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.

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 Suspected of Having Infiltrated Directly from the Liver to the Lung through the Diaphragm

A 37-year-old woman presented to our hospital with mild abdominal pain experienced for 2 months and hepatic nodules in segments 3 and 8. Peripheral blood eosinophilia was observed, and toxocariasis was serologically diagnosed. Seventeen days after the first imaging evaluation, a new lesion was found in segment 9 of the right lung, which was contiguous through the diaphragm to the hepatic nodule in segment 8. After treatment with albendazole, the liver and lung nodules disappeared. We suspect that larvae had directly invaded the lung from the liver, through the diaphragm.

Diagnosis of ocular toxocariasis by detecting antibodies in the vitreous humor

OBJECTIVES

To demonstrate the production of the local toxocara antibodies in the vitreous of patients with negative serology.

MATERIAL AND METHODS

Retrospective review of the medical records of patients seen in a Tertiary Referral Hospital, and at an Eye Institute, with an ocular diagnosis of toxocariasis who had a negative serology and positive titres in the vitreous.

RESULTS

After reviewing the medical records of 40 patients with a diagnosis of ocular toxocariasis, a total of six cases (15%) were found with a negative serology and a positive vitreous titre for toxocara antibody, both of them performed using an ELISA procedure. The mean age was 18 years, there were no differences observed between males and females. A peripheral granuloma was the most common clinic finding, and all patients underwent vitrectomy either to remove epiretinal membranes or to repair retinal detachments.

CONCLUSION

A negative serology does not rule out a diagnosis of ocular toxocariasis. Vitreous samples may be necessary to confirm a clinical diagnosis.

HEPATIC VISCERAL LARVA MIGRANS DUE TO TOXOCARA CANIS IN A 72-YEAR-OLD MAN

Hepatic toxocariasis is visceral larva migrans caused by Toxocara. We report a case of hepatic toxocariasis detected incidentally during a health checkup. The patient had elevated levels of eosinophils, total IgE, and anti-Toxocara IgG antibodies. On contrast-enhanced computed tomography (CT) imaging he had a single, 2.16 cm, oval, ill-defined, low-attenuation hepatic nodule which was best appreciated during the portal venous phase of the scan. Clinicians should consider hepatic toxocariasis as a possible diagnosis in any individual who presents with eosinophilia of unknown etiology and an ill-defined hepatic lesion on CT imaging.

Immunoblot for the detection of Ascaris suum-specific antibodies in patients with visceral larva migrans (VLM) syndrome

Visceral larva migrans (VLM) syndrome caused by Toxocara canis larvae was first described in the 1950s. The role of other nematode larvae, i.e. the pig roundworm Ascaris suum as a causative agent of visceral larva migrans-associated symptoms like general malaise, cough, liver dysfunction, hypereosinophilia with hepatomegaly and/or pneumonia, was discussed controversially during the last decades. Recent serological screening studies for specific A. suum antibodies carried out in the Netherlands and Sweden yielded remarkable high seroprevalences, while a number of case reports from Japan report pulmonal, hepatic and cerebral symptoms caused by A. suum larvae after ingestion of infected raw meat (liver) or contaminated vegetables. We present here a sensitive and specific larval excretory-secretory (E/S) antigen-based immunoblot (As-IB) for the serodiagnosis of A. suum-infected patients suffering from symptoms associated to the VLM syndrome. In total, 34 sera from patients with hypereosinophilia and other clinical symptoms associated to the VLM syndrome tested negative for Toxocara sp. antibodies but positive in our newly established As-IB, 30 sera from healthy volunteers, 53 sera from patients with clinically and serologically confirmed toxocarosis and other helminthoses as well as 3 sera from patients with intestinal ascariosis due to Ascaris lumbricoides were included in the study. When evaluated with 30 sera from healthy volunteers and 53 sera from patients suffering from different helminthoses, the calculated specificity of our new As-IB is 95%. Problems hampering the establishment of simple serological screening tests for specific A. suum antibodies, like extensive antigenic similarities between the nematodes Ascaris and Toxocara or the absence of suitable experimental animals, are discussed. We assume that specific serological testing for antibodies of A. suum is very important for the treatment of individual patients on one hand and seroepidemiological investigations will help to clarify routes of transmission on the other hand. Further studies will be necessary to learn more about the extent of A. suum as a causative agent of the VLM syndrome and the role of pigs and their manure as the main source of human Ascaris infections in Austria and other industrialized countries.

[Technological direction in the diagnosis and therapy of parasittic diseases: state-of-the-art and promises]

The paper presents information on the technological methods aimed at improving the diagnosis and prevention of parasitic diseases.

Adult human case of toxocariasis with pulmonary migratory infiltrate and eosinophilia

INTRODUCTION

Toxocariasis is a zoonosis which is in Serbia characterized with a very high infection rate of dogs and excessive contamination of the soil with the eggs of Toxocara canis, the agent of the disease. Toxocara-induced infections have in recent years been established in a few hundreds of children, but toxocariasis has rather rarely been diagnosed in adults.

