Skip Navigation

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (3)
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by CLEMENS, J. D
Right arrow Articles by HOLMGREN, J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by CLEMENS, J. D
Right arrow Articles by HOLMGREN, J.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© 1989 Oxford University Press

research-article

Exclusion of Clinically Atypical or Microbiologically Mixed Diarrhoeal Episodes from Outcome Events in a Field Trial of Oral Cholera Vaccines

JOHN D CLEMENS*,**,{ddagger}, BONITA F STANTON*, JEFFREY R HARRIS*,{ddagger}, J CHAKRABORTY*, DAVID A SACK*, MALLA R RAO*, FARUQUE AHMED*, M ANSARUZZAMAN*, MD YUNUS*, ANN-MARI SVENNERHOLM§ and JAN HOLMGREN§

* International Centre for Diarrhoeal Disease Research Bangladesh, Dhaka, Bangladesh.
** University of Maryland School of Medicine Baltimore, MD, USA.
{ddagger} Centers for Disease Control (Enteric Infectious Divisions) Atlanta, Ga, USA.
§ University of Göteborg, Göteborg Sweden.

Clemens J D (International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh), Stanton B F, Harris J R, Chakraborty J, Sack D A, Rao M R, Ahmed F, Ansaruzzaman M, Yunus M, Svennerholm A M and Holmgren J. Exclusion of clinically atypical or microbiologically mixed diarrhoeal episodes from outcome events in a field trial of oral cholera vaccines. International Journal of Epidemiology 1989, 18: 441–445.

We investigated whether alternative clinical and microbiological criteria for outcome events affected estimates of vaccine efficacy in a randomized, double-blind field trial of B subunit-killed whole cell (BS-WC) and killed whole cell-only (WC) oral cholera vaccines among 62285 rural Bangladeshi participants. At one year of follow-up estimates of vaccine protective efficacy (PE = 60%, P<0.0001 for BS-WC; PE = 54%, P<0.0001 for WC) against all treated diarrhoeal episodes associated with V. cholerae 01 were similar to estimates of efficacy against only those episodes which were clinically typical and unassociated with additional enteric pathogens (PE = 62%, P<0.0001 for BS-WC; PE = 52%, P<0.0001 for WC). In contrast, estimates of vaccine cross-protection against episodes associated with each of several agents antigenically related to V. cholerae 01 (LT-ETEC, non-cholera Vibrio sp, Aeromonas sp) were substantially reduced when mixed infections with V. cholerae 01 were excluded. We conclude that restrictive criteria intended to improve the specificity of the definition of cholera did not increase the detectability of vaccine efficacy against V. cholerae 01, but that exclusion of mixed infections with V. cholerae 01 was necessary to avoid false-positive conclusions about vaccine cross-protection against other potential target pathogens.

Revised 1 December 1988


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.