Disease Surveillance

Overview ^[1]: Surveillance is the ongoing systematic collection, analysis, and interpretation of outcome specific data for use in planning, implementing, and evaluating public health policies and practices. It is an epidemiological practice by which the incidence and spread of disease can be monitored in order to establish patterns of progression. Surveillance is based on collecting only the information that is required to achieve objectives for disease control. Data requested may differ from disease to disease and some diseases may have specific information needs, requiring specialized systems. Disease reporting is a requirement placed upon health care providers by many regional and national governments, and upon national governments by the World Health Organization (WHO). In recent years, reporting incidences of disease outbreaks has been transformed from manual record keeping to instant world wide internet communication. The number of cases could be gathered from hospitals - who could be expected to see most of the occurrences - collated, and eventually made public. Organizations like the WHO and the Centers for Disease Control (CDC) now can report cases and deaths from significant diseases within days - sometimes within hours - of the occurrence. There is considerable public pressure to make this information – especially regarding infectious disease available quickly and accurately.

There are surveillance systems for many different kinds of diseases, including reporting systems for cancer (i.e. Surveillance Epidemiology and End Results at the National Cancer Institute ^{[2] [3]}), toxic exposures (i.e. Toxic Exposure Surveillance System through the American Association of Poison Control Center ), and suspected child abuse injuries (i.e. Fatal Child Abuse and Neglect Surveillance (FCANS) at the California Department of Public Health^[4] ). However, the most common surveillance systems throughout the world is infectious disease surveillance.

Infectious Disease Surveillance: A Major Subset

Infectious Disease surveillance is the detection, rapid verification and response to epidemic-prone and emerging disease threats. The ability to control infectious diseases requires an effective and comprehensive public health surveillance and response capacity. Public health surveillance is an essential prerequisite for establishing local, national, regional, and global priorities; planning, mobilizing and allocating resources; early detection of epidemics; as well as monitoring and evaluating disease prevention and control programs. Public health surveillance includes the process of detecting diseases through a standardized information collection system that can insure data quality, analyze and interpret the data, get information to the individuals who can act on it, and then facilitate the necessary response that will effectively deal with the problem. The system is structured to deal with routine health threats and epidemic diseases. Whatever the specific public health problem, the surveillance and response capability must be built on a foundation of skills in areas such as case detection, epidemiology, data analysis and interpretation, laboratory diagnostic confirmation, and appropriate response. . In the United States, the World Health Organization (WHO), the Office of International Epizooties (OIE - an international animal disease surveillance program), the U.S. Centers for Disease Control (CDC), and the United States Department of Agriculture (USDA) all work together to minimize the impact of diseases on the health and economy of the world's population.

The WHO is the lead agency for coordinating global response to major infectious diseases, and it maintains websites for a number of diseases and has active teams in many countries where these diseases occur. 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. 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 hemorrhagic fever, hepatitis, influenze, lassa fever, marburg hemorrhagic fever, meningococcal disease, plague, rift valley fever, severe acute respiratory syndrome, smallpox, tularemia, and yellow fever. Regional and national governments typically monitor a larger set of (around 80 in the U.S.) diseases that can potentially threaten the general population. Tuberculosis, HIV, botulism, hantavirus, anthrax, and rabies are examples of such diseases.^[5]

Why is surveillance important?

Integrated disease surveillance envisages all surveillance activities in a country as a common public service that carry out many functions using similar structures, processes and personnel. The surveillance activities that are well developed in one area may act as driving forces for strengthening other surveillance activities, offering possible synergies and common resources. A disease surveillance system serves a few key functions: (1) to predict, observe, and minimize the harm caused by outbreak situation by providing an early warning of potential threats to public health. The early warning functions of surveillance are fundamental for national, regional, and global health security; recent outbreaks such as severe acute respiratory syndrome (SARS), avian influenza, and H1N1, and potential threats from biological and chemical agents, demonstrate the importance of effective national surveillance and response systems; (2) to increase our knowledge as to what factors might contribute to such circumstances and program monitoring functions which may be disease specific or multi-disease in nature. The program monitoring function of surveillance of communicable diseases encompasses a variety of goals such as eradication or elimination (e.g. of guinea worm, measles) and surveillance for acute flaccid paralysis; (3) to monitor trends of endemic diseases, progress towards disease control objectives, and to provide information which may be used to evaluate the impact of disease prevention and control program; and (4) to estimate the burden and cost of all diseases of global importance. ^[6]

Key components of a surveillance system ^[7]

• Legislation for surveillance: public health legislation and regulations provide the regulatory framework for the implementation of surveillance and response systems.
• The important surveillance levels are central, intermediate (province/region, district), peripheral (sub-district, health facility), and community level. Each of these levels may comprise public and private health-care providers that may or may not be included in the surveillance system. Other participants include the disease-specific programs, public health laboratories, and public health training institutions, as well as other establishments such as schools and airports.
• Networking and partnership: surveillance requires concerted efforts and collaboration between participants within and between countries. At the country level, collaboration and coordination between key partners between sectors is crucial for the implementation of effective and comprehensive surveillance systems.
• In order to perform the above mentioned functions, the following are necessary:

• Standards and guidelines (case definitions, laboratory guidelines, outbreak investigation guidelines, etc)
• Training for epidemiology and laboratory personnel and/or community health agents
• Supervisory activities
• Communication facilities
• Resources (human, financial, logistical)
• Monitoring and evaluation
• Coordination

Obstacles^[8]

• Political challenges: Lead organizations in global public health such as the WHO occupy a delicate role in global politics. They must maintain good relationships with each of the many countries in which they are 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". ^[4]
• Resource challenges: (1) Lack of resources to pay for disease surveillance: testing for a disease can be expensive, and distinguishing between two diseases can be prohibitively difficult in many countries. Another obstacle lays in insufficient funds for computers, a reliable working electrical system, and access to the internet. Thus communication is often a challenge, data are not collected and reported, and information about evidence of disease or health practices is difficult to disseminate. However, some creative responses to resource challenges have been noted, including the use of cell phones to improve communication in remote areas as more countries invest in cell phone technology. (2) Developing countries frequently lack personnel capacity to carry out surveillance to detect outbreaks, to conduct disease outbreak investigations, and to respond once an outbreak is identified, and international groups may face additional challenges in quickly identifying the best people on the ground to participate in a rapid response. Consequently, some regions are poorly represented in surveillance systems, which are often hotspot regions with a high likelihood of emerging diseases where surveillance is most needed. Therefore, it is critical to build capacity for sustainable, long-term disease surveillance and response.
• Organization: there is some overlap and redundancy, and in many cases, critical communication and coordination that would make these networks of greater value is lacking. Oftentimes the disease surveillance systems do not coordinate their findings and responses in a systematic way.

References

1. ↑ http://www.usaid.gov/our_work/global_health/id/surveillance/index.html
2. ↑ http://seer.cancer.gov/
3. ↑ http://www.aapcc.org/DNN/
4. ↑ ^{4.0 4.1} http://www.cdph.ca.gov/programs/Pages/FCANS.aspx
5. ↑ http://www.who.int/csr/disease/en/
6. ↑ http://www.cdc.gov/ieip/surveillance.html
7. ↑ Communicable disease surveillance and response systems: Guide to monitoring and evaluation. WHO 2006. http://www.who.int/csr/resources/publications/surveillance/WHO_CDS_EPR_LYO_2006_2/en/
8. ↑ Achieving Sustainable Global Capacity for Surveillance and Response to Emerging Diseases of Zoonotic Origin: Workshop Summary http://www.nap.edu/openbook.php?record_id=12522&page=1