Disease surveillance is an epidemiological practice by which the spread of disease is monitored in order to establish patterns of progression. The main role of disease surveillance 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 disease surveillance is the practice of disease case reporting.
In modern times, reporting incidences of disease 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 Disease Control and Prevention (CDC) now can report cases and deaths from significant diseases within days – sometimes within hours – of the occurrence. Further, there is considerable public pressure to make this information available quickly and accurately.
Mandatory reporting
Formal reporting of notifiable infectious diseases is a requirement placed upon health care providers by many regional and national governments, and upon national governments by the World Health Organization to monitor spread as a result of the transmission of infectious agents. Since 1969, WHO has required that all cases of the following diseases be reported to the organization: cholera, plague, yellow fever, smallpox, relapsing fever and typhus. In 2005, the list was extended to include polio and SARS. Regional and national governments typically monitor a larger set of (around 80 in the U.S.) communicable diseases that can potentially threaten the general population. Tuberculosis, HIV, botulism, hantavirus, anthrax, and rabies are examples of such diseases. The incidence counts of diseases are often used as health indicators to describe the overall health of a population.
World Health Organization
The World Health Organization (WHO) is the lead agency for coordinating global response to major diseases. The WHO maintains Websites for a number of diseases and has active teams in many countries where these diseases occur.
During the SARS outbreak in early 2004, for example, the Beijing staff of the WHO produced updates every few days for the duration of the outbreak. Beginning in January 2004, the WHO has produced similar updates for H5N1. These results are widely reported and closely watched.
WHO's Epidemic and Pandemic Alert and Response (EPR) to detect, verify rapidly and respond appropriately to epidemic-prone and emerging disease threats covers the following diseases: Anthrax Avian influenza Crimean–Congo hemorrhagic fever Dengue hemorrhagic fever Ebola virus disease Hepatitis Influenza Lassa fever Marburg hemorrhagic fever Meningococcal disease Plague Rift Valley fever Severe acute respiratory syndrome (SARS) Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Smallpox Tularemia Yellow fever
Political challenges
As the lead organization in global public health, the WHO occupies a delicate role in global politics. It must maintain good relationships with each of the many countries in which it is active. As a result, it may only report results within a particular country with the agreement of the country's government. Because some governments regard the release of any information on disease outbreaks as a state secret, this can place the WHO in a difficult position.
The WHO coordinated International Outbreak Alert and Response is designed to ensure "outbreaks of potential international importance are rapidly verified and information is quickly shared within the Network" but not necessarily by the public; integrate and coordinate "activities to support national efforts" rather than challenge national authority within that nation in order to "respect the independence and objectivity of all partners". The commitment that "All Network responses will proceed with full respect for ethical standards, human rights, national and local laws, cultural sensitivities and tradition" ensures each nation that its security, financial, and other interests will be given full weight.