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No, Seriously, How Contagious Is Ebola?
NPR ^ | 10/03/2014 | MICHAELEEN DOUCLEFF

Posted on 10/03/2014 3:01:23 PM PDT by SeekAndFind


Holy moly! There's a case of Ebola in the U.S.!

That first reaction was understandable. There's no question the disease is scary. The World Health Organization now estimates that the virus has killed about 70 percent of people infected in West Africa.

The Ebola case in Dallas is the first one diagnosed outside Africa, the Centers for Disease Control and Prevention said Tuesday. And the health care system in Texas didn't quarantine the man right away. He was sick with Ebola — and contagious — for four days before he was admitted to the hospital.

But when you look at health officials responding to the case in Dallas, they seem cool as cucumbers, despite the initial misstep.

"I have no doubt that we will control this importation, or case, of Ebola so that it does not spread widely in this country," said the director of the CDC, Dr. Tom Frieden.

Why is Frieden so sure this virus won't spread beyond a handful of cases?

It boils down to something called "R0."

The reproduction number, or "R nought," is a mathematical term that tells you how contagious an infectious disease is. Specifically, it's the number of people who catch the disease from one sick person, on average, in an outbreak.*

Take, for example, measles. The virus is one of the most contagious diseases known to man. It's R0 sits around 18. That means each person with the measles spreads it to 18 people, on average, when nobody is vaccinated. (When everyone is vaccinated, the R0 drops to essentially zero for measles).

At the other end of the spectrum are viruses like HIV and hepatitis C. Their R0s tend to fall somewhere between 2 and 4. They're still big problems, but they spread much more slowly than the measles.

And that brings us back to Ebola. Despite its nasty reputation, the virus's R0 really isn't that impressive. It typically sits around 1.5 to 2.0.

Even in the current epidemic in West Africa, where the virus has been out of control, each person who has gotten sick has spread Ebola to only about two others, on average.

Why is that?

Many factors contribute to the R0, such as how long you're infectious** and how many virus particles are needed to make another person sick.



TOPICS: Health/Medicine; Science; Society
KEYWORDS: contagion; ebola
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To: Enlightened1

Good chart. All we hear about is Ebola spreading like wild fire in Africa but we have nothing to fear here. Someone is full of BS.


61 posted on 10/04/2014 7:12:43 AM PDT by jetson
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To: TLI
As the number of Ebola infections increase the credibility of NPR decreases.


62 posted on 10/04/2014 7:17:57 AM PDT by Justa
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To: exDemMom
It depends on how long the infected persons were in the wild and what the mode of transmission for the virus is.

So it would be appropriate to frame your contention in that context.

63 posted on 10/04/2014 8:48:50 AM PDT by Mariner (War Criminal #18)
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To: exDemMom

Says you. I live in DFW. We hunt and BBQ bats at least once a week ‘round here. /s

;p


64 posted on 10/04/2014 9:00:22 AM PDT by BuckeyeTexan (There are those that break and bend. I'm the other kind. ~Steve Earle)
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To: exDemMom
So IF: The virus is found in bodily fluids, that would include saliva and sputum, yes? Lets say a person is sick with Ebola and sneezes or coughs, aerosolizing that sputum and saliva into the air that an uninfected person breathes. You are saying,"No chance what so ever of catching it." I assume you would not mind testing that theory out personally, yes?

What if that person just recently vomited and sneezes or coughs? Or they are already bleeding from the gums due to existing periodontal conditions? Or they have nose bleeds? Bite their cheek or tongue?

65 posted on 10/04/2014 1:51:31 PM PDT by nomad
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To: nomad
So IF: The virus is found in bodily fluids, that would include saliva and sputum, yes? Lets say a person is sick with Ebola and sneezes or coughs, aerosolizing that sputum and saliva into the air that an uninfected person breathes. You are saying,"No chance what so ever of catching it." I assume you would not mind testing that theory out personally, yes?

That scenario is typically referred to as "droplet transmission" and has never been ruled in or out as a mode of transmission of Ebola. To avoid droplet transmission, you should stay at least 3 feet from an infected person (this applies to all diseases that cause sneezing and coughing and are spread by droplets). I prefer to stay further than that from someone who is sneezing--3 or 4 yards is good.

The symptoms of Ebola include vomiting and diarrhea, which are the virus's way of exiting the body and looking for a new host.

66 posted on 10/04/2014 2:06:00 PM PDT by exDemMom (Current visual of the hole the US continues to dig itself into: http://www.usdebtclock.org/)
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To: ROCKLOBSTER

SPLAT comes to mind....lol


67 posted on 10/04/2014 4:20:29 PM PDT by Kackikat (Two wrongs do NOT make a right.... unless you are a Democrat!)
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To: Anitius Severinus Boethius
But in Ebola's case, the mode of transmission probably helps keep its R0 low.

MICHAELEEN DOUCLEFF is giving us old information - numbers from past Ebola outbreaks. Here's how this strain is different:

ALL past Ebola outbreaks started in the jungle and moved toward cities. This outbreak started in a city.

All other Ebola outbreaks started in ONE place - a small village or community.... This outbreak STARTED in THREE cities simultaneously.

Because African doctors and other Health Care workers in Africa are familiar with Ebola - - health care workers generally didn't get infected in the past. With this strain health care workers are getting infected. Doctors are getting infected, nurses are getting infected.

