Dirofilariasis as a cause of eosinophilic meningitis in man diagnosed by immunofluorescence and arthus hypersensitivity

Sera from patients with eosinophilia of unknown aetiology or having symptoms suggesting helminth involvement were surveyed for antibodies against Dirofilaria immitis, Toxocara canis, Ascaris suum, Angiostrongylus cantonensis and A. mackerrasae using a fluorescent antibody test and a passive reversed Arthus test in guinea-pigs. Positive reactions were obtained against D. immitis and T. canis but not against the other parasites. 6 out of 9 patients with anti-D. immitis antibodies showed symptoms of cranial involvement with the parasite. It was concluded that D. immitis is an aetiological agent of eosinophilic meningitis. The most common clinical symptom associated with T. canis visceral larva migrans was persistent eosinophilia.