Test results from the Noguchi Memorial Centre for Medical Research have ruled out meningitis as the cause of multiple death at Kumasi Academy.
Students have begun receiving Azithromycin antibiotics against possible bacterial infection.
Four students have died and at least 18 others hospitalized for an unknown diseases in less than one week.
The death of the fourth student on Tuesday morning prompted an emergency stakeholder meeting as parents rushed to the school in seeking to withdraw their wards.
Large crowd trooped outside to catch a glimpse of the students who were rushed to the hospital.
A meeting with parents and students was nearly interrupted for about half of an hour after two students collapsed in a latest attack.
Some parents accused school authorities for suppressing information on the situation.
A worried parent said, "I am very panicking. It has put fear in me and I would like to take my sons; I have two sons here. I want to them to go to a different school," she said.
She continued, "They should allow we the parents to come in regularly to see our wards. We want to see them everyday so they should open their gate for us.
"Because of the numerous deaths, they don't want to open up."
It took officials led by Ashanti Regional Minister, Simon Osei Mensah, a hectic time to dissuade parents from taking their wards home.
Even then, some would not budge and managed to take their wards home.
"We are treating somebody so that you the parent would also not be infected; other siblings would not be infested. You say you don't want it. You are not paying anything and you want to take the child home?" Mr. Osei Mensah quizzed.
According to him, the school would be closed down indefinitely after students are given Azithromycin antibiotics treatment to deal with the illness he describes as a security threat.
"Looking at the level of agitation and apprehension, I think the best thing to do is immediately after they've given the dose, maybe we may have to close the school for sometime."
The treatment comes as tests run at the Noguchi Centre on three victims ruled out viral hemorrhagic fever, including meningitis.
Officials hope the treatment will help stem further transmission as further tests and surveillance continue.
Regional Health Director, Emmanuel Tinkorang, explains the importance of kimo prophylaxis.
"We've done series of investigations; blood investigations, CSM investigations and those who died, we have also carried out postmortem on all of them. With the blood investigations, we are fortunate to announce that it is not viral hemorrhagic fever as people were suspecting.
The decision is that we will start with broad-spectrum antibiotics that every student, every staff would be given this antibiotics so that if there is any serious issue, the antibiotics would be able to cut the transmission down," Dr. Tinkorang explained