Common Questions About Toxocariasis
FAQS: SYMPTOMS, DIAGNOSIS, TREATMENT, AND PREVENTION
What is Toxocariasis? Toxocariasis is an infection caused by parasitic roundworms commonly found in the intestines of dogs and cats. The Center for Disease Control (CDC) estimates that almost 14 percent of the US population has antibodies to the parasite (Toxocara), meaning that tens of millions of people in the United States have been exposed to the disease. Worldwide, toxocariasis ranks as one of the most common infections.
How is Toxocariasis spread?
Toxocariaisis is a zoonotic disease, meaning it can be transferred from animals to humans. Toxocara parasites are found in the intestines of dogs, cats, and foxes. Animals shed the parasite’s eggs through their feces, and the infection passes to other animals or people through the ingestion of dirt contaminated with parasitic eggs. More rarely, people can contract the disease by eating undercooked meat contaminated with Toxocara larvae. Puppies and kittens can also contract the disease in utero or through their mother’s milk. Toxocara larvae are only infectious after 2-5 weeks after being expelled in an animal’s feces. Thus, infection does not occur from contact with fresh feces. In addition, the disease cannot be spread through human-to-human contact.
What are the symptoms of Toxocariasis?
Many people infected with toxocariasis do not develop any symptoms at all. When symptoms do develop, they include mild cough, high fever, stomach pain, and headache. More severe symptoms can occur if the parasite infects the liver, lungs, eyes, or brain; these symptoms include fatigue, loss of appetite and subsequent weight loss, wheezing and difficulty breathing, blurred or cloudy vision, red and painful eyes, and seizures. Severe symptoms are most common in young children.
Symptoms of toxocariasis in dogs and cats include abdominal swelling and pain, diarrhea, loss of appetite and subsequent weight loss, anemia, fatigue, cough, nasal discharge, difficulty breathing, and the development of a rough coat. These symptoms, while serious, are rarely fatal; however, animals can sometimes develop intestinal blockages or perforation of the intestinal wall, resulting in death. This occurs most frequently in young puppies and kittens.
How is it Diagnosed?
In dogs and cats, toxocariasis is diagnosed by examining the animal’s feces to detect either adult worms or worm eggs. In humans, toxocariasis can more be difficult to diagnose with certainty.
In most cases, if your doctor suspects toxocariasis infection, a blood sample will be taken to test for Toxocara antibodies. However, serologic tests may not always be accurate, since antibody responses will vary depending on the location and number of worms present in a person’s body. If toxocariasis is suspected and you are experiencing ocular symptoms, such as vision loss or headaches, an eye exam may also be used to detect the presence of parasites.
What are the different types of Toxocariaisis tests?
As mentioned previously, serologic testing for toxocariasis can be difficult. Blood tests to detect Toxocara antibodies in response to toxocariasis infection include assays and enzyme-linked immunosorbent assays (ELISA) like the New Life Toxocara Microwell Serum ELISA. Research has shown that the latter tests are significantly more effective in reliably detecting Toxocara antibodies.
What is the Treatment?
For mild symptoms, no treatment will be needed. However, for more severe infections that affect major organs (other than the eyes), an anthelmintic medication will be used in both humans and animals; this kills the parasite larvae, which are then expelled through the feces. This process is also known as deworming. For infections of the eye, steroids are used to reduce inflammation and prevent further damage; for severe eye infections, surgery may be required.
How can Toxocariasis infection be prevented in dogs and cats?
Female dogs and cats should be dewormed regularly to prevent the transmission of toxocariasis larvae to offspring; in addition, puppies and kittens should be dewormed at 2, 4, 6, and 8 weeks of age. Animals’ environments, including dishes and bedding, should be cleaned regularly, and care should be taken to prevent animals from eating dirt.
How can Toxocariasis infection be prevented in humans?
To prevent toxocariasis infection in yourself and your family, proper hygiene is key. Be sure to wash your hands thoroughly after playing with or handling pets, before handling food, and after any outdoor activity. Children should be taught proper handwashing techniques and should not be allowed to play in areas where animal feces may be present.
Can it be serious?
Yes, toxocariasis can be serious, though the severity depends largely on where the parasite’s larvae travel in the body and how many eggs were ingested.
While many adults exposed to Toxocara have no symptoms at all or experience only mild, flu-like illness, the infection can lead to significant organ damage and permanent disability—especially in young children.
Because symptoms can take weeks, months, or even years to appear after a sand fly bite, early medical diagnosis and treatment are crucial.
Who is at risk?
While anyone can contract toxocariasis, young children face the highest risk due to their tendency to play in soil or sandboxes and put unwashed hands or objects into their mouths.
Owners of young puppies and kittens are also particularly vulnerable, as young pets frequently shed parasite eggs in their feces before being dewormed. Additionally, gardeners, agricultural workers, and individuals who consume raw or undercooked meat or unwashed produce grown in contaminated soil are at an increased risk of infection.
Is it contagious?
No, toxocariasis is not contagious from person to person, so you cannot catch it through direct physical contact with an infected individual. It is also not directly contagious upon immediate contact with a pet or fresh animal feces. The parasite eggs require two to four weeks in soil or the environment to mature and become infectious. Transmission only occurs when mature eggs from contaminated dirt, sand, water, unwashed produce, or undercooked meat are accidentally ingested.
How common is it?
Toxocariasis is considered among the most widespread parasitic roundworm infections worldwide. Exposure is remarkably common because domestic pets like dogs and cats frequently harbor the parasite, contaminating soil in backyards, public parks, and sandboxes. It occurs most frequently in warm, humid climates, rural communities, and areas with large populations of stray pets or limited sanitation infrastructure.
Although exposure is widespread and contact with the parasite happens frequently, severe clinical illness remains relatively uncommon, as most infections cause mild or unnoticeable symptoms that go unrecognized.
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ORDER THE TOXOCARA SERUM MICROWELL ELISA
The Toxocara Serum Microwell ELISA Kit is designed for accurate detection of anti-Toxocara antibodies in human serum. This easy-to-use kit offers high sensitivity and specificity for reliable results.