Tuesday, 26 July 2011

Tackling Influenza

Published in Panorama

Tackling the ‘Flu’

Influenza, commonly known as flu is a viral infection of the upper respiratory tract which include the nose, throat, windpipe and the air passages or bronchi. Outbreaks of flu occur almost every year, usually in fall, autumn and winter. The influenza virus causes more severe symptoms and can cause more severe complications than cold viruses, reveals Dr.Robert Erasmus, Specialist, Family Medicine, Welcare Hospital, Dubai.

How is influenza caused?
Influenza is an airborne disease and is caused by viruses which continually change over time. This enables the virus to evade the immune system of its host, thus resulting in people being susceptible to influenza virus infection, practically throughout their life. There are about 134 different strains of viruses that can give you flu and cold. But there are two main types of Influenza viruses A and B, which most commonly cause the condition. The virus that causes flu is spread from person to person by droplets that are coughed or sneezed into the air. It may also be passed by the hands of someone who has the flu. The influenza virus is actually spread all over the world by migrating birds. So with the increasing international travel, the spread of the virus is so much easier.

What are the symptoms of Influenza?
Typical clinical features of influenza include fever between 100° F to 103° F in adults and often even higher in children. The respiratory symptoms include runny or blocked nose, cough, sore throat, headache and fatigue. But the most prominent symptom is muscle pain. Children may even have nausea, vomiting and diarrhea. If you perceive a runny nose and muscle pain, you most likely have influenza. On the other hand, you may have the common cold with runny nose, dry cough and a sore throat. The management of the two – influenza and cold, is virtually the same but the complication rate is much higher in influenza. So it’s important to distinguish the two conditions.

Symptoms of Influenza mimic symptoms of various other conditions. So how is diagnosis of flu confirmed?
If you consider in layman’s term, the term flu, as being feeling feverish and muscle pains, there are many other illnesses that can give it. The most notorious one is malaria. Even typhoid can give you a flu-like syndrome without diarrhea; a severe pneumonia, TB, and almost all infections will give you a flu like feeling. But when one speaks about a proper influenza, it’s brought on only by viruses.

Diagnosis is by careful history taking. For instance, if you visit the doctor in September, after having been in Southern Africa in the last 6 weeks, it’s most likely you’re having malaria. If you haven’t traveled out of Dubai and you get flu-like symptoms, it is most likely you’ve got influenza. Clinically it’s not important to distinguish between an influenza virus and one of the other viruses because the management is exactly the same. However, in high risk patients we do a test to see whether they have Influenza A or Influenza B so as to prevent secondary infection. In the run of the mill patients, we go according to the history, physical examination and we make a clinical diagnosis.

What is the treatment for Influenza?
Bed rest, hot tea, hot soup and vitamin C in orange and lemon juice. There is really no specific treatment. However, there are a few drugs which have been shown to suppress the virus but I don’t think these are effective or used routinely. If you have proper influenza, bed rest, good hydration, vitamin C should make you fine in three days. Most people who get the flu recover completely in 1 to 2 weeks.

If you only have a cold, then you don’t need to rest. You can go on with your daily activities and even do physical exercises or sport. However, if you have Influenza, you shouldn’t participate in physical activity because the virus spreads to the muscles of the body and here the heart is one of the more important muscles. So if you get an infection with an influenza virus early, you can get heart muscle infection or myocarditis which is a disease, primarily of young people and that’s why young people often collapse and die on the sports field when they have influenza.

What about medication for fever?
Treatment is symptomatic. If you have fever, you may take anti-pyretics; if you’ve got a dry cough, cough syrups may be used, decongestants may be used for a blocked nose. It must be stressed that antibiotics have got no role whatsoever in treating influenza per se. Only if you have persistent infection for longer than two weeks, then one could think of a secondary infection like a sinusitis or a pneumonia. A normal healthy person, should recover from influenza and be up and about in about 3-4 days. But bed rest is very important.

Can influenza lead to other complications?
Infection with the flu virus often leads to sinus, bronchial and middle ear infections. Pneumonia can also occur as a result of the flu. This may be caused by the flu virus itself or by bacteria invading lung tissues that have been damaged by the virus. Pneumonia is a common cause of death in people over the age of 65 and often occurs during and after flu outbreaks.
An unusual complication of flu, usually occuring in children and adolescents is Reye's syndrome, in which condition the liver fails and the brain swells, often leading to coma and even death. However, this is an extremely rare complication.

Are certain categories of people more prone to complications influenza than others?
Yes. The high-risk groups of people who could develop serious complications from influenza include all people aged 65 years or older and people of any age with chronic diseases of the heart, lung or kidneys, diabetes, asthma, cancer, immunosuppression, or severe forms of anemia.

Is it possible to prevent flu?
Since over 130 virus can cause cold and flu, it’s been impossible to develop a vaccine for cold. However, it’s been possible to develop vaccine for influenza since the influenza virus is fairly stable and predictable. That is why the WHO every year predicts which three strains of influenza viruses will be most prominent in that year and accordingly the vaccine is developed.

When you take the influenza vaccine then you should make sure that it contains at least three different strains of the virus. WHO recommends the vaccine should be taken by everybody, including children.

How efficacious is the flu vaccine since there are so many strains of the virus causing it?
Influenza is most rife in winter and therefore it should be stressed that at this time of the year everybody who has access to healthcare, should take the flu vaccine as soon as possible. Flu shots are about 70% effective in preventing flu. Because the flu virus strain varies from year to year, you need to get a new flu shot each year. The immunity starts about two weeks after the injection and it lasts for about a year. But you must remember that this year we may have viruses A, B and C; next year it might be A, C and E! Every season has its own specific viruses coming up. Therefore the vaccine should be taken annually. By having it annually, you actually increase your immunity.

It is also very important to remember that an influenza vaccine, protects you against three viruses and since there are over 130 viruses, you can still get a cold. But those are the minor infections. So an influenza vaccine may not prevent your runny nose or cough or sore throat. But it will protect you against serious influenza infections.

The simplest method of avoiding spread of infection is frequent hand washing, preferably with antibacterial soap from a sanitary dispenser.


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