When suspected cholera cases trigger an alert in a given location, an on-site investigation should be carried out to determine if there is an outbreak and to describe the population and context in which the outbreak is occurring.
The key elements of the investigation are microbiologic confirmation in clinically relevant cases, assessment of case management, evaluation of the capacity of local institutions to manage an outbreak, and the description of the population, its cholera history, and the risk factors that will determine the type and scale of a response.
The final step of an investigation is to write a report describing the situation based on direct observation in the facility and the community and analysing the current and historical data to provide recommendations for action.