CASE REPORT

We reported toxocariasis (visceral larva migrans) in an adult, manifested by migratory pulmonary infiltrates and positive serological test finding to Toxocara.

CONCLUSION

Human toxocariasis is a rare disease in adults, therefore it should be considered in adult patients presented with eosinophilia and migratory pulmonary infiltrates.

Seroprevalence and risk factors for canine toxocariasis by detection of specific IgG as a marker of infection in dogs from Salvador, Brazil

Toxocara canis is a highly prevalent worldwide canine nematode responsible for enzootic and zoonotic infections. It is considered to be one of the main agents of human visceral and ocular larva migrans. False negative diagnosis may occur because adult infected dogs with "dormant" larvae may have negative fecal test results since they usually do not shed parasite eggs in their stools. During pregnancy, the larvae become active and infect the offspring through the placenta. A serological test can distinguish infected animals, thus increasing the accuracy of the diagnosis for epidemiological studies and prophylactic purposes. In the present work a serological investigation was carried out to study the risk factors for the acquisition of this infection in 301 dogs inhabiting the city of Salvador, northeast Brazil. A validated questionnaire was applied to the donors and caretakers to assess animal management practices. All dogs were submitted to clinical evaluation and blood collection. Serum samples were analyzed for IgG antibodies against excretory-secretory products of T. canis larvae, used as antigens, by indirect ELISA. The overall seroprevalence of anti-T. canis IgG antibodies was 82.7%. Risk factors for T. canis infection included sex, area of origin within the city, homemade leftover food intake, failure to receive regular vaccination against infectious diseases and lack of preventive anti-helminthic treatment. Most of these risk factors suggest a lack of veterinary care and poverty. The high frequency of seropositivity found for toxocariasis in dogs suggests that results based on parasitological fecal examination could underestimate the actual prevalence of the infection.

[Toxocariasis]

The clinical presentation of toxocariasis, a zoonotic parasitosis transmitted from dogs and cats to humans, can be very diverse, which is one of the reasons why Toxocara-related disease may go unnoticed. This paper gives a brief summary of the various clinical presentations (covert/common toxocariasis, visceral larva migrans, ocular toxocariasis and neurotoxocariasis), diagnostic and differential-diagnostic considerations as well as treatment and prevention. In brief, the diagnosis of human toxocariasis relies mainly on patient data, anamnestic information, symptoms, eosinophil count and total-IgE levels.

Eosinophilic pneumonia due to visceral larva migrans possibly caused by Ascaris suum: a case report and review of recent literatures

We report the case of a 62-year-old man who developed eosinophilic pneumonia due to visceral larva migrans (VLM) that was possibly caused by Ascaris suum. The patient, a resident of the middle Kyushu area who was found of eating raw porcine liver, complained of dry cough without dyspnea. The chest radiography showed a migration of infiltrative shadow. Transbronchial lung biopsy of the right middle lobe revealed massive infiltration of eosinophils. The multi-dot enzyme-linked immunosorbent assay (ELISA) and microtiter plate ELISA showed positive results for A. suum; therefore, the patient was diagnosed with VLM caused by A. suum. The patient was administered albendazole (600 mg/day) for 28 days; he recovered successfully with no adverse effects except mild liver dysfunction. Several cases of VLM caused by A. suum have been reported in Japan, with a majority of the cases being reported in Kyushu. Careful history taking of the patient's area of residence and dietary habit is essential for the diagnosis of this parasitic disease with underestimated prevalence.

[Eosinophilic pneumonia in response to cutaneous larva migrans syndrome--a case report]

Cutaneous larva migrans is a parasitic dermatosis imported by travelers returning from tropical and subtropical regions. In cutaneous larva migrans syndrome humans are incidental hosts and the larvae are unable to complete their natural cycle. Adult hookworms live in the intestines of dogs and cats, shedding eggs in feces that hatch and mature into larvae that can remain infective for months in the soil. Larvae penetrate the skin after contact with infected soil and cause an itchy creeping eruption. Cutaneous larva migrans is not usually associated with systemic symptoms and is rarely accompanied by peripheral blood eosinophilia. We report a patient who had both cutaneous larva migrans syndrome caused by Ancylostoma brasiliense and eosinophilic pneumonia after returning from Sri Lanka. The patient has been applied intravenous corticosteroids and local treatment with albendazole ointment with a very good clinical response.

[Case of Toxocara canis larva migrans cured by additional treatment with albendazole]

A 42-year-old man presented at our emergency department with fever, sputum, and dyspnea. His chest X-ray films showed ground-glass opacities mainly in the upper and middle lung fields. We diagnosed pneumonia, gave antibiotic treatment, and his symptoms improved. However he later showed eosinophilia. We performed additional workup, and diagnosed Toxocara canis larva migrans. We treated him with albendazole for four weeks, but his eosinophil count rose again from the end of treatment one month later. Therefore we performed additional treatment with albendazole for 8 weeks, after which the clinical imaging findings and serum antibody titer improved. There are few reports about additional treatment for Toxocara canis larva migrans, and there is not yet a consensus. We think that we should consider additional treatment in cases that do not show improvement on initial treatment.

