Incidence of Bacterial Enteropathogens among Diarrhea Patients from Tribal Areas of Odisha.

Infectious diarrheal diseases remain a leading cause of morbidity and mortality in developing and underdeveloped countries. The present study documented the etiology of bacterial enteropathogens in three tribal districts of Odisha from July 2010 to September 2013. A total of 1427 rectal swabs were collected and bacteriologically analyzed by following standard procedure. Among the 930 (65.2%) culture positive samples, Escherichia coli (E. coli) constituted 636 (44.6%); Vibrio cholerae (V. cholerae) O1, 146 (10.2%); Salmonella species (spp.), 10 (0.7%); Shigella spp., 79 (5.5%); and Aeromonas spp., 59 (4.1%). Of the 729 environmental water samples taken from river, open well, Nala (a small stream), and Chua (a shallow pit on a river bed), 14 (1.9%) contained non-O1/non-O139 V. cholerae and 13 (1.8%) had V. cholerae O1 strains. An analysis of the demographics showed that people in the 14 to 40-year age group were highly susceptible to diarrhea caused by V. cholerae which occurred mainly during the rainy and post-rainy seasons. All enteropathogens were multidrug-resistant and found throughout the study period. The V. cholerae strains isolated were El Tor variants carrying the classical, El Tor, and Haitian cholera toxin subunit B (ctxB) genes. The classical ctxB was the dominant allele, and the prevalence of the Haitian ctxB allele increased during the test period. These findings indicate that active surveillance is needed to monitor the changing antibiotic resistance patterns of V. cholerae serogroups and biotypes present in this region.

An Ogawa cholera outbreak 6 months after the Inaba cholera outbreaks in India, 2006.

BACKGROUND/PURPOSE: Cholera has been reported in the state of Orissa, India during the last decades. An explosive outbreak of diarrhea occurred in Central Cuttack Ward 22 of Orissa (population approximately 10,621), between March 12-23, 2006. This outbreak was investigated by a team from the Regional Medical Research Centre of Bhubaneswar to identify the causative agents and to determine the antimicrobial susceptibility pattern and associated virulent genes. METHODS: Clinical and epidemiological data were collected from 100 hospitalized patients with diarrhea from the Sriram Chandra Bhanja Medical College, Cuttack, Orissa. Rectal swabs and water samples were collected and tested for diarrheagenic enteropathogens. Isolated Vibrio cholerae were subjected to antibiotic susceptibility tests and polymerase chain reaction analysis for the detection of virulent genes. RESULTS: Of the 23 rectal swabs collected, 19 (82.6%) were positive for V. cholerae serogroup O1, serotype Ogawa. All strains were uniformly susceptible to ampicillin, gentamicin, chloramphenicol, ciprofloxacin, norfloxacin, neomycin, and tetracycline, but resistant to co-trimoxazole, furazolidone, nalidixic acid, and streptomycin. Polymerase chain reaction revealed that all strains had ctxA, tcpA (biotype El Tor), zot, and ace genes, suggesting their possible role in the outbreak. CONCLUSION: This is the first localized outbreak of V. cholerae O1, serotype Ogawa, in the state of Orissa in 2006 after a gap of 6 months dominated by Inaba strains.

Incidence of bacterial enteropathogens among hospitalized diarrhea patients from Orissa, India.

Bacteriological analysis of 1,551 stool/rectal swabs from all age groups of diarrhea patients of different hospitals of Orissa from January 2004 to December 2006 was carried out using standard procedures. Among all enteropathogens isolated in 886 culture-positive samples, Escherichia coli constituted 75.5%, including 13.2% pathogenic E. coli; Vibrio cholerae O1 constituted 17.3%; V. cholerae O139, 1%; Shigella spp., 4.5% (Shigella flexneri type 6, 2.9%, S. dysenteriae type I, 0.7%, S. sonnei, 0.6%, and S. boydii, 0.3%); Salmonella spp., 0.7%; and Aeromonas spp., only 2.0%. The isolation of bacterial enteropathogens was highest during July, 2005, followed by September, 2006. The prevalence of shigellosis in this region was relatively low. Cholera cases were more frequent during the rainy seasons. The dominance of V. cholerae O1 Inaba over Ogawa serotypes was observed in 2005, whereas this trend was reversed in 2006. The resistance profile of V. cholerae O1 was co-trimoxazole (Co), furazolidone (Fr), and nalidixic acid (Na); for Aeromonas spp., it was ampicillin (A), Fr, ciprofloxacin (Cf), Na, norfloxacin (Nx), and Co. Pathogenic E. coli strains were resistant to A, Fr, Co, streptomycin (S), Cf, Na, Nx, and neomycin (N); Shigella spp. were resistant to Fr, Na, Co, and S; and Salmonella spp. were resistant to A and Fr. Active surveillance should be continued among diarrhea patients to look for different enteropathogens and to define the shifting antibiogram patterns in this region.

Emergence of Vibrio cholerae O1 biotype El Tor serotype Inaba causing outbreaks of cholera in Orissa, India.

A total of 431 rectal swabs, collected from acute diarrheal cases at a surveillance site and at different diarrheal outbreak areas of Orissa from May to October 2005, were bacteriologically analyzed. Out of 265 culture-positive samples, Vibrio cholerae O1 was isolated in 56 samples (20.8%), of which 37 were the Inaba serotype and 19 were the Ogawa. The antibiogram profile revealed that all the V. cholerae O1 Ogawa and Inaba serotypes were uniformly sensitive to ampicillin, chloramphenicol, gentamicin, ciprofloxacin, norfloxacin and tetracycline. The V. cholerae O1 Inaba serotypes were resistant to furazolidone and nalidixic acid, while the Ogawa strains were resistant to furazolidone, nalidixic acid and neomycin. The multiplex polymerase chain reaction (PCR) assay on some selected strains of both serotypes revealed that all the strains were positive for ctxA and tcpA genes showing biotype El Tor. The present study revealed the emergence of V. cholerae O1 biotype El Tor serotype Inaba, which caused sporadic outbreaks of cholera in 2005. The outbreaks of diarrheal disorders in one geographical area of the state (in the Pattamundai area, Kendrapara district) in 2005 were due to V. cholerae O1 Ogawa, whereas the other outbreaks in other areas (Puri, Khurda and Dhenkanal districts) from August to October 2005 were due to V. cholerae O1 serotype Inaba. This is the first report that an emergence of V. cholerae O1 serotype Inaba caused sporadic outbreaks of cholera in different parts of Orissa. Switching over of V. cholerae O1 Ogawa strains to Inaba, causing diarrheal outbreaks in Orissa, needs close monitoring.