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Toxocariasis

Disease Details

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Description: Toxocariasis is a parasitic infection caused by the larvae of Toxocara worms, often resulting from contact with contaminated soil, animal feces, or consumption of undercooked meat, leading to symptoms ranging from mild to severe, including organ damage.
Type: Toxocariasis is a parasitic infection. It is not genetically transmitted; rather, it is acquired through ingestion of soil or food contaminated with the eggs of Toxocara larvae, usually from the feces of infected dogs or cats.
Signs And Symptoms: Physiological reactions to Toxocara infection depend on the host's immune response and the parasitic load. Most cases of Toxocara infection are asymptomatic, especially in adults. When symptoms do occur, they are the result of migration of second-stage Toxocara larvae through the body.
Prognosis: The prognosis for toxocariasis generally depends on the severity and type of infection. In most cases, especially with minimal exposure, the infection can be mild and self-limiting, resolving on its own or with treatment. However, in cases where the infection leads to visceral larva migrans (where organs are impacted) or ocular larva migrans (where the eyes are affected), complications can be more serious. Prompt medical treatment typically results in a good prognosis, although some patients may experience lingering symptoms or complications. Regular follow-up with a healthcare provider is recommended to monitor and manage the condition effectively.
Onset: Toxocariasis is a parasitic disease caused by the larvae of Toxocara worms. The onset of symptoms can vary depending on whether the infection is mild or severe. For mild cases, symptoms might not appear at all or may take weeks to months to develop. In more severe cases, symptoms can manifest within weeks. Common symptoms include fever, coughing, wheezing, and abdominal pain. In ocular toxocariasis, symptoms such as vision loss and eye inflammation can occur.
Prevalence: The global prevalence of toxocariasis is not well-defined, but it is estimated to infect up to 13.9% of the population in some regions, particularly in areas where there is poor sanitation and a high degree of contact with soil contaminated by animal feces. The prevalence may be higher in children and in communities with a lot of pet dogs and cats.
Epidemiology: Humans are accidental hosts of Toxocara, yet toxocariasis is seen throughout the world. Most cases of toxocariasis are seen in people under the age of twenty. Seroprevalence is higher in developing countries, but can be considerable in first world countries, as well. In Bali, St. Lucia, Nepal and other countries, seroprevalence is over fifty percent. Previous to 2007, the U.S. seroprevalence was thought to be around 5% in children. However, Won et al. discovered that U.S. seroprevalence is actually 14% for the population at large. In many countries, toxocariasis is considered very rare. Approximately 10,000 clinical cases are seen a year in the U.S., with ten percent being OLM. Permanent vision loss occurs in 700 of these cases.Young children are at the greatest risk of infection because they play outside and tend to place contaminated objects and dirt in their mouths. Dog ownership is another known risk factor for transmission. There is also a significant correlation between high Toxocara antibody titers and epilepsy in children.Parasitic loads as high as 300 larvae in a single gram of liver have been noted in humans. The "excretory–secretory antigens of larvae ... released from their outer epicuticle coat [and] ... readily sloughed off when bound by specific antibodies" incite the host's immune response. The tipping point between development of VLM and OLM is believed to be between 100 and 200 larvae. The lighter infection in OLM is believed to stimulate a lower immune response and allow for migration of a larva into the eye. Larvae are thought to enter the eye through the optic nerve, central retinal artery, short posterior ciliary arteries, soft tissues, or cerebrospinal fluid. Ocular granulomas that form around a larva typically are peripheral in the retina or optic disc.Visceral larva migrans seems to affect children aged 1–4 more often while ocular larva migrans more frequently affects children aged 7–8. Between 4.6% and 23% of US children have been infected with the dog roundworm egg. This number is much higher in other parts of the world, in tropical countries there is seroprevalence of up to 80–90%, such as Colombia, where up to 81% of children have been infected, or Honduras where seroprevalence among school-age children was reported to be 88%. In the western part of the world, seroprevalence is lower, around 35–42%.
Intractability: Toxocariasis is not generally considered intractable. It is a parasitic infection caused by Toxocara larvae, typically acquired from soil contaminated by the feces of infected dogs or cats. Treatment usually involves antiparasitic medications such as albendazole or mebendazole, which are effective in eradicating the larvae. Early diagnosis and treatment are important to prevent complications, particularly in severe cases involving organs like the eyes or central nervous system.
Disease Severity: Toxocariasis is typically caused by the larvae of the Toxocara canis or Toxocara cati worms. The severity of the disease can vary widely depending on several factors such as the number of larvae ingested and the individual's immune response. Common symptoms include fever, coughing, enlarged liver, and eye problems, which can lead to vision loss in severe cases. In most cases, toxocariasis is mild and can be treated effectively with anti-parasitic medications. However, if left untreated or in severe infections, it can lead to significant complications, particularly involving the eyes or central nervous system.
Healthcare Professionals: Disease Ontology ID - DOID:9790
Pathophysiology: Toxocariasis is caused by the larvae of the Toxocara canis or Toxocara cati roundworms. The primary hosts for these parasites are dogs and cats, respectively. Humans become accidental hosts through ingestion of embryonated eggs from contaminated soil, water, or food.

