The 2009 flu pandemic is a global outbreak of a new strain of an influenza A virus subtype H1N1, officially referred to as the novel H1N1,http://en.wikipedia.org/wiki/2009_flu_pandemic#cite_note-1 first identified in April 2009, and commonly called swine flu in North America and Mexican flu in some countries. The illness produced by this virus is generally mild and self-limiting,http://en.wikipedia.org/wiki/2009_flu_pandemic#cite_note-DonFinleySept25-2with some exceptions. A person can be in a high risk group and thus more vulnerable.
According to an article in the New england Journal of Medicine, the virus is thought to be a reassortment of four known strains of influenza A virus one endemic in humans, one endemic in birds and two endemic in pigs (swine). Transmission of the new strain is human-to-human. Cooked pork products will not transmit the virus.http://en.wikipedia.org/wiki/2009_flu_pandemic#cite_note-5
The outbreak began in Mexico, with some evidence that Mexico had already been in the midst of an epidemichttp://en.wikipedia.org/wiki/Epidemic for months before the outbreak was officially recognized as such. Soon thereafter the Mexican government closed down most of Mexico city's public and private offices and facilities to help contain the spread. In early June, as the virus spread globally, the World Health organisation (WHO) declared the outbreak to be a pandemic, but also noted that most of the illnesses were of moderate severity. As the virus quickly spread globally, many clinics were overwhelmed by testing and treating patients, and the WHO and the US Centers for disease Control and Prevention (CDC) eventually stopped reporting cumulative cases to focus more on large outbreaks.http://en.wikipedia.org/wiki/2009_flu_pandemic#cite_note-WHO-Briefing-Note-3-6http://en.wikipedia.org/wiki/2009_flu_pandemic#cite_note-NYT-7-16-09-7
The virus spreads via coughing,sneezing,or touching contaminated surfaces and then touching the nose or mouth. Symptoms, which last up to a week, are similar to those of seasonal flu, and can include fever, sneezes, sore throat, coughs, headache, and muscle or joint pains.The CDC notes that cases worldwide were usually mild, and most hospitalizations and deaths had been of persons that also had underlying conditions such as asthma, diabetes, obesity, heart disease, or a weakened immune system. Secondary infections, such as those caused by bacterial pneumonia or a relapse of the illness with worse symptoms, are considered very serious and require medical treatment.To avoid spreading the infection, the CDC recommended that those with symptoms stay home from school, work, and crowded settings; wearing facial masks was reported to be of "limited benefit".http://en.wikipedia.org/wiki/2009_flu_pandemic#cite_note-LATimes4-30-09-10
According to an article in the New england Journal of Medicine, the virus is thought to be a reassortment of four known strains of influenza A virus one endemic in humans, one endemic in birds and two endemic in pigs (swine). Transmission of the new strain is human-to-human. Cooked pork products will not transmit the virus.http://en.wikipedia.org/wiki/2009_flu_pandemic#cite_note-5
The outbreak began in Mexico, with some evidence that Mexico had already been in the midst of an epidemichttp://en.wikipedia.org/wiki/Epidemic for months before the outbreak was officially recognized as such. Soon thereafter the Mexican government closed down most of Mexico city's public and private offices and facilities to help contain the spread. In early June, as the virus spread globally, the World Health organisation (WHO) declared the outbreak to be a pandemic, but also noted that most of the illnesses were of moderate severity. As the virus quickly spread globally, many clinics were overwhelmed by testing and treating patients, and the WHO and the US Centers for disease Control and Prevention (CDC) eventually stopped reporting cumulative cases to focus more on large outbreaks.http://en.wikipedia.org/wiki/2009_flu_pandemic#cite_note-WHO-Briefing-Note-3-6http://en.wikipedia.org/wiki/2009_flu_pandemic#cite_note-NYT-7-16-09-7
