Methods and Principles

Reports from health facilities and medical teams must be received, analysed and evaluated regularly by the responsible authorities. Any reports of specific outbreaks of disease must be rapidly investigated. Sample surveys may be undertaken to determine the prevalence of particular conditions. Note that clinic attendance rates and the incidence of symptoms and diseases observed are not necessarily representative of the health situation in the community as a whole. The appearance of new diseases or sudden changes in the observed rate of incidence are, however, often significant.

The restoration and reinforcement of pre-existing reporting and surveillance systems is a high priority in any emergency. A thorough understanding of how those systems operated previously is essential.

In the absence of any effective and pre-existing arrangements - and especially if laboratory facilities are lacking and diagnostic criteria are not standardized:

· request regular reports from all health posts and medical teams on the occurrence of a limited number of symptom complexes that are suggestive of specific diseases (a) likely to arise in the particular circumstances, (b) amenable to control measures;

· do not try to establish a sophisticated system from scratch.

This minimizes the administrative demands on hard-pressed medical workers, while providing enough information to prompt more specific investigations by epidemiological personnel when particular symptoms become prevalent.

The sample report form is provided in Panel 1. Such a report might be integrated with summary reports of nutrition status data and special (supplementary and therapeutic) feeding operations.

The central surveillance unit should:

· present the appropriate decision makers with a summary of the data, conclusions and specific recommendations for action;

· feed-back summary data and conclusions to all reporting units.

In all situations, reports and information from informal sources should also be taken note of and be investigated to reassure the population by defusing any unjustified rumours or by taking action when the information is confirmed.