toxascariasis

Toxocariasis is an infection caused by the ingestion of larvae of the dog roundworm Toxocara canis or the cat roundworm Toxocara cati. This infection can cause a range of symptoms, including fever, eosinophilia, urticaria, enlarged lymph nodes, cough, bronchospasm, wheezing, abdominal pain, headaches, and/or hepatosplenomegaly.

The manifestations of toxocariasis reflect the number of migrating Toxocara larvae, where the larvae have migrated in the body, and the degree of immune response and inflammation that developed in response to the presence of the larvae. Many infections are asymptomatic. In heavy infections, large numbers of larvae may migrate through the liver, lungs, or other internal organs, causing various symptoms.

Toxocariasis can spread to people through contact with the feces (poop) of dogs and cats with roundworm. Roundworm eggs are carried in animal feces and can get into peoples' mouths through contaminated dirt or unwashed hands. In rare cases, people may get infected if they eat undercooked or raw meat like lamb or rabbit.

The infection is caused by a series of related nematode species (ascarids) that routinely infect dogs and cats throughout the world [4]. The most common helminth infection in many countries is toxocariasis, which is a worldwide helminth zoonosis caused by roundworms of the genus Toxocara [9].

There are three clinical forms of toxocariasis: visceral larva migrans (VLM), ocular larva migrans (OLM), and subcutaneous larva migrans (SLM). Visceral larva migrans is characterized by the presence of larvae in various organs, such as the liver, lungs, or other internal organs. Ocular larva migrans is usually unilateral and has no or very mild systemic manifestations [15].

Diagnosis of toxocariasis is based on clinical, epidemiologic, and serologic findings. For visceral larva migrans (VLM), enzyme immunoassay (EIA) for antibodies against Toxocara is recommended to confirm the diagnosis.

Toxocariasis, also known as toxascariasis, is a parasitic infection caused by the Toxocara parasite. The signs and symptoms of toxocariasis can vary depending on the affected organ and the host's immune response.

Common Symptoms:

• Fever [1]
• Cough or wheezing [2], [3], [11]
• Abdominal pain [2], [4]
• Enlarged liver [2], [5]
• Skin rash [2], [6]
• Pneumonia [7], [12]
• Fatigue [12]

Ocular Toxocariasis:

• Irritation or redness of the eye [3], [8]
• Seeing spots or flashes of light [4]
• Loss of vision [4]
• An abnormally colored pupil [4]

Visceral Larva Migrans (VLM):

• Fever, anorexia, hepatosplenomegaly, rash, pneumonitis, and asthmatic symptoms [5]
• Hepatomegaly and splenomegaly may also be present [7], [12]

Neurotoxocariasis:

• Variable appetite or anorexia
• Vomiting (especially after feeding)
• Diarrhea alternated with constipation
• Growth disturbances

It's worth noting that many infections are asymptomatic, and the symptoms can vary depending on the number of migrating larvae, the affected organ, and the host's immune response. If you suspect you have toxocariasis, it's essential to consult a healthcare professional for proper diagnosis and treatment.

References: [1] - Context result 1 [2] - Context result 2 [3] - Context result 3 [4] - Context result 4 [5] - Context result 5 [6] - Context result 6 [7] - Context result 7 [8] - Context result 8 [11] - Context result 11 [12] - Context result 12

Diagnostic Tests for Toxocariasis

Toxocariasis, also known as toxocara infection or visceral larva migrans (VLM), is a parasitic disease caused by the larvae of the Toxocara species. Diagnosing toxocariasis can be challenging due to its nonspecific symptoms and the lack of specific diagnostic tests. However, several diagnostic methods are available to confirm the presence of this infection.

Serologic Tests

The recommended serologic test for toxocariasis is an enzyme-linked immunosorbent assay (ELISA) using larval-stage antigens [1][2]. This test detects antibodies against Toxocara in the blood, which can indicate a current or past infection. ELISA is considered the most sensitive and specific test for diagnosing toxocariasis.

Other Diagnostic Tests

In addition to serologic tests, other diagnostic methods may be used to confirm toxocariasis:

• Immunoblot: This test detects antibodies against Toxocara in the blood [6].
• Precipitin Test: Although this test is subject to cross-reactions with common antigens of the larvae and blood group substance A, it can still be used as a diagnostic tool [14].
• CT or MRI Scans: These imaging tests can show multiple, ill-defined lesions in the liver or subpleural nodules in the chest, which may indicate toxocariasis [8].

Clinical Evaluation

Diagnosis of toxocariasis also involves clinical evaluation and patient history. A healthcare provider will perform a physical examination to assess symptoms such as fever, fatigue, coughing, and abdominal pain [4][13]. They may ask about possible exposure to Toxocara larvae and request a blood test to check for evidence of toxocariasis.

Blood Tests

A blood test can be used to detect antibodies against the parasite, which confirms the diagnosis of toxocariasis. This test is particularly useful in cases where other symptoms are present [13].

In summary, diagnostic tests for toxocariasis include serologic tests such as ELISA and immunoblot, as well as clinical evaluation and imaging tests like CT or MRI scans. A blood test can also be used to detect antibodies against the parasite.

References:

[1] Toxocara serology test is a referred-out test performed at the NRCP using a commercial indirect enzyme immunoassay (ELISA) using Toxocara larvae antigens [9].

[2] The recommended serologic test for toxocariasis is an enzyme-linked immunosorbent assay using larval-stage antigens [15].

[3] Diagnostic tests for VLM are primarily immunological [14].

[4] A doctor may suspect toxocariasis in a person who has an enlarged liver, inflammation of the lungs, a fever, and high levels of eosinophils (a type of white blood cell) [13].

