2009 pandemic

This article refers to the flu pandemic of 2009, commonly referred to as swine flu.

The outbreak is a new strain of H1N1-type influenza, that mutated from a number of different flu strains. Cases were found to be made up of genetic elements from: North American swine influenza, North American avian influenza, human influenza, and a swine influenza virus typically found in Asia and Europe.

This new strain of flu does not have a formal name yet. It is commonly referred to as swine flu, but this is incorrect - swine flu is only part of the source of this virus strain. Specific details of this strain can be seen at 2009 A/H1N1.

Human infection & transmission

This strain of H1N1 flu can be transmitted between humans, which is what led to the pandemic. This requires close contact with an infected person, or inhaling infected particles. Examples of transmission could include through coughing/sneezing, through touching an infected surface then touching your mouth.

You can not get swine flu from eating pork. Cooking destroys the influenza virus.

Prevention

Washing your hands regularly, preferably with an alcohol-based hand disinfectant, will significantly reduce the risk of contamination. If you are in a high-risk area, you should avoid directly touching well-touched surfaces (such as door handles). Surgical masks can also reduce the risk of contaminants reaching the mouth or nose, but these need to be well-fitting to the skin to give maximum protection, stopping any contaminants floating around the edges.

See more at How can I protect my family and Category:Advice

Symptoms

Adapted from: the CDC

The symptoms of this flu are similar to the symptoms of a mild infection of regular human seasonal influenza and include fever, lethargy, lack of appetite, and coughing. Some people with swine flu also have reported runny nose, sore throat, nausea, vomiting and diarrhea, although these appear to be side-effects rather than direct symptoms.

Diagnosis

If you are concerned that you (or someone you) know may have flu, you should seek the advice of a medical professional. This gives the best chance of accurate diagnosis and early treatment.

To diagnose an infection, a respiratory specimen (mucus/saliva) would generally need to be collected within the first 4 to 5 days of illness. This is when an infected person is most likely to be infectious. However, some persons, especially children, may shed virus for 10 days or longer. Identification as a swine flu influenza A virus requires sending the specimen for laboratory testing, such as to CDC.

Outbreak history

The outbreak was first detected in Mexico City on 18th March 2009, where a surge in cases of flu-like illness was noticed. This was initially assumed by Mexican authorities to be "late-season flu" and not a new virus strain. However, it was later revealed that a mexican boy, working on a pig farm, had had this strain of flu in February.

After the outbreak was officially announced, Mexico immediately requested material support from the US, and worked closely with the CDC and Canada, sending them suspected samples for testing. Soon after, the CDC helped Mexico build their own lab capability to do faster diagnosis and confirmation of the H1N1 virus in Mexico. Within a few days Mexico City was "effectively shut down," and some countries stopped trade and travel to Mexico. Although many in the U.S. called for shutting the Mexican border to help contain the spread, this was rejected by the government.

As the outbreak spread throughout Mexico and into the U.S., however, scientists were trying to understand why there were so many deaths in Mexico while infections in the United States and Canada were relatively mild and not unusually dangerous compared to seasonal flus. The Washington Post wrote that "the fact that most people infected... had recently been to Mexico... is indirect evidence that the country may have been experiencing a silent epidemic for months."

This is implying that general bad health and overcrowding in Mexico stopped this outbreak being noticed. This also explains the seemingly high mortality rate. A study published May 11 in the journal Science estimated Mexico alone may have already had 23,000 cases of swine flu by April 23, the day it announced the epidemic.

Cases & deaths

As of early June, the flu has been reported in more than 60 countries, mostly in the Northern Hemisphere, with the United States reporting the most cases — more than 10,000, including at least 18 deaths.

It is predicted that the virus will likely continue to spread worldwide, as the Southern Hemisphere is entering the winter months and it becomes flu season. South America already has had more than 3,000 cases, including 1,694 cases, two deaths in Chile and one in Colombia.

On June 6, Melbourne in Australia was reported to be the "swine flu capital of the world". On 11 June there were 1,011 cases in Victoria, mostly in Melbourne; with 1,307 in the country in total. However, Professor Robert Booy from the University of Sydney believes this is due to a strict testing regime leading to a high rate of detection. He implies that the US and Mexico have a much larger infection than has been detected or reported.

Pandemic

On June 11 2009, the WHO declared the outbreak had become a pandemic, by raising the Pandemic Alert Level to six out of six. This refers only to the geographical spread and transmission of the virus, and does not indicate its severity.