Posts Tagged ‘Influenza Viruses’

Author: Katt Mollar

Influenza, commonly known as the flu, is a respiratory illness caused by viruses. There are many different types of flu, from swine flu to the most feared avian flu. This article, however, deals only with the so-called common or seasonal flu. The flu season usually starts in the fall and subsides in late spring. Because of its seasonality, the flu season differs between the Northern and the Southern hemisphere.

On the global scale, flu can affect tens of millions of people and cause 250,000 to 500,000 deaths each year. The United States CDC gives the following statistics. Yearly 5 to 20% of the population get the flu, 200,000 cases are hospitalized due to severe flu complications and 36,000 cases prove to be fatal. Annual healthcare costs approaches US$10 billion

THE FLU is caused by types A, B and C. Each type consists of different subtypes and substrains with A and B being responsible for most epidemics.

(1) Influenza A viruses are of subtypes based on two proteins on the surface of the virus: the hemagglutinin (H) and the neuraminidase (N). The current subtypes of influenza A viruses in humans are A (H1N1) and A (H3N2).

(2) Influenza B viruses do not have subtypes but can be further broken down into different strains.

(3) Influenza C seems to be relatively benign compared to the first two and is not as contagious.

Like many viruses, influenza viruses change with time producing new strains each season. This change occurs by antigenic drift or shift.

(1) Antigenic drift is slow and can lead to new strains after several seasons and is the typical change observed in influenza type B viruses but can also occur in type A.

(2) Antigenic shift happens abruptly and creates a major change that can lead to a new subtype but only occurs in type A.

The influenza viruses attack the epithelial cells lining the respiratory tract starting from the nose, throat, and down to the lungs. They do this by binding using hemagglutinin and neuraminidase proteins on the cells’ surface.

Influenza symptoms may be mild to severe to life-threatening. Symptoms can include high fever, headache, chills, sore muscles, fatigue, dry cough, red, watery eyes, sore throat and runny or stuffy nose. The so-called “tummy flu” symptoms may also occur in children, which include abdominal pain, vomiting, and diarrhea.

The flu symptoms shouldn’t be confused with the ordinary cold, which is another respiratory illness. A cold usually doesn’t cause high fever, muscle pains or stomach symptoms.

The incubation period of the flu can vary from a few days to a week. During this “asymptomatic period”, the infected person is already a carrier of the disease and is therefore highly contagious. The flu can last from a few days to less than two weeks. However, in certain cases, complications can develop which are potentially life-threatening. Some of these complications are bronchitis, pneumonia, sinusitis, and ear infections. Anybody can get the flu but those who are highly susceptible to the flu are young children, the elderly and those with existing chronic health conditions and weakened immune systems.

Flu is very contagious. Direct transmission occurs from person to person via droplets that are released when a person coughs or sneezes. Indirect transmission happens when droplets from an infected person are transferred to inanimate objects, which are then touched by another person.

Flu-like symptoms can also occur with many other diseases. It is therefore sometimes difficult for doctors to diagnose the illness. There are many laboratory tests which can confirm whether a person has the flu or not but they cost money and time and are therefore impractical. However, in times of outbreaks and epidemics, it is important to perform tests. Usually, flu cases are diagnosed based on tests performed in a few individuals within a group. If one or two persons test positive for the flu in a closed environment, then the likelihood of subsequent illnesses within the group as being flu is rather high. Samples for flu testing are usually secretions from the nose and the throat, collected either by sterile swab, nasal wash, or aspiration. There are rapid influenza tests which can give results in 30 minutes. The tests are 70% sensitive in detecting the flu and are prone to false negatives. Another alternative is the more reliable but time consuming viral culture which takes about 3 to 10 days.

Several antiviral pharmacological agents have been approved for the treatment of the flu. Because of the seasonal changes in the types and strains of influenza viruses the recommended anti-flu drugs may change. This season, Tamiflu is the choice for treatment and chemoprophylaxis of persons aged 1 year and older and Relenza is approved for treatment of persons aged 7 years and older. Currently, the CDC discourages the use of previously used anti-flu drugs such as Amantadine and Rimantadine because the current circulating strains of flu viruses are resistant to these drugs.

