Swine flu outbreak international 'public health emergency': WHO
Nova Scotia students among first suspected Canadian cases
Last Updated: Saturday, April 25, 2009 | 11:48 PM ET Comments435Recommend337
CBC News
Hiram Diaz, 8, gives his six-year-old sister Adely Diaz a ride on the pegs of his bicycle while they wear protective masks Saturday near the market where their parents own a store in Mexico City.Hiram Diaz, 8, gives his six-year-old sister Adely Diaz a ride on the pegs of his bicycle while they wear protective masks Saturday near the market where their parents own a store in Mexico City. (Julio Cortez/Associated Press-Houston Chronicle)Calling the swine flu outbreak in Mexico and the United States a "public health emergency of international concern," the World Health Organization asked countries around the world Saturday to step up their reporting and surveillance of influenza.
The move signals that the WHO fears the outbreak could spread to other countries and is calling for a co-ordinated international response to contain it.
CBC News has learned that students in Nova Scotia are among the first suspected Canadian cases of the virus. Nose and throat swabs collected from them have been sent to the national laboratory in Winnipeg for testing.
Elsewhere:
* As many as 81 flu deaths are suspected and 20 are confirmed, with more than 1,000 people ill across Mexico. The Mexican government has given its health department the power to isolate patients and inspect homes in the swine flu outbreak. The mayor of Mexico City cancelled all public events until further notice and classes have been suspended until May 6.
* Eleven cases are confirmed in the U.S. — in California, Texas and Kansas. All are expected to recover. At least eight students at a New York City high school likely have the swine flu but it won't be known whether it is the same strain of virus that killed people in Mexico until testing is completed.
Passengers, wearing surgical masks as a precaution against infection, arrive at the airport in Tijuana, Mexico, on Saturday.Passengers, wearing surgical masks as a precaution against infection, arrive at the airport in Tijuana, Mexico, on Saturday. (Guillermo Arias/Associated Press)Dr. Margaret Chan, director general of the WHO, said the outbreak involves "an animal strain of the H1N1 virus and it has pandemic potential," though it's too early to announce a full pandemic alert.
The organization uses six phases to categorize the risks of such an outbreak and its pandemic alert level is currently at Phase 3, for very limited human-to-human transmission.
Phase 6 is a full "pandemic"— sustained human-to-human transmission of disease across national borders.
"The situation is evolving quickly," said Chan. "A new disease is by definition poorly understood. We do not yet have a complete picture of the epidemiology or the risk, including possible spread beyond the currently affected areas."
Swine flu is a respiratory disease of pigs caused by type-A flu viruses. Human cases of swine flu are uncommon but can occur in people who are exposed to pigs and can be spread from person to person.
Symptoms include fever of more than 37.8 C (100 degrees F), body aches, coughing, sore throat, respiratory congestion and, in some cases, diarrhea and vomiting.
Health officials are worried because people appear to have no immunity to the virus, a combination of bird, swine and human influenzas.
Human-to-human transmission of swine flu is thought to occur in the same way as seasonal influenza — through coughing and sneezing, or touching contaminated surfaces.
A Toronto infection control specialist said it's important to keep the outbreak in perspective.
"This sounds like a pandemic — while it's not trivial — that is less severe. And less severe is something that we spent a lot of time planning for and a lot of time working on," Dr. Allison McGeer, director of infection control at Mount Sinai Hospital told CBC News.
While the cases in Mexico sound like a large number, "in truth for influenza, that's a very small number," she added. "You need to remember that in Canada alone, which is not that much bigger than Mexico City actually in population terms, 4,000 people die of seasonal flu every year."
With files from The Associated Press
Read more: http://www.cbc.ca/world/story/2009/04/25/flu-mexico-090425.html#ixzz0gwe3SOEH
Monday, March 1, 2010
Thursday, February 18, 2010
SWINE FLUE MEDICINE
SWINE FLUE MEDICINE
What is swine flu (novel H1N1 influenza A swine flu)?
