Ebola: Here's some science for you

[B2G]

Last edited Thu Oct 30, 2014, 12:56 PM - Edit history (1)

Nobel Prize Winner for Medicine: People Without Symptoms Or Fever May Still Spread Ebola

Posted on October 28, 2014 by WashingtonsBlog

Is “Conventional Wisdom” All Wrong?

A study in the prestigious journal Lancet published in 2000 found that some people can carry Ebola without showing any symptoms.

The largest study on the current Ebola outbreak – sponsored by the World Health Organization – found that 13% of those infected with Ebola never had a fever.

ETA link fo the study:

http://www.nejm.org/doi/pdf/10.1056/NEJMoa1411100

Today, NJ.com reports:

Dr. Beutler, an American medical doctor and researcher, won the Nobel Prize for Medicine and Physiology in 2011 for his work researching the cellular subsystem of the body’s overall immune system – the part of it that defends bodies from infection by other organisms, like Ebola.

He is currently the Director of the Center for the Genetics of Host Defense at the University of Texas Southwestern Medical Center in Dallas ….

“It may not be absolutely true that those without symptoms can’t transmit the disease, because we don’t have the numbers to back that up,” said Beutler, “It could be people develop significant viremia [where viruses enter the bloodstream and gain access to the rest of the body], and become able to transmit the disease before they have a fever, even. People may have said that without symptoms you can’t transmit Ebola. I’m not sure about that being 100 percent true. There’s a lot of variation with viruses.”

In fact, in a study published online in late September by the New England Journal of Medicine and backed by the World Health Organization, 3,343 confirmed and 667 probable cases of Ebola were analyzed, and nearly 13 percent of the time, those infected with Ebola exhibited no fever at all.

Why does he think the CDC would so emphasize Ebola is not communicable in patients without symptoms?

“There’s some imperative to prevent panic among the public,” says Dr. Beutner, “But to be honest, people have not examined that with transmissibility in mind. I don’t completely trust people who’d say that as dogma.”

http://www.washingtonsblog.com/2014/10/doctor-won-nobel-prize-work-immune-system-people-without-symptoms-fever-may-still-ebola.html

[Fred Sanders]

1. 14 year article? Go for it. Keep up the fear, support the ebola governors in imprisoning a hero.

http://crooksandliars.com/2014/10/gov-lepage-puts-kaci-hickox-under-police

Gov. LePage Puts Kaci Hickox Under Police Guard To Keep Her Locked Up

[B2G]

2. 14 years old? What are you talking about?

[onenote]

8. I think he's talking about the fact the study cited in the article is from 2000.

[B2G]

11. Ah I see. I was referring to the fact that 13% don't develop fevers

That study was conducted for the current outbreak, with this strain, and was sponsored by the WHO.

***************************************************************************

The Los Angeles Times reported last week:

The largest study of the current outbreak found that in nearly 13% of “confirmed and probable” cases in Liberia, Sierra Leone, Guinea and elsewhere, those infected did not have fevers.

The study, sponsored by the World Health Organization and published online late last month by the New England Journal of Medicine, analyzed data on 3,343 confirmed and 667 probable cases of Ebola.

***

U.S. health officials have repeatedly emphasized that fever is a reliable sign of infectiousness. As a defense against the spread of the virus to this country, the Obama administration has ordered that passengers arriving from West Africa at five U.S. airports be checked for fever.

***

Referring to those who had close contact with Duncan, [CDC director] Frieden said a week ago: “The only thing we need to ensure is that their temperature is monitored, and if they develop a fever, that they are immediately assessed, isolated and if found to be positive, then appropriately cared for.”

***

Dr. Anthony Fauci, who is helping to shape the U.S. response to Ebola as director of the National Institute of Allergy and Infectious Diseases, was asked by a CNN interviewer on Oct. 4 whether a person could be “contagious without having a fever.”

Fauci replied that “the answer to that is no.”

http://www.washingtonsblog.com/2014/10/13-ebola-victims-west-africa-never-fever.html

[B2G]

3. So let's recap the science

The onset of a low grade fever precedes the contagious stage of the disease and this is what we're relying on for self-monitoring...to catch it early and isolate.

