SWINE FLU (Influenza A H1N1)

SWINE FLU(Influenza A H1N1)

>> Cases of swine flu, which has killed people in Mexico, have been confirmed around the world. With experts scrambling to develop a vaccine, there is concern at the potential for a pandemic affecting millions around the world…

>>>> What is swine flu?

>>Swine flu is a respiratory disease, caused by influenza type A which infects pigs.

There are many types, and the infection is constantly changing.

Until now it has not normally infected humans, but the latest form clearly does, and can be spread from person to person – probably through coughing and sneezing.


>>Some authorities object to calling the flu outbreak “swine flu”. U.S. Agriculture Secretary Tom Vilsack expressed concerns that this would lead to the misconception that pork is unsafe for consumption. Israeli deputy health minister Yakov Litzman proposed the name “Mexican flu” because Muslims and Jews consider pork to be unclean, but the Israeli government retracted this proposal after Mexican objections. The South Korean Ministry for Food, Agriculture, Forestry and Fisheries asked the press to use the term “Mexican Virus” on April 29. Taiwanese authorities suggested the names “H1N1 flu” or “new flu”, which most local media now use. The World Organization for Animal Health has proposed the name “North American influenza”, while the European Commission uses “novel flu virus”. Medical terminology refers to the virus as “Influenza A (H1N1) virus, human”.

The WHO objected to renaming the disease, as “swine influenza” had been used since the beginning of the outbreak.According to The New York Times, “based on its genetic structure, the new virus is without question a type of swine influenza, derived originally from a strain that lived in pigs”.

>>>> What is new about this type of Swine flu?

>>The World Health Organization has confirmed that at least some of the human cases are a never-before-seen version of the H1N1 strain of influenza type A.

H1N1 is the same strain which causes seasonal outbreaks of flu in humans on a regular basis.

But this latest version of H1N1 is different: it contains genetic material that is typically found in strains of the virus that affect humans, birds and swine.

Flu viruses have the ability to swap genetic components with each other, and it seems likely that the new version of H1N1 resulted from a mixing of different versions of the virus, which may usually affect different species, in the same animal host.

Pigs provide an excellent ‘melting pot’ for these viruses to mix and match with each other.

>>>> How dangerous is it?

>>Symptoms of Swine flu in humans appear to be similar to those produced by standard, seasonal flu.

These include fever, cough, sore throat, body aches, chills and fatigue.

It is worth remembering that seasonal flu often poses a serious threat to public health: each year it kills 250,000 – 500,000 around the world.

So far, most cases of swine flu around the world appear to be mild, albeit with diarrhoea more common than is found with seasonal flu.

But lives have been lost in Mexico, and a single death – of a Mexican child – has been confirmed in the US.

>>>>How worried should people be?

>>When any new strain of flu emerges that acquires the ability to pass from person to person, it is monitored very closely in case it has the potential to spark a global epidemic, or pandemic.

The World Health Organization has warned that swine flu could potentially trigger a global pandemic, and stress that the situation is serious.

However, experts say it is still too early to accurately assess the situation fully.

Currently, they say the world is closer to a flu pandemic than at any point since 1968 – upgrading the threat from three to four on a six-point scale following an emergency meeting on Monday.

Nobody knows the full potential impact of a pandemic, but experts have warned that it could cost millions of lives worldwide. The Spanish flu pandemic, which began in 1918, and was also caused by an H1N1 strain, killed millions of people.

There is hope that, as humans are often exposed to forms of H1N1 through seasonal flu, our immune systems may have something of a head start in fighting infection.

However, the fact that many of the victims are young does point to something unusual. Normal, seasonal flu tends to affect the elderly disproportionately

>>>> Can the virus be contained?

>>The virus appears already to have started to spread around the world, and most experts believe that containment of the virus in the era of readily available air travel will be extremely difficult.

The World Health Organization says that restricting flights will have little effect. It argues that screening of passengers is also unlikely to have much impact, as symptoms may not be apparent in many infected people.

>>>> Can it be treated?

>>The US authorities say that two drugs commonly used to treat flu, Tamiflu and Relenza, seem to be effective at treating cases that have occurred there so far. However, the drugs must be administered at an early stage to be effective.

Use of these drugs may also make it less likely that infected people will pass the virus on to others.

The UK Government already has a stockpile of Tamiflu, ordered as a precaution against a pandemic.

It is unclear how effective currently available flu vaccines would be at offering protection against the new strain, as it is genetically distinct from other flu strains.

A new bespoke vaccine is being worked on by scientists in the UK and the US, but it may take months to perfect it, and manufacture enough supplies to meet what could be huge demand.

A vaccine was used to protect humans from a version of swine flu in the US in 1976.

However, it caused serious side effects, including an estimated 500 cases of Guillain-Barré syndrome. There were more deaths from the vaccine than the outbreak.

>>>> May it take some time for a pandemic to strike?

>> Possibly. The flu virus tends to thrive in cooler conditions, and to struggle in warmer weather.

The initial cases have developed right at the tail end of the winter flu season in the northern hemisphere, so it is possible that the number of infections may only begin to accelerate once the weather turns colder in the autumn.

However, the southern hemisphere is about to enter its winter season, and it is possible that the virus will take real hold there first.

>>>> Is it safe to eat pig meat?

>> Yes. There is no evidence that swine flu can be transmitted through eating meat from infected animals.

However, it is essential to cook meat properly. A temperature of 70C (158F) would be sure to kill the virus.


>> The strain of bird flu which has caused scores of human deaths in South East Asia in recent years is a different strain to that responsible for the current outbreak of swine flu.

