Recognizing and Reducing the Risks of Helminthic Eosinophilic Meningitis in Travelers: Differential Diagnosis, Disease Management, Prevention, and Control

Abstract

The helminthic infestations that can cause eosinophilic meningitis (EM), including neuroangiostrongyliasis (NAS), baylisascariasis (BAS), gnathostomiasis, and neurocysticercosis (NCC), have now been recognized as emerging infectious diseases. NAS is endemic throughout the Indo‐Pacific Basin and many Atlantic and Gulf of Mexico port cities following the worldwide importation of its causative parasite, Angiostrongylus cantonensis , by stowaway rats on container ships.1–6 Today, giant African land snails and most indigenous snail and slug species serve as competent intermediate hosts of A cantonensis , now capable of completing its complex life cycle almost anywhere.3–6 BAS, a raccoon zoonosis, extended its US distribution range from the northern United States to the southeast and west coast in the 1980s; was shortly thereafter exported to Japan in the exotic pet trade; and is now enzootic in raccoons throughout the United States. Gnathostomiasis, a tropical zoonosis of wild carnivores, is an endemic cause of EM throughout Asia and Latin America and has been recognized recently as an emerging etiology of EM among travelers returning to the UK. NCC, a central nervous system (CNS) infestation with the larval or cystic (cysticercus) stage of the pork tapeworm, Taenia solium , is now the most common parasitic disease of the CNS worldwide and a leading cause of late‐onset epilepsy in adults.7,8 This review will compare and contrast the presenting manifestations and outcomes of the most common causes of helminthic EM in returning travelers, describe the most dependable diagnostic and treatment strategies, recommend proven methods to prevent helminthic EM in travelers, and suggest strategies for the control of regional outbreaks of helminthic EM. This review analyzes scientific articles selected by MEDLINE search, 1966 to 2008, to differentially compare the presenting clinical manifestations and outcomes of the most common causes of infectious and noninfectious EM worldwide; to assess the utilities … Corresponding Author: James Diaz, MD, MPH&TM, DrPH, Program in Environmental and Occupational Health Sciences, School of Public Health, Louisiana State University Health Sciences Center in New Orleans, 1615 Poydras Street Suite 1400, New Orleans, LA 70112, USA. E‐mail: jdiaz{at}lsuhsc.edu