There is no way that fruits from such plants are dangerous or not healthy to consume.

But if we consider that the fruits are originated from a sick plant and thus they can be considered as not healthy in terms of fruit physiology but it has nothing to do with non healthy for consumption. Sure they could be less nutritious but other than that, they are as normal as normal fruit.

agree with Abhijeet_Singh

Nematodes are pathogenic agents attacking roots

There is no relation with the fruits.

In case you obtain orange fruits from infested trees there is no healthy risk to eat these fruits

agree with Abhijeet_Singh