Myocarditis associated with visceral larva migrans due to Toxocara canis

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.

Toxocariasis-associated urinary system diseases: a systematic review of reported cases

BACKGROUND

Toxocariasis is a neglected tropical disease caused by Toxocara canis and Toxocara cati. Toxocara species can involve many organs, such as the brain, heart and lungs, however, the urinary system involvement of toxocariasis is largely unknown.

METHODS

We performed a systematic review to identify cases infected with urinary tract toxocariasis.

RESULTS

We identified seven cases that were eligible to be reviewed. Among the included citations, four studies reported bladder involvement and three reported kidney involvement. Fever, urinary, and abdominal presentations were amongst the most important clinical symptoms. Eosinophilic cystitis and nephrotic syndrome were the most common diagnoses.. The treatment regimen included a combination of anthelmintic drugs and steroids.

CONCLUSIONS

In cases of urinary tract presentations accompanied by eosinophilia or histopathologic findings suggestive of parasitic infection, toxocariasis should be included in the list of differential diagnoses, especially in endemic areas.

Brain food: rethinking food-borne toxocariasis

Human toxocariasis is a neglected tropical disease, which is actually global in distribution and has a significant impact on global public health. The infection can lead to several serious conditions in humans, including allergic, ophthalmic and neurological disorders such as epilepsy. It is caused by the common roundworm species Toxocara canis and Toxocara cati, with humans becoming accidentally infected via the ingestion of eggs or larvae. Toxocara eggs are deposited on the ground when infected dogs, cats and foxes defecate, with the eggs contaminating crops, grazing pastures, and subsequently food animals. However, transmission of Toxocara to humans via food consumption has received relatively little attention in the literature. To establish the risks that contaminated food poses to the public, a renewed research focus is required. This review discusses what is currently known about food-borne Toxocara transmission, highlighting the gaps in our understanding that require further attention, and outlining some potential preventative strategies which could be employed to safeguard consumer health.

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.

Toxocariasis and the clinical spectrum

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

Prevalence of Toxoplasma gondii and Toxocara canis Among Myositis Patients in the Southwest of Iran

INTRODUCTION

Parasitic myositis is caused by some parasites, such as Toxoplasma gondii) T. gondii (and Toxocara canis (T. canis). So, the aim of the study was to evaluate the prevalence T. gondii and T. canis in patients with myositis and healthy individuals.

METHODS

A total of 108 samples were randomly selected as the control (54 healthy individuals) and test (54 myositis patients) groups. IgG and IgM antibodies (Ab) against T. gondii and IgG Ab against T. canis were measured by the enzyme-linked immunosorbent assay (ELISA). The detection of chronic and acute toxoplasmosis was performed by the ELISA IgG avidity. The presence of T. gondii in the blood was evaluated using the nested polymerase chain reaction (nested-PCR).

RESULTS

Of 108, 33 (30.6%) cases were positive for IgG against T. gondii that 19 (35.2%) and 14 (25.9%) were observed in myositis patients and healthy individuals, respectively (P=0.296). Of 19 positive cases, 12 (63.2%) and 7 (36.8%) cases were detected as chronic and acute toxoplasmosis, respectively, while, all positive cases in the control group had chronic toxoplasmosis (P=0.013). One (1.9%) sample was positive for anti- T. gondii IgM and two (3.7%) samples were positive for IgG against T. canis by the ELISA that these positive cases were observed only in myositis patients (P=1.000 P=0.495, respectively). B1 T. gondii gene was amplified in 12 (63.2%) and 1 (7.1%) in myositis patients and healthy subjects (P=0.001).

CONCLUSION

Our findings showed that there was a relatively high prevalence of acute toxoplasmosis in myositis patients in comparison with the control subjects in the Southwest of Iran.

