Roundworms can be transmitted to people who accidentally ingest the parasite's eggs containing larvae, if children or adults ingest the eggs, the eggs hatch, and infective-stage larvae migrate through the liver, lungs, and other organs and tissues where they produce damage and induce allergic responses. Infection may leave children with permanent visual or neurological damage. Roundworms can remain infective in the soil for a prolonged period. Drugs are available to kill this parasite in cats and people. Hookworms, a type of roundworm that lives in a cat's digestive tract, can infect human skin, causing lesions.
People acquire hookworm larvae through contact with wet sand.
For example, children, electricians, plumbers, and other workers who crawl beneath raised buildings, are more susceptible than the general public, as are sunbathers. The larvae can remain alive and travel in the skin for up to several months. Drugs are available for cats and people. Plague is an acute bacterial disease transmitted primarily by wild rodent fleas mainly in the Southwest and California. Cats can become infected from flea bites or from eating infected small mammals.