Practical aspects of a cholera surveillance programme.

The recent invasion of southern Africa by cholera stimulated the establishment of a regional cholera reference laboratory and surveillance centre. This article describes its activities in general and details the methods employed in the isolation of Vibrio cholerae from sewage, water, seafoods, patients, and carriers. Importance is also attached to the isolation of NAG (non-agglutinable) V. cholerae and V. parahaemolyticus from certain categories of specimens. In recognition of the importance of regional co-operation in combating the problem of cholera, the collaboration of other countries on the subcontinent was invited, and the response is encouraging.