CtxB7 Genotypes of Vibrio cholerae O1 Causing the 2022 Cholera Epidemic in Tribal Areas of Odisha, India

Cholera in Odisha’s tribal and coastal areas has been a persistent problem due to Vibrio cholerae O1/O139 for the past 30 years. This study investigates diarrheal outbreaks reported between July to November 2022 from five tribal regions of Odisha; aiming to identify the causative pathogen, its antibiogram profile and virulence genes. Standard techniques were used to culture rectal swabs taken from patients with diarrhea and samples of water to isolate the pathogen, its antibiogram profiles and PCR assays (simplex/multiplex) were used to detect different toxic genes. The heavy rainfall reported in July 2022 led to the spread of the diarrheal disease from Rayagada to neighbouring districts. The V. cholerae O1 Ogawa El Tor, characterised by the ctxB7 genotype and exhibiting multidrug resistance, were identified. Demographic analysis revealed that people aged 14-40 and over 40 years were the most affected with equal distribution among males and females. A high proportion of strains (ranging from 80% to 100%) tested positive for various virulence and drug-resistance genes. The findings offer important insights into the ctxB7 genotypes of V. cholerae O1 strains responsible for outbreaks in Odisha, which will aid in the development of improved prevention and control strategies for future cholera outbreaks. The study also suggests that there might be a possible linkage between the strains in Odisha and those from the recent cholera outbreak in Bangladesh, which can be known through whole genome sequencing after collaboration in future.