Swine flu (swine influenza) is a respiratory disease caused by viruses (influenza viruses) that infect the respiratory tract of pigs and result in nasal secretions, a barking-like cough, decreased appetite, and listless behavior. Swine flu produces most of the same symptoms in pigs as human flu produces in people. Swine flu can last about one to two weeks in pigs that survive. Swine influenza virus was first isolated from pigs in 1930 in the U.S. and has been recognized by pork producers and veterinarians to cause infections in pigs worldwide. In a number of instances, people have developed the swine flu infection when they are closely associated with pigs (for example, farmers, pork processors), and likewise, pig populations have occasionally been infected with the human flu infection. In most instances, the cross-species infections (swine virus to man; human flu virus to pigs) have remained in local areas and have not caused national or worldwide infections in either pigs or humans. Unfortunately, this cross-species situation with influenza viruses has had the potential to change. Investigators think the 2009 swine flu strain, first seen in Mexico, should be termed novel H1N1 flu since it is mainly found infecting people and exhibits two main surface antigens, H1 (hemagglutinin type 1) and N1 (neuraminidase type1). Recent investigations show the eight RNA strands from novel H1N1 flu have one strand derived from human flu strains, two from avian (bird) strains, and five from swine strains.
Why is swine flu (H1N1) now infecting humans?
Many researchers now consider that two main series of events can lead to swine flu (and also avian or bird flu) becoming a major cause for influenza illness in humans.
First, the influenza viruses (types A, B, C) are enveloped RNA viruses with a segmented genome; this means the viral RNA genetic code is not a single strand of RNA but exists as eight different RNA segments in the influenza viruses. A human (or bird) influenza virus can infect a pig respiratory cell at the same time as a swine influenza virus; some of the replicating RNA strands from the human virus can get mistakenly enclosed inside the enveloped swine influenza virus. For example, one cell could contain eight swine flu and eight human flu RNA segments. The total number of RNA types in one cell would be 16; four swine and four human flu RNA segments could be incorporated into one particle, making a viable eight RNA segmented flu virus from the 16 available segment types. Various combinations of RNA segments can result in a new subtype of virus (known as antigenic shift) that may have the ability to preferentially infect humans but still show characteristics unique to the swine influenza virus (see Figure 1). It is even possible to include RNA strands from birds, swine, and human influenza viruses into one virus if a cell becomes infected with all three types of influenza (for example, two bird flu, three swine flu, and three human flu RNA segments to produce a viable eight-segment new type of flu viral genome). Formation of a new viral type is considered to be antigenic shift; small changes in an individual RNA segment in flu viruses are termed antigenic drift and result in minor changes in the virus. However, these can accumulate over time to produce enough minor changes that cumulatively change the virus' antigenic makeup over time (usually years).
Second, pigs can play a unique role as an intermediary host to new flu types because pig respiratory cells can be infected directly with bird, human, and other mammalian flu viruses. Consequently, pig respiratory cells are able to be infected with many types of flu and can function as a "mixing pot" for flu RNA segments (see Figure 1). Bird flu viruses, which usually infect the gastrointestinal cells of many bird species, are shed in bird feces. Pigs can pick these viruses up from the environment and seem to be the major way that bird flu virus RNA segments enter the mammalian flu virus population.
Picture of antigenic shift and antigenic drift in swine flu (H1N1).
Figure 1.
* 1
* 2
* 3
* 4
* 5
* 6
* 7
* 8
* 9
* 10
* 11
* 12
* 13
* Next »
* Swine Flu Index
* Glossary
Next: What are the symptoms of swine flu (H1N1)? »
Swine Flu - Concerns
The MedicineNet physician editors ask:
Are you concerned about contracting swine flu? Has it affected your travel plans?
Comment submissions for this question have ended. Patient Discussions FAQs
See 29 Viewer Comments
View Comments
The following Patient Discussions have not been medically reviewed. See additional information.
Printer-Friendly Format | Email to a Friend
Suggested Reading by Our Doctors
MedicineNet Doctors
* oseltamivir, Tamiflu - Learn about Tamiflu (oseltavivir), a drug prescribed for the treatment of flu infections including H1N1 (swine flu) infections. Tamiflu is recommended for pregnant women, adults, and children one year of age or older.
* Flu Vaccine - Get the facts about influenza vaccine (flu shot) ingredients, side effects and vaccination effectiveness. Learn who should (children, pregnant women, elderly) and shouldn't get a flu shot.
* Pneumonia - Learn pneumonia symptoms, causes, treatment, signs, diagnosis and types: viral and bacterial (Pneumocystis carinii, Klebsiella, Mycoplasma, Chlamydia pneumoniae).
Read more Swine Flu related articles »
Latest Medical News
* Malaria Parasite Infects Gorillas, Not Just Humans
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* 55 Million Americans Had H1N1 Swine Flu
* Rheumatoid Arthritis Drug Lowers Flu Shot Effectiveness
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Swine Flu
Seizure (Epilepsy) »
Introduction
Few experiences match the drama of a convulsive seizure. A person having a severe seizure may cry out, fall to the floor unconscious, twitch or move uncontrollably, drool, or even lose bladder control. Within minutes, the attack is over, and the person regains consciousness but is exhausted and dazed. This is the image most people have when they hear the word epilepsy. However, this type of seizure -- a generalized tonic-clonic seizure -- is only one kind of epilepsy. There are many other kinds, each with a different set of symptoms.