13% of those who contract ebola do not develop a fever. This means by the time they realize they are sick, they are contagious.

See the issue here?

[Fred Sanders]

4. Where does it say this 13% are contagious? How would they transmit without symptoms?

It may be that it is not 100% true! That is all the one guy is saying, and science is like that, it always leaves a bit of room for doubt, it is still the theory of evolution, the theory of gravity and the theory of evolution...remember?

You are aware there are 5 species of ebola?

[B2G]

5. 13% of those who contract ebola don't present with a fever

But they have the disease.

Yes, I am aware there are different strains. This on is very close to Zaire.

[840high]

7. Thanks.

[LisaL]

6. How would they transmit without symptoms?

You don't need symptoms if you have significant amount of virus in your body fluids to transmit.

[B2G]

9. It's not that they don't develop symptoms

It's just that they don't develop FEVER as a symptom.

Which is very problematic because fever precedes the more serious symptoms.

[LisaL]

15. My understanding that it's possible for some people to not develop symptoms at all.

It's called an asymptomatic carrier.

"The possibility of asymptomatic infection was only suggested in earlier studies, they said in last week's issue of The Lancet, a medical journal published in London. Now they said they had documented such infections for the first time. They found that the Ebola virus could persist in the blood of asymptomatic infected individuals for two weeks after they were first exposed to an infected individual. How much longer the virus can persist is unknown."

http://www.nytimes.com/2000/06/27/world/people-carrying-ebola-in-some-cases-may-be-free-of-symptoms.html

[morningfog]

19. And those people are not at all infectious.

[Nitram]

10. Context: 13% of Ebola victims become too weak to sustain a fever shortly before death.

100% of Ebola victims have a fever early in their infection, while their ability to transmit the disease is still very low.

[B2G]

12. That is incorrect

The largest study of the current outbreak found that in nearly 13% of “confirmed and probable” cases in Liberia, Sierra Leone, Guinea and elsewhere, those infected did not have fevers.

The study, sponsored by the World Health Organization and published online late last month by the New England Journal of Medicine, analyzed data on 3,343 confirmed and 667 probable cases of Ebola.

[NM_Birder]

13. ability to transmit the disease is still very low,

"chances are" ....that's good enough for me......let everybody exposed to Ebola patients loose into the city. How dare we inconvenience people for 3 weeks, given that there is only a "low" chance of spreading a disease that if contracted is 50/50 you'll die.


Jack Napier, "This Town Needs An Enema"

[Nitram]

35. If you live in West Africa you have between a 70% and a 90% chance of dying.

In the U.S one person has died so far, and 8 have recovered. That's a 13% mortality rate. No one in the family living in close quarters to the person who died, while he was contagious, contracted the disease. The facts speak for themselves. Take a deep breath and calm down, people.

[gollygee]

14. Bit of game playing here

"I'm not 100% sure about that being true" doesn't really = "that isn't true."

[Avalux]

16. The clinical presentation of any viral infection can be different from person to person.

From the article:

"People may have said that without symptoms you can’t transmit Ebola. I’m not sure about that being 100 percent true."

Dr. Beutler knows that in any viral infection there are always outliers; those who do not have the typical constellation of symptoms associated with the causative organism. Based on what we know, it's reasonable to make an assumption that small percentage of those who are infected with Ebola may be somewhat asymptomic.

This is what scientists do - they make assumptions from data all the time. What we know about Ebola is based on historical data from Ebola outbreaks that were very relatively small.

The message presented to the public from the WHO and the CDC is not incorrect; and is the best message at this point. Adding 'what if's' will only cause additional panic while everyone is still trying to learn and figure out the best way to stop this current outbreak.

[B2G]

17. 13% presenting with no fever is not a small number

Especially when the CDC is using that as the sole tool for early detection for those self-monitoring.

[Avalux]

18. Let's look at this a different way....

so presume that out of 1000 people infected, 130 are asymptomatic, but able to transmit Ebola. If a person is asymptomatic, it's really difficult to catch Ebola from them since they aren't vomiting, don't have diarrhea, aren't in the hospital with body fluids everywhere. Unprotected sexual contact would be primary mode of transmission (much like HIV infection).

