Corin Silva is not present in the last scene due to filming commitments. This role was filled by Giles Gough, who appears in several of the directors films.
A copy of Franz Kafka's "Metamorphosis" is located in the bed scene at the end, and is intended to reflect the bed ridden characters fate.
This film was originally named "She is Sick". After a conversation with the director's film making partner, the title was changed to "Positive" to add an air of mystery.