Effectiveness in prevention of travellers' diarrhoea by an oral cholera vaccine WC/rBS.
OBJECTIVE
To investigate the effectiveness of an oral cholera vaccine (Dukoral((R))) in preventing travellers' diarrhoea.


METHODS
A retrospective study was conducted among travellers who had attended the International Vaccination Centre in Malaga, Spain, before starting their journey. A telephone interview was undertaken from November 2005 to January 2006 after the travellers had returned from their trip. The relationship between vaccination with Dukoral((R)) and travellers' diarrhoea was analysed by means of a logistic regression model, adjusting for possible confounding variables (traveller's age, duration of trip and region visited).


RESULTS
The overall incidence of diarrhoea in vaccinated travellers was 23% compared with 40% in non-vaccinated travellers (historical control group) (p=0.004). Short episodes of diarrhoea were reported in significantly more travellers of the vaccinated group than of the non-vaccinated group (average duration of diarrhoea 2.21 days versus 3.97 days, p=0.005). The incidence of diarrhoea was significantly lower among vaccinated than non-vaccinated travellers who went to Africa for less than 3 weeks (16% versus 48%, p=0.002) or India and South East Asia (19% versus 50%, p =0.052) for more than 3 weeks. No adverse events were reported in the group of vaccinated travellers.


CONCLUSIONS
Vaccination reduced the risk of travellers' diarrhoea by 43%; possibly due to the protective effect of the oral vaccine Dukoral((R)) against travellers' diarrhoea caused by enterotoxigenic Escherichia coli (ETEC) or cholera. The efficacy of vaccination increased after adjusting for confounding factors, being modified by traveller age (under 30 years, or 45 years and older the protective effect of the vaccine is 4.8 greater, 95% confidence interval (CI): 2.1-10.7). The number needed to treat to prevent one traveller from suffering from one or more episodes of travellers' diarrhoea was 5.8.
López-Gigosos
R
R
International Vaccination Centre, Offices of the Health Area, Sub-Delegation of the Government of Malaga, Paseo Marítimo de Pablo Ruiz Picasso 43, Malaga 29070, Spain. rosamaria.lopez@map.es
García-Fortea
P
P
Reina-Doña
E
E
Plaza-Martín
E
E
D000284:Administration, Oral; D000328:Adult; D000350:Africa, Central; D002771:Cholera / Q000382:microbiology / Q000517:prevention & control*; D022121:Cholera Vaccines / Q000627:therapeutic use*; D015331:Cohort Studies; D003967:Diarrhea / Q000382:microbiology / Q000517:prevention & control*; D054307:Enterotoxigenic Escherichia coli / Q000302:isolation & purification*; D004927:Escherichia coli Infections / Q000382:microbiology / Q000517:prevention & control*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013030:Spain; D014195:Travel; D014734:Vibrio cholerae / Q000276:immunology
D022121:Cholera Vaccines