Swine flu outbreak

Pigs, as well as humans, can harbor influenza viruses adapted to other species, allowing the viruses to exchange genes and create a pandemic strain.

The 2009 swine flu outbreak is an epidemic that began in April 2009 with a new strain of influenza virus. Although commonly called swine flu, this new strain has not been found in swine.^[51] It is also known as Mexican flu,^[52]North American influenza,^[53] and 2009 H1N1 flu.^[52] On April 30, 2009, the World Health Organization began to call it influenza A(H1N1).^[54] The outbreak is believed to have started in March 2009.^[55] Local outbreaks of an influenza-like illness were first detected in three areas of Mexico, but the virus responsible was not clinically identified as a new strain until April 24, 2009. Following the identification, its presence was soon confirmed in various Mexican states and in Mexico City. Within days, isolated cases (and suspected cases) were identified elsewhere in Mexico, the U.S., and several other Northern Hemisphere countries.

By April 28, the new strain was confirmed to have spread to Spain, the United Kingdom, New Zealand, and Israel, and the virus was suspected in many other nations, with a total of over 3,000 candidate cases, prompting the World Health Organization (WHO) to change its pandemic alert phase to "Phase 5",^[56][57][58] which denotes "widespread human infection". Despite the scale of the alert, the WHO stated on April 29 that the majority of people infected with the virus have made a full recovery without need of medical attention or antiviral drugs.

The new strain is an apparent reassortment of four strains of influenza A virus subtype H1N1.^[59] Analysis at the United States Centers for Disease Control and Prevention (CDC) identified the four component strains as one endemic in humans, one endemic in birds, and two endemic in pigs (swine).^[59] One swine strain was widespread in the United States, the other in Eurasia.^[59] The common human H1N1 influenza virus affects millions of people every year, according to the WHO, "In annual influenza epidemics 5–15% of the population are affected with upper respiratory tract infections. Which results in between 250,000 and 500,000 deaths every year around the world. "^[60] In industrialized countries most of these deaths occur in those 65 or older.^[60]

In late April both the United Nations WHO and the U.S. CDC expressed serious concern about the situation, as it had the potential to become a flu pandemic due to the novelty of the influenza strain, its transmission from human to human, and the unusually high mortality rate in Mexico.^[61] On April 25, 2009, the WHO formally determined the situation to be a "public health emergency of international concern", with knowledge lacking in regard to "the clinical features, epidemiology, and virology of reported cases and the appropriate responses".^[62] Government health agencies around the world also expressed concerns over the outbreak and are monitoring the situation closely. Up to around 300 U.S. schools have closed as the disease became more widespread in the U.S.,^{[63][64][65][66][67]} the same day the Mexican government ordered a shutdown of all non-essential activities in the government and private sector, amounting to a shutdown of most of the country's economy.^[68]

References

Links

• U.S. Government swine, avian and pandemic flu portal
• Pandemic Flu Planning Checklist for Individuals and Families
• Global map of reported H1N1 outbreaks in 2009
• H1N1 swine flu outbreak timeline
• Swine Flu Outbreak, Influenza Virus Resource — sequences and related resources (GenBank, NCBI)
• BioHealthBase Bioinformatics Resource Center Database of influenza genomic sequences and related information.
• Medical Encyclopedia Medline Plus: Swine Flu

UN World Health Organization (WHO)

• Swine influenza, at the World Health Organization
  • RSS feed
• WHO's current Pandemic Influenza Phase
• @whonews twitter account

USA Centers for Disease Control (CDC)

• Swine Influenza (Flu) portal
  • Guidance for Clinicians on Identifying and Caring for Patients with Swine-origin Influenza A (H1N1) Virus Infection
  • Interim Guidance on Case Definitions for Swine Influenza A (H1N1) Human Case Investigations for state and local health department investigations, defines confirmed, probable and suspected
• Social Media Tools, inc. Swine Flu (mobile information, widgets, videos, podcasts, RSS feeds, social networking, etc.)

Pan-American Health Organization (PAHO)

• Swine Influenza portal
  • Influenza cases by a new sub-type: Regional Update (28 April 2009 13:00 WDC) (Epidemiological Alerts Vol. 6, No. 14)

European Centre for Disease Prevention and Control (ECDC)

• Threat Assessment for Swine Influenza at 19:00 hours 24 April 09
• Swine Influenza Information Home
  • ECDC H1N1 Situation Report
  • Swine Influenza FAQs
  • ECDC Pandemic Preparedness Report

This guide is licensed under the GNU Free Documentation License. It uses material from the Wikipedia.

Video: Symptoms of Swine Flu