There's not much to say on this build, it's your typical Strain build for [Nidus], though with some differences here and there. It's pretty much my attempt at merging two playstyles for Nidus: The Strain set usage for survivability and the more conventional Larva -> melee/Virulence to death.
I personally like this kind of compromise as it gives [Nidus] enough survivability to face pretty much anything, also thanks to [Adaptation] and Parasitic Link, but without worrying about energy too much nor having to spam your skills too often.
Thanks to [Hunter Adrenaline] and the passive energy refund on Virulence, you should be able to keep some good energy levels even if you spam it, provided you hit enough enemies.
Parasitic Link also helps in that regard, as well as giving you some more damage reaction and therefore survivability. I guess you could go for Arcane Energize instead and get rid of [Hunter Adrenaline], in which case you would equip [Transient Fortitude], but I like to have some more duration on my builds and so I decided to go for this instead.
You could also replace it with Umbral [Steel Fiber] if you want to be even tougher than you already are, but I don't think it's needed, given that you can pretty much constantly heal yourself.

P.S.: Of course you'd need an [Helminth Charger] and a melee weapon of your choice in order to get the full Strain set effect.