You must have heard or read about the possibility of a new flu pandemic. As I see myself as your specialist in putting things into perspective, today, I would like to take this opportunity to write about influenza.
As a doctor, you often hear patients say that they think they have the flu. What they mostly suffer from is a heavy, common cold, which is caused by a rhinovirus. Real flu is different. It is caused by the orthomyxoviruses and can be a severe illness leading to high fever, an aching body, total lack of energy and appetite, and bad inflammation of the airways. Recovery is often prolonged for many weeks and the patient has a tendency to be quite depressed.
There are several antiviral medications, which shorten the course of the disease, such as Relenca or Tamiflu, and Amantadin. None of these are used much. In the NHS, there was a long discussion about the cost effectiveness, about six years ago, when Relenca was first brought onto the market. It never took off despite its proven efficiency.
What is used a lot is the flu vaccine. It is always in a slightly different form every year, with the aim of catching the relevant viruses. The influenza viruses are constantly changing. Have you ever wondered why?
Viruses depend on their multiplication inside bacteria and they, like humans, live in a competitive world. If you can’t change, you are likely to be less successful, meaning likely not to grow as much or even die. It is a survival advantage for viruses to change.
On the other hand, it is a pain for scientists because the vaccines have to be changed every so often. This is also one of the reasons why, so far, there is no HIV vaccine available.
The flu vaccine has an efficiency record of up to 85 per cent, but I could not say that it creates too many satisfied clients for the doctor. I have had innumerous patients coming back to complain that they had the worst cold ever despite having had the flu jab. Well, unfortunately the jab only protects from the real flu and nothing else.
In the 20th century, the world experienced three influenza A pandemics. Pandemic meaning a severe outbreak of an illness all over the world – pan is Greek for allor everything. The Spanish Flu in 1918/19 claiming 30 million lives, the Asian Flu of 1957 and the Hong Kong Flu of 1968, which together claimed about two million lives. Many experts believe that we are about to face another pandemic.
The reason – migrating birds and the bird flu. Birds are the natural hosts of the influenza viruses. The bird flu viruses do not necessarily affect humans, but, on occasions, they have mutated (Latin for changed) and were transmitted to people who had close contact with birds, for example, chicken farmers in Asia.
The virus in question today is named H5N1. Influenza viruses are subclassed by antigens they carry on their surface – H stands for haemaglutinin and N for the enzyme neuroaminidase. It was first described in 1997 in Hong Kong and is more aggressive than the usual ones. It has caused millions of deaths among wild and domestic birds, and can be transmitted to humans.
This virus has spread from South East Asia to Russia and Kazakhstan and is now at the door step of Europe – hence the fears among doctors, scientists and politicians. One vital step is missing in the necessary sequence of a pandemic – the transmission of the virus from human to human. If the virus should change again to find more suitable hosts – us humans in Europe – then we would probably have millions of cases of influenza.
Politicians have been alerted by medical experts that they need to prepare. That is why many countries, like the UK, are buying in large stocks of antiviral medication to be able to respond quickly, in case the disaster should strike.
In these cases, politicians are in a difficult position. Everybody would blame them if they had not prepared for the catastrophe. But, if it never arrives, they have wasted a lot of money, in this case for medication they might never need. Not to mention the fact that they would have worried a lot of people unnecessarily.
Pandemic infections have grave consequences for the countries involved. In addition to the sad loss of lives, come the difficulties for the economy and administration. Imagine a hospital where 50 per cent of the staff is off sick, while the country suffers from the effects of a flu epidemic.
And the bottom line, nobody knows exactly if and when a new flu pandemic will strike, but the chances are high that it could happen sooner rather than later. What can you do?Be vaccinated, live healthily and consult your doctor if you feel you may have the flu. And – probably most importantly – don’t worry…be happy!
Dr Thomas Kaiser.