After months of deliberation, a controversial study from the Netherlands examining how the H5N1 virus - also known as avian influenza or bird flu, could be genetically altered and transmitted by mammals as an airborne pathogen was published last week. The paper was completed in 2011, but because of widespread concerns that bioterrorists could use this information to engineer a weapon, the findings were not published until now.
Avian flu affects several types of birds, including farmed poultry (chickens, geese, turkeys and ducks). Bird flu can also be transmitted from livestock to wild birds and also to pet birds, and vice-versa. The virus spreads through infected birds, via their saliva, nasal secretions, feces, and feed.
The first avian influenza virus to infect humans occurred in Hong Kong in 1997 and was linked to infected chickens.
Human cases of H5N1 have since been reported in Asia, Africa, Europe, Indonesia, Vietnam, the Pacific, and the near East. Since 2003, nearly 60% of the 606 cases of human infection of H5N1 reported to the World Health Organization (WHO) worldwide, have resulted in death.