Disease surveillance
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2008-01-06T18:02:03Z
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Reverted edits by [[Special:Contributions/Jalamgir2|Jalamgir2]] ([[User talk:Jalamgir2|talk]]) to last version by SmackBot
{{Cleanup|date=August 2007}}
{{Inappropriate tone|date=December 2007}}
'''Disease surveillance''' is an [[epidemiology|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 our knowledge as to what factors might 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 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. With the advent of modern [[communication technology]], this has changed dramatically. Organizations like the [[World Health Organization]] (WHO) and the [[Centers for Disease Control]] 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==
Infectious diseases reporting is a requirement placed upon health care providers by many regional and national governments, and upon national governments by the [[World Health Organization]]. Since [[1969]], WHO has required that all cases of the following diseases be reported to the organization: [[cholera]], [[Bubonic plague|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]], and [[anthrax]] are examples of such diseases.{{Fact|date=February 2007}}
==World Health Organization==
The [[World Health Organization]] is the lead agency for coordinating global response to major diseases. The [[World Health Organization|WHO]] maintains Web sites 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 [[World Health Organization|WHO]] produced updates every few days for the duration of the outbreak.<ref> [http://www.who.int/csr/don/archive/disease/severe_acute_respiratory_syndrome/en/index.html WHO SARS]</ref> Beginning in January, [[2004]], the [[World Health Organization|WHO]] has produced similar updates for [[H5N1]].<ref> [http://www.who.int/csr/disease/avian_influenza/en/ WHO H5N1]</ref> These results are [[Global spread of H5N1|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:<ref>[http://www.who.int/csr/disease/en/ WHO EPR]</ref>
*[[Anthrax]]
*[[Avian influenza]]
*[[Crimean-Congo hemorrhagic fever]]
*[[Dengue hemorrhagic fever]]
*[[Ebola hemorrhagic fever]]
*[[Hepatitis]]
*[[Influenza]]
*[[Lassa fever]]
*[[Marburg virus|Marburg hemorrhagic fever]]
*[[Meningococcal disease]]
*[[Bubonic plague|Plague]]
*[[Rift Valley fever]]
*[[Severe Acute Respiratory Syndrome]]
*[[Smallpox]]
*[[Tularaemia]]
*[[Yellow fever]]
==Political challenges==
As the lead organization in global public health, the [[World Health Organization|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 [[World Health Organization|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.<ref>[http://www.who.int/csr/outbreaknetwork/guidingprinciples/en/index.html WHO Outbreak Network]</ref>
==Technical challenges==
Testing for a disease can be expensive, and distinguishing between two diseases can be prohibitively difficult in many countries. One standard means of determining if a person has had a particular disease is to test for the presence of [[antibodies]] that are particular to this disease. In the case of H5N1, for example, there in a low pathogenic H5N1 strain in wild birds in North America that a human could conceivably have antibodies against. It would be extremely difficult to distinguish between antibodies produced by this strain, and antibodies produced by [[H5N1|Asian lineage HPAI A(H5N1)]]. Similar difficulties are common, and make it difficult to determine how widely a disease may have spread.
There is currently little available data on the spread of [[H5N1]] in wild birds in Africa and Asia. Without such data, predicting how the disease might spread in the future is difficult. Information that scientists and decision makers need to make useful medical products and informed decisions for health care, but currently lack include:
* Surveillance of wild bird populations
* Cell cultures of particular strains of diseases
==H5N1==
Surveillance of [[H5N1]] in humans, poultry, wild birds, cats and other animals remains very weak in many parts of Asia and Africa. Much remains unknown about the exact extent of its spread.
