Enterovirus meningitis in Brazil, 1998-2003

Acute viral infections of the central nervous system (CNS) such as acute flaccid paralysis, meningitis, and encephalitis, are responsible for a high morbidity, particularly in children. Non-Polio enteroviruses (NPEV) are known to be responsible for over 80% of viral meningitis in which the etiologic agent is identified. In the present study, we show the frequency of enterovirus meningitis in Brazil from December 1998 to December 2003. Enterovirus were isolated from 162 (15.8%), of a total of 1,022 cerebrospinal fluid (CSF) specimens analyzed. Echovirus 30 was identified in 139 of these isolates (139/162-85.2%). Other identified enteroviruses were: Coxsackievirus B5 (3.7%), Echovirus 13 (3.7%), Echovirus 18 (3%), Echovirus 6 (1.2%), Echovirus 25 (1.2%), Echovirus 1 (0.6%), and Echovirus 4 (0.6%). Patients's age ranged from 28 days to 68 years old. The most frequent symptoms were fever (77%), headache (69.5%), vomiting (71.3%), neck stiffness (41.3%), convulsion (7.1%), and diarrhea (3.7%). Although, the majority of the patients recovered without any complication or permanent squeal, five deaths occurred. Throughout the surveillance period, five viral meningitis outbreaks were confirmed: four in the Southern Brazil and one in the Northeast Brazil. Echovirus 30 was responsible for four out of the five outbreaks while Echovirus 13 caused the fifth one. Besides the outbreaks, 734 sporadic cases were also identified during the study period and 59 of these were positive for virus isolation (8%). Echovirus 30 accounted for 70% of the isolates. Our results showed that Echovirus 30 was the most prevalent etiological agent of viral meningitis in Brazil, causing both outbreaks and sporadic cases.