Enterovirus 75 and Aseptic Meningitis, Spain, 2005

To the Editor: Although most human enterovirus (EV) (genus Enterovirus, family Picornaviridae) infections are asymptomatic, they can cause upper respiratory illness, febrile rash, aseptic meningitis, pleurodynia, encephalitis, acute flaccid paralysis, and neonatal sepsislike disease (1). Most EVs have been implicated in aseptic meningitis, most notably echovirus (E) 30, 9, 6, and 11 and coxsackie B virus (CBV) type 5 (2); other serotypes are less frequently associated with neurologic disease. New EV serotypes have come to light, chiefly as a result of molecular typing methods (3–6). EV75 was proposed as a new serotype of the EV genus in 2004 (5). Retrospective analysis showed that it had circulated sporadically in Asia, the United States, and Africa since at least 1974. (n = 2). Infection in those cases was associated with respiratory disease , acute flaccid paralysis, neonatal jaundice, failure to thrive, or unspeci-fied neurologic disease or was asymp-tomatic. At the time of writing this manuscript, EV75 had not been linked to aseptic meningitis. From May 2005 through January 2006, 106 EVs were received for typing from Spanish hospital laboratories ; 46 of them were from patients with aseptic meningitis, 10 from patients or contacts of patients with acute flaccid paralysis, 27 from patients with fever, 7 from patients with respiratory diseases, and 16 from other patients. Twenty EVs could not be typed by serum neutralization (7); however, 3′ terminus VP1 gene sequence analysis (8) showed that they were E18 (n = 7), CBV3 (n = 1), and E16 (n = 2); 2 could not be typed with serologic or molecular methods because the 3′ terminus of VP1 gene amplification was negative. The analysis of the 3′ terminus of VP1 gene of the remaining 5 cerebrospinal fluid (CSF) and 3 nasopharyngeal isolates showed that they were similar to the recently proposed EV75 serotype (5). These 8 isolates were obtained from samples from children in Bilbao (n = 3), Granada (n = 3), Barcelona (n = 1), and the Canary Islands (n = 1). In 4 patients with aseptic meningitis, EV75 was isolated from CSF. EV75 was isolated from CSF of a fifth patient who had symptoms of fever and irritability. The remaining 3 EV75 isolates were from nasopharyngeal swabs of children who had fever, respiratory disease, or gastroenteritis. All isolates were grown in cell lines (rhabdomyosarcoma, lung adenocar-cinoma, and human fetal lung fibrob-last) and identified as EV by immuno-fluorescence with pan-EV antibody assays …