No, Seriously, How Contagious is Ebola?

[AJL]

Link - www.npr.org/blogs/health/2014/10/02/352983774/no-seriously-how-contagious-is-ebola

No, Seriously, How Contagious Is Ebola?

by MICHAELEEN DOUCLEFF

October 02, 201410:59 AM ET

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.

Traffic moves past Texas Health Presbyterian Hospital in Dallas, where a patient showed up with symptoms that were later confirmed to be Ebola.
Shots - Health News
On The Alert For Ebola, Texas Hospital Still Missed First Case
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.

So 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, then R0 drops to essentially zero for measles).

A mock patient is wheeled in an isolation pod during a drill at the biocontainment unit in the Nebraska Medical Center in Omaha.

At the other end of the spectrum are viruses like HIV and hepatitis C. Their R0s tend to fall somewhere between and two and four. 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' 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.

A Frightening Curve: How Fast Is The Ebola Outbreak Growing?
But in Ebola's case, the mode of transmission probably helps keep its R0 low. Ebola isn't spread through the air, like the measles or flu. It requires close contact with some bodily fluid, such as blood or vomit, containing the virus.

Now at this point, you're probably thinking, "OK. But an R0 of two is nothing to brush off." You're right. R0 of two means one person infects two people, who then infect four people, then eight, 16, 32 — the numbers go up fast.

But that isn't likely to happen in a place with a good public health system, like the U.S. Why? Because people with Ebola aren't contagious until they show symptoms.

So to stop the chain of transmission, all health workers in Texas have to do is get the people possibly infected by the sick man into isolation before these people show signs of Ebola.

Then R0 drops to zero. And Texas is free of Ebola.

*We're talking the "basic" R0 here, for all you epidemiologists. So the R0 that you get when everyone in the population is susceptible to the disease.

**The R0 is integrated over the time that a person is infectious to others. For HIV, this could be years. But for Ebola, that time is only about a week. So even though they have similar R0s, Ebola's infections per unit of time is much higher than HIV's.

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

Or in other words...

[sangria]

Fucking measles. Fucking anti vaxxers. Those assholes are more likely to bring about the apocalypse than this dude.

[madisen]

'So to stop the chain of transmission, all health workers in Texas have to do is get the people possibly infected by the sick man into isolation before these people show signs of Ebola.'

Phew! Oh wait :/

[stever]

Emerging from lurkerdom to say that "calm your tits" is now my new favorite thing to say.

[debatethis]

My SIL is alllll kinds of freaked out about ebola. I should remind her that I've been married to my Hep C + DH for 8 years and still haven't caught that, so she really should calm her tits (thanks @ajl).

[orangeblossom]

OMG, I am raging. Why are they plastering this man's face and actual apartment number all over TV. WHY.

[ttt]

Oct 2, 2014 11:32:14 GMT -5 AJL said:

But that isn't likely to happen in a place with a good public health system, like the U.S. Why? Because people with Ebola aren't contagious until they show symptoms.

A good public health system like the kind that sends people with suspected viral infections home with antibiotics and doesn't bother to communicate that said person is showing symptoms of the very disease that has been ALL OVER THE NEWS for the past few months and recently arrived from THE VERY COUNTRY WHERE IT HAS BEEN A HUGE CRISIS. That kind of "good public health system"? 

[orangeblossom]

Oct 2, 2014 23:07:03 GMT -5 ttt said:

Oct 2, 2014 11:32:14 GMT -5 AJL said:

But that isn't likely to happen in a place with a good public health system, like the U.S. Why? Because people with Ebola aren't contagious until they show symptoms.

A good public health system like the kind that sends people with suspected viral infections home with antibiotics and doesn't bother to communicate that said person is showing symptoms of the very disease that has been ALL OVER THE NEWS for the past few months and recently arrived from THE VERY COUNTRY WHERE IT HAS BEEN A HUGE CRISIS. That kind of "good public health system"? 

It's over on MLs Ebola thread, but the hospital released a statement, and said that the proper information was input into the system, but the computer workflow between triage nurses, intake nurses and doctors was not right, and that's how the info didn't get relayed.

The press release was pretty thorough, and laid out what he said as didn't say, re feeling sick as having symptoms.

As for the ABX, just sigh. There's no reason for it.

[ttt]

Looks like they're doing a great job with the quarantine, too...

www.cnn.com/2014/10/02/us/texas-woman-quarantine-ebola-thomas-duncan/index.html

The sweat-stained sheets of Thomas Eric Duncan, the first person diagnosed with Ebola in the United States, still on her bed, a woman quarantined in a Dallas apartment said Thursday that she desperately wants her family's nightmare to end.

"We can't wait to be over with everything," the woman, who asked to be identified only by her first name, Louise, told CNN's Anderson Cooper. "We can't wait."

While Duncan is in isolation at Texas Health Presbyterian Hospital, his partner and three others have been stuck in a Dallas apartment since his diagnosis this week. Louise told CNN that authorities had her sign paperwork stating "if we step outside, they are going to take us ... to court (because) we'll have committed a crime."