[Case of toxocariasis showing migratory nodular shadows with halos]

A 30-year-old man, who had kept a dog for nine years and often ate raw beef liver, visited a hospital because of a chest nodular shadow in the left lung field found on a checkup examination. Chest computed tomography obtained 8 days after the checkup showed no abnormal shadow in the left lung but two nodular shadows with halos in the right upper and lower lobes. Peripheral blood eosinophil counts and serum IgE values were elevated. Immunological examination including microplate ELISA showed a high titer of specific antibody against Toxocara canis in the serum. He was successfully treated with albentazole. Parasitic disease, especially toxocariasis, is an important consideration in the differential diagnosis of migratory nodular shadow with a halo on chest computed tomography, and serology is useful in diagnosis screening.

[Analysis of children with a presumptive diagnosis of toxocariasis in Santa Fe, Argentina]

Human toxocariasis is a parasitic disease found worldwide. The most important etiological agent is Toxocara canis, a dog parasite. Humans are infected by the ingestion of their eggs; the eggs hatch in the small intestine and the larvae migrate through the capillaries, taking up residence in different tissues. Clinical manifestations are associated with mechanical and/or reaction damage caused by these parasites larvae. Clinical diagnosis is difficult. The method applied in this work is the demonstration of antibodies against the helminth in the blood of children, target host population of this parasitic disease. An ELISA test was performed using T. canis larval excretory-secretory products as antigen. A total of 100 children presumptively diagnosed of toxocariasis that had been derived from different services of the Regional Children's Hospital for complementary studies, were included in the analysis. The test detected two different populations: infected (59) and non-infected (41). The statistical analysis showed a non significant association between infection and sex (p = 0.279). Infected subjects tended to be older than the non infected (p = 0.009). Eosinophilia was detected in 100% of seropositive children and in 85.2% of the seronegative. There was no significant association between infection and leucocytosis (p = 0.950). The association of these two parameters was significantly higher among infected patients (R = 0.918). Respiratory symptoms and signs were more frequently detected in the positive population (p = 0.05). Dogs tenancy was as frequent among infected as in the non infected homes (p = 0.53). According to these results, prevention, early diagnosis and opportune treatment for toxocariasis should be considered as priority health activities in this region.

[Toxocariasis in children--difficult clinical problem]

Toxocariasis in humans is a zoonosis due to the migration of Toxocara canis or T. cati larvae in human body. This review provides basic information on pathology of infection and clinical signs and symptoms of toxocariasis in children. The cases diagnosed in the recent years in central Poland are presented. The disease was recognised accidentally based on the results of laboratory analysis performed for other reasons, when abnormalities suggesting an active helminthiasis were found (eosinophilia, elevated IgE level and/or anemia). The high rate of soil contamination in households of the patients demonstrated elevated risk of infection and reinfection in both, rural and urban areas. Presented data show the need for educational programs which should be implemented for prevention of Toxocara infection in children.

[Visceral and cutaneous larva migrans]

The syndrome of visceral larva migrans was described for the first time in 1952 by Beaver. He demonstrated that the presence of nematodes larvae, particularly in the liver, were those of Toxocara canis and T. cati. Baylisascaris procyonis, the common racoon ascarid in the U.S.A. can also cause serious diseases in human. Digestive and respiratory clinical symptoms are usually moderate, however severe disease resulting from invasion of the myocardium or the brain has been reported. A blood hypereosinophilia is usually present the first few years after infection. Diagnosis uses serological methods, among them the ELISA test. Ocular larva is also possible with in that case, immunological modifications of the aqueous. Cutaneous larva migrans characterized by a linear, progressing, serpigenous eruption and intense itching is easy to diagnose. Larva migrans is due to dogs, cats and horses helminths. Dogs and cats (referred here as pets) now receive antihelmintitic treatments and parasites are now in decrease.

Characterization of a Toxocara canis species-specific excretory-secretory antigen (TcES-57) and development of a double sandwich ELISA for diagnosis of visceral larva migrans

This study describes the isolation of a Toxocara canis species-specific excretory-secretory (ES) antigen and the development of an enzyme-linked immunosorbent assay (ELISA) based on this antigen. Analysis of the ES antigens of T. canis, Toxocara vitulorum, Ascaris lumbricoides and Necator americanus larval antigen was performed by SDS-PAGE followed by western blotting. A 57 kDa T. canis-specific antibody fraction (TcES-57) was identified by western blotting and labelling with anti-Toxocara antibodies (from experimental rabbits and human patients) and tracing with anti-human or anti-rabbit peroxidase conjugate. No protein fraction of 57 kDa was detected in ES or larval antigens collected from T. canis, T. vitulorum, A. lumbricoides and N. americanus. Using TcES-57, a specific antiserum was produced in rabbits and a double sandwich ELISA was developed. This test was validated using known seropositive sera from toxocariasis patients, sera from A. lumbricoides or N. americanus patients, and 50 serum samples from cats. These tests revealed that TcES-57 antigen is specific to T. canis infection and does not cross react with sera of other related infections. Thus, ELISA based on TcES-57 antigen was proven to be an effective tool in the diagnosis of toxocariasis and studies on the role of T. canis in the epidemiology of human toxocariasis.

