Investigating outbreaks: practical guidance in the Indian scenario.

The new international Health Regulations, 2005, which came into force in 2007, establish a national focal point in each country to manage public health emergencies of international concern, including outbreaks. Investigating outbreaks is a challenging task. Often, pressure from decision-makers to hasten investigation may preclude proper evidence-based conclusions. Furthermore, the task of outbreak investigation is given to senior staff, who have limited time for field activities. The classical 10-step approach includes 4 main stages of (i) confirmation of the presence of the outbreak and of diagnosis using laboratory tests, (ii) generation of hypotheses regarding causation using descriptive epidemiology findings, (iii) hypothesis-testing using analytical epidemiology techniques, and (iv) institution of prevention measures. Peer-review at all stages of the investigation and reporting is the keystone of the quality assurance process. It is important to build capacity for outbreak Investigation. Two Field Epidemiology Training Programmes in India are trying to do this. In these programmes, epidemiologists-in-training take a lead in investigating outbreaks, while learning the ropes, with full technical support from the faculty. This training should spawn a culture of generating and using evidence for decision-making in the context of public health, and help strengthen health systems even beyond the domain of outbreaks.