[hackuser]

> I thought it was well known that ebola can be spread through any bodily fluids and that this includes droplets from coughing and sneezing. What they don't yet know is whether ebola is 'airborne' - i.e. dried droplets that can float in air as is the case with measles for example.

I would suggest to everyone: Don't comment on questions like this one (how Ebola spreads) unless you know for certain what you are saying and can back it up. We have complete saturation of rumors and bad information; adding to it won't improve the situation.

I don't mean to criticize the commenter above; they just happened to have the top-most comment of this kind.

EDIT: What a strong signal of over-reaction when a post that says you should know what you are talking about, on HN, is modded down. (I don't care how it's modded, it's just depressing to see this response here.)

EDIT: The same applies to my other post, which asks serious, legitimate questions in a non-offensive way. How sad.

[001sky]

This (above) comment has no citations and the one you are responding to (GP) is substantially correct.

http://www.ncbi.nlm.nih.gov/pubmed/15588056

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4113787/

Ebola and Marburg viruses are the sole members of the genus Filovirus in the family Filoviridae. There has been considerable media attention and fear generated by outbreaks of filoviruses because they can cause a severe viral hemorrhagic fever (VHF) syndrome that has a rapid onset and high mortality. Although they are not naturally transmitted by aerosol, they are highly infectious as respirable particles under laboratory conditions. For these and other reasons, filoviruses are classified as category A biological weapons. However, there is very little data from animal studies with aerosolized filoviruses. Animal models of filovirus exposure are not well characterized, and there are discrepancies between these models and what has been observed in human outbreaks. Building on published results from aerosol studies, as well as a review of the history, epidemiology, and disease course of naturally occurring outbreaks, we offer an aerobiologist's perspective on the threat posed by aerosolized filoviruses."

or

Our study has shown that Lake Victoria marburgvirus (MARV) and Zaire ebolavirus (ZEBOV) can survive for long periods in different liquid media and can also be recovered from plastic and glass surfaces at low temperatures for over 3 weeks. The decay rates of ZEBOV and Reston ebolavirus (REBOV) plus MARV within a dynamic aerosol were calculated. ZEBOV and MARV had similar decay rates, whilst REBOV showed significantly better survival within an aerosol."

Reston is not Ebola, but a close relative.

[hackuser]

What you posted is from good sources and is interesting, but I'm not sure it's conclusive or helps. They are two studies/reports of possibly many and I don't know their credibility or if they represent consensus or fringe, good science or bad. Also, they require expertise to interpret and draw conclusions from.

We're not qualified to perform our own analysis; what we need are conclusive analyses from experts about the scientific consensus and range of possibilities.

[bradleyland]

So we should all be quiet and listen for the experts to give us guidance? Sounds like the antithesis of hacker culture to me. It also sounds like horribly bad advice based on large establishments' historical propensity (categorically) to act from what they know, fail to react to changing environments, and cover up what might make them look bad.

Yes, this is all dangerous thinking. Yes, this is acting from one's gut, rather than waiting on the data. But when it's my life on the line, I'm going to err on the side of caution. When death is on the other side of the decision, I'm going to be a little more skeptical of other people's certainty.

[hackuser]

> when it's my life on the line

The risk to your life hasn't changed, unless you are writing from West Africa. I would be happy to make a bet with anyone on HN that they will not contract Ebola (assuming they are not posting from West Africa), and that the flu will kill far more Americans this year.

Let's be honest; people are acting on fear. It's very compelling to people in the moment, but I think we all know better and know that it's how people make dumb decisions for themselves and do very bad things to others. The person who stays calm when everyone else is panicking is much safer.

Fear is dangerous and contagious -- much more so than Ebola, because fear can spread over HN. Don't follow the herd; set the example for those around you.

[bradleyland]

I'm not speaking specifically about the risk to my life, but in the effect that potential outcomes have on evaluating risk. The flu argument you make is a common example thrown around in this conversation, but it's not an accurate comparison. What is the mortality rate of the flu versus ebola? When I assess risks related to ebola, I tend to favor a more cautious approach, because the mortality rate is so high.

This is part of a popular meme that is showing up on the news. They ask questions like, "True or false, you are more likely to die from ebola than the flu." The mark replies "true", and a doctor (medical doctor, not a statistician) is quoted explaining that "You're actually more likely to die from the flu." This could not be more incorrect.

