Wednesday, 8 February 2012
Schmallenberg Virus, McKenna clears the fog
For those unfamiliar with English humour, there was the famous newspaper headline "Fog in Channel, Continent Cut Off." Actually, nobody is quite sure it was a joke.
Maryn McKenna makes her usual brilliant explanation of matters scientific, in relation to Schmallenberg Virus arriving in Britain.
Whether in the written word, or in her now frequent TV appearances in the USA, she collates the facts coldly and explains the implications.
They need her on the BBC.
This is a long piece chronicling the arrival of Schmallenberg in Britain as we currently understand the facts.
Especially helpful is the detail of the place this virus occupies with others, some of which that are known to be zoonotic and dangerous to humans.
We note elsewhere that Defra have, this morning, finally grasped the difference between the English Channel and the North Sea as their preferred route of arrival.
Full article with links here
Fast-Spreading Animal Virus Leaps Europe, UK Borders
By Maryn McKenna
Author February 7, 2012 | 4:32 pm |
...The European Center for Disease Prevention and Control has said
that the new virus’s closest relatives do not cause disease in humans
— but that other more distantly related viruses do:
The new virus belongs to the Bunyaviridae family, genus
Orthobunyavirus, Simbu serogroup (preliminary information, based
solely on genetic information)… Genetic characterisation has shown
that the new virus is closest to the following Simbu serogroup
viruses: Shamonda-, Aino- and Akabane-viruses, which do not cause
disease in humans.
However, at least 30 orthobunyaviruses are zoonotic and may cause
disease in humans, with symptoms ranging from mild to severe — e.g. La
Crosse encephalitis virus, California Encephalitis virus, Cache Valley
virus, Batai virus, Tahyna virus, Inkoo virus, Snowshoe Hare virus,
Iquitos virus and Oropouche virus.
The viral vector — the thing which spreads it — is believed to be
midges, small flying biting insects (Culicoides) and maybe also
mosquitoes (Culicidae). The disease doesn’t pass from adult animal to
another animal, but apparently does from a mother animal to its
offspring in utero, and that is why it is showing up now: It’s lambing
season. With Europe enduring its coldest winter in decades, there are
no virus-carrying insects flying around now. Instead, the animals that
are giving birth to deformed and dead offspring were infected last
summer and fall. No one has been able to say so far whether the
organism can survive in insects over the winter (the way West Nile
virus, for instance, may)...