Question About Spreading Virus
 

Here is a paragraph I read this morning and I want to know your opinions about the validity of it.

If these two virus are only spread through human manipulation such as potting, dividing and such. Could you not reasonably have a virused and a non-virused orchid sitting side by side without transmitting the disease? Maybe as long as they didn't touch?

"Both CyMV and ORSV are only transmitted by humans through handling and division of orchid plants. There is no known transmission of these viruses by insects or through seed. Once an individual plant is infected, it is impossible to cure it. Control of virus diseases in orchid collections is possible if you have good management practices that do not permit spread of virus from any infected plants to healthy ones. Therefore, when propagating plants, all propagation implements such as knives, razor blades, benches and any other tools, should be sterilised. Cutting implements should be dipped in alcohol or methylated spirits and flamed, and benches should be washed down thoroughly with soap and hot water. "

Here is the link to the page...Virus diseases of orchids


Thanks!!!

I have no idea how valid the info is, but it is of great interest to me as I think some chids have contracted CyMV, and I am quite worried it is spreading.

That is one thing I have never understood. If neither virus is transmitted via insects and not transmitted via seed (to be checked), then why are there so many infected orchids?? I have checked books and internet, there do not appear to be any known insect vectors. Maybe they spread really easy when plants are touching.
Knowing that, I don't see why it would be a problem to keep healthy and infected plants side by side or in the same room. The only issue would be to have 2 sets of tools or to sterilize well between uses, as well as remember which orchids are virused!

Here is more current information directly from the AOS site.
AOS | Orchid Virus

Interesting , Thanks for posting the link .. Gin

I feel a ton better now Camille!! Thanks for putting my mind at ease! I will have to pick up a second set of tools just to ensure I do not spread anything!!

I have really no clue if it's a good idea or not! That's what I think based on the fact that it's transmitted only mechanically and by touching. I don't know if I'd remember to always wash my hands between the two sets of plants. I have a cym which is most likely infected, but have no plans on ditching it since it lives in a completely different area of the house, and anyway most of my collection is here with me (the cym stays in france).

Oh ok, I must have misunderstood a bit. It is probably best that I have seperated the possibly infected chids from the rest of the collection. Darn viruses!

While one can cite reports that state that insects do not spread orchid viruses, it's possible to find a report to counter each which states that insects CAN spread them. For example, in the March 2009 edition of Orchids, Thomas Mirenda wrote, "These innocuous creatures (reference to soft-bodied insects) are insidious and, if allowed to travel from plant to plant, with their sucking mouthparts are also implicated in the spread of viruses." (Article "March: The Month of Flowers", page 148)

I personally am not going to take chances, and approach any non-sterile tool as well as any insect as a possible virus spreader.

The underlying problem I have with blanket statements that CMV and ORSV are mechanically transmitted rather than transmitted by pests is that it ignores the fact that these viruses have evolved in the absence of human manipulation. Tissue/sap contact isn't an effective mode of viral transmission if the host doesn't move!

I guess pollinator transmission is possible although I would expect a pollinator transmitted virus to be much more prevalent in the wild than these viruses apparently are; given that infection rates are supposedly very low in nature judging by the unlikely 'orchid supposition' that orchid viruses don't occur in the wild. After all, HIV and herpes certainly don't have a problem spreading through the human population.

Granted pest transmission rates may be very low compared to mechanical trasmission but can pest transmission be completely ruled out?