Bird flu or avian flu is an influenza virus type that normally infects birds. However, it can also infect other animals including pigs. Wild birds are natural hosts to the virus and normally don't get sick from it. But domestic animals such as chickens and turkeys could be severely affected. Humans, on the other hand, can be infected with influenza types A, B, and C.
Genetic changes and sharing can occur under certain circumstances. This could happen in crowded conditions where poultry, pigs, and people live in close quarters. This change could allow a virus to turn into more infectious to humans. This could also mean that the virus can more easily transmitted from person to person. This is precisely when a pandemic could break out.
The avian flu's jump to humans was first detected in 1997. Though there have been around 60 human deaths reported, they have been due to transmission from animals to humans. Migratory birds have been detected with the virus and these cannot be caught and killed - these birds have alreadd carried the virus to Europe and Africa. It is difficult to predict when the pandemic could break out - It all depends on when that genetic shift (from birds to humans) takes place.
For now, there has been no detection of this virus in the U.S. It is however possible for travelers to be infected, but most of cases in humans have been in those with closer contact to birds than a casual traveler has. Since the infection occurs via fecal-oral route, people are advised to reduce their risk while traveling by avoiding bird markets, zoos, and areas in parks, where there could be high concentrations of bird feces.
Countries that are the most vulnerable to this flu are Indonesia, Vietnam, and Cambodia, due to their high concentration of bird markets. Other areas include Thailand, China (south and north), Tibet, Kazakhstan, Russia and Mongolia.
Symptoms of bird flu in humans have ranged from typical flu-like symptoms (fever, cough, sore throat, muscle aches) to eye infections and pneumonia. If you feel you've been exposed, there are a couple of treatment recommendations available today that you may want to discuss with your doctor. Until these are tested in a pandemic, however, their true efficacy is unknown. There are currently no vaccines available, but many companies are working on them.
More information on Avian Flu and preventive measures can be had from Avian Flu Protection.