Friday, May 1, 2009
Swine Flu Outbreak rated 'Phase 5'
The Swine-flu outbreak refers to the spread of a new strain of influenza virus that was clinically identified in April 2009. The new virus strain is a type of influenza A (H1N1) virus, commonly called the swine flu. The outbreak has also been called the H1N1 influenza, 2009 H1N1 flu, Mexican flu, or swine-origin influenza.
Although the exact time and location of the outbreak is unknown, it is believed to have been first detected when an influenza-like illness was reported by both health agencies and local news media in Mexico. The virus responsible was clinically identified as a new strain on April 24, 2009. Within days, isolated cases (and suspected cases) were identified elsewhere in Mexico, the U.S., and several other countries. In late April officials from both WHO and the CDC expressed serious concern about the situation, stating that the virus had the potential to become a flu pandemic.
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 4,400 candidate cases, prompting the World Health Organization (WHO) to change its pandemic alert phase to "Phase 5", which is defined as "...human-to-human spread of the virus into at least two countries in one WHO region".