An outbreak of aseptic meningitis in a nursery school caused by echovirus type 30 in Kobe, Japan.

Human enteroviruses infect a large number of people every year. The great majority of infections are asymptomatic or cause only mild respiratory illness (common cold). However, these viruses may cause various clinically distinct diseases including aseptic meningitis (1). In the summer of 2006, there was an outbreak of aseptic meningitis in a nursery school in Kobe City, Japan. The school is situated in an urban district, where 21 staff care for 112 children (from 6 months old to 6 years old). On July 30, a 5-year-old boy (Patient A) demonstrated a high fever, headache and vomiting, and was hospitalized with a diagnosis of aseptic meningitis. Then, three children (5 to 6 years old) were hospitalized with similar symptoms on July 31 and August 1 (Patient B, C, D), followed by a 23-year-old nursery teacher on August 3 (Patient E). Three to 4 children were constantly absent from school with symptoms similar to those of a common cold between July 31 and August 9. From August 10 to 14, the school was partially closed for summer vacation, though a small number of children continued coming. There were no meningitis patients appearing for more than a week and the outbreak seemed to be terminated. However, on August 14, a 4-year-old boy was hospitalized with a diagnosis of aseptic meningitis (Patient F); he was the last patient in this outbreak. In all cases, the meningeal symptoms were self-limited and the patients recovered without any neurological abnormalities. From the 6 patients described above, clinical specimens (2 cerebrospinal fluids, 4 stools and 5 throat swabs) were obtained (Table 1). RD-18S, HEp-2, FL and Vero-E6 cells were used for virus isolation. The virus was isolated from 7 Jpn. J. Infect. Dis., 60, 2007