Gnathostomiasis is a zoonotic disease found primarily in tropical regions. It occurs when patients ingest the third larval stage of roundworms in the Gnathostoma genus, and it can cause several weeks of discomfort. The spread of this condition is primarily the result of indifferent hygiene during food preparation and failure to observe safety precautions when preparing foods. Travelers might develop gnathostomiasis if they eat badly prepared local foods. For people who frequently travel, it is important to mention this at medical appointments.
Roundworms naturally live in animal hosts, who periodically excrete eggs. If the eggs reach the water, they can develop into an embryonic state and will be consumed by other organisms. As animals such as fish and frogs eat these organisms, the eggs continue developing, and when humans eat raw or incompletely cooked meats or fish, they can ingest the larval roundworms and develop an infection. It can take as little as 24 hours for symptoms to start appearing.
Patients who have gnathostomiasis typically notice skin swelling and discomfort first. Their skin might become itchy, and the swelling tends to move across the body with the course of the infection. Gastrointestinal distress is common, and some patients develop severe pain because the organisms migrate through their abdominal organs. If the patient receives antiparasitic drugs to kill the organisms, the swelling will reduce, and the patient should feel much more comfortable.
Without treatment, gnathostomiasis can cause serious complications. The parasites might damage internal organs and can trigger the release of a variety of chemical compounds in the body. Patients might go into organ failure in extreme cases. The pain and swelling can be severely uncomfortable and might limit the patient's activity levels and make it difficult for him or her to perform regular tasks. It is possible for the organisms to live for as long as 10 years in a human host if he or she does not receive medical care, and they can cause considerable damage along the way.
This infection is rare outside tropical regions, and in the tropics, gnathostomiasis can be tightly controlled relatively easily. Cooking foods thoroughly and being careful about food handling and storage should be sufficient to prevent transmission of the dangerous third larval stage of the roundworm. It is important for people to cut meats and vegetables on different surfaces, to clean cutting boards and other surfaces thoroughly after they come into contact with raw meat and to check meats after cooking to confirm that they are cooked through.