Monday December 13 2010
Swine flu, or the H1N1 virus
Swine flu has claimed the lives of 10 British adults in recent weeks, newspapers reported. The Independent and the Daily Mail said there are signs that the virus ‘is back’, raising fears of ‘a new epidemic’. Although most of the 10 fatalities had underlying health conditions, the newspapers said 'a small proportion' had been healthy before the virus. Numbers of people hospitalised with severe flu have also risen, and there have been several outbreaks in schools and on a military base.
The Health Protection Agency (HPA) has warned that although the overall number of cases of flu is not unusual for this time of year, the number of severe cases of H1N1 is higher than expected in England.
For most people, H1N1 flu is a mild illness lasting seven to ten days. However, some groups of people are at greater risk of serious illness if they catch flu, such as people over 65, pregnant women and those with other long-term illnesses. These people should ask their GP to be given the vaccine as soon as possible. A detailed list of at-risk groups is given below.
It is important that people at greater risk are vaccinated. However, the actual numbers of people visiting their GP with flu are low and there is no indication yet of another swine flu epidemic. The virus is not known to have mutated into a new strain or developed any new characteristics. As the H1N1 virus was widely circulating last year, it is not surprising that it is still present this winter.
What are the news reports based on?
There has been a notable rise in the number of people with severe flu who have been admitted to hospital recently. The Health Protection Agency has warned of this increase and advised that people in high-risk groups should be vaccinated.
Last week there were 16 people aged 18 to 35 in hospital with severe H1N1 influenza. Many of these people have an underlying health condition, and some are pregnant. Several other people with probable H1N1 are currently under investigation. Nine people have died from flu since early September, of whom eight had H1N1. Many of these people also had other underlying high-risk conditions.
Are more people getting flu than usual?
The numbers of people visiting their GP with flu-like illnesses are low, but there have been several outbreaks in the community and a number of severe cases. Nine acute respiratory disease outbreaks were reported in the UK at the beginning of September, eight in schools and one on a military base. Two of these nine outbreaks have been attributed to H1N1.
Worldwide, flu rates are currently low, although some areas of South Asia and central and western Africa are currently reporting surges in H1N1 detections.
How many of these flu cases are swine flu?
It is difficult to say how many of these cases are swine flu. Each year several flu strains circulate in the population. This year H1N1 is one of the strains, but others, such as influenza B, are circulating too. It is only possible to tell whether a particular case is caused by swine flu through laboratory testing.
Eight of the nine flu deaths since early September were confirmed as being caused by H1N1 after testing and one was caused by influenza B.
Is this the same strain of swine flu that caused the pandemic?
Yes, it is the same strain of H1N1. The virus is not known to have mutated into a new strain or developed any new characteristics. As the H1N1 swine flu virus was widely circulating in the previous flu season, it is not surprising that it is still present this winter.
Why has swine flu come back?
It didn’t go away. Swine flu (like other strains of flu) just becomes less common during summer months and then may increase in prevalence during winter months. Although many people developed immunity or received immunisations to H1N1 last year, not everyone did. Those with reduced immunity to this infection are more likely to contract the infection.
Is swine flu still a pandemic?
In August 2010, the World Health Organization (WHO) declared that the H1N1 influenza pandemic was over, and that the world was in a 'post-pandemic period'. It cautioned that 'based on experience with past pandemics, we expect the H1N1 virus to take on the behaviour of a seasonal flu virus and continue to circulate for some years to come'. The WHO also anticipated that 'localised outbreaks' showing 'significant levels of H1N1 transmission' may occur.
Post-pandemic periods can be unpredictable, and continued monitoring of cases worldwide is important.
How dangerous is swine flu?
For most people, H1N1 flu is a mild illness lasting seven to ten days. However, some groups of people are more at risk of serious illness if they catch flu, such as the elderly, pregnant women and some people with other illnesses. Of the nine people who have died with flu since early September, eight were confirmed as having H1N1. Of these, the majority had underlying health conditions.
People with the following conditions are known to be particularly at risk:
- chronic (long-term) lung disease
- chronic heart disease
- chronic kidney disease
- chronic liver disease
- chronic neurological disease (neurological disorders include chronic fatigue syndrome, multiple sclerosis and Parkinson's disease)
- immunosuppression (whether caused by disease or treatment)
- diabetes mellitus
Also at risk are:
- patients who have had drug treatment for asthma within the past three years
- pregnant women
- people aged 65 and older
- young children under five
How do I protect myself from swine flu?
Vaccination offers the best protection for those at high risk from flu.
Professor John Watson, head of the respiratory diseases department at the HPA, said:
'If you are in an at-risk group and you haven't had your jab, we recommend you make an appointment with your GP or medical practitioner now.'
The swine flu vaccine is now part of the seasonal flu jab, which also protects against the other circulating strains. Pregnant women are being offered the seasonal vaccine for the first time because, as a group, they were affected more during the pandemic and are at greater risk of serious complications. Contact your GP for further advice on getting the vaccine.
Who should be vaccinated?
For most people, seasonal flu is unpleasant but not serious and they recover within a week. However, certain people are at greater risk of developing serious complications of flu, such as bronchitis and pneumonia. These may require hospital treatment. A large number of elderly people die from flu every winter.
The seasonal flu vaccine is offered free of charge to these at-risk groups to protect them from catching flu and developing these complications.
Also, this winter (2010-11) the seasonal flu vaccine will be offered to pregnant women not in the high-risk groups who have not previously been vaccinated against H1N1 (swine) flu.
It is recommended you have a flu jab if you:
- are 65 or over
- have a serious medical condition (see box)
- live in a residential or nursing home
- are the main carer for an elderly or disabled person whose welfare may be at risk if you fall ill
- are a healthcare or social care professional directly involved in patient care
- work with poultry
If you are the parent of a child (over six months) with a long-term condition, speak to your GP about the flu jab. Your child's condition may get worse if they catch flu.
If you are the carer of an elderly or disabled person, make sure they have had their flu jab.
How do I get vaccinated?
If you think you need a seasonal flu vaccination, check with your doctor, nurse or local pharmacist.
What are the symptoms of swine flu?
If you or a member of your family has a fever or high temperature (over 38C/100.4F) and two or more of the following symptoms, you may have H1N1 flu:
- unusual tiredness
- runny nose
- sore throat
- shortness of breath or cough
- loss of appetite
- aching muscles
- diarrhoea or vomiting
It makes sense to have a working thermometer at home, as an increase in temperature is one of the main symptoms. If you are unsure how to use a thermometer, go to How to take someone's temperature.
I think I have swine flu, what should I do?
If you are in an at-risk group, you should seek medical advice if you are having flu symptoms. If you are not in one of these groups, stay at home, get plenty of rest and use over-the-counter painkillers to relieve symptoms. If the symptoms persist or get more severe, seek medical advice.
Maintaining good cough and hand hygiene, should limit the spread of germs and reduce the chances of people you come into contact with getting flu:
- cover your nose and mouth with a tissue when you cough and sneeze
- dispose of the tissue as soon as possible
- clean your hands as soon you can