The Clinicopathological Profile of Eosinophilic Myocarditis

Eosinophilic myocarditis (EM) is a rare form of myocarditis. As there is extreme diversity in its manifestations, the true incidence is difficult to assess and no proper epidemiological criteria are present. It generally presents with a wide array of clinical manifestations. Clinical presentation tends to differ in cases and not all the patients show the same signs and symptoms. The etiology of EM often remains obscure but potential causes have been identified which may include hypersensitivity to drugs, exposure to certain viruses and parasites, and hyper-eosinophilic syndromes. Endomyocardial biopsy is considered to be a gold standard for the diagnosis of EM. Echocardiography, cardiac magnetic resonance, and bio markers particularly serum eosinophilic cationic protein concentrations are also known to aid in diagnosis. EM may lead to progressive, irreversible, and fatal myocardial damage if prompt diagnosis is not made and therapy is not initiated. The current treatment regimens include corticosteroids, cytotoxic agents, and immunosuppressive therapy. However, a proper treatment criterion is yet to be established.

Helminth Infections and Cardiovascular Diseases: Toxocara Species is Contributing to the Disease

Toxocariasis is the clinical term used to describe human infection with either the dog ascarid Toxocara canis or the feline ascarid Toxocara cati. As with other helminths zoonoses, the infective larvae of these Toxocara species cannot mature into adults in the human host. Instead, the worms wander through organs and tissues, mainly the liver, lungs, myocardium, kidney and central nervous system, in a vain attempt to find that, which they need to mature into adults. The migration of these immature nematode larvae causes local and systemic inflammation, resulting in the “larva migrans” syndrome. The clinical manifestations of toxocariasis are divided into visceral larva migrans, ocular larva migrans and neurotoxocariasis. Subclinical infection is often referred to as covert toxocariasis. One of the primary causes of death all around the world is cardiovascular disease that accounted for up to 30 percent of all-cause mortality. Cardiovascular disease and more precisely atherosclerotic cardiovascular disease, is predicted to remain the single leading cause of death (23.3 million deaths by 2030). A-quarter of people presenting the disease does not show any of the known cardiovascular risk factors. Therefore, there is considerable interest in looking for novel components affecting cardiovascular health, especially for those that could improve global cardiovascular risk prediction. This review endeavours to summarize the clinical aspects, new diagnostic and therapeutic perspectives of toxocaral disease with cardiovascular manifestations.

Endomyocardial involvement in asymptomatic sub-Saharan immigrants with helminth-related eosinophilia

Background

Among immigrants of sub-Saharan origin, parasitic infection is the leading cause of eosinophilia, which is generally interpreted as a defense mechanism. A side effect of the inflammatory mediators released by eosinophils is damage to host organs, especially the heart. The main objectives of this study were to i) assess cardiac involvement in asymptomatic sub-Saharan immigrants with eosinophilia, ii) relate the presence of lesions with the degree of eosinophilia, and iii) study the relationship between cardiac involvement and the type of causative parasite.

Methodology/Principle findings

In total, the study included 50 black immigrants (37 patients and 13 controls) from sub-Saharan Africa. In all subjects, heart structure and function were evaluated in a blinded manner using Sonos 5500 echocardiographic equipment. The findings were classified and described according to established criteria. The diagnostic criteria for helminthosis were those reported in the literature. Serum eosinophil-derived neurotoxin levels were measured using enzyme-linked immunosorbent assay. A significant association was found between the presence of eosinophilia and structural alterations (mitral valve thickening). However, the lack of an association between the degree of eosinophilia and heart valve disease and the absence of valve involvement in some patients with eosinophilia suggest the role of other factors in the appearance of endocardial lesions. There was also no association between the type of helminth and valve involvement.

Conclusions

We, therefore, suggest that transthoracic echocardiography be performed in every sub-Saharan individual with eosinophilia in order to rule out early heart valve lesions.

Endomyocardial fibrosis is characterized by fibrosis of the apical endocardium of the right ventricle, left ventricle, or both. Epidemiological studies of endomyocardial fibrosis indicate a predominance in tropical regions, with young people and men being affected predominantly. Little is known about the natural history and pathogenic factors of this condition. One of the most important factors is the presence of eosinophilia, which is mainly related to helminth infections. The aim of the study was to evaluate cardiac involvement in patients with absolute eosinophilia. We performed an echocardiographic study in asymptomatic sub-Saharan immigrants with eosinophilia and compared them with a group of control patients from the same region and of the same age. Our results suggest that eosinophilia associated with helminth infection (regardless of the causative microorganism) contributes to the asymptomatic phases of endomyocardial involvement. Treatment of these infections is simple, effective, and economical. Therefore, we suggest that all immigrant patients with eosinophilia undergo etiologic study and causal treatment as well as transthoracic echocardiography in order to rule out early damage.