Mortality rates for diseases like the flu (or any disease) are not homogenous for all members of the population. It's not like a roll of the dice. You simply cannot extrapolate an individual's odds from the broad population mortality rate for the flu (or any disease). It is extremely unlikely that I will die from the flu. I am a middle-aged male in good health and fitness. My chances of dying from the flu are extremely low. The reason the flu kills so many americans is because it is so prevalent. It could be said that flu kills so many precisely because it is so non-lethal. This allows it to fly under our radar and infect people who are at risk. I'm not arguing that we shouldn't take action to prevent the spread of influenza, I'm arguing that the flu presents a different set of problems.

My chances of contracting ebola are also extremely low, but if I do, my chances of dying from it are very high. Across the board (all ages and classes), the mortality rate for ebola are much higher than the flu. Unfortunately, we don't have a strong grasp on ebola mortality rates in the west, because we haven't (thankfully) experienced an outbreak. Even in develping countries, the mortality rate varies widely [1].

I agree that we shouldn't let fear run away with our sensibility, but when dealing with a highly infectious disease [2] with a remarkably high mortality rate, we should be cautious. If not fully quarantined, a period of sensible precaution is a reasonable expectation. When the sun is at its strongest we're advised to wear sunscreen and limit our exposure. When an individual spends time with ebola patients, they should be advised to avoid situations where they would expose a large number of people to the pathogen. Flying, taking public transit, and participating in sports are all activities that put you in direct or indirect contact with large numbers of people. This seems like an unreasonble amount of risk to me.

1: http://www.npr.org/2014/10/23/358363535/why-do-ebola-mortali...

2: Even though ebola must spread through bodily fluids, it is extremely infectious. A small amount of the virus can infect you.

[hackuser]

> What is the mortality rate of the flu versus ebola? When I assess risks related to ebola, I tend to favor a more cautious approach, because the mortality rate is so high.

I think that raises a several good points. A few considerations:

1) The 'proper' way to evaluate risk, as I understand it, is (likelihood * cost). A 10% chance you'll lose $100 costs you $10 each time you take that risk, over time.

2) I agree that some costs are so high that the math works poorly even with low likelihoods. A 1% chance of death is far too high a risk to take, unless there is some high payoff such as saving someone else's life -- a risk the infected doctor and nurse took.

3) The cost of Ebola is that high, but the likelihood is so infinitesimally low that it's still not worth worrying about. You'll add more life years exercising or simply reducing other risks with the same time spent thinking about Ebola. It's a complete waste of time (I realize the irony of writing that! :) ).

4) There are many more equally deadly and far more likely risks for healthy middle-aged people: Lightening strikes, natural gas explosions, being shot in the head, carbon monoxide poisoning, food poisoning (of certain kinds), other contagious and non-contagious diseases, etc.

5) > When an individual spends time with ebola patients, they should be advised to avoid situations where they would expose a large number of people to the pathogen ... This seems like an unreasonble amount of risk to me.

Generally I agree that we should minimize risks, but again I'm not sure there is one here:

* It's very possible that it's very safe. Nobody in the United States (in fairness, that we yet know of) has contracted Ebola in this manner from the infected 3, though two of them spent much time around others. Also, wouldn't Ebola be rampant in the hospital where the infected nurse worked, if this was a risk? Wouldn't it be rampant among medical staff in W. Africa, given the prevalence in their environment (higher than flu in those facilities)? * HIV spreads via bodily fluids but we don't quarantine the infected or their caregivers. However when HIV first become known, people were afraid to be near the infected (resulting in a lot of discrimination). I think we should not repeat that mistake. * I would guess that hospital workers encounter many contagious, deadly diseases, yet nobody worries about those spreading.

People want to treat Ebola differently despite many similar and much greater risks. That's why I believe it's fear and not real risk that drives it.

Anyway, I'm approaching redundancy. Good talking to you!

[JamesSwift]

I would argue that every time a case in the US turns up, my personal risk does change. Think of it in terms of a social graph, or the 6 degrees of separation. Each jump that is made, the potential to eventually link to me increases. I'm not worried about getting Ebola tomorrow. I'm worried about getting Ebola next year.