Enterovirus infections were investigated with special emphasis on performing rapid molecular identification of enterovirus serotypes responsible for aseptic meningitis directly in cerebrospinal fluid (CSF). Enterovirus genotyping was carried out directly with specimens tested for the diagnostic procedure, using two seminested PCR assays designed to amplify the complete and partial gene sequences encoding the VP1 and VP4/VP2 capsid proteins, respectively. The method was used for identifying the enterovirus serotypes involved in meningitis in 45 patients admitted in 2005. Enterovirus genotyping was achieved in 98% of the patients studied, and we obtained evidence of 10 of the most frequent serotypes identified earlier by genotyping of virus isolates. The method was applied for the prospective investigation of 54 patients with meningitis admitted consecutively in 2006. The enterovirus serotypes involved were identified with the cerebrospinal fluid (CSF) of 52 patients (96%) and comprised 13 serotypes within the human enterovirus B species and 1 within the human enterovirus A species. The three most common serotypes were echovirus 13 (E13; 24%), E6 (23%), and coxsackievirus B5 (11.5%), a pattern different from that observed in 2005. Genotyping of virus isolates was also performed in 35 patients in 2006 (meningitis, n ؍ 31; other diseases, n ؍ 4). By comparison, direct genotyping in CSF yielded a more complete pattern of enterovirus serotypes, thereby allowing the detection of rare serotypes: three less common serotypes (CB2, E21, and E27) were not detected by indirect genotyping alone. The study shows the feasibility of prospective enterovirus genotyping within 1 week in a laboratory setting.Enterovirus infections comprise a wide spectrum of clinical presentations and diseases (35). As with poliomyelitis, the most problematic clinical syndromes caused by nonpolio enteroviruses (NPEV)-meningitis, encephalitis, and acute flaccid paralysis-result from infection of the central nervous system (CNS) and are major causes of illness and morbidity in both children and adults (57).Enterovirus meningitis (also known as aseptic meningitis) is the most commonly observed CNS infection, and its clinical presentation varies with the patient's age and immune status (38,39). It occurs typically during outbreaks (in restricted geographical areas or communities) in the summer and autumn, leading to increased admissions to hospital wards for short periods. Unlike meningitis, enterovirus encephalitis is a more severe acute illness with more long-term sequelae (16) and, while it is less frequently observed than meningitis, its frequency should not be underestimated. For instance, in the California Encephalitis Project, an enterovirus infection was detected in 25% of patients with a viral etiology; 24% had a herpes simplex virus type 1 infection (20). NPEV can also be responsible for acute flaccid paralysis, a syndrome that mimics poliomyelitis. In Europe, 84 NPEV associated cases were registered in 2005 by the Polio Lab Network (3).En...