The latest form of swine flu is a new type of the H1N1 strain, while bird, or avian flu, is H5N1.

Experts fear H5N1 hold the potential to trigger a pandemic because of its ability to mutate rapidly.

However, up until now it has remained very much a disease of birds.

Those humans who have been infected have, without exception, worked closely with birds, and cases of human-to-human transmission are extremely rare – there is no suggestion that H5N1 has gained the ability to pass easily from person to person.

>>>> How do humans catch it?

>> While humans do not catch the more common forms of swine flu, this current strain of the H1N1 virus does infect humans because during mutation it was combined with parts of a human flu virus.

The original change to the virus is thought to have happened inside a pig, which was then caught by someone in close contact with it in Mexico.

But the World Health Organisation has now confirmed this strain of swine flu can spread from human to human, raising fears of a global pandemic.

Doctors don’t yet know how easily the virus spreads between people, but experts believe it spreads in the same way as seasonal flu – through coughing and sneezing.

>>>> What are the symptoms?

>> The symptoms of swine influenza in people are similar to the symptoms of a regular human seasonal influenza infection and include fever, fatigue, lack of appetite, coughing and a sore throat.

Some people with swine flu have also reported vomiting and diarrhoea.

It may have more severe symptoms in some victims because the virus is so new that it is very unlikely that we will have natural immunity to it.

Doctors have found some antiviral drugs to have helped control symptoms with the new form of swine flu, as they prevent the virus from spreading into cells within the body.

>>>> Have humans been infected with swine flu in the past?

>> Cases of swine flu in humans usually occur after a history of exposure to pigs. For example, direct or close contact with infected pigs.

Cases of person-to-person transmission have been previously reported but are rare.

There have been no cases identified in the UK for at least 10 years.

A single case of swine flu was reported in November 2008 in Spain. The person only had mild symptoms.

>>>> Does the current flu vaccine offer protection against swine flu?

>> We’re not sure. The existing flu vaccine does contain an H1N1 strain – but of a slightly different type. Experts don’t know how much protection – if any – it would offer against the swine flu.

The effect is likely to be negligible, which is why a new vaccine would have to be developed. Tests will give a clearer answer in the next few days.

>>>> How dangerous is it?

>> Thousands of people have been made ill by swine flu – with some cases
proving fatal.

Tests show that the antiviral drugs oseltamavir (Tamiflu) and zanamivir (Relenza) appear to be effective against the human swine influenza H1N1 strain.

>>>> Should we be worried about it?

>> ANSWER IS NO – but we should take sensible precautions. The World Health Organisation has warned that the outbreak has “pandemic potential” and countries have been advised to step up surveillance and preparation in case the infection spreads rapidly.

Flu viruses have the ability to change and mutate, making it difficult for drugs manufacturers to ensure effective vaccines are available.

The new version of the H1N1 virus is a mix of different animal and human versions of the disease. Mixing can lead to the development of changed viruses to which humans have little immunity.

>>>> What is a pandemic?

>> If the flu spreads over a wide geographic area and affects a large proportion of the population it goes beyond an epidemic and becomes a pandemic.

According to the Health Protection Agency, an influenza pandemic is defined as a new or novel influenza virus that spreads easily between humans.

When new influenza viruses are introduced into the environment, humans do not have any natural immunity to protect against them.

Therefore, there is a risk that that new influenza viruses could develop into a pandemic if the virus passes easily from human-to-human.

>>>> What is the doctors’ definition of someone suffering from flu?

>> You have flu is you have a fever over 38 degrees centigrade and two or more of the following: cough, headache, runny nose, vomiting/diarrhoea.

>>>> Do WE need a mask to prevent getting an infection?

>> Standard issue surgical masks offer little if any protection against the virus. The best advice is to keep your hands clean, wash surfaces regularly and dispose of tissues as they are used.

NHS officials are being issued with special masks but these are only effective when used by trained personnel exposed to the virus – other precautions must be taken to prevent infection.

>>>> Does swine flu pose a more serious threat to pregnant women?

>> All viruses are potentially dangerous to pregnant women as their immune systems are under extra strain – but they should be fine if they eat well and keep up essential minerals.

>>> How long does the flu virus survive on surfaces?

>> The flu virus survives for roughly 24 hours on hard surfaces, two hours on soft surfaces.


Avoid close contact with people who appear unwell and who have fever and cough.

General infection control practices and good hygiene can help to reduce transmission of all viruses, including the human swine influenza. This includes covering your nose and mouth when coughing or sneezing, using a tissue when possible and disposing of it promptly.

It is also important to wash your hands frequently with soap and water to reduce the spread of the virus from your hands to face or to other people and cleaning hard surfaces like door handles frequently using a normal cleaning product.

If caring for someone with a flu-like illness, a mask can be worn to cover the nose and mouth to reduce the risk of transmission.

Very frequent hand-washing is something that we talk about time and time again and that is an effective way to reduce transmission of disease.

If you’re sick, it’s very important that people stay at home. If your children are sick, have a fever and flu-like illness, they shouldn’t go to school. And if you’re ill, you shouldn’t get on an airplane or another public transport to travel. Those things are part of personal responsibility in trying to reduce the impact.

The UK is looking at increasing its stockpile of masks for healthcare workers for this reason.

In Mexico masks have been handed out to the general public, but experts are sceptical about how useful this is.


Medical officers, representatives from the WHO and International Centre for Diarrhoeal Diseases Research are stationed at airports and all travellers, particularly from affected countries, are to be screened