re-emergence of vibrio cholerae o139 serogroup during 1998 in nagpur (maharashtra), india. | in nagpur, maharashtra in 1993, v. cholerae serogroup o139 emerged as a novel epidemic strain. the decline in the isolation rate of this serogroup in subsequent year was followed by its re-emergence during 1998 indicating that this serotype requires careful monitoring. | 1999 | 10489733 |