Once inside the human body, the eggs hatch in the intestine, releasing larvae that can migrate through various tissues. This migration can result in two main forms of the disease:

1. **Visceral Larva Migrans (VLM)**: The larvae invade organs like the liver, lungs, and heart, causing symptoms such as fever, fatigue, coughing, wheezing, and abdominal pain.

2. **Ocular Larva Migrans (OLM)**: The larvae specifically invade the eye, leading to symptoms such as vision loss, eye inflammation, and retinal damage.

The immune response to the migrating larvae leads to inflammation and tissue damage, which are responsible for the clinical manifestations of toxocariasis.
Carrier Status: Toxocariasis is a zoonotic infection caused primarily by the larvae of the Toxocara canis or Toxocara cati roundworms. Humans become accidental hosts by ingesting infective eggs from contaminated soil, water, or food. There is no carrier status in humans for toxocariasis, as it is not a condition where asymptomatic carriers transmit the disease to others.
Mechanism: Toxocariasis is caused by the larvae of Toxocara canis or Toxocara cati, which are parasitic roundworms commonly found in dogs and cats. The disease occurs when humans inadvertently ingest embryonated eggs from contaminated soil, food, or water.

**Mechanism:**
1. **Ingestion and Larval Migration:** After ingestion, Toxocara eggs hatch in the small intestine, releasing larvae that penetrate the intestinal wall.
2. **Systemic Distribution:** The larvae enter the bloodstream and migrate to various tissues, including the liver, lungs, eyes, and central nervous system.
3. **Persistent Larvae:** In human tissues, the larvae cause inflammation, granuloma formation, and eosinophilia, leading to a wide range of symptoms depending on the site of infection.

**Molecular Mechanisms:**
1. **Larval Hatching and Penetration:** The eggs hatch in response to stomach acids and enteric signals, releasing larvae that use enzymes like proteases to penetrate the intestinal mucosa.
2. **Immune Evasion:** Toxocara larvae secrete proteins that modulate host immune responses. These include antioxidant enzymes to neutralize reactive oxygen species and surface antigens to evade detection by the immune system.
3. **Inflammation and Immune Response:** The presence of larvae induces a Th2-biased immune response, characterized by the production of cytokines such as IL-4, IL-5, and IL-13, which stimulate eosinophil proliferation and activation.
4. **Granuloma Formation:** Immune cells, particularly eosinophils, macrophages, and lymphocytes, form granulomas around the larvae to contain the infection. These granulomas contribute to tissue damage and the clinical manifestations of toxocariasis.
Treatment: Toxocariasis will often resolve itself, because the Toxocara larvae cannot mature within human hosts. Corticosteroids are prescribed in severe cases of VLM or if the patient is diagnosed with OLM. Either albendazole (preferred) or mebendazole (“second line therapy”) may be prescribed. Granulomas can be surgically removed, or laser photocoagulation and cryoretinopexy can be used to destroy ocular granulomas.Visceral toxocariasis in humans can be treated with antiparasitic drugs such as albendazole or mebendazole, tiabendazole or diethylcarbamazine usually in combination with anti-inflammatory medications. Steroids have been utilized with some positive results. Anti-helminthic therapy is reserved for severe infections (lungs, brain) because therapy may induce, due to massive larval killing, a strong inflammatory response. Treatment of ocular toxocariasis is more difficult and usually consists of measures to prevent progressive damage to the eye.
Compassionate Use Treatment: Toxocariasis is primarily treated with antiparasitic medications such as albendazole or mebendazole. For severe cases or those involving ocular or visceral larva migrans, corticosteroids may also be used to reduce inflammation.

