Bird flu strain in China 'passed between humans'

The British Medical Journal said a 32-year-old
woman was infected after caring for her
father. Both later died.
Until now there had been no evidence of
anyone catching the H7N9 virus other than
after direct contact with birds.
But experts stressed it does not mean the
virus has developed the ability to spread easily
between humans.
By 30 June there had been 133 cases of H7N9
bird flu reported in eastern China and 43
deaths.
Most people had visited live poultry markets
or had close contact with live poultry in the
week or two before they became ill.
Intensive care
Yet researchers found that the 32-year-old
woman had become infected in March after
caring for her 60-year-old father in hospital.
Unlike her father - who had visited a poultry
market in the week before falling ill - she had
no known exposure to live poultry but fell ill
six days after her last contact with him.
Both died in intensive care of multiple organ
failure.
Tests on the virus taken from both patients
showed the strains were almost genetically
identical, which supports the theory that the
daughter was infected directly from her father
rather than another source.
Public health officials tested 43 close contacts
of the patients but all tested negative for
H7N9, suggesting the ability of the virus to
spread was limited.
The researchers said that while there was no
evidence to suggest the virus had gained the
ability to spread from person to person
efficiently, this was the first case of a
"probable transmission" from human to
human.
'Strong warning sign'
"Our findings reinforce that the novel virus
possesses the potential for pandemic spread,"
they concluded.
Dr James Rudge, of the London School of
Hygiene and Tropical Medicine, said that
limited transmission between humans is not
surprising and has been seen before in other
bird flu viruses, such as H5N1.
He added: "It would be a worry if we start to
see longer chains of transmission between
people, when one person infects someone else,
who in turn infects more people, and so on.
"And particularly if each infected case goes on
to infect, on average, more than one other
person, this would be a strong warning sign
that we might be in the early stages of an
epidemic."
An accompanying editorial in the BMJ, co-
authored by Dr Rudge, concluded that while
this study might not suggest that H7N9 is any
closer to delivering the next pandemic, "it
does provide a timely reminder of the need to
remain extremely vigilant".