Avian Influenza (Bird Flu)
Some facts about the disease:
Avian flu is an influenza virus occuring amongst birds, or more precisely defined: an infectious disease of birds caused by type A strains of the influenza virus. The virus is carried mainly by wild birds in their intestines, but most of them don't get sick or harmed. The virus can be passed on by infected birds through their saliva, nasal secretions and faeces. In domestic poultry the viruses causes two clearly different forms of disease: while the course of one kind is mild, the other one is rare and in most cases fatal . Outbreaks of the first kind can in fact be so mild so mild that they are often failed to be seen, just some ruffled feathers, a slightly reduced egg production or some mild effects on the respiratory system. In contrast, the second and far less common highly pathogenic form is difficult to miss. The second aggressive form is has been around for a long time. It has already been noticed in Italy in the 19th century.Risk for human beings:
But this website is about misunderstanding and abuse of statistics, so we will not linger on the medical facts about this disease. Most people are mainly in two closely connected questions:- What is the risk for humans to get infected by this virus, i.e. the lethal kind not the harmless one?
- What are the chances to survive if one is infected?
In answer to the second question one finds on websites, newspapers and journals a mortality rate between 50 and 100 %. Most of them giving the rate at about 50 %. But where do these figures come from? First of all people like talking about 50-50 chances, if the don't have other numbers available. (It's like the mystic 10 %, article coming soon on this website).
The international World Health Organization (WHO), which is
coordinating the global response to human cases of H5N1 avian
influenza and monitoring the corresponding threat of an influenza
pandemic has released
a detailed statistics (24 March 2006) about the cases of H5N1
worldwide:
|
Country
|
2003 |
2004 |
2005 |
2006 |
Total |
|||||
|
cases |
deaths |
cases |
deaths |
cases |
deaths |
cases |
deaths |
cases |
deaths |
|
| Azerbaijan | 0 | 0 | 0 | 0 | 0 | 0 | 7 | 5 | 7 | 5 |
| Cambodia | 0 | 0 | 0 | 0 | 4 | 4 | 1 | 1 | 5 | 5 |
| China | 0 | 0 | 0 | 0 | 8 | 5 | 8 | 6 | 16 | 11 |
| Indonesia | 0 | 0 | 0 | 0 | 17 | 11 | 12 | 11 | 29 | 22 |
| Iraq | 0 | 0 | 0 | 0 | 0 | 0 | 2 | 2 | 2 | 2 |
| Thailand | 0 | 0 | 17 | 12 | 5 | 2 | 0 | 0 | 22 | 14 |
| Turkey | 0 | 0 | 0 | 0 | 0 | 0 | 12 | 4 | 12 | 4 |
| Viet Nam | 3 | 3 | 29 | 20 | 61 | 19 | 0 | 0 | 93 | 42 |
| Total | 3 | 3 | 46 | 32 | 95 | 41 | 42 | 29 | 186 | 105 |
If we divide the 105 (number of worldwide deaths) by 186 (the number
of cases worldwide) we get 56 %.
But is it correct to take this as the mortality rate?
We don't think so. Most probably the number of deaths due to H5N1
is totally correct. But what about the reported cases.? Only
those with serious symptoms will have fone to a doctor. ther might be
hundreds or thousands who could have had an infection without
developping any serious symptoms. So the number 105 should have been
divided by a much higher number than 186, giving us fatality rates
which might be closer to a regular flu pandemic. The problem is: We
can't be sure about the number of cases, so any calculation of the
mortality rate is just guesswork! Experts should stop using these
numbers to frighten the population.
The first question can only be answered, if we could calculate seriously the risk of a mutation of the virus. Again, there are those who know already. They have found out that there is a fifty-fifty chance that the avian flu could mutate to become a human form, i.e one which will be easily transmittible to humans. A point of view taken by the bird flu expert Robert G. Webster. Webster said on ABC news (March 14, 2006) that we must prepare for the worst. "I personally believe it will happen and make personal preparations," said Webster and this means that he has stored a three-month supply of water and food at his home.