. This infection is generally asymptomatic but clinical manifestations can be diverse, and they vary according to number and localization of entrenched larvae and host's immune system. In the last years it has been studied a relation between Toxocara sp. and some cutaneous manifestations. We describe the case of a 19-month infant with visceral larva migrans and cutaneous manifestations from vasculitis, explaining its form of presentation, evolution, diagnose and treatment.

La toxocariosis es una parasitosis generada por la larva del género Toxocara sp., que causa dos síndromes clásicamente definidos: larva migrans visceral o larva migrans ocular, dependiendo de la localización de la larva. Sin embargo, la mayor parte de los niños presenta una infección asintomática. El ser humano se comporta como un hospedador paraténico, en el que Toxocara sp. no llega a completar su ciclo biológico. Las manifestaciones clínicas pueden ser diversas y dependen del número y de la localización de las larvas enquistadas, así como de la respuesta inmune del huésped. En los últimos años, se ha descrito una relación entre Toxocara sp. y ciertas manifestaciones cutáneas. Se describe el caso clínico de un lactante de 19 meses con toxocariosis visceral y manifestaciones cutáneas de vasculitis. Se detalla su forma de presentación, evolución clínica, metodología diagnóstica y terapéutica empleada.

[A case of hepatic toxocariasis in a patient with hepatitis B].

A 49-year-old man with chronic hepatitis B receiving treatment with entecavir visited a hospital with a complaint of abdominal pain. Computed tomography (CT) showed 2 liver tumors, each measuring 1cm in diameter, 1 in segment 7 and 1 in segment 4. Magnetic resonance imaging (MRI) showed a hypervascular tumor in segment 7 that appeared in a site different from that seen on CT. The liver tumor in segment 4 was not detected by MRI. Two months later, MRI showed a new liver tumor in segment 7/6 and that the liver tumor in segment 7 had increased to 2cm in diameter;blood tests showed eosinophilia. Enzyme-linked immunosorbent assay showed a high serum Toxocara antibody. The patient was diagnosed as having hepatic toxocariasis and was treated with albendazole for 8 weeks. After treatment, MRI showed that the liver tumors disappeared. Eosinophilia, multiple lesions, and the disappearance of the tumors were characteristic findings of visceral larva migrans.

Immune response to chronic Toxocara canis infection in a mice model.

AIMS: The zoonotic nematode Toxocara canis causes larva migrans syndrome that induces an immune response characterized by the production of antibodies and eosinophilia. A Th2 polarization has been associated with the infection, but there are still details of the cellular and humoral immune response that need to be described. Thus, the aim of this study was to describe the systemic host immune response to T canis chronic infection in a mouse model. METHODS AND RESULTS: BALB/c mice were inoculated once with 500 T canis embryonated eggs, per os. After 49 days, the amounts of larval found in brain and muscle tissues were statistically two and four times higher, respectively, than the amounts found in lung, liver, kidney or heart tissues. Splenic proportions of F4/80+ cells, as well as B, cytotoxic T and CD4+ Foxp3+ lymphocytes, were statistically higher (P ≤ .05, P ≤ .01, P ≤ .001 and P ≤ .001, respectively) as compared with control mice. In lymph nodes, some of these proportions changed, with the exception of F4/80+ cells. IgG1 levels in infected mice sera were increased. IL-4, IL-10 and VEGF levels were statistically higher in spleen (P ≤ .05, all) and sera (P ≤ .01, P ≤ .05 and P ≤ .05, respectively) in the infected mice. Also, in infected animals, IL-5 serum levels were increased (P ≤ .01). CONCLUSION: These results suggest that T canis chronic infection in BALB/c mice results in a type 2 response with an incipient regulatory response.

Frequency of Toxocara canis antibodies in Mexican paediatric patients with epilepsy.

The relationship between epilepsy and the presence of visceral larva migrans caused by Toxocara canis in Mexican children remains uncertain; however, this relationship needs to be elucidated because these parasite larvae can invade the human central nervous system. Accordingly, this study aimed to determine the frequency and specificity of anti-T. canis antibodies in the sera of children with epilepsy to determine the relationship between this parasite and epilepsy. The sera samples of 214 children were examined: 111 children diagnosed with epilepsy and 103 clinically healthy children without neurological disorders. In the sera of each group, the presence and specificity of anti-T. canis and anti-Ascaris lumbricoides antibodies, as well as the cross-reactivity between them, were assessed using enzyme-linked immunosorbent assay and Western blotting analysis. Among the children with epilepsy, 25.2% exhibited seropositivity to T. canis. Cross-reactivity against the A. lumbricoides antigen was present in 46.8% of the children with epilepsy, whereas 11.7% of the children with epilepsy and anti-T. canis antibodies did not exhibit cross-reactivity against this antigen. The Western blotting analysis of the sera from the children with epilepsy demonstrated the presence of T. canis proteins, with molecular weights of 24, 35, 55, 70, 120 and 210 kDa, and A lumbricoides proteins with molecular weights of 70, 80 and 110 kDa. Our results revealed the presence of anti-T. canis antibodies in the children with epilepsy; furthermore, cross-reactivity tests with A. lumbricoides showed the importance of the presence of anti-T. canis antibodies in revealing the relationship between this parasite and epilepsy in children.