Toxocariasis in Japan

Toxocariasis has long been considered a parasitic disease affecting pet owners and children who often play in sandboxes at public parks. Recent cases of this animal-borne infection, however, indicate that its clinical manifestations and etiologies are changing. In this article, we will describe the critical characteristic features of toxocariasis alongside the contributions of Japanese researchers to a better understanding of the disease.

Visceral and presumptive neural baylisascariasis in an orangutan (Pongo pygmaeus)

A 32.5-year-old female hybrid orangutan (Pongo pygmaeus) developed hind-limb stiffness that progressed to tetraparesis over 2 wk. Repeated diagnostic evaluations, including serial magnetic resonance imaging of the central nervous system, revealed nonspecific lesions involving both the deep white and gray matter with an intact blood-brain barrier. Multiple empirical treatments failed to produce improvement and the animal was humanely euthanized. Histology of a granuloma in the ileum contained a nematode parasite, most consistent with Baylisascaris procyonis. Additionally, neuropil vacuolization, rarefaction, astrocytic scarring, and an eosinophilic granuloma and lymphoeosinophilic perivascular cuffing in the brain were suggestive of nematode migration. These findings confirm the presence of visceral larval migrans and support the presence of neural larval migrans. This case report of Baylisascaris procyonis confirms the presentation for the first time in an ape and documents the difficulty in antemortem diagnosis of neural larval migrans.

MRI studies of spinal visceral larva migrans syndrome

We report serial MR findings in four patients with myelitis caused by visceral larva migrans syndrome due to Toxocara canis or Ascaris suum infection. MR imaging revealed spinal cord swelling with or without gadolinium enhancement in three patients. T2-weighted images showed high signal intensities preferentially located in both lateral and posterior columns. Antihelmintic and corticosteroid treatment yielded improvement in neurologic deficits and spinal lesions. However, one patient with T. canis infection relapsed associated with reappearance of MRI abnormalities.

ELISA antibody determination in patients with anisakiosis or toxocariosis using affinity chromatography purified antigen

One of the fundamental aspects of a parasitic infection diagnosis is the use of adequate antigens to develop specific and sensitive immunoassays. This fact is especially complicated in nematode infection cases because of the high cross-reactivity among different parasites in this group. We performed an evaluation of Anisakis simplex antigens purified by affinity chromatography. We used sera from 38 patients diagnosed with Anisakis sensitization and sera from 35 patients with clinical suspicion of visceral larva migrans (VLM). These sera were assayed by the ELISA method against the crude extracts (CEs) and the purified antigens. When the sera from patients diagnosed with Anisakis sensitization were tested against the A. simplex CE, the IgG was the most abundant immunoglobulin. When the A. simplex larval antigens were purified using a column of IgG anti-A. simplex (PAK) or a column of IgG anti-Ascaris suum (PAS) were tested, we observed a higher diminution in the IgG levels, which coincides with the augmentation of the mean values against the "eluted of Ascaris" (EAS antigen). When the IgE was detected, only 18.4% of the sera reacted with the PAS antigen. We have observed that in the purification process of A. simplex antigen by affinity chromatography, the majority of the proteins that produced cross-reactivity against A. suum and Toxocara canis were eliminated.

A familial case of visceral larva migrans after ingestion of raw chicken livers: appearance of specific antibody in bronchoalveolar lavage fluid of the patients

We report a familial case of visceral larva migrans (VLM) caused by Toxocara canis larvae. Patient 1 was a 45-year-old man who presented to our university hospital complaining of mild fever, general fatigue, and headache. Patient 2 was a 71-year-old man and was the father of Patient 1; he presented complaining of cough and hyper-viscous white sputum. Laboratory data from both patients showed extensive eosinophilia, their chest X-ray findings revealed multiple pulmonary infiltrates, and their bronchoalveolar lavage fluid (BALF) showed an elevated eosinophil count. The diagnosis of VLM was made based on a positive result in a serological test using T. canis larval excretory-secretory both in the serum and BALF. T. canis larvae were identified in meat that was prepared from chicken taken from the same source as that ingested. This is the first report to identify antibodies in BALF in patients with VLM.

