<unk>  is an epidemiological practice by which the spread of<unk>  is monitored in order to establish patterns of progression. The main role of<unk>  is to predict, observe, and minimize the harm caused by outbreak, epidemic, and pandemic situations, as well as increase knowledge about which factors contribute to such circumstances. A key part of modern<unk>  is the practice of<unk>  case reporting. In modern times, reporting incidences of<unk>  outbreaks has been transformed from manual record keeping, to instant worldwide internet communication. The number of cases could be gathered from hospitals – which would be expected to see most of the occurrences – collated, and eventually made public. With the advent of modern communication technology, this has changed dramatically. Organizations like the World Health Organization (WHO) and the Centers for<unk>  Control and Prevention (CDC) now can report cases and deaths from significant<unk> s within days – sometimes within hours – of the occurrence. Further, there is considerable public pressure to make this information available quickly and accurately.
Disease surveillance
Biomonitoring
Public health surveillance
Sentinel surveillance
Molecular risk assessment
Screening 
Targeted immunization strategies
Wastewater surveillance