1961年以前,各国流行的霍乱病原除印尼(1937年以来)及泰国(1959～1960)等少数国家为霍乱弧菌的埃尔托生物型(biotype El-Tor)外,其余均系霍乱弧菌的古典生物型(Classical biotype)。1961年以来虽然在西太平洋海面广大地区内发生了付霍乱流行,但在有些国家或地区真性霍乱依然有所发生。直至1963年,印度、巴基斯坦(包括现在的孟加拉国在内)、缅甸、马来西亚等国发生的也还是由霍乱弧菌古典生物型引致的真性霍乱。但是近数年的情况却明显不同了,多年来一直为孟加拉国占优势 Prior to 1961, the prevalence of cholera in various countries except for Indonesia (since 1937) and Thailand (1959 ~ 1960) was a biotype El-Tor of V. cholerae. Classical biotype. Cholera has been endemic in some countries and regions since the cholera epidemic occurred in most parts of the western Pacific Ocean since 1961. Until 1963, true cholera caused by the classical biotype of Vibrio cholerae was also found in India, Pakistan (including the present Bangladesh), Myanmar and Malaysia. However, the situation in recent years has been markedly different and has dominated Bangladesh for many years