Lyssavirus
On
the 16th October 2004, a teenage girl was brought to the
Children's Hospital of Wisconsin and tested positive for a disease
that all the hospital staff knew had a 100% mortality throughout all
recorded history. Her parents were given two options, to put her in a
dark room in the Hospital to die or take her home to die.
That
September, the girl, Jeanna Giese, was bitten by a strangely acting
bat on her left index finger. On 13th October, Jeanna felt
ill and had tingling in her left arm, but from there deteriorated
rapidly. She couldn't walk, her left arm twitched uncontrollably and
her speech was slurred. Hours after arriving at the Hospital she
became stuporous. She had rabies, and appeared to be going the same
way as all other rabies victims.
Rabies
is caused by viruses of the genus Lyssavirus, all of which as around 11,00 base pairs long. The disease is
zoonotic, meaning it's host is non-human animals. Rabies can infect
almost all warm-blooded animals, though the disease is mainly
transmitted to humans via contact with the saliva of bats, dogs,
raccoons and some other animals. Rabies is a peculiar virus. The
classic virus enters the blood stream and circulates until it reaches
it's target where it replicates. Rabies does not take this blood
route; instead it takes the nervous route. The virus binds to the
nerve nearest the bite and inches it's way up the periphery nerves
and into the central nervous system until it gets to the brain. It
travels under 2 cm a day, therefore it will take longer to travel to
your brain if you are bitten on the toe, maybe months, but when
bitten on the face it could take a week. This window of time is
crucial, as this is when you can administer a vaccine to cause the
body to mount an immune response which destroys the virus. When the
virus reaches the brain the vaccine is useless, as the virus will now
act at a swifter speed that any normal immune response can.
What
the virus does in the brain is unknown. The two main theories are
that it either over-excites the brain so that it cannot carry out
normal functions and the person dies (known as excitotoxicity) or
that it simply inflames and kills neural tissues.
This
is what is does to a patient's biology, but it does much more to the
patient's behaviour.
30% of patients experience paralytic rabies, where they are paralysed
and then slip into a coma and die of heart or other organ failure.
The
rest have a different fate. A few days before death they experience
convulsions, hallucinations and explosive rage. The brain cannot
regulate their body; throat spasms cause wild cries and they can die
by drowning in their own blood or organ failure. This behaviour is
very animalistic and uncontrollable, it could explain the werewolf
myth.
But
the truth is more chilling. A person's behaviour is not driven by
human logic but by a virus' need to replicate; a sentient being acts
this way because of a simple virus. Patients experience hydrophobia
so they can't drink, which then dilutes their saliva and they cannot
swallow, meaning that their virus-rich saliva can only go one way.
They are aggressive so they might bite and spread the virus. This is
an assault to our idea of free will; if a micro-organism that isn't
really alive can change our behaviour so much, then are we as
autonomous as we like to think? It is one of the most undignified
ways to die imaginable.
Therefore,
Jeanna's doctor, Rodney Willoughby, was not content to see his
patient die without doing something. He thought that, if rabies was
an excitotoxic disease, then if the immune system was given enough
time to catch up with the virus so antibodies were produced in time
so the patient could recover. So Dr Willoughby put Jeanna into a coma
and waited. This was an enormous risk, as she could be brain-damaged
if she even survived at all. 7 days later she was brought out of a
coma and though weak and frail, alive, against the entirety of scientific consensus.
She had produced enough antibodies in enough time for her immune
system to fight off the virus, the first person known to have
encountered rabies and come out alive.
Jeanna
was very weak, and had to be treated with drugs including ketamine
and antivirals. She has been through many years of rehabilitation and
treatment, but today is healthy and spends her time with her sled dog
team, and despite her experiences still has a love for bats (as we all should).
There is, however, controversy as to the effectiveness of Dr Willoughby's treatment, which is called the Milwaukee protocol and has been used on a handful of other patients, with only 4 of 35 surviving, which is still an impressive survival rate for rabies. It has been suggested that Jeanna and the others survived because they were genetically "fitter" to withstand rabies, they were infected with a weakened form or rabies or bitten on a "safer" area or all of these together. There are even reports of some populations (mostly remote, Amazonian populations) found with rabies anti-bodies in their blood (with no signs of rabies, and they probably couldn't have recovered without the Milwaukee protocol), indicating a genetic resistance to rabies, in a similar way that some tropical populations have a genetic resistance to malaria.
Bibliography
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3414553/ : This is by Rodney Willoughby himself.
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