Toxocariasis-associated cardiac diseases--A systematic review of the literature

Toxocariasis, caused by Toxocara canis or Toxocara catis, is a worldwide occurring parasitic disease, reaching high prevalences especially in tropical and subtropical countries. The clinical presentation can range from asymptomatic seropositivity to life threatenting disease, depending on the organ system involved. Cardiac involvement, one of the possible manifestations of human Toxocara spp. infection, is rarely reported in case reports. As far as we know, no systematic reviews of clinical presentations have been published till now and no clear recommendations regarding the treatment of Toxocara spp. infection involving the heart exist. In a systematic review of the literature, 24 published cases of Toxocara spp. infection involving the heart were identified. The cardiac entities described included myocarditis, pericarditis, and Loeffler's endocarditis. The clinical presentation ranged from asymptomatic or mild disease to life threatening myocarditis/pericarditis with heart failure or cardiac tamponade, leading to death. In most cases, the diagnosis was based on a combination of clinical, laboratory and radiological findings. Only in three of the nine cases in which histological analysis was performed (either pre- or post-mortem), granulomas or remnants of the parasite were detected. In the other six cases, findings were non-specific; the damage of the heart was equally caused by direct invasion of the larvae and by immunological reactions, either caused by the systemic hypereosinophilia or by the presence of the larvae in the tissue. The treatment regimen described mostly consisted of anthelmintic drugs in combination with corticosteroids. Even though dosage and duration of treatment varied widely, ranging from days to months, most patients were treated successfully. Cardiac involvement in Toxocara spp. infection is a rare but potentially life-threatening complication of a very common disease. The therapeutic regimens vary widely especially with regard to the duration of therapy, however, the combination of an anthelmintic drug and a corticosteroid appears to be a valuable option. For the daily clinical work, tissue manifestation by parasites should be considered in cases of unspecific organ manifestations, (i.e. heart, lungs, liver), accompanied by fever and eosinophilia with or without allergic skin rashes.

[Cardiovascular manifestations of human toxocariasis]

Toxocariasis is a parasitic infection produced by helminths that cannot reach their adult stage in humans. For their etiological species (Toxocara canis and Toxocara cati), man is a paratenic host. Infection by such helminths can produce a variety of clinical manifestations, such as: visceral larvae migrans syndrome, ocular larvae migrans syndrome and covert toxocariasis. In the visceral larvae migrans syndrome, the organs that are mainly involved include liver, lungs, skin, nervous system, muscles, kidneys and the heart. Regarding the latter, the importance of cardiovascular manifestations in toxocariasis, as well as its clinical relevance, has increasingly begun to be recognized. The current article is based on a systematic information search, focused mainly on the clinical and pathological aspects of cardiovascular manifestations in toxocariasis, including its pathophysiology, laboratory findings, diagnosis and therapeutical options, with the objective of highlighting its importance as a zoonosis and its relevance to the fields of cardiovascular medicine in adults and children.

Eosinophilic myocarditis associated with visceral larva migrans caused by Toxocara canis infection

A 41-year-old woman who was diagnosed with myocarditis presented eosinophilia. Since the antibody against Toxocara canis (T. canis) was positive, we diagnosed that she had visceral larva migrans due to T. canis associated with myocarditis. She was treated with oral albendazole and prednisolone for two weeks, eosinophil count and hepatic enzymes were normalized after completion of treatment. This is the first report of myocarditis caused by T. canis infection in Korea.

Toxocariasis masquerading as liver and lung metastatic nodules in patents with gastrointestinal cancer: clinicopathologic study of five cases

BACKGROUND

There are sporadic reports in the literature in which radiologic liver and lung lesions found incidentally during follow-up metastatic surveillance were shown to be caused by toxocariasis.

