Transcript Mad Cows & Brits with holes in their brains & other

Mad Cows &
Brits with holes in
their brains
(& other infectious diseases)
Lecture 3
Dulai - FIB - 2008
Comeback Diseases
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 Infectious diseases such as
 Cholera
 Rheumatic fever
 Plague
Vibrio comma
though still quite rare, are on the rise and are
threats to be reckoned with.
 For example, cholera, Vibrio comma , is turning up
in the shellfish population, mainly on the U.S. Gulf
Coast.
 It's usually transmitted to humans when they eat
undercooked shellfish.
Revisiting!
 Likewise, outbreaks of such maladies of
yesteryear as
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Measles
Mumps
Diphtheria
Tuberculosis
Syphilis
 are on the rise.
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Why?
 Lax use of drugs by patients
 Because parents, doctors and public health
authorities have failed to mount the effort
needed to make sure everyone susceptible to
preventable diseases, regardless of
economic status, is vaccinated.
 Even people who have been properly
immunized are being stricken.
 Population Growth and overcrowding
What next?
 It is common knowledge amongst scientists
that IT IS NOT IF, BUT WHEN, the next major
pandemic will be coming.
 Millions, if not hundreds of millions, may die!
 What will it be?
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Influenza
Ebola
TB
MSRA
Prions
Lets quickly consider these
examples…
Influenza
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Agent: Virus which attacks our cells.
What can the stupid flu do to me?
I am healthy and strong
I live in a country with a lot of wealth
I have nothing to fear…
…or so you think!
Influenza - learn from history
 Flu pandemics tend to occur on a regular basis
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1918
1957
1968
?2008-9
 The disease bears little resemblance to the the
‘flu’ - except at the molecular level
 The virus gets its start when one of the many
strains which constantly circulates in wild and
domestic birds evolves into a form that infects
humans
Hybrid strain
 The bird strain then exchanges genes with
the native human flu strain to produce a novel
germ - that is highly contagious!
 Some of these strains are mild
 Others, which mutate faster than the immune
system can defend against, cause severe
and/or fatal illness
 It is predicted that the next pandemic has the
potential to claim more lives in a single year
than AIDS has in the last 25 years!…
Warnings
 Epidemiologists have warned that the
next pandemic could sicken 1/3 people
on the planet
 Killing 10,000,000 to 100,000,000 people
 It would spare no nation, no race, no
income group
 There will be no way to avoid it!
My government will have a
vaccine for me.
So I will be just fine.
…will you?
Asian Bird Flu is doing the rounds
 Hard to predict when it will come
 Conditions are ripe at this time
 There is a fierce strain of avian flu killing
people in Asia, and infecting birds in a rapid
westward lunge towards Europe
 Influenza A (H5N1) does not pass readily
from person to person - not yet!!!!
 The virus is evolving and the birds are
beginning their migrations…
 What can we do?
Defense
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Our best bets
Surveillance
Vaccines
Containment
Medications
Remember the Alamo Katrina
 The government had a great plan for a
hurricane hitting the Texas coast
 It failed to implement properly
 It has a great plan for the ‘bird flu’ too
 Can they stick to their plans if the same
workers are downed by the flu?
Case in point…
Jakarta, Indonesia
They HAD a plan too…
FLU Strain H5N1
 Late June - In a wealthy suburb of
Jakarta, a 8-year old daughter of
government auditor falls ill.
 She gets antibiotics, but gets worse
 June 28th - She is hospitalized
 July 4th - Her father and sister fall ill too
 July 9th - Sister dies
 July 12th - Father dies
H5N1 continued
 July 13th - doctors alert US Navy medical base
 July 14th - the girl dies
 July 14th - techs isolate and ID H5N1 form blood
samples
 July 22nd - Government acknowledges that there
is a problem.
 Hospitals prepare for an outbreak.
 - Over 30 days elapsed - containment window
would have closed.
 Luckily - This time it was a false alarm.
Use Vaccines to Control Flu
 Vaccines have worked to almost eradicate
smallpox and polio
 BUT, this tactic will not work with influenza
(unless we have a major advance in vaccine
technology)
 Why?
 It takes about 6 months to make vials of vaccine
 One will need two injects of vaccine 4 weeks apart
- primer and booster
 Add it up and it would take about 8 months to get
immunity from the start of the pandemic
Vaccines - Who will get them?
