[1] Kagawa Prefectural Cent Hosp, Clin Training Ctr, 1-2-1 Asahi Machi, Takamatsu, Kagawa 7608557, Japan
[2] Kagawa Prefectural Cent Hosp, Dept Infect Dis, 1-2-1 Asahi Machi, Takamatsu, Kagawa 7608557, Japan
[3] Kagawa Prefectural Cent Hosp, Dept Neurol, 1-2-1 Asahi Machi, Takamatsu, Kagawa 7608557, Japan
[4] Kagawa Univ Hosp, Ctr Infect Dis Educ, Miki, Kagawa 7610793, Japan