A case of Ascaris suum visceral larva migrans diagnosed by using A. suum larval excretory-secretory (ES) antigen

A 42-y-old female presented with common cold-like symptoms. Laboratory data showed mild liver dysfunction together with peripheral blood eosinophilia. She was suspected of having a helminthic infection, however parasite eggs or larvae were not detected by repeated stool examinations. Eventually she transpired to have a high IgG antibody titer against excretory-secretary (ES) antigen of Ascaris suum larvae, but not of Toxocara canis larvae, suggesting that she had been suffering from visceral larva migrans (VLM) caused by A. suum. Her sickness improved without any treatment. Current results clearly highlight the usefulness of ES antigens derived from larvae of A. suum for the fine discrimination of VLM caused by A. suum and by T. canis. Application of A. suum derived ES antigens as a diagnostic tool may reveal the distinctive clinical features of VLM caused by A. suum.

Visceral larva migrans presenting as acute abdomen in a child

An unusual presentation of visceral larva migrans observed in a patient is reported. A 5-year-old boy suffering fever, abdominal pain, tenderness, and rigidity in the right lower and upper quadrant of the abdomen was operated on, with the false diagnosis of acute abdomen, and exploratory surgery was carried out. The pathological examination of the liver biopsy revealed eosinophil-rich necrotizing granulomatous inflammation with Toxocara spp larva. The diagnosis was also confirmed by serologic results. Clinicians should remember that toxocaral visceral larva migrans may rarely mimic an acute abdomen and cause unnecessary operations.

Visceral larva migrans associated with earthworm ingestion: clinical evolution in an adolescent patient

A 16-year-old girl developed a cough, hypereosinophilia (absolute eosinophil count: 32000/mm3), hypergammaglobulinemia, and multiple noncavitary pulmonary nodules 1 month after having ingested an earthworm on a dare. Spirometry revealed moderate restriction and reduced gas diffusion. Parabronchial biopsy demonstrated eosinophilic organizing pneumonitis with multiple eosinophilic microabscesses, and Toxocara titers were elevated (>1:4096). Ophthalmologic examination ruled out ocular larva migrans. The patient received a 10-day course of albendazole (400 mg orally twice daily) and demonstrated significant clinical improvement with resolution of cough and pulmonary function abnormalities. Her white blood cell count and hypergammaglobulinemia normalized within 20 days, yet eosinophils (absolute eosinophil count: 1780/mm3) and Toxocara serologies (>1:4096) remained elevated 3 months after completing antihelminthic therapy. In this instance, the ingested earthworm served as the paratenic carrier of Toxocara larvae from the soil to the patient. This case highlights the clinical evolution of pulmonary visceral larva migrans infection caused by Toxocara spp. associated with a discrete ingestion in an adolescent patient. In addition, it provides a rare opportunity to define the incubation period of visceral larva migrans and emphasizes the importance of education regarding sources of Toxocara infection.

Hepatic toxocariasis: US, CT and MRI findings

Visceral larva migrans (VLM) most commonly occurs as a febrile disease of childhood particularly affecting children between 1 and 7 years of age. Pulmonary, dermatological, hepatic, lymphatic, cardiac, rheumatological and neurological manifestations may occur. VLM seems to be a rare disease in adults. We report the imaging findings of a woman with hepatic toxocariasis. Ultrasonography showed a solitary hepatic lesion measuring 4 x 3 cm, displaying a hypoechoic-heterogeneous pattern with ill-defined borders and distal acoustic enhancement, located in the right sub-diaphragmatic area. Two enlarged periportal lymph nodes and moderately dilated intrahepatic biliary ducts were also noted. The probability of toxocariasis was discussed, based on sonographic and biopsy findings, and the final diagnosis was confirmed by a specific ELISA test. In summary, a clinical picture of cholestasis initially resembling hepatitis or malignancy should be further evaluated by imaging techniques, and the ultrasound examiner should be familiar with the possible findings of hepatic toxocariasis, which consist of focal ill-defined hepatic lesions, hepato-splenomegaly, biliary dilatation, sludge and periportal lymph node enlargement.

[Toxocara canis central chorioretinitis]

This issue presents the case of a patient which presents monolateral chorioretinitis caused by Toxocara canis.

[Toxocariasis--a current clinical and diagnostic problem]

Toxocariasis is zoonotic disease caused by worms Toxocara canis and Toxocara cati. Human is its paratenic host. There are some clinical forms: Visceral larva migrans, cerebral larva migrans, ocular larva migrans and covert toxocariasis. At the present time diagnostics of toxocariasis is very difficult due to polymorphism of clinical symptoms and low specificity of laboratory tests.

