The film has been criticized as "punishing a lesbian for being raped", which I guess is arguably true. I would however rather interpret Contracted as telling the story of the tragic aftermath of a rape. Being raped and contracting a disease not only destroys Samatha's body, but also her relationships.
The film deserves praise for the way it handles a complex and sensitive subject and for Samantha's character development. It also did a great job with the practical special effects, showing Samantha's gruesome physical transformation. Other than that, Contracted is just okay. The ending is a bit predictable and doesn't really mix well with the rest of the film. Still, I think the film is definitely worth watching. It is far from perfect, but unlike most horror films featuring a literal rape it isn't a revenge story, which is kind of refreshing.
As a last note, I would like to comment on how stupid the title is. Why does almost every horror film nowadays have to have these vague one-word titles? Contracted might as well be the story of a contract killer!