H5N1 in China is less than fully reported. Blogs have described many discrepancies between official China government announcements concerning H5N1 and what people in China see with their own eyes. Many reports of total H5N1 cases have excluded China due to widespread disbelief in China's official numbers.<ref>[http://www.who.int/csr/disease/avian_influenza/Timeline_28_10a.pdf WHO] [http://www.who.int/csr/disease/avian_influenza/country/cases_table_2006_01_19/en/index.html WHO] [http://www.who.int/csr/don/2003_02_27a/en/index.html WHO] [http://www.who.int/csr/don/2003_07_04/en/ WHO] </ref>
"Only half the world's human bird flu cases are being reported to the World Health Organization within two weeks of being detected, a response time that must be improved to avert a pandemic, a senior WHO official said Saturday. Dr. Shigeru Omi, WHO's regional director for the Western Pacific, said it is estimated that countries would have only two to three weeks to stamp out, or at least slow, a pandemic flu strain after it began spreading in humans."<ref> [http://abcnews.go.com/Health/wireStory?id=1931433 ABC News] from AP published May 7, 2006</ref>
Dr. [[David Nabarro]], chief avian flu coordinator for the [[United Nations]], says avian flu has too many unanswered questions.<ref> [http://www.iht.com/articles/2006/03/27/news/worrier.php NYT article picked up by IHT]</ref><ref name=IISD>[http://www.iisd.ca/ymb/ais/ymbvol123num1e.html International Institute for Sustainable Development (IISD)] ''SCIENTIFIC SEMINAR ON AVIAN INFLUENZA, THE ENVIRONMENT AND MIGRATORY BIRDS ON 10-11 APRIL 2006'' published 14 April 2006. </ref>
CIDRAP reported on August 25,2006 on a [http://wildlifedisease.nbii.gov/ai/ new US government Web site] that allows the public to view current information about testing of wild birds for H5N1 avian influenza which is part of a national wild-bird surveillance plan that "includes five strategies for early detection of highly pathogenic avian influenza. Sample numbers from three of these will be available on HEDDS: live wild birds, subsistence hunter-killed birds, and investigations of sick and dead wild birds. The other two strategies involve domestic bird testing and environmental sampling of water and wild-bird droppings. [...] A map on the new USGS site shows that 9,327 birds from Alaska have been tested so far this year, with only a few from most other states. Last year officials tested just 721 birds from Alaska and none from most other states, another map shows. The goal of the surveillance program for 2006 is to collect 75,000 to 100,000 samples from wild birds and 50,000 environmental samples, officials have said."<ref> [http://www.cidrap.umn.edu/cidrap/content/influenza/avianflu/news/aug2506wildbirds.html CIDRAP News] article ''New Web tool tracks H5N1 testing of US wild birds'' published August 25, 2006</ref>
==See also==
*[[1985 World Health Organization AIDS surveillance case definition]]
*[[AIDS defining clinical condition]]
*[[Clinical surveillance]]
*[[Council of State and Territorial Epidemiologists]]
*[[EWRS]]
*[[GIDEON-Global Infectious Disease Epidemiology Network]]
*[[Infection control]]
*[[List of notifiable diseases]]
*[[Mass surveillance]]
*[[STD testing]]
*[[UK statutory notification system]]
==Further reading==
*[http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5325a1.htm CDC - Update: Influenza Activity --- United States and Worldwide, 2003--04 Season, and Composition of the 2004--05 Influenza Vaccine]
*[http://www.who.int/csr/outbreaknetwork/en/ Global Outbreak Alert & Response Network]
*[http://www.who.int/csr/alertresponse/en/ WHO Alert & Response Operations]
*[http://www.who.int/csr/don/archive/disease/severe_acute_respiratory_syndrome/en/index.html WHO Severe Acute Respiratory Syndrome Web site]
*[http://www.who.int/csr/disease/avian_influenza/en/ WHO Avian Influenza Web site]
*[http://www.promedmail.org/pls/promed/f?p=2400:1000 ProMED-mail] The global electronic reporting system for outbreaks of emerging infectious diseases & toxins, open to all sources. [[ProMED-mail]], the Program for Monitoring Emerging Diseases, is a program of the [[International Society for Infectious Diseases]] with the support and encouragement of the [[Federation of American Scientists]] and [[SatelLife]]. [http://www.cdc.gov/ncidod/eid/vol7no3_supp/woodall.htm] [http://www.isid.org/]
==References==
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[[Category:Epidemiology]]