The ultimate preventive measure against the flu is vaccination. However, again due to the constantly changing nature of the influenza viruses, flu vaccines do not afford 100% and lifetime immunity against the flu. Each season, flu vaccines are updated by adding strains collected and identified from the previous season. Flu vaccines contain different strains of the influenza types A and B but not type C.

Based on the 2005 guidelines of the Federal Advisory Committee on Immunization Practices (ACIP), annual flu shots are recommended for children aged 6 months to 5 years old and adolescents up to 18 years old. Vaccination is also highly recommended for people in key professions which may expose them to the infection and spread it to others. These include health care professionals and those working and living in closed units such as dormitories. Flu shots are usually given prior to flu season and afford protection for about a year. However, it takes about two weeks before the protection kicks in.

Over the years, several types of flu vaccines have been developed.

(1) The intranasal vaccine is the live, attenuated influenza vaccine (LAIV) made from living but weakened flu viruses. LAIV is prescribed for people aged 2 to 49 years old. LAIV should not be given to pregnant women, children under 2 years old, adults above 40 years old, and chronic medical conditions including compromised immune system disorders.

(2) The inactivated vaccine, the common flu shot is made from different strains of killed flu viruses. This vaccine is recommended for children from 6 months to 18 years old as well as those older than 50 years old. In addition, people who are not qualified to receive LAIV (as listed above) are recommended to have this vaccine.

Like all pharmacological agents, flu shots can have some side effects. Most of these side effects are mild. Rare severe side effects, mainly in the form of allergic reactions have been reported.

Some inactivated flu vaccines have contained thimerosal in the past, a form of mercury used as preservatives for vaccines. In recent years, there have been concerns about the link between thimerosal and autism in children. This controversy continues although no ample scientific evidence is available to prove this link.

Perhaps the main shortcoming of the flu shot is its efficacy, which is highly dependent on how well the vaccine is matched to the circulating influenza viruses of that season. For this reason, the efficacy of the vaccine in protecting healthy adults from the flu is only 70 to 90% and even less in children and the elderly.

The Global Influenza Surveillance Network (GISN) was set up in 1952 and currently includes more than 110 laboratories in 83 countries. It has recently set up FluNet, a web-based tool for surveillance, reporting, and alert mechanisms. The European Influenza Surveillance Scheme (EISS) issues a weekly report on influenza activity in 30 countries. It collects data from a network of more than 25,000 sentinel doctors covering a total population of 498 million people in Europe. In the US, the CDC is responsible for national influenza surveillance and is dependent on reports from more than 1500 sentinel doctors.

Google Flu Trends, being the new kid on the block, claims that it can estimate flu activity up “to two weeks faster than traditional flu surveillance systems” and bases its predictions on the number of people searching for flu-related topics. Actually its data compared well with the CDC’s. Google is now working together with the CDC in flu surveillance and their work has been published in the prestigious scientific journal Nature. Google Flu Trends also presents the data in graphs, maps, and animations which are easy to comprehend by the general public.

Don’t forget the CDC’s initiative “Take 3″ Steps To Fight The Flu; take time to get a flu vaccine, take everyday preventive actions and take flu antiviral drugs if your doctor recommends them.

And if you are still unlucky and get the flu, stay home from work or school including limiting contact with others, wash your hands often with soap and water and avoid touching your eyes, nose or mouth.

About the Author:

The article It’s Flu Season Somewhere – What’s The Scoop may be found in its entirety with references and links on http://HealthWorldNet.com .

Article Source: ArticlesBase.com – It’s Flu Season Somewhere – Here’s The Scoop

Author: Vinay Gupta

Swine flu is a type of virus. It’s named for a virus that infects mainly pigs. It normally does not infect people, but human infections can and do happen. The virus is contagious and can spread from human to human. The current swine influenza A (H1N1) virus has components of pig and bird influenza viruses in it, so the humans don’t have any immunity to it. That makes it more likely to become a pandemic virus (have the ability to cause a global outbreak) if it can easily spread from person-to-person. There are antiviral medicines you can take to prevent or treat swine flu. This particular virus is resistant to the antiviral medications amantadine (Symmetrel) and rimantadine (Flumadine), but is sensitive to oseltamivir (Tamiflu) and zanamivir (Relenza). There is no vaccine available right now to protect against swine flu.

