Egypt is causing a bit of a stir in the Flubiehood today. The story of a young sister and brother becoming infected with H5N1 four days apart has been buzzing around, because of the timing of onset of symptoms between the girl, first to become ill and the younger brother it is suspected that the boy caught the virus from his sister, H2H (human-to-human) transmission. H2H transmission is The Thing that Flubies incessantly watch for.
No human transmission in Egypt bird flu case-WHO
03 Apr 2007 16:43:16 GMT
More (Updates with human transmission ruled out)
GENEVA, Apr 3 (Reuters) - Egyptian health authorities excluded the possibility of human to human transmission in the case of a brother and sister with bird flu, the World Health Organisation (WHO) said on Tuesday.
A four-year-old boy, from Qena province around 670 km (400 miles) south of Cairo, was among three human cases announced by the health ministry at the weekend. His six-year-old sister was one of two children diagnosed with the virus late last week.
"We have heard from the Ministry of Health that human to human transmission has been ruled out," WHO spokesman Greg Hartl told Reuters.
Both of the children had been exposed to poultry infected with the H5N1 virus, the most common way in which bird flu has been spreading.
In all, five Egyptian children have been reported as being in hospital in stable condition. "Egypt has an extremely good record of child survival of H5N1," Hartl added.
The highly pathogenic H5N1 virus is not easily transmissible between people, although there has been evidence of several clusters involving human to human transmission over the past three years, according to the WHO.
Experts fear that the virus will mutate or combine with the highly contagious seasonal influenza virus and spark a deadly pandemic which could circle the globe and kill millions.
Egypt has the highest number of confirmed human bird flu cases outside Asia. Of the 32 confirmed cases in the country to date, 13 have been fatal.
While the article states WHO made the announcement, the information seems to have come from Egyptian health authorities. It seems to be just too early for such a definitive announcement, although with NAMRU-3 there, perhaps it isn't outside the realm of possibility.
Siblings with a spread of symptom on-set dates leave only two possibilities: A common environmental contaminate or the sister infected the brother.
If the sister infected the brother we still may not be seeing a humanly transmissible virus. Avian Influenza preferentially binds to alpha 2,3 sialic acids because birds have the 2,3 receptors, while human influenza preferentially binds to alpha 2,6 sialic acids. Humans, adults anyway, have both receptors in their respiratory tracts, however almost exclusively the 2,6 receptors in the URT, the 2,3 being mostly restricted to the the lower tract, LRT.
There is a strange happenstance though, young children it seems have almost exclusively 2,3 binding receptors which slowly change to the 2,6 receptors as they age. So, our young victims would have the same types of cells H5N1 would use to infect ducks and chickens, but adults would have far, far fewer, and in a much harder place to reach.
This means that it is logically possible to have had an occurrence of H2H with H5N1 without having a human adapted virus. Is it factual? Who knows... we simply do not have enough information in the hands of Flubies who are capable of puzzling the pieces at this time. Until we do, the Flubiehood will be buzzing, and my PPF (Personal Pucker Factor) won't be going down any.