Avian influenza, or bird flu, is a highly contagious severe respiratory disease which primarily infects birds. It has a high mortality rate, especially in poultry, but doesn’t usually infect humans. It is spread through birds’ droppings, saliva, or through contaminated food and water. Since it first emerged, it has become endemic in some parts of the world, with several strains of the virus in circulation.

Since 2003, around 860 cases of H5N1 infection in humans have been reported from 21 countries, around half of which were fatal. There have also been a smaller number of cases of infection by other strains of the virus.

The WHO points out that whenever bird flu circulates in poultry, there is a risk for sporadic infection in humans. However, the virus doesn’t currently infect humans easily, and person-to-person transmission remains unusual. Almost all cases of infection have resulted from people coming into close contact with live or dead infected birds or contaminated environments.

But with such high levels of the virus circulating, there is the risk that the virus may become better adapted to infect humans and animals. Outbreaks seen in mink farms, for example, could be particularly problematic as infections among animals living in close proximity could exacerbate this risk, the World Organisation for Animal Health warns.

The virus has been found in animals from grizzly bears to dolphins, seals, otters and foxes. Find out more at this event with two prominent scientists who will talk about H5N1 outbreak among sea lions in Peru, and its detection in a mink farm in Spain. What does it all mean for reporters? The event recording is in Spanish. The live event offered English translation.