RATIONALE FOR SURVEILLANCE
One of the major causes of morbidity and mortality in young children, diarrhoeal diseases caused more than 3 million deaths in 1995 (80% in children under 5 years). About half of these deaths are due to acute watery diarrhoea. Contaminated food is now thought to be responsible for over two-thirds of cases.
WHO supports regional initiatives in coordinating activities aimed at improved preparedness and response to outbreaks of diarrhoeal diseases (including cholera and dysentery). WHO strategy is to reduce incidence and fatality through integrated case management in children at primary care level, in collaboration with governments and other agencies.
RECOMMENDED CASE DEFINITION
Clinical case definition
Acute watery diarrhoea (passage of 3 or more loose or watery stools in the past 24 hours) with or without dehydration.
Laboratory criteria for diagnosis
Laboratory culture of stools may be used to confirm possible outbreaks of specific agents, but is not necessary for case definition.
RECOMMENDED TYPES OF SURVEILLANCE
Patient records should be maintained at peripheral level.
Routine monthly/weekly reporting of aggregated data from peripheral level to intermediate and central level.
Community surveys/sentinel surveillance to complement routine data and for evaluation of control programme activities.
Note: If laboratory examinations are undertaken at the start of an outbreak in order to identify the causative agent, this need not be continued once the causative agent has been identified (unnecessary burden on laboratory facilities).
RECOMMENDED MINIMUM DATA ELEMENTS
Case-based data at peripheral level
• Unique identifier, age, sex, geographical area
• Date of onset
• Laboratory results if appropriate
Aggregated data for reporting
• Number of cases <5 years by geographical area
• Number of deaths <5 years by geographical area
• Number of hospitalizations if appropriate.
RECOMMENDED DATA ANALYSES, PRESENTATION, REPORTS
• Number of cases by month, geographical area, age group
• Comparisons with same month and geographical area in previous years
• Information on seasonal and secular trends best presented as line graphs
• Plots of laboratory-confirmed cases by month and year, as appropriate
• Monthly surveillance summaries should be produced nationally and regionally and fed back. A quarterly or annual overview is helpful in trying to identify areas of concern and set priorities
PRINCIPAL USES OF DATA FOR DECISION-MAKING
• Monitor trends in disease incidence
• Detect possible outbreak at the local level
• Identify high risk areas for further targeting of intervention
• Estimate incidence rate and case-fatality rate
• Support plan for the distribution of medical supplies (diagnostic test, antibiotics etc.) and allocation of control teams
• Determine the effectiveness of control measures
• Provide research data in the area of means of transmission and antibiotic susceptibility of isolates (monitor antimicrobial resistance)
• Help mobilize donors to support epidemic control measures
Diarrhoeal diseases are handled as part of the integrated case management approach to child health. The syndrome-based reporting approach is recommended as the most effective way to report on cases. However, from the perspective of surveillance of diseases, this approach has to be proven. Multiple diagnoses are frequently made in children. The integrated case management approach, while important in the primary care setting, may thus not lend itself to specific disease surveillance.
See Regional Communicable Disease contacts on section "Communicable disease contacts in Regional Offices".
Headquarters: 20 Avenue Appia, CH-1211 Geneva 27, Switzerland
Division of Child and Adolescent Health and Development (CAH)
Tel: (41 22) 791 2894/2672/2111
Fax: (41 22) 791 4853
Communicable Diseases Surveillance and Response (CSR)
E-mail: email@example.com / outbreak@.who.ch
Tel: (41 22) 791 2624/2660/2111
Fax:(41 22) 791 4198 attn CSR