[Epidemiologic study of an outbreak of echovirus type-9 meningitis].

Background: Several agents are able to produce lymphocytic meningitis, but sometimes it's not possible their identification. The viruses are the etiological agents more frequently found, especially enteroviruses, mumps virus and herpes simplex virus, with different epidemiological patterns depending on time and geographic location. Most of the infections caused by enteroviruses are asymptomatics. In general the viral meningitis have a good prognostic with an acute benign course and serious signs of neurological affectation are infrequent. From 1991 it has been observed an increase of nonpolio enteroviral meningitis outbreaks in our Country. Echovirus-4 was isolated in most of the outbreaks notified during that year. Echovirus-9 was not isolated in any of them.

Methods: We describe the epidemiological and clinical characteristics of a lymphocytic meningitis outbreak that took place from June to July of 1993 in Burgos.

Results: Forty-eight patients, most of them children, were hospitalized with fever, headache, vomits and stiff neck with an increase in the total cell count in cerebospinal fluid (CSF). Echovirus-9 was isolated from fecal samples in eight patients.

Conclusions: The etiology was attributed to Echovirus-9 because of microbiologic and epidemiologic findings. The incubation period can fluctuate between four an five days and fecal-oral transmission is the most probable mechanism.