[Diagnosis and treatment of CNS parasite infection with special reference to parasitic myelitis]

The occurrence of visceral larva migrans due to Ascaris suum (A. suum) and Toxocara canis (T. canis) has occasionally been reported in Japan, although parenchymatous involvement of the CNS is extremely rare in A. suum/T. canis visceral larvae migrans. Recently we experienced 7 cases with myelitis caused by visceral larva migrans due to A. suum/T. canis (parasite myelitis). The characteristics of this myelitis are: (1) sensory disturbances (Lhermitte's sign, paresthesia, and hypesthesia) are predominant symptoms, while severe motor weakness is rare, (2) spinal cord lesions on T2-weighted MRI show more extensive lesions compared with mild symptoms, (3) Gadolinium enhancement of spinal cord lesions are limited as compared with spinal cord lesions on T2-weighted MRI lesions, (4) Some cases show the presence of eosinophils in CSF, while others show Th2 deviation in CSF supernatant, and (5) Tests for anti-A. suum/T. canis IgG antibody are strongly positive in serum and CSF. Moreover, 6 percent of 108 consecutive cases with non-compression myelopathy presenting at the Department of Neurology at Kyushu University Hospital from January, 1998 to December, 2002 had parasitic myelitis. Myelitis from visceral larva migrans due to A. suum/T. canis might be overlooked because of its mild neurologic impairment without systemic symptoms, but should be considered as one of the differential diagnoses in non-compression myelopathy.

Cross-reactions with Ascaris suum antigens of sera from mice infected with A. suum, Toxocara canis, and Angiostrongylus cantonensis

Ascaris suum larval excretory-secretory (AsES) antigen and larval (AsLA) as well as adult somatic antigen (AsAA) which were thought to be possibly helpful in the diagnosis of visceral larva migrans (VLM) due to A. suum infection were investigated in the present study. Serum taken from mice orally inoculated with approximately 250 embryonated eggs of A. suum or Toxocara canis, or 40 third-stage larvae of Angiostrongylus cantonensis were assessed by enzyme-linked immunosorbent assay (ELISA) using the AsES antigen, AsLA or AsAA at 1, 2, 3, 4, 6 and 8 weeks post infection (WPI). The titer of serum IgG from mice infected with A. suum increased from 1 WPI and a peak at 4 WPI was observed when it reached approximately three times the level of uninfected control mice. Thereafter, it decreased gradually but remained high as found from 6 to 8 WPI. No cross-reactions of heterologous serum IgG against AsES antigen was observed, whereas heterologous serum IgM exhibited significant cross-reactions to AsES antigen. Cross-reactivities to AsLA and AsAA by heterologous serum IgG as well as IgM antibodies were also observed in the trial. Altogether, the AsES antigen apparently seemed to be superior to the other two somatic antigens when used in the diagnosis of A. suum-induced VLM with serum IgG as tested by ELISA. Moreover, it was the first report to test the possibly antigenic cross-reactivity between A. suum and A. cantonensis.

[Diagnostics of larval toxocariasis]

PURPOSE OF THE STUDY

The paper, conceived as a retrospective study, resumes the results of our own investigations of the presence of serum IgG antibodies against Toxocara canis (as a crossover also against T. cati) in the sera of patients suspected of presenting larval toxocariasis in the region of Eastern Bohemia of the Czech Republic in the years 1997-2002. Our aim was to determine the immunity rate of IgG, its relationship to age and sex, further the whole range of diagnoses, the frequency of demands for such an examination by physicians and the evaluation of our experience with the detection of low avidity IgG.

MATERIAL AND METHODS

With a commercial diagnostic kit the ELISA method was used to detect the presence of IgG antibodies against T. canis in 2 994 sera. IgG avidity was determined in 92 positive samples with an avidity solution, which is included in the diagnostic kit and has been used in our laboratory since 2001.

RESULTS

The immunity rate of larval toxocariasis in our set was 20.4 % (612 samples). With age this rate increases (in individual decades of life - 11.9; 8.3; 11.4; 17.9; 26.1; 29.8 and 34.2%). Up to adolescence positive findings predominate among boys (males 0-10 years 84.2 %; 11-20 years 76 %). In the third decade we see a dramatic change in favour of women (women 21-30 years - 74.6 %). In absolute figures the number of positive findings stagnates in men after the age of 30 years, while among women positive findings continue to grow - yet expressed in percentages there is signifinct change in the male-female ratio (beginning with the 4th decade we find among the women 61.2; 69.7; 72.6 and 64.8 %). Physicians' interest in the diagnosis of toxocariasis in the years 1997-2002 is confirmed by the significantly higher number of investigated samples (135; 446; 617; 422; 558; 816). This, however, does not go hand in hand with a higher proportion of IgG positivity. IgG avidity was investigated in 92 positive samples - low avidity was confirmed in six of them (6.5 %); the appropriate case histories are not a part of the study.

CONCLUSIONS

Our results tally with the data published by other departments in the Czech Republic. They confirm that the methods used have, as before, their place in the diagnostic range of microbiological laboratories.

[Ocular toxocariasis. Diagnostic and therapeutic options]

BACKGROUND

The diagnosis of ocular toxocariasis can be difficult and the aim of this study was to evaluate the benefit of ELISA testing of vitreous body fluid.