AIMS

The objective of the work discussed in this report was to identify common clinical and histopathological features of toxocariasis resembling metastatic nodules in five patients with gastrointestinal cancer.

METHODS

We retrospectively analyzed clinical features of five gastrointestinal cancer patients with liver or lung nodules mimicking metastasis. Serologic tests for parasitic infestations and pathologic examinations were performed.

RESULTS

All five patients were males and three patients had gastric cancer and two had colorectal cancer. All the cases of toxocariasis were confirmed serologically. On follow-up imaging, the lesions improved or resolved, suggestive of the phenomenon of visceral larva migrans. In two patients, liver biopsy was performed and showed eosinophilic abscess.

CONCLUSION

Serologic tests and liver or lung biopsy should be performed aggressively to exclude toxocariasis when patients with underlying gastrointestinal cancer present with hepatic or pulmonary nodules associated with eosinophilia, particularly if the patients have a clinical history of raw animal liver ingestion. Curative surgical intervention should not be excluded just because of multiple nodules in the liver or the lungs.

Clinical features and outcomes of eosinophilic myocarditis patients treated with prednisolone at a single institution over a 27-year period

BACKGROUND

Eosinophilic myocarditis is a rare clinical entity characterized by eosinophilia and myocardial inflammation with infiltrating eosinophils. The prognosis of patients with eosinophilic myocarditis is difficult to determine due the disease's rarity and varied causes; consequently, standard treatment has not been established.

OBJECTIVE

To elucidate the clinical characteristics and treatment outcome of eosinophilic myocarditis, we retrospectively studied 7 patients fulfilling the criteria of the Japanese Circulation Society for eosinophilic myocarditis from among 64 patients admitted to our institution with eosinophilia over a 27-year period.

RESULTS

The patients' ages at diagnosis ranged from 36 to 83 years (median: 52 years). The etiologies of the eosinophilic myocarditis were found to be idiopathic (3 patients), Churg-Strauss syndrome (2 patients), parasitic infection (1 patient) and chronic eosinophilic leukemia (CEL) (1 patient). In addition to treatment for the underlying disease, we also administered prednisolone at a dose appropriate to the disease severity (6 of 7 patients). The patient who was diagnosed with a parasitic infection was treated only with albendazole, because eosinophilic myocarditis was mild. The patient with CEL was positive for the FIP1 L1-PDGFRα fusion gene and was treated with imatinib. Eosinophilic cationic protein was a useful marker for assessing disease activity and treatment efficacy. At the end of the study, of the seven patients treated, six were alive (86%), giving a mean survival time of 37 ± 40 months (mean ± SD).

CONCLUSION

Because eosinophilic myocarditis has various etiologies, it is essential to identify the etiology of the underlying disease. In the majority of eosinophilic myocarditis patients, administration of prednisolone may be an effective therapeutic modality producing a good outcome.

Pulmonary toxocariasis masquerading as metastatic tumor nodules in a child with osteosarcoma

A 14-year-old male, who completed chemotherapy following limb salvage surgery for osteosarcoma approximately 2 years ago, was seen for routine follow-up. A CT scan revealed new scattered multifocal nodular lesions. An ultrasonography-guided percutaneous needle biopsy was done to confirm pulmonary metastasis of the underlying osteosarcoma. The lung biopsy showed findings of eosinophilic pneumonia with no evidence of malignancy. Peripheral eosinophilia was also noted. When a more thorough history revealed frequent intake of raw cow liver, we diagnosed pulmonary toxocariasis by ELISA for specific serum IgG antibody.