The virus spreads via coughing,sneezing,or touching contaminated surfaces and then touching the nose or mouth. Symptoms, which last up to a week, are similar to those of seasonal flu, and can include fever, sneezes, sore throat, coughs, headache, and muscle or joint pains.The CDC notes that cases worldwide were usually mild, and most hospitalizations and deaths had been of persons that also had underlying conditions such as asthma, diabetes, obesity, heart disease, or a weakened immune system. Secondary infections, such as those caused by bacterial pneumonia or a relapse of the illness with worse symptoms, are considered very serious and require medical treatment.To avoid spreading the infection, the CDC recommended that those with symptoms stay home from school, work, and crowded settings; wearing facial masks was reported to be of "limited benefit".http://en.wikipedia.org/wiki/2009_flu_pandemic#cite_note-LATimes4-30-09-10
Initial outbreaks
It is not known where the virus originated.http://en.wikipedia.org/wiki/2009_flu_pandemic#cite_note-Nature-29http://en.wikipedia.org/wiki/2009_flu_pandemic#cite_note-30Analysis
articles in scientific journals have suggested that the H1N1 strain responsible for the current outbreak first evolved around September 2008 and circulated in the human population for several months before the first cases were identified as being due to a new strain.http://en.wikipedia.org/wiki/2009_flu_pandemic#cite_note-Nature-29http://en.wikipedia.org/wiki/2009_flu_pandemic#cite_note-31http://en.wikipedia.org/wiki/2009_flu_pandemic#cite_note-32
Mexico
The virus was first reported in two U.S. children in March 2009, but health officials have said that it apparently infected people as early as January 2008 in Mexico.http://en.wikipedia.org/wiki/2009_flu_pandemic#cite_note-Reuters6-11-33 The outbreak was first detected in Mexico city on March 18, 2009,http://en.wikipedia.org/wiki/2009_flu_pandemic#cite_note-NYT4-26-34 immediately after the outbreak was officially announced, Mexico requested material support from the U.S., and within days of the outbreak Mexico City was "effectively shut down."http://en.wikipedia.org/wiki/2009_flu_pandemic#cite_note-Fox5-12-35 Some countries canceled flights to Mexico while others halted trade. Calls to close the border to contain the spread were rejected.http://en.wikipedia.org/wiki/2009_flu_pandemic#cite_note-Fox5-12-35
Mexico already had hundreds of cases before the outbreak was officially recognized, and was therefore in the midst of a "silent epidemic".http://en.wikipedia.org/wiki/2009_flu_pandemic#cite_note-Fox5-12-35 As a result, Mexico was reporting only the most serious cases, possibly leading to a skewed initial estimate of the case fatality rate."
United States
The new strain was first diagnosed in two children, neither of whom had been in contact with pigs, by the CDC, first on April 14, 2009 in San Diego county, California and a few days later in nearby Imperial County, California http://en.wikipedia.org/wiki/2009_flu_pandemic#cite_note-MMWR5815a5-36 (it was not identified as a new strain in Mexico until 24 April).http://en.wikipedia.org/wiki/2009_flu_pandemic#cite_note-37While approximately 26,000 people have been diagnosed with "the novel" H1N1 in the US during this outbreak, fewer than 600 have died, making this strain about one third as deadly as the common flu.