Symptoms

The symptoms of swine flu are very similar to the common flu that occurs in humans. The symptoms are mostly fever, cold, cough, runny nose, body aches, diarrhea, vomiting, headache etc. In swine flu the symptoms might be more severe like breathlessness, very high grade fever, loss of appetite and fluid intake, listlessness etc.

The important fact is to prevent the spread of this infection. Since it spreads through fomites i.e. through air, infected articles like tissue, paper, pen etc, the preventive measures are very important.

Prevent spread

The measures that can be taken to prevent spread of this particular swine flu are –

1 Cover your nose and mouth with a tissue when you cough or sneeze. Throw the tissue in the trash after you use it.

2 Wash your hands often with soap and water, especially after you cough or sneeze. You can also use alcohol-based hand sanitizers.

3 Avoid touching your eyes, nose or mouth. Germs spread this way.

4 Try to avoid close contact with sick people.

5 Stay home from work or school if you are sick.

6 Consult a doctor immediately when in doubt about your symptoms.

Important thing to remember is that people with swine flu are likely contagious for one day before and up to seven days after they began to get sick with swine flu symptoms. Also, anti-flu medications, including Tamiflu (oseltamivir) and Relenza (zanamivir), are available to prevent and treat swine flu.

For more tips on prevention and cure of illnesses, post your queries on http://www.simplyanswer.com

About the Author:

Vinay Gupta is an experienced writer who is writing on Online Doctor Advice,Swine flu symptoms and throat infection for the site simplyanswer.com

Article Source: ArticlesBase.com – Swine flu symptoms, causes and prevention tips

Swine Flu Facts- Everything You Need To Know!

Author: Roxanne Gordimer

Due to the rising interests and questions being posted to around the web I thought it might be helpful for some of you out there to gather some information on the facts about the swine flu outbreak.

1. The swine flu influenza transmission use to jump from pig to pig and only in rare cases transmit to humans. The origins of it might be that humans first transmitted the influenza virus to pigs before they developed their own. The influenza season brings a mix of influenza viruses resulting in the increased risk of transmission and infection from pig to humans, causing cross-species transmission. Known swine flu viruses are the H1N1 subtype as well as less popular subtypes like H1N2, H3N1 or H3N2. Therefore a pig can be infected by more than one virus type at the same time.

Infection Risk

Human-to –human infection was once limited to a close group of people, before the Mexico incidents on April 2009. Prior to that swine influenza was transmitted from infected pigs that had direct contact to human, mostly their owners.

Safety Consumption of Pork?

It is indeed still safe eating pork food. So far no documentation is available indicating a link between safely prepared pork food and human swine flu infection. The swine flu influenza virus is killed by cooking temperatures of 70 degrees C or 160 F.

Any Vaccine Protection Against The Swine Flu Virus?

Up to now (End of April 2009) there are no vaccines known protecting human from this influenza virus illness. Usually each year they is an influenza protection vaccine being issued, however it is unclear if this influence protection does work on the swine flu virus. Please, do not take chances visit your health professional in any case of feeling typical symptoms of influenza infection.

Furthermore, it is recorded that previous swine flu infections have successfully been cured without any additional treatment, requiring no medical treatment at all.

The influenza virus is widespread and is a seasonal outbreak. In some cases it has developed resistance towards antiviral medication and therefore reducing the effectiveness of treatment.

So far in Mexico or the United States the health officials have recommended the use of oseltamivir or zanamivir for treatment. But again, make an informed decision by visiting your local health centre or professional in case of observed symptoms on yourself or somebody you suspect within your social network.

What Are Typical Symptoms of Swine Flu Infection?

Acute respiratory tract infections of any kind well known throughout the influenza season could be an indication for swine flu infection. Even mild symptoms should be taken seriously, especially by children, aged people, pregnant or any physical weakened individuals like patients or people in some kind of medication program. Please seek your next nearest health information spot be it your doctor or any qualified.

How To Reduce The Risk Of Infection?

Please avoid the direct contact to pigs if possible. Should you be a pig farmer or dealer make sure the pigs you are around on a regular basis are checked by a veterinary and are labelled swine flu free. Clean your hands with soap every time after you were in contact with pigs.

