No, it is not the virus but we need more info... plant and plant maintenance information to get a better "mental picture". I am considering that you may still have an iron nutrient deficiency. This can happen if the amendment was not enough (did not lower the soil pH enough) or when the soil is soggy wet and the roots cannot absorb nutrients because of too much water. Can you answer a few questions to rule other things out?

Do you know the type of camellia and its cultivar name?

Where are you? What is your city, state, USDA Zone?

Did this problem occur after unusual cold/hot weather?

From what hour until what hour does it get sun?

Why do you think it has root rot?

Is it getting too much water? Get some soil in between two fingers from a depth of 2-4 inches and press the soil in between the fingers. If the soil produces water droplets, the soil is too soggy. How often do you water and how much water do you give it when you water? Do you water the plant when the soil feels dry or by using a schedule like every "x" days?

Are there other plants nearby that could be competing for water and soil nutrients? Including weeds?

Please confirm... I cannot see the base of the plant but it looks as if the camellia is planted in the garden outside?

When did the problem start? Did you apply any amendments or fertilizers before that date?

Why did you suspect a mineral deficiency? Have other plants in that general area presented issues too? Have you done a soil test before? Your soil appears to be acidic enough for some camellia foliage but... do you know what your soil pH might be? What fertilizer do you typically use? How much and how often?

Where within the camellia tree do you see these leaves with yellow edges? Randomly throughout, near the top, new growth only, old leaves only, one side or one branch only? Etc. The bottom picture has no leaf yellowing. Where is the area pictured in Pic #3 with regards to Pictures 1 and 2?

I live in Carmel Valley California and believe I am in zone 9.

Ufortunately I have not been here long enough to know about how much water or fertilizer it normally gets. I know there is a sprinkler system but it has been turned off because it has been raining off and on here for the past month. I think the gardener fertilizes them once a year although they are pretty much left alone since his main focus is a rose garden on the other side of the house.

It is located under oak trees and for this month has gotten some filtered sun during the mid morning.

I did the "at home" PH soil test with baking soda and vinegar but will go get a real soil test from the nursery.

These were my Mom's plants and my Dad is selling the property in 9 months, I just wanted to learn to care for them while I am living here.

I am sorry I have no knowledge of how it has been cared for recently. My Mom died 2 years ago and was sick for at least 2 before that. She was the one who planted and cared for it, so I'm pretty sure it has not gotten any care for at least that long.

I realize I am jumping in without much information or knowledge. I was just guessing what might be wrong from information on Google.

I should have written down your questions before answering! The other Camellia next to it also has yellow leaves but not to the same extent. There is a very brown fern underneath it plus other ferns and a fuschia. I just realized the ferns are pretty yellow too. I pulled out 2 wheelbarrows worth of ferns a month ago but they were 2 to 4 feet away from it.