Rat Lungworm Invades California

A parasitic disease, rat lungworm, has recently been detected in animals within San Diego County, California, expanding its known range in North America. Researchers have confirmed the presence of the parasite in multiple wild animals and one zoo animal since early 2026. This discovery is notable as the area was previously considered outside the parasite's typical habitat.

Infections can spread to humans who consume raw or undercooked snails, slugs, or frogs, as well as produce contaminated by infected snails or slugs. Symptoms in humans can range from severe headaches and fever to neurological issues, and in some severe cases, can be fatal. State health officials emphasize that the disease is not yet considered endemic in California.

To mitigate risks, authorities are advising the public to adhere to strict food safety practices. This includes avoiding the consumption of raw or undercooked wild snails and slugs. Additionally, thorough washing of all produce is recommended to prevent potential contamination and the spread of the parasite.