Symptoms and severity
The symptoms of swine flu are similar to other influenza, and may include a fever, coughing, headaches, pain in the muscles, and neurological problems were also reported in some cases.http://en.wikipedia.org/wiki/2009_flu_pandemic#cite_note-CDC090724-61http://en.wikipedia.org/wiki/2009_flu_pandemic#cite_note-CDCgeninfo-62People at higher risk of serious complications include people age 65 and older, children younger than 5 years old, children with neurodevelopmental conditions, pregnant women, and people of any age with underlying medical conditions, such as asthma, diabetes, obesity, heart disease, or a weakened immune system (e.g., taking immunosuppressive medications or infected with HIV).http://en.wikipedia.org/wiki/2009_flu_pandemic#cite_note-NYT5-27-63Most hospitalizations in the U.S. were people with such underlying conditions, according to the CDC.http://en.wikipedia.org/wiki/2009_flu_pandemic#cite_note-64 and runny nose. Diarrhea, vomiting or joints, sore throat, chills, fatigue,
Adults In adults, shortness of breath, pain in the chest or abdomen, sudden dizziness or confusion may require emergency care. In both children and adults, persistent vomiting or the return of flu-like symptoms that include a fever and cough may require medical attention.http://en.wikipedia.org/wiki/2009_flu_pandemic#cite_note-CDCgeninfo-62
Dr. Thomas R. Frieden, New York City's health commissioner, suggests that people with "underlying conditions" who come down with flu symptoms should consult their doctors first before visiting an "emergency room full of sick people," since it "may actually put them in more danger." This was especially true of pregnant women.http://en.wikipedia.org/wiki/2009_flu_pandemic#cite_note-NYT5-27-63
Children As with the seasonal flu, certain symptoms may require emergency medical attention. In children, signs of respiratory distress include blue lips and skin, rapid breathing, dehydratation, excessive sleeping, seizures,http://en.wikipedia.org/wiki/2009_flu_pandemic#cite_note-65 and significant irritability including a lack of desire to be held. Although "too early" to tell for certain, Dr. Frieden of the CDC has noted that so far the swine flu "seems to be taking a heavier toll among chronically ill children than the seasonal flu usually does." Of the children who have died so far, nearly two-thirds had pre-existing nervous system disorders, such as cerebral palsy, muscular dystrophy, or developmental delays. "Children with nerve and muscle problems may be at especially high risk for complications," the CDC report stated.
Treatment
The Mayo Clinic and Medline listed a number of ways to help ease symptoms, including adequate liquid intake and rest, soup to ease congestion, and over-the-counter drugs to relieve pain.Aspirin was a very effective way to treat fever in adults,http://en.wikipedia.org/wiki/2009_flu_pandemic#cite_note-Mayo-100although in children and adolescents. While over-the-counter drugs relieve symptoms, they do not kill the virus.http://en.wikipedia.org/wiki/2009_flu_pandemic#cite_note-Medline-102 Most patients were expected to recover without medical attention, although those with pre-existing or underlying medical conditions were more prone to complications.http://en.wikipedia.org/wiki/2009_flu_pandemic#cite_note-CDC_symptoms-103 It is still not understood if the currently accepted vaccination is harmless to humans.
According to the CDC, antiviral drugs could be given to treat those who become severely ill, two of which were recommended for swine flu symptoms: oseltamivir (Tamiflu) and zanamivir (Relenza).http://en.wikipedia.org/wiki/2009_flu_pandemic#cite_note-104To be most useful, they were to be given within two days of showing symptoms and "may shorten the illness by a day or so," according to the Mayo Clinic. To help avoid shortages of these drugs, the CDC recommended Tamiflu treatment primarily for people hospitalized with swine flu; people at risk of serious flu complications due to underlying medical conditions; and patients at risk of serious flu complications. The WHO likewise recommended that Tamiflu only be given to particularly vulnerable people and noted that healthy people who catch mild to moderate cases of swine flu didn't need the drug at all.http://en.wikipedia.org/wiki/2009_flu_pandemic#cite_note-Tami1-105
The CDC warned that the indiscriminate use of antiviral medications to prevent and treat influenza could ease the way for drug-resistant strains to emerge which would make the fight against the pandemic that much harder. In addition, a British report found that people often failed to complete a full course of the drug which encouraged resistance.http://en.wikipedia.org/wiki/2009_flu_pandemic#cite_note-Tami1-105
Both medications could have caused side effects, including lightheadedness, nausea, vomiting, loss of appetite, and trouble breathing, and it was recommended that patients discuss possible side effects with their doctor before starting any antiviral medication. Children were reported to be at increased risk of self-injury and confusion after taking Tamiflu.http://en.wikipedia.org/wiki/2009_flu_pandemic#cite_note-Mayo-100The WHO warned against buying anti-viral medications from online sources, estimating that half the drugs sold by online pharmacies without a physical address are counterfeit
