Still hospitalized is Nurse Tameka Carter.
Crime sleuths have already taken away the remaining amount of a soda that the nurse consumed and caused her to vomit blood.
Sources said all the persons, who worked the 12 noon to 7 PM shift, would be questioned by police on Thursday.
Demerara Waves Online News was told that after reporting for duty, she placed a bottle with drink in the fridge and left with several colleagues to attend a funeral of one of their colleagues.
After returning to the health care institution shortly before 3 PM, she consumed some of the drink and moments later began vomiting blood.
Carter was rushed to the Emergency Department for treatment. Her condition has been listed as stable.