PATIENTS AND METHODS

We present five consecutively treated patients with ocular symptoms of toxocariasis, three of these patients presenting with epiretinal membranes and subretinal granulomas were vitrectomized. Vitreous and body fluid and serum were tested for toxocara antibodies by ELISA. Moreover vitreous body fluid of 10 patients with epiretinal membranes of other origins were examined by the same ELISA.

RESULTS

In all three operated patients toxocara antibodies were detected in the vitreous fluid but ELISA testing of serum samples was negative in two of the three patients. Visual acuity increased or remained stable in the operated patients. The ELISA test was negative in all vitreous fluid samples of the control group.

CONCLUSIONS

ELISA testing of vitreous body fluid can prove the presence of toxocara infection when no systemic signs of infection are present and no antibodies are detectable in the serum. Well-timed vitrectomy is a suitable therapy for vitreo-retinal complications in ocular toxocariasis to improve prognosis and to confirm the diagnosis.

[Use of specific immunoglobulin G antibody avidity in the differential diagnosis of active and chronic Toxocara canis infections]

To differentiate between acute and past Toxocara canis infections, a modified enzyme-linked immunosorbent assay, based on the dissociation of antigen-antibody complex with 6 M urea solution was used to measure levels of avidity of specific immunoglobulin G antibody against Toxocara canis excretory-secretory antigen. IgG avidity index was determined in the sera of 212 patients, divided into two groups with various stages of Toxocara infection. Patients were classified according to time period, from the onset of clinical symptoms or first positive serology result. Low IgG avidity index was found in the sera of 6.6% of patients in the acute phase, and all samples from the chronic stage of infection were characterized by high avidity values above 0.5 (mean 0.74). It was documented, that the avidity test for specific IgG antibodies is a valuable diagnostic method that helps to distinguish the early from the later phase of Toxocara canis infection. Indications for anti-parasitic treatment according to immunological activity of Toxocara infection were discussed.

[Nosology and epidemiology of human toxocarosis--the recent situation in Austria]

Toxocara canis and T. cati are not only ubiquitously distributed parasites of dogs, foxes and cats, but may also infest humans, causing a great variety of symptoms and sometimes also severe diseases: the visceral larva migrans syndrome, the ocular larva migrans syndrome, covert toxocarosis, common toxocarosis, neurological toxocarosis, and some other clinical pictures (asthma bronchiale, epilepsy, rheumatoid arthritis) are considered to be induced by Toxocara species. Both Toxocara species are also widely distributed in Austrian dog, fox and cat populations; seroepidemiological studies carried out in Austria revealed seroprevalence rates of 3.7% among the normal human population and up to 44% among persons particularly exposed to those parasites (i.e. veterinarians, farmers). Although many Toxocara infestations do not cause severe clinical manifestations, a few dozens of toxocarosis patients have been registered every year during the last years; in reality, however, we have to assume that several hundreds of patients suffer from toxocarosis. This paper tries to give a synoptic overview of the nosology of this (still) largely almost unknown helminthozoonosis, moreover it summarizes the most important epidemiologic parameters, and presents the diagnostic and therapeutic possibilities available today.

[Clinical course of toxocarosis in children]

The aim of the study was to monitor the clinical course of T. canis infection in children with particular consideration of the estimation of infected children's immune system. The study comprised 52 children, aged 3 to 18 years, diagnosed and treated at the I Department of Paediatrics and Gastroenterology, Institute Polish Mother Health Centre, in whom infection with Toxocara canis larva was confirmed with serologic test. The control group included 38 children, aged 3 to 16 years in whom no infection with this parasite was detected in serologic test. In the investigated children subjective and physical examinations were performed, clinical symptoms, changes in organs, haematological, biochemical investigations and selected parameters of humoral and cellular immunity were analysed. In children with toxocarosis most frequently not localized abdominal pain, subfebrile body temperature and generalized lymphadenitis were observed. Significantly higher percentage of eosinophil cells and immunoglobulin E serum concentration with decreased percentage of lymphocytes CD3+, CD4+ and CD4/CD8 ratio were found in the investigated children. Toxocarosis diagnosis is difficult because its clinical symptoms are differentiated and not characteristic, what requires broadening of differential diagnosis concerning numerous entities.

Cross-reactivity between Anisakis simplex sensitization and visceral larva migrans by Toxocara canis

The aim of this work was to study cross-reactivity in the diagnosis of two related ascaridosis. Nineteen patients diagnosed with recidivous acute urticaria (RAU) caused by Anisakis simplex and 26 patients diagnosed with visceral larva migrans (VLM) caused by Toxocara canis were studied employing commercial diagnostic kits and "in house" assay kits. Cross-reactivity observed was greater when using "in house" assay kits, suggesting that T. canis excretory-secretory antigens were not only recognized by antibodies from patients with RAU but with greater intensity compared to the A. simplex excretory-secretory antigens.

