212 Ebola messages in my mailbox...

[Francisco Muril Zerbini]

On Sun, 14 May 1995, Patrick O'Neil wrote:

> Thanks, an informative post and it also had the benefit of relieving some 
> of the fool factor for suggestion plant-to-animal transfer.  The thought 
> had hit me almost only as I wrote it so I didn't have much reflection 
> time.  In any case, I subsequently tried to recall from all the reading, 
> studying, classes, etc if I had ever come across a reference to a virus 
> in plants that also adversely affected humans now and again...to no 
> avail. 

I can't remember of any case either (fortunately !! - some of the viruses I 
work with are real plant killers !!!). 

> I also considered the idea of transfer:  a plant doesn't just 
> shed virus into the air for a passing animal to pick up, but would likely 
> have to have an insect vector intermediate or simple vertical transfer.  
> As for insects, I thought that a number of insects had already been 
> checked for possible hosting with negative results.  Of course, it might 
> be a rare event and the insects not yet tested.

I wonder how many insects were tested. Can you imagine how many 
undescribed species of insects are hidden in the rainforest ? 

I don't want anybody to get the impression that I think Ebola's natural
host is a plant. As I said in my previous post, it's just an idea I like
to entertain, and it's not impossible given what we know about
plant/animal viruses and plant molecular biology. Who knows... 

>   Another _hypothetical_ possibility ocurred to me in regards to cotton.  
> If cotton handling and picking is largely done by hand (which is likely 
> in a Third World Nation), then there is high likelyhood of poked, 
> pricked, and scratched hands and fingers.  IF the virus were in cotton 
> and a cotton picker or handler pricked his/her finger, it might allow for 
> a direct innoculation into the bloodstream...  It would be interesting to 
> find out that a plant virus could do such a thing, but I feel it is 
> highly unlikely in my gut.  Hell, if nothing else, it is a plot for a 
> sci-fi story...

I thought about that too, but I think it's highly unlikely. Cotton is a 
major crop and as such most of its diseases have been described and 
studied. If Ebola was a cotton virus we would know by now. I think that, 
if Ebola is a plant virus, it infects some obscure wild African plant 
(again, can you imagine how many species of plants exist in the 
rainforest that we don't know about ?). But really, my best guess is that 
Ebola is an insect virus. 

I got Ed's message saying that someone from South Africa is going to 
Zaire to try to find Ebola's natural host. Good luck to him !!!

Murilo
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| Murilo Zerbini                   | Out of 3,000,000,000 DNA nucleotides, |
| Dep. of Plant Pathology          | human beings and chimpanzees have     |
| University of California, Davis  | 2,999,400,000 in common.              |
| fmzerbini at ucdavis.edu            |                                       | 
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