Validation trumps speculation

[Thornton]

A common technique in CBT (Cognitive Behavior Therapy) is to challenge assumptions, turn black and white beliefs into a continuum of gray. This allows for a wider range of response behaviors compared to all or nothing.

In that spirit, I suggest that when health officials have the opportunity to obtain reliable data that they do so rather rely on assumptions.

A specific opportunity now is to test the notion of the "21 day quarantine and clear" policy. In terms of disease process does this mean that if a person does not develop symptoms within 21 days then they were never infected? they escaped exposure? or does it mean that the viral load exposure was low enough for this persons that they successfully fought the infection to prevent disease? This distinction is important because it steers us to focus on avoiding exposure or enhancing early interventions (or of course do both). Additionally this could imply if the person initially fought off infection for 21 days but a week or tow later developed influenza and compromised their immune response the original remnants of the Ebola infection could flare up.

So - how do we test this situation ?
One strategy is to study the people who were on monitoring but now 21 days clear. Test their blood with rt-pcr for any evidence of virions and also test IgM for early immune response. For those who received plasma transfusion I believe the IgM IgG ratios will help to distinguish the contribution of the plasma transfusion. If you find an IgM response then we have evidence the person was exposed but warded off disease.

For a small number (<8 people) and with their permission, the process could be done publicly. Or the institutions could expedite IRB review and get the studies done within the week.

Of course there will be some costs and logistics with questions on who pays etc - but it in my opinion the pay off of validation trumps the costs of speculation (ie the cost of failed assumptions).

Hopefully we will see questions and processes as above in the media soon.

Thornton

[Vibrant62]

Re: Validation trumps speculation

Given the level of funding made available to fight ebola, costs would be very small in relation to the information learned.

Further than this, one 'advantage' of the dallas outbreak is that there may now be sufficient people exposed as close contacts to test the theory on US soil. That makes the testing far easier to execute.

[zincfinger]

Re: Validation trumps speculation

That's a critical first step.

But IMHO they should also monitor patients' viral levels for the entire period from exposure to the end of the incubation period to determine whether or not some asymptomatic patients have high enough levels to be infectious. (and we probably have to determine what those levels are as well.) There have been some indication that the number of asymptomatic cases may be much higher than the number of symptomatic ones. If that's the case, even a much lower ability to pass on infection would be highly significant given that, lacking a cheap, instant, low tech test, asymptomatic cases won't be identified.
(FAR more important than a drug is either (preferably both) a vaccine and an instant, low tech, inexpensive test.)

As Oslterholm said, we have a great deal to learn.

And we need to learn it at the fastest possible speed.

The need to do urgent research (such as the above) should be considered every bit as important as the need to develop vaccines, drugs, "on the spot" tests, etc.

Dollars spent well today are worth at the very least thousands of dollars spent in a few months.

We are moving far too slowly. Politics everywhere appear to be very poorly adapted for dealing with emergencies. Our glacially slow political processes add to the necessity for advanced preparation. We have been caught out woefully short. Insanely misguided cost cutting ("budget cutting" "austerity" whatever) is a major cause of the inadequacy of preparation. We knew most of what needed to be done and failed to do more than a very small part of it.

Nigeria's success was largely due to appropriate preparations done for other reasons (Gates foundation work toward control of other diseases). Nigeria highlights that the ROOT PROBLEM in this outbreak is severe inadequacy of facilities, and not any change in the virus. (Significant changes will, and probably already are occurring in the virus but they are not the cause of the loss of control but rather the RESULT of it.)

[JJackson]

Re: Validation trumps speculation

zincfinger
Thanks for that. I note you have only made a few posts, I look forward to reading more. For what its worth I think your post is bang on the money.

[Emily]

Re: Validation trumps speculation

If you find an IgM response then we have evidence the person was exposed but warded off disease.

I think they might also have just had simple antigenic stimulation.

http://www.biomedcentral.com/1471-2334/9/159/

ZEBOV seropositivity in R. aegyptiacus bats likely reflects true viral infection, although passive antigenic stimulation cannot be ruled out. In Gabon, Megachiroptera members, including R. aegyptiacus, E. franqueti, M. torquata and H. monstrosus bats, consume the same fruits (especially Ficus spp). Bats of different species tend to visit the same trees, and interspecies virus transmission (or simple antigenic stimulation) could occur via infected saliva deposited on fruits. Hendra virus and Nipah virus transmission has been suggested to occur in this way between bats belonging to Asian Pteropus species [16].

That would be exposure to environmentally inactivated virus particles. You'd get antibody response without even a mild infection.