Is <i>Vibrio fluvialis</i> Emerging As a Pathogen with Epidemic Potential in Coastal Region of Eastern India Following Cyclone <i>Aila</i>?

Abstract

An isolated area with diarrhoea epidemic was explored at Pakhirala village of the Sundarbans, a coastal
region of South 24 Parganas district of West Bengal, eastern India. The Pakhirala village was surrounded by
other villages affected by a similar epidemic. The affected villages experienced this epidemic following the
cyclone Aila, which had hit the coastal region of the Sundarbans in eastern India. In Pakhirala, the situation
was the worst. Within a span of six weeks (5 June–20 July 2009), 3,529 (91.2%) of 3,871 residents were
affected by watery diarrhoea. Of all the cases (n=3,529), 918 (26%) were affected by moderate to severe
diarrhoea. In other villages, 28,550 (70%) of the 40,786 people were affected; of them, 3,997 (14%) had
moderate to severe watery diarrhoea. The attack rate and the severity of the cases were significantly higher
in Pakhirala village compared to other affected villages. The laboratory results revealed that Vibrio fluvialis
was the predominant pathogen in Pakhirala village (5 of 6 laboratory-confirmed organisms) whereas Vibrio
cholerae O1 Ogawa was the predominant pathogen in other villages of Gosaba block (7 of 9 bacteriologically-
confirmed organisms). This result indicates that V. fluvialis behaves more aggressively than V. cholerae
O1 in an epidemic situation with a higher attack rate and a different clinical picture. An in-depth study is
required to explore its pathogenicity in detail, geographical distribution, and possible control measures,
including development of specific vaccine preparation and determination of its efficacy.

Key words: Diarrhoea; Cyclone; Disasters, Natural; Vibrio cholerae; Vibrio fluvialis; India

DOI: 10.3329/jhpn.v28i4.6037

J HEALTH POPUL NUTR 2010 Aug 28(4):311-317