There was some discussion here awhile back that the RO factor was at 0.5 (if I’m remembering correctly) Does anyone know what it currently is? And for those that don’t know what it is a simple explaination?
IF (fake data!!!!) there have been say 7 instances of suspected h2h, involving 7+20 people (7 index cases + 20 secondary cases), and we assume we’re right 50% about our suspicion, this would mean 10 cases of h2h in say 240 cases, and 10 in 240 is x% which would be a very low R0 factor, but larger than zero.
I bet someone can compute this with real figures and some assumptions regarding how sure we are about our suspicions in general. That would do, but the truth still remains that even if there’s just one instance then R0 is larger than zero.
It would also be interesting to look at the tendency, right?
First there is not enough data. Second there is no confirmation of H2H.
However, if I were to ESTAMATE, I would say there are more cases now than there was before. So if there is such a thing as a B2H version of R0 (but that means virtually nothing) then: Calculating using the death rates (42 last year, 70 this year) cases this year, and about 10 days incubation period That about 27 cycles so solving 42 *R0^27 = 70 Or an effective R0 for B2H of around 1.02.
Notice it would have to be larger than 1 or we would be seeing fewer cases.
However all this means very little since we have no data for H2H and I used death numbers instead of case numbers. The only real thing we know is there are more cases every day from what ever source there is.
Very few of the actual cases are being confirmed due to the WHO’s gaming of the testing process. In fact, very few of the known index cases are counted as confirmed H5N1 by the WHO.
How did the resulting confirmed H5N1 cluster cases that had no contact with animals become infected if not by the index case?
If you keep seeing smoke, look for fire.
Remember, “If you hear hoofbeats, think horses, not zebras”. Anybody want to guess who said that?
House of God is where I first ran into the phrase.
And, it`s a goodun.
But, searching it seems to have been started by Dr. Theodore Woodward, a former professor at the University of Maryland, Baltimore.( per wikiepedia.)
Ooops, was me. I forgot to change name.
Hangs head and goes to the corner.
NS1 – at 20:11 said “Remember, “If you hear hoofbeats, think horses, not zebras”. Anybody want to guess who said that?”
Someone who didn’t grow up on the african savannah ?
Here’s a funny thing . . . I’ve often heard the quote attributed to the then 33 year old 1958 Nobel laureate Joshua Lederberg.
But it’s unknown really. A bit of musing takes place about Woodward.
Perhaps they met somewhere, Lederberg and Woodward, and both wore pinstripes that day?
NS1 – at 20:11 “Remember, “If you hear hoofbeats, think horses, not zebras”. Anybody want to guess who said that?”
William of Occam
(What do I win?)
Pixie – at 08:07 I think it was known as Occam’s toothbrush :)
It was “When you hear hoofbeats, look for horses…”
I saw this thread in the middle of the night. I couldn’t figure out what RO means. I have had sleep and coffee. Still can’t figure it out.
What does RO mean?
It should be R0 (a zero) instead of RO. It is a multiplication factor for the spread. Think of it how many people (on an average) get the disease from each infected person.
So if it was 2 (example) then you would start with 1 then have 2 then 4 then 8, … Each person would give it to two others. The math is Y= X * R0 ^ n, where Y is how many you have and you start with X people and n is how many “cycles” you have. It is sort of like compounding interest and R0 would be you interest rate. I think of it like the K effective of a nuclear reactor- any K over one and it goes critical.
Any number over 1 means you get more and more cases, any value less than 1 means it will die out.
OMG! There isn’t enough sleep or coffee on the planet LOL! Thank you DennisC. I gues I’ll be leaving this segment to those who are more qualified to understand it. ;^)
Sorry, I didn’t mean to scare. The short version is that if you multiply by something bigger than one, things get bigger; if you multiply by something less than one, things get smaller.
So if the R0 for N5N1 is bigger than 1 then we can have a pandemic since more and more people will get sick. If it is <1 then people are getting well (or die) faster than people are getting sick and it will go away. If the R0 is much above 1.5 or so, then it will spread very very fast. If it is just a little above 1 it will spread slowly.
The problem in all this is we just don’t have the confirmed H2H numbers to know what the R0 will be for the “real virus strain”.
The problem in all this is we just don’t have the confirmed H2H numbers to know what the R0 will be for the “real virus strain”.
It could be anything from zero to, reductio ad absurdum, 246/1 if all cases except the first were h2h.
It could also be possible that the human RO is decreasing but the number of B2H contacts is increasing or that th (x)2H RO is increasing. It is hypothetical except that the number of contacts between Avian carriers and humans is increasing. The state of RO is speculation.
The state of this RO may well be speculation(??), but seems worthy of discussion! (bump) (only applies to H2H and is a measure of how long it will take to overcome the world,..as far as I’ve gathered!)
If infection is coming from mammals, even the timing of cases (with lags between human cases) may not conclusively show H to H transmission if the mammals and people live near each other. That is good news, except my understanding is that having mammals carry H5N1 could result in a really deadly pandemic strain at some point. Ideas on this line of thought? And if humans reinfect other mammals, do we need to think about inter-species R0, if that concept exists?
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