Reduction of travellers' diarrhoea by WC/rBS oral cholera vaccine in young, high-risk travellers

Abstract

Aims: A bidirectional cohort study investigates whether pre-travel vaccination with whole cell/recombinant B subunit inactivated, killed oral cholera vaccine reduces the incidence of diarrhoea in young adult travellers to high-risk areas.

Scope: Risk of travellers' diarrhoea was assessed according to destination and reason for travel in high-risk travellers of a travel clinic in Barcelona, Spain. Those at high-risk between January and December 2005 were advised on water/food safety and hygiene. High-risk travellers between January and December 2006 were additionally vaccinated with WC/rBS oral cholera vaccine. Data regarding diarrhoea were gathered by structured telephone interview or e-mailed questionnaire following the travellers' return. The incidence of diarrhoea in the group vaccinated with WC/rBS oral cholera vaccine (n=321) was 17.4%, compared with 39.7% in the non-vaccinated group (n=337) (adjusted risk ratio 0.40). The first episode was significantly shorter in the vaccinated group (mean 2.3 days) than in the non-vaccinated group (mean 3.8 days) (p<0.001).

Conclusions: The protective effect of the WC/rBS oral cholera vaccine was 57% in the young, high-risk travellers. Vaccination with the WC/rBS oral cholera vaccine as well as food safety and hygiene advice could offer effective means of reducing the risk of diarrhoea while abroad.