Last but not least - before this outbreak became political (something the CDC wallows in) several African doctors had commented on how 'healthy' patients appeared almost up until their death. That's different - and telling.

" Longer good 'walking around' health" means statistics from earlier outbreaks are NOT valid. Older strains of Ebola took people down quickly - the sickness stopped them from being able to walk around and infect others. It was self contained for that reason.

68 posted on 10/04/2014 5:36:40 PM PDT by GOPJ ("The welfare of humanity is always the alibi of tyrants" - Albert Camus)
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To: GOPJ

No. You have your facts wrong.

patient zero was a 2 year old,
http://www.scientificamerican.com/article/patient-zero-believed-to-be-sole-source-of-ebola-outbreak/

and no, local physicians don’t have experience treating ebola...I worked in Liberia...

Ebola’s early symptoms are similar to other serious diseases such as flu, malaria, typhoid and measles... etc... until the bleeding starts.


69 posted on 10/04/2014 5:46:53 PM PDT by LadyDoc (liberals only love politically correct poor people)
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To: LadyDoc

Since it`s a bit tough on the skin, what besides Chlorine bleach is effective on the virus? Quats, Iodophors, Phenolics (I know, not intended for skin contact) , alcohol based products?


70 posted on 10/04/2014 5:55:27 PM PDT by nomad
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To: SeekAndFind

“Even in the current epidemic in West Africa, where the virus has been out of control...”

That was my take-away sentence on this article of why Ebola is not a big deal.


71 posted on 10/04/2014 5:55:43 PM PDT by 21twelve (http://www.freerepublic.com/focus/f-news/2185147/posts 2013 is 1933 REBORN)
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To: SeekAndFind
No, Seriously, How Contagious Is Ebola?

Ask me again in 3 weeks.

72 posted on 10/04/2014 5:56:37 PM PDT by Jim Noble (When strong, avoid them. Attack their weaknesses. Emerge to their surprise.)
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To: LadyDoc
BECAUSE I'm an American MY patient ZERO is the first person to have ebola in the United States.

That patient ZERO in a grown man who was looking for free medical care - he came from Africa and he didn't care how many people he infected on the way...

73 posted on 10/04/2014 6:29:05 PM PDT by GOPJ ("The welfare of humanity is always the alibi of tyrants" - Albert Camus)
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To: LadyDoc
no, local physicians don’t have experience treating ebola...I worked in Liberia...

My point was that the doctor's without borders person got ebola and he knew how 'not to get the disease'... a nurse working near him both came down with Ebola too. Both of them were experienced with the disease. I didn't mean to imply that all local doctors had worked with Ebola.

74 posted on 10/04/2014 6:32:44 PM PDT by GOPJ ("The welfare of humanity is always the alibi of tyrants" - Albert Camus)
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To: SeekAndFind

For the binary impaired: A value of 1 to 2 is a major concern. If 1 person can infect two then the following chart suggests just how fast every person on the planet can be infected.

1: 1
2: 2
3: 4
4: 8
5: 16
6: 32
7: 64
8: 128
9: 256
10: 512
11: 1,024
12: 2,048
13: 4,096
14: 8,192
15: 16,384
16: 32,768
17: 65,536
18: 131,072
19: 262,144
20: 524,288
21: 1,048,576
22: 2,097,152
23: 4,194,304
24: 8,388,608
25: 16,777,216
26: 33,554,432
27: 67,108,864
28: 134,217,728
29: 268,435,456
30: 536,870,912
31: 1,073,741,824
32: 2,147,483,648
33: 4,294,967,296
34: 8,589,934,592

That’s it: 34 replications and 8 billion people could have it. There is less than 7 billion people alive now.


75 posted on 10/04/2014 7:43:25 PM PDT by CodeToad (Islam should be outlawed and treated as a criminal enterprise!)
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To: SeekAndFind

This chart and the reality of the epidemic do not match.

Substitute influenza or chickenpox and I think you would see similar spreads of infection, maybe less.

The spread of Ebola is not on par with harder to get diseases like hepatitis.


76 posted on 10/04/2014 7:51:46 PM PDT by daisy12
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To: nomad

Most strong disinfectants work but the government doesn’t name any specific brand.
http://www.cdc.gov/vhf/ebola/hcp/environmental-infection-control-in-hospitals.html

But the older web site for Africa suggests hand sanitzers or soap and water.
http://www.cdc.gov/vhf/ebola/prevention/index.html


77 posted on 10/05/2014 12:49:20 AM PDT by LadyDoc (liberals only love politically correct poor people)
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To: LadyDoc
Thanks, thinking in terms of the decon shower that`s a requirement after potential chemical/particulate hazmat exposure. As a former HAZWOPER trained worker, we decon showered even after removal of extensive PPE,(Level A) only now it`ll be with anti-microbials as well as soap/water, yes?
78 posted on 10/05/2014 8:37:10 AM PDT by nomad
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To: LadyDoc

Technical question: If the compounds used are to be used at higher than normal concentrations, as suggested on the CDC link provided, than that suggests the current “best practice” as labeled on the disinfectant compounds is not really the best practice, shouldn`t they now alter the standard recommended concentrations?


79 posted on 10/05/2014 8:48:02 AM PDT by nomad
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To: nomad
I mean in light of the last Hospital screw up, (sending the Liberian oogie-woogie-cootie boy home), we need to be spot on every time and every case, or it`ll come back and bite in the @ss, something fierce!
80 posted on 10/05/2014 8:58:12 AM PDT by nomad
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