Unlike bacteria or fungus infection, a virus attack on an orchid plant can be deadly. One of the viruses that can infect your orchids includes the Tobacco Mosaic Virus Disease (TMV). Found on about 150 different kinds of plants, the TMV can enter your orchidís system and hinders its metabolic process. It can lead to your plant not being able to grow normally because its process of utilizing the nutrients has been compromised. As the name indicated, once your plant is infected with this virus, it can create leaf wilting and formation of mosaic patterns on the leaf and can sometimes create blisters.
Transmission of this virus can go from plant to plant via insects that carry the virus in their saliva when chewing on the leaves. Thus, they can carry the virus to a new plant when munching on their leaf. The small wounds left by the mouth of the insects eating the leaf or the damaged leaf can create opening for virus to enter the plant. It can also be carried by human hands, upon coming into contact with the virus through tobacco smoking. Smokers are advised to carefully wash their hands before handling plants in green house or in home environment. Once a plant is suspected of being infected, it is best to isolate the plant or to destroy it in order to save the rest of your orchid collection and other houseplants you may have.
It is often difficult to diagnose this condition in your orchid. You can easily misread it as some other problems. It is most commonly interpreted as herbicide damage, air pollution, or other form of plant sicknesses. But an infected plant tends to be stunted and do not have the same rate of growth as other orchids. For Phalaenopsis orchid, check for ring spots on the leaf. When infected on Cattleya leaf, they could be longer spots with sometimes black stripes. It is easily mistaken for other kinds of virus so the correct diagnose of the problem is important to the treatment. However, almost always it is better to isolate or say good bye to your infected plant than to risk it infecting others.