Clinical diagnosis and geographic distribution of leptospirosis, Thailand. von Wuthiekanun, V, Sirisukkarn, N, Daengsupa, P, Sakaraserane, P, Sangkakam, A, Chierakul, W, Smythe, L, Symonds, M, Dohnt, M, Slack, A, Day, N, Peacock, S