What is the message from the CDC to the public? Especially since there are no cases of Ebola transmitted in the US, outside of the Dallas cluster?

[B2G]

20. The 13% without fevers are NOT asymptomatic

They just don't have FEVERS.

Fevers is the early indicator. It's the symptom those self-monitoring are looking for.

Without a fever someone might just feel fatigued and 'not right' in the early stages. But given the fact they don't have a fever, they could just assume it's some other illness, causing them to not report and being in the general public when the more severe symptoms begin and when they are far more contagious.

I don't know what's so hard to understand about this.

[Avalux]

22. I understand completely; I do this stuff for a living.

Read this again:

“It may not be absolutely true that those without symptoms can’t transmit the disease, because we don’t have the numbers to back that up,” said Beutler, “It could be people develop significant viremia, and become able to transmit the disease before they have a fever, even. People may have said that without symptoms you can’t transmit Ebola. I’m not sure about that being 100 percent true. There’s a lot of variation with viruses.”

That statement alone is not clear. It says "without symptoms" (asymptomatic) twice, then also says "able to transmit the disease before they have a fever".

Those looking at Ebola data are making assumptions. You are fixated on a number derived from historical data that in and of itself, is unclear. It would be irresponsible for anyone or any organization to present such data as fact, especially since there have been no cases of Ebola transmitted in the US (outside of the Dallas cluster).

[B2G]

23. Asymptomatic vs nosymptoms of fever are 2 completely separate topics

Here's the link to the NEJM report on the current outbreak.

http://www.nejm.org/doi/pdf/10.1056/NEJMoa1411100

[Avalux]

24. Have you read the publication in its entirety?

There is nothing in the publication, or in the article you present in your OP, that would cause the WHO or CDC to change their message.

Nothing.

I am now convinced you don't really want to understand, but want to find something about Ebola to cause panic.

[B2G]

25. Maybe you could explain it to me

Have some crayons. And I'd love to hear what your credentials are.

[WinkyDink]

21. "I don’t completely trust people who’d say that as dogma.” Nor do I, Doc; nor do I.

[Warpy]

26. Watch those WEASEL WORDS

"May" and "could" and "might" do not ever mean DOES.

After all, HIV was isolated from nasal secretions but no one has ever caught it from a sneeze.

[Kelvin Mace]

27. Fever is ONE symptom

In the 13% of the cases where it was not present, where other symptoms present? here are the guidelines from the CDC:

The new guidance defines four risk levels based on degree of exposure:

High risk—direct contact of infected body fluids through:

needle stick, or splashes to eyes, nose, or mouth
getting body fluids directly on skin
handling body fluids, such as in a laboratory, without wearing personal protective equipment (PPE) or following recommended safety precautions
touching a dead body without correctly wearing PPE in a country with widespread Ebola transmission (In countries with widespread Ebola transmission, it is not always known what a person died of. Therefore touching any dead body in one of these countries is considered a high risk exposure.)
living with and caring for a person showing symptoms of Ebola

Some risk—

close contact with a person showing symptoms of Ebola such as in a household, health care facility, or the community (no PPE worn). Close contact means being within 3 feet of the person with Ebola for a long time without wearing PPE.
in countries with widespread Ebola transmission: direct contact with a person showing symptoms of Ebola while wearing PPE

Low risk (but not zero)—

having been in a country with widespread Ebola transmission within the previous 21 days and having no known exposure
being in the same room for a brief period of time (without direct contact) with a person showing symptoms of Ebola
having brief skin contact with a person showing symptoms of Ebola when the person was believed to be not very contagious
in countries without widespread Ebola transmission: direct contact with a person showing symptoms of Ebola while wearing PPE
travel on an airplane with a person showing symptoms of Ebola

No risk—

contact with a person who is NOT showing symptoms AFTER that person was in contact with a person with Ebola
contact with a person with Ebola BEFORE the person was showing symptoms
having traveled to a country with Ebola outbreak MORE than 21 days ago
having been in a country where there is no widespread Ebola transmission (e.g., the United States), and having no other exposures to Ebola

*Symptoms of Ebola: Fever, severe headache, fatigue, muscle pain, vomiting, diarrhea, stomach pain, unexplained bruising or bleeding.