Epilepsy was one of the first brain disorders to be described. It was mentioned in ancient Babylon more than 3,000 years ago. The strange behavior caused by some seizures has contributed through the ages to many superstitions and prejudices. The word epilepsy is derived from the Greek word for "attack." People once thought that those with epilepsy were being visited by demons or gods. However, in 400...
Read the Seizure (Epilepsy) article »
Featured on MedicineNet
* Is Sleepiness Hurting You?
* Causes of Fatigue Slideshow
* Quiz: Sleep and Crazy Hours on the Job
Top 10
Swine Flu Related Articles
* Aches, Pain, Fever
* Chronic Cough
* Diarrhea
* Flu Vaccination
* Headache
* Influenza
* Nausea and Vomiting
* Pneumonia
* Seizure
* Sore Throat
* Complete List »
Cold and Flu Topics
* Strep Throat
* Sore Throat
* H1N1 Swine Flu
* Fever
* Fever Reducers
* XML Cold and Flu RSS
Ringworm Slideshow
Latest Cold and Flu News
* Flu Test Most Accurate for Young Kids
* Flu Vaccine Safe for Infants 6 Weeks Old
* H1N1 Swine Flu Down, Not Out
* As Swine Flu Fades, Experts Ponder Next Season
* Swine Flu: Preventive Steps for Summer Campers
* Want More News? Sign Up for MedicineNet Newsletters!
* XML Health News Feed
What is swine flu (novel H1N1 influenza A swine flu)?
Swine flu (swine influenza) is a respiratory disease caused by viruses (influenza viruses) that infect the respiratory tract of pigs and result in nasal secretions, a barking-like cough, decreased appetite, and listless behavior. Swine flu produces most of the same symptoms in pigs as human flu produces in people. Swine flu can last about one to two weeks in pigs that survive. Swine influenza virus was first isolated from pigs in 1930 in the U.S. and has been recognized by pork producers and veterinarians to cause infections in pigs worldwide. In a number of instances, people have developed the swine flu infection when they are closely associated with pigs (for example, farmers, pork processors), and likewise, pig populations have occasionally been infected with the human flu infection. In most instances, the cross-species infections (swine virus to man; human flu virus to pigs) have remained in local areas and have not caused national or worldwide infections in either pigs or humans. Unfortunately, this cross-species situation with influenza viruses has had the potential to change. Investigators think the 2009 swine flu strain, first seen in Mexico, should be termed novel H1N1 flu since it is mainly found infecting people and exhibits two main surface antigens, H1 (hemagglutinin type 1) and N1 (neuraminidase type1). Recent investigations show the eight RNA strands from novel H1N1 flu have one strand derived from human flu strains, two from avian (bird) strains, and five from swine strains.
Why is swine flu (H1N1) now infecting humans?
Many researchers now consider that two main series of events can lead to swine flu (and also avian or bird flu) becoming a major cause for influenza illness in humans.
First, the influenza viruses (types A, B, C) are enveloped RNA viruses with a segmented genome; this means the viral RNA genetic code is not a single strand of RNA but exists as eight different RNA segments in the influenza viruses. A human (or bird) influenza virus can infect a pig respiratory cell at the same time as a swine influenza virus; some of the replicating RNA strands from the human virus can get mistakenly enclosed inside the enveloped swine influenza virus. For example, one cell could contain eight swine flu and eight human flu RNA segments. The total number of RNA types in one cell would be 16; four swine and four human flu RNA segments could be incorporated into one particle, making a viable eight RNA segmented flu virus from the 16 available segment types. Various combinations of RNA segments can result in a new subtype of virus (known as antigenic shift) that may have the ability to preferentially infect humans but still show characteristics unique to the swine influenza virus (see Figure 1). It is even possible to include RNA strands from birds, swine, and human influenza viruses into one virus if a cell becomes infected with all three types of influenza (for example, two bird flu, three swine flu, and three human flu RNA segments to produce a viable eight-segment new type of flu viral genome). Formation of a new viral type is considered to be antigenic shift; small changes in an individual RNA segment in flu viruses are termed antigenic drift and result in minor changes in the virus. However, these can accumulate over time to produce enough minor changes that cumulatively change the virus' antigenic makeup over time (usually years).
