A blind passenger: a rare case of documented seroconversion in an Angiostrongylus cantonensis induced eosinophilic meningitis in a traveler visiting friends and relatives

Abstract

Background Eosinophilic meningitis (EOM) is a rare condition that is caused by various communicable and non-communicable factors. The rat-lungworm Angiostrongylus cantonensis , which is associated with consumption of raw or undercooked paratenic or intermediate hosts, is the most common cause of parasitic eosinophilic meningitis worldwide. While the majority of A. cantonensis cases are reported from endemic regions, cases in travelers pose a challenge to clinicians in non-endemic countries. Here we report a rare case of eosinophilic meningitis caused by A. cantonensis in a Swiss traveler who was diagnosed after returning from Thailand. Case presentation A 33-year old woman with a travel history to rural north-eastern Thailand presented to an emergency department in Switzerland with severe headache and vomiting. Eosinophilic meningitis was confirmed as the cause of the symptoms; however, serologic investigations failed to confirm an A. cantonensis infection on the first evaluation. Nevertheless, empirical treatment with an anthelminthic and steroid regimen led to a rapid alleviation of symptoms. Repeated serology confirmed seroconversion 2 weeks after treatment initiation. Discussion Parasitic etiology must be considered in returning travelers who present with symptoms compatible with a central nervous system infection. A thorough medical history, including types of food consumed, is paramount and can often suggest differential diagnosis. Neuroangiostrongyliasis is rare and might be missed if serology does not cover possible seroconversion.

Angiostrongylus cantonensis in North African hedgehogs as vertebrate hosts, Mallorca, Spain, October 2018

“…In humans, it is a leading cause of parasitic eosinophilic meningitis [6]. Angiostrongyliasis eosinophilic meningitis (AEM) is difficult to diagnose [3] and requires a high degree of clinical suspicion since eosinophilia may not be initially observed in peripheral blood [7] and serology may be misleading [8]. In areas where angiostrongyliasis is not endemic, AEM may thus be overlooked [9].…”

Eosinophilic meningitis due to Angiostrongylus cantonensis in Europe

“…Eighteen percent (2/11) of reported magnetic resonance imaging (MRI) scans and no (0/7) computed tomography (CT) scans showed a specific pathology indicative of A. cantonensis neuroinfection. (One CT scan showed suspected vascular occlusion compatible with Moyamoya disease, which was, however, not confirmed on a subsequent MRI scan (Brummaier et al, 2019); we have treated this finding as incidental in our analysis. )…”

Misdiagnosis and inappropriate treatment of cutaneous leishmaniasis: a case report

“…Failure to diagnose cutaneous leishmaniasis and an incomplete patient history led to many weeks of inadequate antibiotic treatment. Many researchers note the importance of collection of a thorough medical history in medical practice [ 5 – 8 ].…”