Regarding compassionate use or experimental treatments, these are typically considered when standard therapies are ineffective or not well-tolerated:

1. **Compassionate Use Treatments**: These allow access to investigational drugs outside clinical trials for patients with serious conditions who have no other treatment options. For toxocariasis, specific compassionate use might rarely be necessary since standard antiparasitic drugs are generally effective. However, in rare, severe cases involving significant organ damage, investigational antiparasitics or immunomodulatory therapies might be considered through this route.

2. **Off-label or Experimental Treatments**: Thiabendazole, an older anthelmintic, has seen some off-label use although it is less common due to higher toxicity compared to albendazole or mebendazole. Other experimental approaches might include newer antiparasitic drugs under investigation in clinical studies or adjunct treatments aimed at modulating the immune response more effectively.

Any consideration of experimental or compassionate use treatments typically involves a thorough evaluation by healthcare providers, including regulatory and ethical assessments.
Lifestyle Recommendations: For toxocariasis, lifestyle recommendations include:

1. **Hygiene Practices**: Regularly wash hands with soap and water, especially after handling soil, pets, or raw meat. Teach children good hand hygiene.

2. **Pet Care**: Deworm pets regularly and ensure they receive regular veterinary check-ups. Dispose of pet feces promptly and hygienically.

3. **Food Safety**: Wash fruits and vegetables thoroughly before eating. Cook meat thoroughly to kill any potential parasites.

4. **Avoid Geophagia**: Discourage children from eating soil or putting dirty objects in their mouths.

5. **Safe Play Areas**: Ensure children's play areas are free from animal feces. Sandboxes should be covered when not in use to prevent contamination by animals.

6. **Yard Maintenance**: Keep yards clean and free from animal waste.

Implementing these measures can help reduce the risk of contracting toxocariasis.
Medication: Toxocariasis is typically treated with antiparasitic medications such as albendazole or mebendazole. These medications help to eliminate the parasitic larvae from the body. In some cases, especially where there is significant inflammation or ocular involvement, corticosteroids may also be prescribed to manage symptoms and reduce inflammation.
Repurposable Drugs: Toxocariasis, caused by the parasitic larvae of Toxocara canis or Toxocara cati, can be challenging to treat. Repurposable drugs for toxocariasis include:

1. **Albendazole**: This anti-parasitic medication inhibits the growth of nematodes.
2. **Mebendazole**: Another anti-parasitic drug effective against a variety of helminths, including Toxocara species.
3. **Diethylcarbamazine (DEC)**: Originally used for filarial infections, it can also be used in cases of toxocariasis.

Repurposing existing drugs like these can optimize the treatment of toxocariasis due to their known safety profiles and mechanisms of action against parasitic infections.
Metabolites: Toxocariasis is a parasitic disease caused by roundworms of the genus Toxocara. Specifically, it is caused by the larvae of Toxocara canis (from dogs) or Toxocara cati (from cats). The disease is primarily associated with the larvae migrating in human tissues, causing a condition known as visceral larva migrans or ocular larva migrans depending on the affected area.

Metabolites: In the context of toxocariasis, specific metabolites related to the presence of Toxocara larvae have not been clearly identified. However, the presence of elevated immunoglobulin E (IgE) and eosinophilia (increased eosinophils in blood or tissues) are common immunological responses seen in infected individuals.

Nan: "Nan" could be a typo or abbreviation that is not standard in the context of toxocariasis. If you are referring to nanotechnology or nanoparticles, there isn’t current mainstream use of nanotechnology in diagnosing or treating toxocariasis. The diagnosis typically relies on serological tests (such as enzyme-linked immunosorbent assay, ELISA) to detect specific antibodies against Toxocara larvae and imaging studies if organ involvement is suspected. Treatment usually involves anti-parasitic medications like albendazole or mebendazole.
Nutraceuticals: Toxocariasis is a parasitic infection caused by Toxocara larvae, commonly transmitted through the ingestion of contaminated soil or undercooked meat. While traditional treatment involves antiparasitic medications, there's limited scientific evidence supporting the effectiveness of nutraceuticals in treating toxocariasis. Research on the application of nanotechnology for this disease is still in its early stages. If you suspect toxocariasis, consult a healthcare professional for appropriate diagnosis and treatment.
Peptides: Toxocariasis is a parasitic infection caused by the larvae of Toxocara canis or Toxocara cati, which are roundworms typically found in dogs and cats. There are no specific peptides used for the treatment or diagnosis of toxocariasis. Nanotechnology has potential applications in diagnosing and treating parasitic infections, but there are no established nanomedical treatments or diagnostic techniques specifically for toxocariasis as of now. Treatment typically involves antiparasitic medications such as albendazole or mebendazole.