2.2.1 Alert definitions
An alert should be triggered when one of the following events occurs, as defined by the World Health Organization (WHO).
World Health Organization. Global Task Force on Cholera Control. Surveillance Working Group. Interim Guidance to Document on Cholera Surveillance.
WHO suspect case definitions for a cholera alert
a) Two or more people aged 2 years and older (linked by time and place) with acute watery diarrhoea and severe dehydration or dying from acute watery diarrhea from the same areas within one week of one another.
b) One death from severe acute watery diarrhoea in a person at least 5 years old.
c) One case of acute watery diarrhoea testing positive for cholera by rapid diagnostic test a Citation a. MSF does not use these cholera rapid diagnostic tests in its programmes as none of them are prequalified (see Section 2.4.2) in an area (including those at risk for extension from a current outbreak) that has not yet detected a confirmed case of cholera.
Alerts may come from many sources, including a national surveillance system, supervisors and managers of health facilities or even the local media.
2.2.2 Alert verification
Regardless of source, alerts should be verified (by telephone, in general) and followed by an onsite investigation if the alert is credible.
- 1.World Health Organization. Global Task Force on Cholera Control. Surveillance Working Group. Interim Guidance to Document on Cholera Surveillance.