Angiostrongylus cantonensis Infection in Brown Rats (Rattus norvegicus), Atlanta, Georgia, USA, 2019-2022

Abstract

Rat lungworm (Angiostrongylus cantonensis), a zoonotic parasite invasive to the United States, causes eosinophilic meningoencephalitis. A. cantonensis harbors in rat reservoir hosts and is transmitted through gastropods and other paratenic hosts. We discuss the public health relevance of autochthonous A. cantonensis cases in brown rats (Rattus norvegicus) in Atlanta, Georgia, USA.

Keywords: Angiostrongylus cantonensis; Rattus norvegicus; United States; brown rats; eosinophilic meningoencephalitis; nematodes; parasites; rodents; vector-borne infections; zoonoses.

Figure

Brain and lung tissue samples showing Angiostrongylus cantonensis infection in brown rats (Rattus norvegicus), Atlanta, Georgia, USA, 2019–2022. A) Representative tissue section from the brain, stained with hematoxylin and eosin. The meninges and ventricles are multifocally and moderately expanded by abundant hemorrhage. Within the meninges and ventricles, occasional cross sections through nematodes can be seen. Nematodes were ≈250–300 μm in diameter with a thin eosinophilic cuticle, pseudocoelom, polymyarian coelomyarian musculature, lateral chords, and multinucleated intestine. Original magnification ×200 μm. B) Representative tissue section from the lung stained with hematoxylin and eosin. A large pulmonary artery contains fragments of a degenerative nematode characterized by a thin eosinophilic cuticle, pseudocoelomic space, and polymyarian coelomyarian musculature. The subtending arterial wall was sometimes necrotic and variably infiltrated by eosinophils, lymphocytes, and macrophages. The vessel also displays hypertrophy of the tunica media and occasional hypertrophy of the endothelial cells. Original magnification ×100 μm.