Toxocariasis

Toxocariasis is a form of an infection caused due to worms that are usually found in the cat and dog intestines. The worms found in the dog’s intestine are called toxocara canis and those found in cat’s intestine are called Toxocara cati. The Toxocara worm lays eggs in the stomach of the cat/dog and leaves the body with the faeces. These eggs and worms contaminate the soil and infect humans if they have eaten the worm or the eggs by accident. Once the eggs are consumed by humans, it hatches and begins to eat away the tissues. The three types of Toxocariasis are:
Covert Toxocariasis
Visceral larva migrans
Ocular larva migrans

Covert Toxocariasis is the most common form of Toxocariasis and has very mild symptoms.

Visceral larva migrans is a condition when Toxocariasis occurs repeatedly.

Ocular larva migrans is a condition when the worm enters the eye, causing reduction in vision and, in extreme cases, blindness.

The seriousness of the condition depends on the number of eggs swallowed and the severity of reaction that follows. Children are the easiest targets for Toxocariasis as they usually come in frequent contact with mud and follow less hygiene.

Symptoms:

The symptoms may occur less than a week after consumption or it may take weeks and sometimes even months. Some of the symptoms include fever, wheezing, cough, reduced appetite, patches or red bumps on the skin that are itchy and swollen, difficulty in sleeping, headache and abdominal pain.

Other results due to this infection are liver enlargement, swollen glands, and collection of fluid in spaces in the lungs.

Ocular larva migrans leads to inflammation on the retina (called as granulomas), and inflammation of the retina and the tissue behind it (called as chorioretinitis). This condition also causes blurry vision and black spots in front of the eyes.

Causes:

Toxocara eggs hatch inside the intestines and the worms eat into the walls of the intestine to enter into the bloodstream. The blood stream carries them to different parts of the body and eats into the tissues. These worms can live in the human body for weeks and eventually they die. Direct contact with cats and dogs do not infect humans as the eggs need to be in the soil for several months before they can infect. Sometimes it takes several years.

Diagnosis:

Toxocariasis can be detected by seeing if the patient has the aforementioned symptoms. Another way of testing is the ELISA test or the Enzyme-Linked Immunosorbent Assay test. This test is used to find out if the antibodies of the Toxocara are present in the blood. In rare cases the liver is checked for inflammation or worms.

Treatment:

It is quite often the case that people recover from Toxocariasis without treatment. There are times when the infection is never detected at all. If symptoms of Toxocariasis surfaces then the patient is given anti-parasitic drugs to kill the worms. Ocular Toxocariasis is treated by using steroids and in some cases laser is used to destroy the worm.