Second, pigs can play a unique role as an intermediary host to new flu types because pig respiratory cells can be infected directly with bird, human, and other mammalian flu viruses. Consequently, pig respiratory cells are able to be infected with many types of flu and can function as a "mixing pot" for flu RNA segments (see Figure 1). Bird flu viruses, which usually infect the gastrointestinal cells of many bird species, are shed in bird feces. Pigs can pick these viruses up from the environment and seem to be the major way that bird flu virus RNA segments enter the mammalian flu virus population.
Picture of antigenic shift and antigenic drift in swine flu (H1N1).
Figure 1.
* 1
* 2
* 3
* 4
* 5
* 6
* 7
* 8
* 9
* 10
* 11
* 12
* 13
* Next »
* Swine Flu Index
* Glossary
Next: What are the symptoms of swine flu (H1N1)? »
Swine Flu - Concerns
The MedicineNet physician editors ask:
Are you concerned about contracting swine flu? Has it affected your travel plans?
Comment submissions for this question have ended. Patient Discussions FAQs
See 29 Viewer Comments
View Comments
The following Patient Discussions have not been medically reviewed. See additional information.
Printer-Friendly Format | Email to a Friend
Suggested Reading by Our Doctors
MedicineNet Doctors
* oseltamivir, Tamiflu - Learn about Tamiflu (oseltavivir), a drug prescribed for the treatment of flu infections including H1N1 (swine flu) infections. Tamiflu is recommended for pregnant women, adults, and children one year of age or older.
* Flu Vaccine - Get the facts about influenza vaccine (flu shot) ingredients, side effects and vaccination effectiveness. Learn who should (children, pregnant women, elderly) and shouldn't get a flu shot.
* Pneumonia - Learn pneumonia symptoms, causes, treatment, signs, diagnosis and types: viral and bacterial (Pneumocystis carinii, Klebsiella, Mycoplasma, Chlamydia pneumoniae).
Read more Swine Flu related articles »
Latest Medical News
* Malaria Parasite Infects Gorillas, Not Just Humans
* No Role Found for Birds in Swine Flu Pandemic
* 55 Million Americans Had H1N1 Swine Flu
* Rheumatoid Arthritis Drug Lowers Flu Shot Effectiveness
Privacy Policy
Women's Health
Find out what women really need.
Your Guide to Symptoms & Signs: Pinpoint Your Pain
From WebMD
Featured Centers
* Better Health Checkup: 5 Risks You Can't Ignore
* Got a Nicotine Craving? How To Tame It
* Healthy Home: To Buy or Not to Buy Organic?
Health Solutions From Our Sponsors
* Osteoporosis Info
* BPH Treatment & Savings
* MS Rx Options
Swine Flu
Seizure (Epilepsy) »
Introduction
Few experiences match the drama of a convulsive seizure. A person having a severe seizure may cry out, fall to the floor unconscious, twitch or move uncontrollably, drool, or even lose bladder control. Within minutes, the attack is over, and the person regains consciousness but is exhausted and dazed. This is the image most people have when they hear the word epilepsy. However, this type of seizure -- a generalized tonic-clonic seizure -- is only one kind of epilepsy. There are many other kinds, each with a different set of symptoms.
Epilepsy was one of the first brain disorders to be described. It was mentioned in ancient Babylon more than 3,000 years ago. The strange behavior caused by some seizures has contributed through the ages to many superstitions and prejudices. The word epilepsy is derived from the Greek word for "attack." People once thought that those with epilepsy were being visited by demons or gods. However, in 400...
Read the Seizure (Epilepsy) article »
Featured on MedicineNet
* Is Sleepiness Hurting You?
* Causes of Fatigue Slideshow
* Quiz: Sleep and Crazy Hours on the Job
Top 10
Swine Flu Related Articles
* Aches, Pain, Fever
* Chronic Cough
* Diarrhea
* Flu Vaccination
* Headache
* Influenza
* Nausea and Vomiting
* Pneumonia
* Seizure
* Sore Throat
* Complete List »
Cold and Flu Topics
* Strep Throat
* Sore Throat
* H1N1 Swine Flu
* Fever
* Fever Reducers
* XML Cold and Flu RSS
Ringworm Slideshow
Latest Cold and Flu News
* Flu Test Most Accurate for Young Kids
* Flu Vaccine Safe for Infants 6 Weeks Old
* H1N1 Swine Flu Down, Not Out
* As Swine Flu Fades, Experts Ponder Next Season
* Swine Flu: Preventive Steps for Summer Campers
* Want More News? Sign Up for MedicineNet Newsletters!
* XML Health News Feed
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