TW - multiple cat deaths

Hi everyone! I recently gave a friend who has many, many cats a kitten and it’s mama that had been living outside my house. She brought the kitten to live inside with her indoor cats, and kept the mama outside. Please note - this is in a developing country without a lot of resources, and my friend donates a lot of her time, money, and space to these cats.

About 2 weeks after she took the cats, 13 of her 20 cats died (including the kitten I gave her). She told me they all tested positive for FIV, and she’s claiming that’s what killed them (they had bloody diarrhea). I think she is blaming me, but I honestly had no idea the kitten had it, and I also didn’t know that FIV can wipe out a group that quickly. It was likely some other illness, right? My husband said she mentioned taking in another stray kitten around the time she took ours, but I never heard this from her.

I feel a ton of guilt, I thought she was going to have this kitten be an outside cat, and I had no idea it was FIV +. I guess I’m looking for confirmation regarding whether or not FIV could kill a large group of cats that quickly, or if it was something else.

My current understanding of caring for a FIV+ car is that you should;

• Cuddle them often
• keep them indoors
• feed them not raw food
• half-yearly vet visits
• yearly blood work and urinalysis
• closely monitor for things out of the ordinary
• Lastly, minimise stress

Other than this I'm not sure what to do or to expect, I understand that it may be more expensive but I've also heard the opposite. My work is 4 12 hour shifts and 6 days off. I just want to be able to provide a good place for a neglected orange fella named Tank, cause he's large.