An Outbreak of Neuroangiostrongyliasis (Rat Lungworm Disease) in Hawai‘i: Evidence Supporting the Early Use of Albendazole–Corticosteroid Co-Therapy

Neuroangiostrongyliasis (NAS) is an emerging parasitic infection caused by the neurotropic nematode Angiostrongylus cantonensis (A. cantonensis). It is the leading infectious etiology of eosinophilic meningitis worldwide. In 2017, six men living on Hawai'i Island developed NAS after drinking homemade kava. After the event, a dead slug, likely infected with A. cantonensis, was found at the bottom of a communal vessel. Neuroangiostrongyliasis was subsequently confirmed in three patients through polymerase chain reaction testing of their cerebrospinal fluid. Two patients were presumptively diagnosed with NAS on the basis of highly suggestive signs and symptoms, the presence of eosinophilic meningitis, and a shared history of exposure. A lumbar puncture was unsuccessful in one patient, who was presumptively diagnosed with NAS on the basis of his symptoms and shared exposure history. Five of six patients received at least 2 weeks of co-therapy with albendazole and corticosteroids, which was initiated within 15 days of infection. The treatment was well-tolerated, and no significant adverse events were noted. One patient who did not have health insurance completed only two doses of albendazole because of the cost of the drug and experienced symptom recurrence on several occasions. This rare, common-source outbreak of A. cantonensis infection supports the early use of albendazole-corticosteroid co-therapy in proven or suspected cases of NAS. It also provides additional evidence for the water transmissibility of this parasite.