Ocular lesions in gerbils (Meriones unguiculatus) infected with low larval burden of Toxocara canis: observations using indirect binocular ophthalmoscopy

To study the frequency of ocular lesions in 30 gerbils infected with 100 embryonated eggs of Toxocara canis, indirect binocular ophthalmoscopy was performed 3, 10, 17, 24, 31 and 38 days after infection. All the animals presented larvae in the tissues and 80% presented ocular lesions. Hemorrhagic foci in the choroid and retina were present in 92% of the animals with ocular lesions. Retinal exudative lesions, vitreous lesions, vasculitis and retinal detachment were less frequent. Mobile larvae or larval tracks were observed in four (13.3%) animals. Histological examination confirmed the ophthalmoscopic observations, showing that the lesions were focal and sparse. In one animal, there was a larva in the retina, without inflammatory reaction around it. The results demonstrated that gerbils presented frequent ocular lesions after infection with Toxocara canis, even when infected with a small number of embryonated eggs. The lesions observed were focal, consisting mainly of hemorrhages with signs of reabsorption or inflammation in different segments of eye, and differing from the granulomatous lesions described in ocular larva migrans in humans.

Fulminant eosinophilic myocarditis associated with visceral larva migrans caused by Toxocara canis infection

A 19-year-old man was transferred to hospital because of myocarditis with cardiogenic shock. Echocardiography showed a left ventricular ejection fraction of 23.8% and an intermediate amount of pericardial effusion. The patient immediately received an intra-aortic balloon pump and percutaneous cardiopulmonary support. Right ventricular endomyocardial biopsy was performed in the acute phase and showed extensive eosinophilic inflammatory cell infiltration, severe interstitial edema and moderate myocardial necrosis. High-dose corticosteroids were administered. Because the patient's antibody titer against Toxocara canis was high and his symptoms had appeared after eating raw deer meat, the diagnosis was fulminant eosinophilic myocarditis caused by a hypersensitivity reaction to visceral larval migrans. After starting high-dose corticosteroids, the ejection fraction dramatically improved, the eosinophilia decreased and the patient made a full recovery.

Bacterial, fungal, parasitic, and viral myositis

Infectious myositis may be caused by a broad range of bacterial, fungal, parasitic, and viral agents. Infectious myositis is overall uncommon given the relative resistance of the musculature to infection. For example, inciting events, including trauma, surgery, or the presence of foreign bodies or devitalized tissue, are often present in cases of bacterial myositis. Bacterial causes are categorized by clinical presentation, anatomic location, and causative organisms into the categories of pyomyositis, psoas abscess, Staphylococcus aureus myositis, group A streptococcal necrotizing myositis, group B streptococcal myositis, clostridial gas gangrene, and nonclostridial myositis. Fungal myositis is rare and usually occurs among immunocompromised hosts. Parasitic myositis is most commonly a result of trichinosis or cystericercosis, but other protozoa or helminths may be involved. A parasitic cause of myositis is suggested by the travel history and presence of eosinophilia. Viruses may cause diffuse muscle involvement with clinical manifestations, such as benign acute myositis (most commonly due to influenza virus), pleurodynia (coxsackievirus B), acute rhabdomyolysis, or an immune-mediated polymyositis. The diagnosis of myositis is suggested by the clinical picture and radiologic imaging, and the etiologic agent is confirmed by microbiologic or serologic testing. Therapy is based on the clinical presentation and the underlying pathogen.

Fever of unknown origin due to zoonoses

Fevers of unknown origin have been classified as classic, nosocomial, immune-deficient, and HIV-related. More than half of the 1407 human pathogens are zoonotic, making zoonotic infections an important subcategory in each of the classifications. This article describes both common and unusual zoonoses causing fevers of unknown origin. Simian immune virus is considered as a possible emerging infection. For special populations (the homeless, zoophiliacs, those whose occupation or leisure brings them in close contact with oceans or lakes, and veterinarians), zoonotic infection potentials are discussed.

Pulmonary Lesions Associated With Visceral Larva Migrans Due toAscaris suumorToxocara canis: Imaging of Six Cases

OBJECTIVE

The objective of our study was to evaluate chest radiographic and CT findings of patients with pulmonary lesions associated with visceral larva migrans due to Ascaris suum or Toxocara canis. CT investigation was focused on the location, size, contour, and internal features of the lesions; migration of lesions; mediastinal lymphadenopathy; and pleural effusion.

CONCLUSION

Pulmonary visceral larva migrans appears on CT as multifocal subpleural nodules with halo or ground-glass opacities and ill-defined margins.