Rat Lungworm Likely Endemic in Southern California, Study Finds

San Diego researchers report infections of the brain-infecting rat lungworm Angiostrongylus cantonensis in a Parma wallaby at the zoo and in local rats and opossums, suggesting the parasite has become endemic in Southern California. The life cycle involves rats and snails, and humans can develop eosinophilic meningitis after ingesting contaminated snails or produce. While human cases remain rare, the study notes broader geographic expansion is possible with warming climates, and rat-lungworm should be considered in differential diagnoses for CNS disease in the region.