[magical thyme]

28. I'm trying to following the links back to the study, but so far just keep finding more articles

The reason I want to see the study, or at least a reasonable summary of it, is because not having a fever and being asymptomatic are two different things. And because non-medical people get a lot of details wrong, so pass on inaccurate information.

The people who had Ebola virus present with no fever presumably show other symptoms.

The CDC's original monitoring had 3 criteria: 1. travel history 2. fever and 3. another Ebola symptom.

The revised monitoring has 2 criteria: 1. travel history and 2. any Ebola symptom.

Also, was the study of people with virus present in their system, or was the study of people with antibodies present?

Because from 10-13% of people in the region have antibodies without having ever been ill. That does not mean they ever were contagious. It's entirely possible that they had extremely low exposure and their immune system knocked it out before they became ill. In fact, that is a major hypothesis for it. It also fits nicely with the untreated mortality rate of ~90%. That untreated survivors had at some prior point had very low exposure and already had circulating antibodies.

[B2G]

29. I posted it upthread, but here it is

"The reason I want to see the study, or at least a reasonable summary of it, is because not having a fever and being asymptomatic are two different things."

That's exactly what I've been saying on here. The study was of confirmed ebola cases for this outbreak with active virus present.


http://www.nejm.org/doi/pdf/10.1056/NEJMoa1411100

[magical thyme]

30. ty. it was a subset of confirmed and *probable* cases...boldface mine

Also, note that all probable cases were symptomatic -- they had to have symptoms in order to be probable Ebola.

As I wrote above, the CDC modified their criteria shortly after the Duncan case. They lowered the threshold temperature and, equally important, changed suspect to only 2 criteria -- travel and *any* symptom. It's no longer temperature dependent. On entry they take your temperature but they also ask you questions about symptoms.


We analyzed a detailed subset of data on 3343 confirmed and 667 probable Ebola cases collected in Guinea, Liberia, Nigeria, and Sierra Leone as of September 14.


"In brief, a suspected
case is illness in any person, alive or dead,
who has (or had) sudden onset of high fever and
had contact with a person with a suspected,
probable, or confirmed Ebola case or with a dead
or sick animal; any person with sudden onset of
high fever and at least three of the following
symptoms: headache, vomiting, anorexia or loss
of appetite, diarrhea, lethargy, stomach pain,
aching muscles or joints, difficulty swallowing,
breathing difficulties, or hiccupping; or any person
who had unexplained bleeding or who died
suddenly from an unexplained cause. A probable
case is illness in any person suspected to have
EVD who was evaluated by a clinician or any person
who died from suspected Ebola and had an
epidemiologic link to a person with a confirmed
case but was not tested and did not have laboratory
confirmation of the disease. A probable or
suspected case was classified as confirmed when
a sample from the person was positive for Ebola
virus in laboratory testing."

[SheilaT]

31. If asymptomatic Ebola patients were infecting others,

I think it would have been noticeable by now. Because people would be showing up with Ebola who apparently had no contact of any kind whatsoever with someone with actual Ebola.

Not having a fever, even at the beginning, simply isn't a factor since by the time you can transmit the virus to others you are REALLY sick. Vomiting, bloody diarrhea, maybe bleeding uncontrollably from minor wounds.

This is not like flu or chicken pox when you can pass those viruses on when you have no symptoms. Nor is it like Typhoid Mary, who would have been just fine if she hadn't insisted on getting work as a cook, which is precisely how she spread the typhoid around.

So, once again, all of these articles that talk about possibly, and maybe, and if, are sheer speculation and we are not seeing Ebola spread around very easily.

[B2G]

32. Only about 18% bleed with this outbreak

just an FYI...

[SheilaT]

33. So? Don't they all get explosive diarrhea

and projectile vomiting?

More to the point, worrying about the small fraction of those who don't get a fever at the very outset totally misses the point of exactly how this disease is spread.

[B2G]

34. Actually it doesn't, but

I'm not going to continue to repeat myself.