H5N1

We have a big problem in Viet Nam and this one could be even bigger than the one we had before. Bird flu, especially the one caused by strain H5N1, is a disease with a reservoir in birds and especially chickens and ducks which are raised for domestic consumption by humans. The virus causes disease in the chickens, which is of considerable economic consequence, since the animals die and when the disease occurs in a flock, the only real way to contain its spread is to eradicate the rest of the birds. Viet Nam, the country hardest hit, has some 70% of its population raising chickens in the backyard to provide a major source of the family income. Problem no. 1 arises when the family refuses to report the disease in their birds to avoid losing all of their income. So the disease can't be contained. A second problem is the birds are essentially raised in the same space occupied by the humans so close contact with infected birds is inevitable. Problem no. 3 is caused by the fact that the virus is mutating rapidly, like all influenza viruses, and this guarantees that the virus will jump from animals to humans as it adapts to a new host. This has already happened and there has been a 70% mortality in the humans who have contracted the disease.

So, the dire prognosis is for the bird flu virus to establish itself in a greater and greater number of people and spread rapidly from person to person through respiratory droplet transmission. Depending on the extent of transmission, a pandemic could be experienced in which literally millions of people die. A vaccine is being developed, but it will be very difficult to vaccinate the population likely to be affected and if the virus mutates rapidly enough the vaccine being developed could be a poor one. This is really scary.