[Larva migrans syndrome or ocular toxocariasis]

Thirteen cases of ocular toxocariasis attended in the Oftalmology Service of the Pediatric Hospital "Niño Jesús", from Córdoba; and in the Parasitology and Micology Cathedra of the Medicine Collegue of the University of Córdoba were studied from July 1993 till July 1995. The authors determine the needs of taking into account this parasitosis; above all in children and with the antecedent of contact with pets.

[Toxocariasis in Poznan region, Poland, in years 1990-2000]

The results of multidisciplinary studies on toxocariasis in Poznan region, Poland carried out in 1990-2000 in co-operation with CDC, Atlanta GA, USA are summarised as follows. In Poznan region toxocariasis in dogs, cats and foxes is common. Environmental contamination with Toxocara spp. eggs was higher in courtyards between apartment houses in the centres of cities than in sandboxes and in rural or recreational areas. High percentage of the T. cati eggs found raises the yet unanswered question how frequent is T. cati toxocariasis in humans? Seroepidemiological studies demonstrated a rather high percentage of positive results in urban population as well as in adults. The majority of toxocariasis cases in humans is asymptomatic even in the foci with a high soil contamination. Optic density OD405 = 1.200 in a commercial ELISA test was accepted as a border line between the toxocariasis cases usually asymptomatic and the cases, which might have symptoms. In toxocariasis a high correlation was found between the value of OD, eosinophilia and the clinical expression. A new classification of clinical toxocariasis was proposed, including incomplete larva migrans syndrome and neurotoxocariasis and an up-dated definition of covert toxocariasis. It was found that 5 days treatment with albendazole is equally effective as 3-weeks treatment with diethylcarbamazine. Considering the risk of ocular toxocariasis in non-intensive invasions one course of treatment with albendazole is suggested in every case of infection, even asymptomatic.

Visceral larva migrans mimicking lymphoma

We report a case of visceral larva migrans in an adult with fever, night sweats, weight loss, hilar and mediastinal lymphadenopathy, bilateral pleural effusion, and eosinophilia-mimicking lymphoma. Visceral larva migrans was diagnosed subsequently because of negative findings for malignancy and positive serologic test result for Toxocara canis. Progressive improvement was observed with albendazole therapy.

[Eosinophilia, diarrhea]

A 46-year-old Swiss woman presents with intermittent abdominal pain and persistent eosinophilia that is suggestive of helminthic etiology. Though her stay in Africa goes back > 35 years, an imported disease is a possibility. However, contact with a puppy suggests a locally acquired organism. Antibodies to filariae and Toxocara are demonstrated in the serum. Following treatment with albendazole 400 mg daily for 14 days the patient makes a full recovery, and the final diagnosis is active Toxocara canis infection.

[Manifestations of visceral and ocular symptoms of toxocariasis in a 6-year-old boy]

In the past 10 years we have examined 137 cases of toxocariasis, predominantly in children. Three cases were with unilateral ocular involvement. The article reviews a 6-year-old boy with left side strabismus and granulomatous chorioretinitis. Laboratory examinations revealed blood eosinophylia 24% and IgG against Toxocara canis larvae in titer 1:320 by indirect immunofluorescent assay. In epidemiologic anamnesis we concluded that about 4, 5-year-long geophagia was the source of infection.

Visceral larva migrans due to Ascaris suum which presented with eosinophilic pneumonia and multiple intra-hepatic lesions with severe eosinophil infiltration--outbreak in a Japanese area other than Kyushu

A 32-year-old man presented with the chief complaint of severe cough. Examination of peripheral blood showed a marked increase in eosinophils. Chest CT demonstrated multiple ground glass opacities in both lungs. Bronchoalveolar lavage showed abundant eosinophils. Abdominal CT demonstrated multiple low attenuation areas in the liver. Liver biopsy with ultrasonography revealed severe eosinophil infiltrations around the portal veins. Serologically, a multi-dot enzyme linked immunosorbent assay (DOT-ELISA) and ELISA inhibition test using microtiter plates were positive for Ascaris suum. Thus, visceral larva migrans due to Ascaris suum was diagnosed. Outbreaks of this disease in Japan have previously been confined to the Kyushu area. The present case which occurred outside that area, illustrates the importance of constant attention to the epidemiology of this disease.

Chronic eosinophilic pneumonia due to visceral larva migrans

A 38-year-old woman presented with worsening cough, blood eosinophilia, and pulmonary infiltrates. Bronchoalveolar lavage showed 96.4% eosinophils. The diagnosis of visceral larva migrans (VLM) was made based on the positive results in enzyme-linked immunosorbent assay for Toxocara canis together with clinical symptoms and laboratory data. Pulmonary infiltrates due to VLM generally manifest as a transient form of Löffler's syndrome or simple eosinophilic pneumonia mainly in children. Here we report an adult case of VLM, with pulmonary infiltrates pathologically proven to be eosinophilic pneumonia, which persisted for 7 weeks before anthelmintic treatment with albendazole and manifested as chronic eosinophilic pneumonia.