Outbreak

For other uses of "Outbreak", see Outbreak (disambiguation).

Virus outbreaks occur when a virusbypasses infection control measures and a relatively high number of infections are observed where no cases or sporadic cases occurred in the past. The study of pathogenicviral outbreaks is a branch of epidemiologyand usually refers to virus outbreaks that make people, animals, or plants sick. As with bacterial outbreaks, viral outbreaks are classified as sporadic (occasional occurrence), endemic(regular cases often occurring in a region), epidemic(an unusually high number of cases in a region), or pandemic(a global epidemic).

Major human epidemic viruses include influenza, Human Immunodeficiency Virus (HIV), measles, and rubella. Smallpoxhas been eradicated as a major epidemic virus, however emerging viruses and engineered viruses pose a significant challenge for the future. HIV is no longer considered an emerging virus as it was discovered over 20 years ago, and it has grown to become a major epidemic. Other emerging viruses include Severe Acute Respiratory Syndrome (SARS), henipavirusesand Ebola* which have been contained through aggressive contact tracingand isolation of patients and suspected carriers of the disease.

Hoof and mouth disease(UK foot and mouth disease) is a major animal epidemic virus affecting the agricultural industry of any country with an outbreak. It affects cows, pigs, sheep, goats, deer and other cloven hoofed animals.

Ebola virus (the most deadly virus known) is at a disadvantage compared to other viruses, this virus kills its host too quickly, and thus there is insufficient time for an infected person to spread the disease. Therefore, it is more likely that Ebola outbreaks will destroy themselves, however, they will cause certain death to almost the entire area at which they break out.

Types

• Common source
• Propagated
• Zoonotic

See also

• epidemiology
• bacterium
• virus

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It uses material from the http://en.wikipedia.org/wiki/Outbreak Wikipedia article Outbreak.