So there she has stayed, along with her 13-year-old son and two nephews in their 20s. But it hasn't been easy.

Louise told CNN's Cooper by phone that she is checking her temperature every hour, and based on that and everything else, isn't sick. She expressed frustration being confined nonetheless, since people are only contagious with Ebola if they are symptomatic.

Duncan's girlfriend has been frustrated in other ways as well.

She said no one brought food Thursday to four people who can't leave to get it themselves, at least until later in the day. There was also the matter of their power going out, which was likely related to strong storms that rolled through the area. Then, of course, there's the idea of living in a place that -- just a few days ago -- was home to an Ebola sufferer.

Her 35-year-old daughter brought over Clorox to help clean the house, and she sealed up Duncan's dirty clothes and towels in a bag.

"But (authorities) said we shouldn't throw anything away until they can get back with me," Louise said.

That hadn't happened as of Thursday evening. That's when men in trucks from Cleaning Guys, a company that specializes in hazmat and biohazard cleaning services, went inside the apartment.

[MrsAggie]

Oct 2, 2014 15:23:10 GMT -5 madisen said:

'So to stop the chain of transmission, all health workers in Texas have to do is get the people possibly infected by the sick man into isolation before these people show signs of Ebola.'

Phew! Oh wait :/

Right?? Lol! Should be easy peasy. Why the hell haven't we rid ourselves of HIV and Hep C yet? Lazy ass healthcare workers.

[Deleted]

Oct 2, 2014 23:30:31 GMT -5 MrsAggie said:

Oct 2, 2014 15:23:10 GMT -5 madisen said:

'So to stop the chain of transmission, all health workers in Texas have to do is get the people possibly infected by the sick man into isolation before these people show signs of Ebola.'

Phew! Oh wait :/

Right?? Lol! Should be easy peasy. Why the hell haven't we rid ourselves of HIV and Hep C yet? Lazy ass healthcare workers.

I hope you already know this, but just in case others don't I have to address it.  It takes a long time for HIV to become symptomatic (6 months, a year, that kind of long time) but you're still able to pass it on to other people.  It's really hard to miss the symptoms of ebola since they onset suddenly and you become a puddle of fluids within a few days if you don't get thee to a hospital.  You're not contagious until you're obviously sick.

So, contagious virus hanging out getting spread without the carrier knowing they're sick in the first place vs. very sick person within days.

[madisen]

Oct 3, 2014 8:40:41 GMT -5 @silver said:

Oct 2, 2014 23:30:31 GMT -5 MrsAggie said:

Right?? Lol! Should be easy peasy. Why the hell haven't we rid ourselves of HIV and Hep C yet? Lazy ass healthcare workers.

I hope you already know this, but just in case others don't I have to address it.  It takes a long time for HIV to become symptomatic (6 months, a year, that kind of long time) but you're still able to pass it on to other people.  It's really hard to miss the symptoms of ebola since they onset suddenly and you become a puddle of fluids within a few days if you don't get thee to a hospital.  You're not contagious until you're obviously sick.

So, contagious virus hanging out getting spread without the carrier knowing they're sick in the first place vs. very sick person within days.

My initial comment was TIC because a TX hospital already did a bang up job at 'identifying and isolating a person with ebola symptoms rather than sending him back out to be contagious'.

[MrsAggie]

Oct 3, 2014 8:40:41 GMT -5 @silver said:

Oct 2, 2014 23:30:31 GMT -5 MrsAggie said:

Right?? Lol! Should be easy peasy. Why the hell haven't we rid ourselves of HIV and Hep C yet? Lazy ass healthcare workers.

I hope you already know this, but just in case others don't I have to address it.  It takes a long time for HIV to become symptomatic (6 months, a year, that kind of long time) but you're still able to pass it on to other people.  It's really hard to miss the symptoms of ebola since they onset suddenly and you become a puddle of fluids within a few days if you don't get thee to a hospital.  You're not contagious until you're obviously sick.

So, contagious virus hanging out getting spread without the carrier knowing they're sick in the first place vs. very sick person within days.

Was the joke not obvious?

[Deleted]

Oct 3, 2014 9:26:16 GMT -5 MrsAggie said:

Oct 3, 2014 8:40:41 GMT -5 @silver said:

I hope you already know this, but just in case others don't I have to address it.  It takes a long time for HIV to become symptomatic (6 months, a year, that kind of long time) but you're still able to pass it on to other people.  It's really hard to miss the symptoms of ebola since they onset suddenly and you become a puddle of fluids within a few days if you don't get thee to a hospital.  You're not contagious until you're obviously sick.

So, contagious virus hanging out getting spread without the carrier knowing they're sick in the first place vs. very sick person within days.

Was the joke not obvious?

I assumed you knew.  My concern was that other people would see that and jump to "oh my god she's right, HIV isn't stopped yet!! PANIC!"  If the comments sections in news articles have done nothing else this week, they have taught us that the general public is not well informed about healthcare and the nature of viruses.

Until there is a sarcasm font, there is always a chance someone is going to freak out.