 There is capacity to make about 300 million doses per year
 More capacity on the way but still have other problems too
 Make flu vaccine or pandemic vaccine - cannot make both at
the same facility
 Delays and shortages will abound
 Who will get them first?
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Government works
Police
Health works
Teachers
Elderly & infants
Ill people
Will YOU?
EBOLA
The new “jungle fever”
Ebola
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 Ebola is both the common term used to
describe a group of viruses
 …and the common name for the disease
which they cause, Ebola fever
 Thought to be transmitted by the fruit bat
 Ebola hemorrhagic fever
 Vomiting, diarrhea, general body pain, internal and
external bleeding, and fever.
 Mortality rates are generally high, ranging from
50% - 90%, with the cause of death usually due to
shock or organ failure - one of the most virulent
viral diseases known to humankind
Ebola - Infectious
 Among humans, the virus is transmitted by direct
contact with infected body fluids - sex
 or to a lesser extent, skin or mucus membrane
contact
 The incubation period can be anywhere from 2 to
21 days, but is generally between 5 and 10 days
 Monkeys - seems to be airborne, not humans- yet!
 Transmission of the Ebola virus has also occurred
by handling ill or dead infected chimpanzees.
(Did we not blame them for giving us HIV/AIDS too!)
Tuberculosis
TB for tubercle bacillus
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Chest X-ray of Patient
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TB - ‘The comeback kid’
 Today about 5000 people die of this once
thought conquered disease!
 It is caused by a bacteria
 Primarily attacks the lungs, although it can
also attack a number of other locations nerves, blood, lymph, genitals, skin, etc.
 Symptoms include chest pain, coughing
up blood, and a productive, prolonged
cough for more than three weeks.
TB - ‘The comeback kid’
 Over 20% of the cases are now drug
resistant in many countries
 With a further 4% requiring 2nd line
treatments
 Will it be the next
‘BIG ONE’?
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MRSA
Methicillin-resistant
Staphylococcus aureus
MRSA
 MRSA is characterized by antibiotic
resistance to all penicillins
 including methicillin and other narrow-spectrum
penicillin antibiotics.
 MRSA was discovered for the first time in
1961 in the UK, but it is now widespread in
the hospital setting.
 MRSA is commonly termed a superbug.
 MRSA infection can be fatal.
Natural flora
 Staphylococcus bacteria are normally found
on the skin or in the nose of about one-third
of the population
 If you have staph on your skin or in your nose
but aren't sick, you are said to be "colonized"
but not infected with MRSA
 Healthy people can be colonized with MRSA
and have no ill effects, however, they can
pass the germ to others.
MRSA…
 Enters through
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Nose
Cuts
IV sites
Urinary tract
Infections
 About 5 times the risk of dying over those that
do not get it.
 Costs more to treat too, as you have to spend
about 3X longer in the hospital.
Common place
 Cases are now being reported outside
the hospital setting - in communities
 This has huge implications for us.
 Will we reach a point where we will have
no further antibiotics left to treat this
infection - the bacteria is evolving very fast!
Finally… HELLO I’M BACK!
WATCH ME…
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Prions
“ATTACK OF THE KILLER
PROTEINS”
In pure
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At a slaughter house near you…
MAD COW DISEASE
 BSE - Bovine Spongiform Encephalitis
 Spongy Brain Disease
 Makes cows mad
 Known as Creutzfeldt-Jakob disease
(CJD) in man
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proteinaceous infectious particle
Watch and learn
Whilst watching the video answer the
following questions please:
1. How old was the first patient?
2. What did the natives of Papua New Guinea eat
that caused them to get ‘kuru”?
3. How did it get into cows?
4. What is the cause of BSE?
5. What happens to the patients brain?
Group Questions
Group Questions
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6.
If you were a health worker, how would you change your
habits after today's lecture?
Do you believe that killer diseases are inevitable?
As we become more and more parasitic on other species,
what could be some of the outcomes? Discuss and then
outline at least three possibilities.
Some say that the best way to control the human population
is to allow these diseases to run their course. What do you
think?
Downer Cattle & the meat factory in the news in California.
Now do you understand why downer cattle are not allowed
into the human foodchain.