[5] The diagnosis of toxocariasis is confirmed by identifying Toxocara antibodies in the blood [13].

[6] Immunoblot test detects antibodies against Toxocara in the blood [6].

[7] Precipitin Test is subject to cross-reactions with common antigens of the larvae and blood group substance A [14].

[8] CT or MRI scans can show multiple, ill-defined lesions in the liver or subpleural nodules in the chest [8].

[9] Toxocara serology test is a referred-out test performed at the NRCP using a commercial indirect enzyme immunoassay (ELISA) using Toxocara larvae antigens [9].

[10] Diagnosis. Toxocariasis can be hard to diagnose because its symptoms look similar to the symptoms of other infections [10].

Treatment Options for Toxocariasis

Toxocariasis, an infection caused by the Toxocara parasite, can be treated with various medications. The primary goal of treatment is to eliminate the parasite from the body and alleviate symptoms.

• Anthelmintic Drugs: Mebendazole and albendazole are commonly used anthelmintic drugs to treat toxocariasis. These medications work by killing the Toxocara larvae in the body [1, 3, 7].
• Corticosteroids: Corticosteroids may be prescribed to reduce inflammation and alleviate symptoms such as wheezing or other allergic reactions [4, 11].
• Ivermectin: Ivermectin has been sporadically used to treat human toxocariasis due to its effectiveness and few side effects [9].

Treatment Duration and Considerations

The optimal duration of treatment with albendazole or mebendazole is undefined. However, prolonged use (weeks to months) of these medications may lead to the development of pancytopenia in some patients [11]. Treatment typically involves a 5-day course of albendazole, which may be supplemented with corticosteroids to suppress allergic reactions.

Treatment for Specific Cases

• Visceral Toxocariasis: Visceral toxocariasis can be treated with antiparasitic drugs such as albendazole or mebendazole [13].
• Ocular Toxocariasis: Treatment of ocular toxocariasis is more difficult and usually consists of measures to prevent progressive damage to the eye. Optimal duration of treatment with albendazole or mebendazole for ocular toxocariasis is undefined [11].

References

[1] JF Magnaval, et al. (2022) - Four benzimidazole drugs can be used in humans: ABZ, mebendazole (MBZ), thiabendazole (TBZ) and triclabendazole...

[3] Toxocariasis - Etiology, pathophysiology, symptoms, signs, ... Treatment of Toxocariasis. Symptomatic treatment.

[7] D Despommier (2003) - Albendazole is the treatment of choice for toxocariasis.

[9] JF Magnaval (2022) - Because ivermectin may be given in a single 12 mg dose and has few side effects...

[11] Treatment and recovery. Treat visceral toxocariasis with antiparasitic drugs such as albendazole or mebendazole.

Note: The references provided are based on the search results within the context.

Differential Diagnosis of Toxocariasis

Toxocariasis, an infection caused by the ingestion of larvae of the dog roundworm Toxocara canis or the cat roundworm Toxocara cati, presents a challenge in diagnosis due to its nonspecific symptoms. The differential diagnosis for toxocariasis is broad and includes various conditions that may cause similar clinical manifestations.

Conditions to Consider

• Amebic Meningoencephalitis: A rare but serious infection caused by the amoeba Naegleria fowleri, which can lead to inflammation of the brain and meninges.
• Angioedema: A condition characterized by sudden swelling of the skin and mucous membranes, often accompanied by abdominal pain and respiratory distress.
• Ascariasis: An infection caused by the large roundworm Ascaris lumbricoides, which can lead to intestinal obstruction and other complications.
• Aspergillosis: A fungal infection that can cause a range of symptoms, including coughing, fever, and shortness of breath.
• Asthma: A chronic respiratory condition characterized by recurring episodes of wheezing, coughing, and shortness of breath.
• Cardiac Tumor Imaging and Diagnosis: A condition where tumors or masses form on the heart, which can lead to various symptoms depending on their location and size.

Other Considerations

• Ocular toxocariasis is a rare infection caused by roundworms, Toxocara canis and Toxocara cati. It was first recognized to be associated with dogs in the 1940s.
• The diagnosis of an active covert toxocariasis relies upon indirect arguments, e.g., the presence of otherwise unexplained symptoms along with blood eosinophilia and/or elevated levels of eosinophil cationic protein (ECP).
• Coat’s disease and retinoblastoma are the 2 main differential diagnoses. However, there is generally no calcification in ocular toxocariasis.
• The diagnosis is made on enzyme-linked immunosorbent essay (ELISA) test on blood or vitreous aspirate.

Confirming Diagnosis

The diagnosis of toxocariasis is confirmed by identifying Toxocara antibodies in the blood. Rarely, a sample of liver or other tissue is obtained and examined (biopsied) for evidence of larvae or inflammation resulting from the infection.

References

• [1] Toxocariasis refers to human infection caused by roundworms that are not natural human parasites, but rather are canine or feline parasites.
• [2] Diagnosis of VT and OT is based on clinical evaluation, patient history, and laboratory testing. The recommended laboratory test is serology to detect the presence of Toxocara antibodies in the blood.

Sources

• [1] PF Weller · Cited by 9 — Toxocariasis refers to human infection caused by roundworms that are not natural human parasites, but rather are canine or feline parasites.
• [2] Jul 12, 2024 — Diagnosis of VT and OT is based on clinical evaluation, patient history, and laboratory testing. The recommended laboratory test is serology to detect the presence of Toxocara antibodies in the blood.

Additional Information

To improve the management of toxocariasis, it is essential to distinguish this disease from similar conditions. This can be achieved by considering the differential diagnosis mentioned above and using appropriate diagnostic tests to confirm the presence of Toxocara infection.