New bird flu: How bad is H10N8?
A new strain of bird flu has killed a woman in China.
Scientists say experts should be on alert in case the virus - H10N8 - could cause a pandemic.
How bad is it?
So far there have been two people in China infected and one of them has died.
As yet, there is no evidence that the virus can be transmitted from person to person. This means the risk of rapid spread is still low.
But we could see more human cases of H10N8, particularly among people who have close contact to poultry carrying the infection.
And experts are concerned that the virus could evolve or mutate to become more infectious.
Where has it come from?
Researchers believe the first human case - a 73-year-old woman from China who died nine days after falling ill with the infection - was probably caught from a live poultry market. The woman had visited the site a few days before getting sick.
Tests on samples from the market have been inconclusive, but scientists say birds are the likely source.
What is bird flu?
There are many different strains of bird flu. All are a type of influenza virus. Usually they don't infect humans, but sometimes they can mutate and gain this ability. Recently, there have been human cases of other bird flu strains -H7N9 and H5N1.
How is it spread?
Bird flu is spread through direct contact with infected birds (dead or alive), an infected bird's droppings, or secretions from their eyes or respiratory tract.
Bird flu is not transmitted through cooked food.
There have been few reports of bird flu passing from person to person.
Should I worry?
Not yet. No human cases have been detected outside of China and there have only been two cases so far within the country. The woman who died had other medical conditions that may have made her frail and susceptible to the infection.
The risk of this virus spreading from the patient to nursing staff and other contacts also seems low.
But that does not mean we should be complacent, say experts.
Dr Jeremy Farrar of the Wellcome Trust says we should always be worried when a virus jump from birds to people as it is unlikely that we will have prior immunity to protect us. Also, H10N8 looks like a candidate for potentially turning nasty.
Disease experts will continue to monitor the situation in China and elsewhere. These first cases were detected thanks to good surveillance. Indeed, it is highly unlikely this event would even have been noticed or reported just a few years ago.
There are still major questions that need answering. We do not fully understand what causes flu viruses to cross into humans, cause disease and become transmissible.
Is it safe to visit China?
The World Health Organization has not put in place any travel restrictions.
Should I have a flu jab?
Perhaps, but not to protect you against bird flu. The seasonal flu jab does not protect against avian flu. Seasonal or winter flu is a highly infectious and very common viral illness that is spread readily between people by coughs and sneezes.