Toxocariasis is simply an infection caused by the larvae of the roundworm Toxocara canis or cati. The condition mainly develops among young children who acquire the parasite eggs by swallowing soil that has been contaminated by feces of cats, dogs or other animals carrying the parasite.
Sandboxes where cats and dogs often defecate pose as a hazard for exposure to the parasite eggs. Children are likely to transfer the eggs from their hands to the mouth and might swallow the contaminated sand. In some cases, adults ingest eggs from contaminated soil, hands or surfaces. Both adults and children who have pica are at risk.
Once the eggs are ingested, the larvae hatch in the intestine. The larvae penetrate the intestinal wall and spread throughout the bloodstream. Almost any tissue in the body can become infected, but the lungs and liver are usually involved. The larvae do not mature to adulthood since they require another host to reach maturity such as cats, dogs or other animals.
What are the indications of toxocariasis?
The indications of toxocariasis can start within several weeks after the eggs are swallowed. Cough, fever, wheezing and enlargement of the liver are the most common. Some individuals develop rashes, spleen enlargement or recurrent pneumonia. In addition, there is also appetite loss.
Once the larvae infect the eyes, inflammation and diminished vision can occur.
How is it diagnosed
The doctor might suspect toxocariasis in an individual who has an enlarged liver, fever, lung inflammation and elevated level of eosinophils. A diagnosis is confirmed by identifying Toxocara antibodies in the blood.
In rare occasions, a sample of liver or other tissue is obtained and analyzed for presence of the larvae or inflammation due to their presence.
The prevention involves deworming of cats and dogs on a regular basis. It is vital to cover sandboxes when not in use to prevent animals from defecating in them.
Children must be discouraged from eating non-food items such as clay and soil as well as adults with such cravings.
Among those who have toxocariasis, the infection resolves on its own and the treatment is not needed. Mebendazole or albendazole along with corticosteroids are given when the symptoms are severe or the eyes are involved.
Occasionally, laser photocoagulation is utilized to eliminate larvae in the eyes.