Big Mac- Died from the disease. He died in the fields of sweet apple acres after he finished mauling sweetie belle.
Sweetie Belle- as stated before she got mauled by Big Mac. She got mauled in Carousel Boutique while she was drawing a picture for her older sister.
Twilight Sparkle- She's currently looking for a way to stop this disease before it reaches anybody else. So far she has found nothing. She is not infected because she stays locked inside the comfort of her library.
Rainbow Dash- She's not infected, but worried about Scootaloo because she hasn't seen the young girl since this disease started.
Rarity- She is not infected but still grieving over her sisters death. She has stayed locked inside Carousel Boutique with Trixie and the apple siblings stays there sometimes.
Applebloom- She's not infected but worried about AppleJack. Because she's been acting strange ever since they found their brothers body. She's also grieving the death of her best friend Sweetie Belle.
AppleJack- She isn't infected. But ever since she and Applebloom found Big Mac's body she quickly grew into a stage of depression, causing her to act strangely, and worrying the others.
Fluttershy- She isn't infected, but she was the first to know about the infection. Still traumatized by what she had seen in the woods. She wants to help Rarity while she grieves but she doesn't wanna leave the safety of Twilights home.
Lyra- She is stage 4 infected, but the disease isn't affecting her like how it should be. She is loosing consciousness from her blood loss. She isn't hostile and still has every last bit of her memory and is worried about everyone else and if they'll get infected.
Bon Bon- First stage infected. Ever since she went into Lyra's room she had been coughing up blood and black petals. She's starting to think she shouldn't have taken that one black petal from her room.
Zecora- she is not infected but is looking for a cure so she can save Lyra before it is too late. She knows Bon Bon will be hurt so she's working hard, and is praying that she can find it.