Usually people like pig farmers are the ones who get infected as there are in a regular contact with them. Especially during slaughter is the exposure high. Please avoid sick animals and do not slaughter them on your own, but report them immediately to your local health authorities. This way you may avoid worse. The next best thing to do is to follow local and national news, especially from credible news sources like governmental health departments or respected NGO`s.

Furthermore, avoid people who seem to have catch flu, with fever symptoms or cough frequently.

Eat healthy food and drink 100 % fruits based liquids or just clean water. Avoid uncooked meat, especially pig, cooked as stated above should be ok. Just practice recommended health habits like physical fitness as much as possible. Together you reduce the risk of being infected and when infected you reduce the risk of illness or further deterioration.

Should someone in your family be infected make sure you take that person asap to the next clinic or doctor for advice and treatment. In case it’s not immediately possible keep that person at least 1 meter away from others, best into a separate room. Be there for the person, so he or she doesn’t feel abandoned which can lead to worsening situation.

Improve the airflow in where the infected person is. Use door or window for the breeze.

Keep the area clean from dirt or any open cans, dustbins etc. Do not forget to wash your hands properly each time after contact with the infected person. COVER MOUTH AND NOSE permanently with professional masks from your local authority or pharmacy and the like. They must be clean and unused.

Please note the information above was assembled from various credible sources, especially the World Health Organisation, a United Nations public health arm. However, in no case can it be regarded as sufficient or advisory for any action taken by you in case regarding the topic discussed here. It is for your basic information and education only, you are therefore, solely responsible for any action resulting from reading this. Only your local or national health authorities can advice you how to proper deal with infection and related, make sure you seek only expert advice and not just general basic information gathered from around the web like this one above. Healthy day, your activagers.com team!

About the Author:

Roxanne Gordimer is a travel, health and lifestyle expert working
for companies such as activagers.com and other social networks.

Article Source: ArticlesBase.com – Swine Flu Facts- Everything You Need To Know!

Author: robert orr

Everyone by now has probably seen the news stories and heard of the fatalities caused by Swine flu.

It appears that we now face a swine flu pandemic, that means that outbreaks are being seen across the world.

But what exactly is and how can we protect ourselves.

Swine flu is a form of influenza that started in pigs but can be caught by, and spread among, people.

The current outbreak, human infection with swine influenza A (H1N1) viruses has been confirmed in the US, Canada, the UK, and other countries.

Swine flu is a respiratory disease of pigs caused by type A influenza viruses. Outbreaks of swine flu happen often in pigs. People do not normally get swine flu, though infections do occasionally happen. Recently, most human cases of swine influenza have been in people who were in close contact with pigs, such as farmers. In the current outbreak the virus has been spread by person-to-person contact.

This has caused concern that the outbreak could become a pandemic flu – a global outbreak of flu that spreads quickly because it is a new type of virus that few of us have any resistance to.

The normal type of flu ,usually called seasonal flu caused by an existing flu virus, is a common infection in the that usually occurs during the winter. For most people, it is an unpleasant but not life-threatening infection. People who are more at risk from it, such as older people or those weakened by illness can be given a flu vaccination.

The single most effective way to stop or slow the spread of diseases such as swine flu is to prevent the spread of germs. Wash your hands regularly with soap and water and cover your mouth if you cough or sneeze this is advice that has been given for many years by is still a very effective way to help you avoid spreading or contracting swine flu,also remember if you or a family member are ill or have the swine flu symptoms it

Is much better to stay at home away from work or school and thus reduce the risk of spreading the infection.

Its also worth noting that swine flu cannot be caught by eating pork or other pig related foodstuffs.

There is also no need for panic we do have effective treatments antiviral drugs are effective against swine flu if you are suffering flu symptoms visit your doctor or pharmacist who will be able to prescribe the correct medication.

Those most at risk are young children older people and those with underlying medical conditions.

Remember wash your hands regularly with soap and water cover your mouth if you cough or sneeze and stay away from work or school if you have flu symptoms and always seek professional medical advice.

Find a great health and fitness plan at dietwell

About the Author:

Robert is a resident of Liverpool Uk and webmaster at www.leglocker.co.uk

Article Source: ArticlesBase.com – Swine Flu Facts