Changing trends in the epidemiology of Vibrio cholerae in an outbreak of 2013 in Solapur, Maharashtra

Cholera, one of the Notifiable Diseases is known to cause serious epidemics and pandemics in developing countries like India. An outbreak had occurred in 2013 in Solapur and the isolates revealed certain change in the trends of the epidemiological markers.

A total of 30 cases presented with gastroenteritis during the months of July and August of 2013. 30 stool specimens were cultured on Blood agar, Mac Conkey agar and TCBS medium and enriched on alkaline peptone water broth. Identification of the isolates was done by standard Biochemical and Serological Agglutination tests. Antibiotic susceptibility testing was done using Kirby Bauer disc diffusion method, according to CLSI guidelines. Phage typing was done at the National Institute of Cholera and Enteric Diseases, Kolkata.

Out of the 30 stool specimen cultured, 14 strains of V.cholerae biotype El Tor serotype Ogawa was isolated. Phage Typing could be done on 6 isolates. All the strains identified belonged to T-2 phage type, according to Basu and Mukherjee scheme. According to the new scheme, two isolates belonged to T-27 phage type, two belonged to T-3 phage type, while one each belonged to T-6 and T-12 phage types. Most of the strains isolated in 2013 epidemic were sensitive to tetracycline, cotrimoxazole, and ciprofloxacin and resistant to ampicillin and gentamicin.

Due to the changing epidemiological markers of V.cholerae such as Phage type and Antibiogram, all the epidemics must be thoroughly investigated and the isolates must be subjected to complete identification and Antibiotic Susceptibility Testing.