Volume 13, Number 11—November 2007
Distribution of Eosinophilic Meningitis Cases Attributable to Angiostrongylus cantonensis, Hawaii
|Diagnosis||Inclusionary criteria||Exclusionary criteria|
|EM||Had lumbar puncture (LP) during January 2001–February 2005*
||Not in Hawaii during exposure period†
|Had any of the following:‡
Leukocytes or eosinophils in CSF below inclusionary
levels after adjusting for presence of erythrocytes Grossly bloody CSF
Diagnosis or signs (e.g., CSF, radiologic) of
|Had cerebrospinal fluid (CSF) with both:
>6 leukocytes per mm3
Eosinophil percentage (of leukocyte count) or absolute
eosinophil count >10
|A. cantonensis infection||Met criteria for EM
||Had intracranial hardware when LP was performed
|Met parasitologic or clinical criteria for A. cantonensis infection: Parasitologic: A. cantonensis larvae or young adult worms in CSF Clinical: manifestations compatible with A. cantonensis infection and including >2 symptoms/signs§||Was <2 mo of age when LP was performed
|Had been hospitalized from birth through time of LP
|Had another possible cause of EM identified|
*If a patient had >1 LP, the LP considered in the analyses was the one that met criteria for EM and had the highest absolute eosinophil count.
†The exposure period was defined as the 45-d period before the symptom-onset date (if unknown, the date of the LP).
‡Potential cases of EM were excluded if the eosinophilic pleocytosis was potentially attributable to blood and thus was difficult to evaluate (e.g., traumatic LP, grossly bloody CSF, or intracranial hemorrhage). For CSF specimens with >500 erythrocytes/mm3, the leukocyte and eosinophil criteria had to be met after using a correction ratio of a decrease of 1 leukocyte for every 500 erythrocytes.
§The symptoms and signs included headache, neck stiffness or nuchal rigidity, visual disturbance, photophobia or hyperacusis, cranial nerve abnormality (e.g., palsy), abnormal skin sensation (e.g., paresthesia, hyperesthesia), sensory deficit, nausea or vomiting, documented fever, increased irritability (if <4 y of age), and bulging fontanelle (if <18 mo of age).