A minor storm has erupted over a new paper in the Lancet detailing human to human transmission of bird flu in China. The 24 year old son died, while his 52 year old father survived.

However there’s no need to panic just yet.

“It is not normal social contact that has led to the human transmission,” Jeremy Farrar, a researcher at Vietnam’s Institute of Hygiene and Epidemiology told AFP. “In this case it took extensive exposure to secretions of somebody who was very sick in hospital.”

The BBC notes that in a Lancet editorial released with the paper on the new cases Farrar seems worried about the bird flu problem in general. “Whatever the underlying determinants, if we continue to experience widespread, uncontrolled outbreaks of H5N1 in poultry, the appearance of strains well adapted to human beings might just be matter of time,” he says.

This is not the first case of suspected human to human transmission (see Bird flu may have passed between humans, Nature 2004; Large bird flu cluster emerges, Nature 2007, for example).

As the editorial notes:

Person-to-person transmission of H5N1 was fi rst mooted after the 1997 Hong Kong outbreak, in which family members and at least two health workers might have been infected by contact with patients. Since then, one report of a family cluster concluded that person-to-person transmission was probable, and an additional four reports stated that it could not be ruled out in at least six families. In today’s Lancet, another convincing report of probable person-to-person transmission is published by researchers from China and the USA.

The fact this is often happening in families is prompting speculation that there might be a genetic component to human-to-human transmission. “That may account for why certain families seem to be susceptible whereas most people aren’t,” says Philip Alcabes, of the School of Health Sciences of Hunter College in New York City (Forbes).

The Lancet commentary agrees, noting “Although this finding could be related to the intensity and intimacy of contact between family members, host genetic factors might also play a part in susceptibility to H5N1” (Reuters).

I can’t find any coverage of this from the normal Chinese news sources.

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