One of the reasons why a new-type flu is dangerous is that human being does not have immune against it. Because of this fact, pandemic can happen explosively and symptoms become very severe.
Another reason is that it will have strong infectivity. Flu is transmitted mainly through droplet infection. You get infected by inhaling the virus spread about 2 meters by other patient’s cough or sneeze. When virus-containing droplets lose water, they turn into small grains called droplet nuclei, which stay in air for a long time and cause airborne infection.
The third reason is the situation of modern society. Infection can spread rapidly in this society now. Of course, the hygiene level of modern society has become better than the Spain flu era, but on the other hand, transportation method has been much faster and more massive, like airplane. There is a danger that a disease spreads to worldwide explosively. Spain flu is thought to have broken out in Eastern America, and it took 7 months to spread all over the world by ships. In the modern society where airplane transportation is so developed, one estimation says that a new-type infectious disease could spread all over the world from 4 days to 7 days.
As the forth reason, highly-pathogenic virus can change into a new-type virus. There are two types in bird flu, highly-pathogenic virus that has strong toxicity, and weakly-pathogenic virus. The origin of still-active type-A Hong Kong flu and type-A Soviet flu is weakly-pathogenic virus. If a highly-pathogenic bird flu like the famous H5N1 transforms into a new-type influenza virus, it could have extremely strong toxicity. There are already many death cases centering South East Asia actually. The new-type flu in Southeast Asia tends to have severer symptoms than regular flu, and half of the entire infected patients die within a week from infection. If it acquired an ability to move from human to human with the same strong toxicity, the disease would be even much more dangerous.
The threat of new-type flu is growing each day.
Expansion of Infection Among Birds
In 1997, H5N1 virus became epidemic among birds in Hong Kong, and was transmitted to humans as well, which caused some death cases. Six out of 18 infected patients died, which was a very high death ratio. This incident gave a big shock to people because this was the first case that bird flu virus is transmitted directly to a human and caused deaths. Moreover, the infection of H5N1 has kept expanding in Asia until now since 2003. From 2003 to 2004, H5N1 appeared in Japan, Korea, Vietnam, Thailand, Cambodia, Laos, Indonesia, China and Malaysia one after another.
It is very hard to root out bird flu in Southeast Asia because people there own chickens in small numbers. Since there is no refrigerator in Southeast Asia, people buy chicken in a market, bring it home, and butcher it right before a meal. Cold chain is used in Japan or Korea to transport chicken, but in Southeast Asia, people are living very closely to live chickens.
Once a new-type disease appears in Southeast Asia, it is hard to root it out and very easy for the virus to spread.
This is a picture of cockfight, which is a very popular gamble in Southeast Asia. As a strong cock is worth pretty good price, although I don’t know how much in yen, the owner of a good cock would never execute it just because bird flu breaks out in the area. From these facts, people say it is almost impossible to eradicate bird flu in Southeast Asia.
The infection still didn’t stop in 2005. Southeast Asia and China still had infection, and the epidemic area spread from Mongol through Russia, Turkey to Europe, and finally, it reached the most feared place, Nigeria, Africa. Now, the infected area has spread to India also, and still spreading in Europe and African countries. It has been reported a pet cat was infected in a certain area of Germany.
,p.Bird flu has spread as the following figure:
It has been a big issue that there is a possibility that the bird flu is spreading along the route of migratory birds.
Researchers have clarified some intercontinental routes of migratory birds: Central Asia route, East Africa West Asia route, Black Sea Mediterranean route, and so on. Migratory birds usually breed in the north, and go down to south in winter for food.
Food and Agriculture Organization (FAO) is indicating that it is possible that the spread of bird flu from Asia to Russia and Kazakhstan was brought through one of these routes of migratory birds.
FAO has also announced that the recent infection in Turkey and Romania is also following a route of migratory birds. Now, FAO is most concerned about the future epidemic in Africa, where the migratory birds are heading.
Actually, the bird flu landed on Africa. It also went over to India, and even Northern Europe. But, the bird flu was spread all over the world not only by migratory birds, but it is possible that it was spread also by livestock trades and movements of human beings and cars.
