Sacred Heart Mukumu Girls' High School teacher, Juliana Mujema has passed away.
NTV has reported that the family said she succumbed to multiple organ failures.
Mujema's death brings the count to four after three students passed away in a similar case of suspected food poisoning.
Her family says she exhibited symptoms similar to those of three students.
She was admitted to Oasis medical centre in Kakamega before her condition worsened.
She was then referred to an ICU at Lifecare Speciality Hospital in Eldoret town, where she passed on.
This comes after a diarrhoea outbreak was reported in the school.
The outbreak saw over 124 students hospitalised at the Kakamega County General Hospital in a suspected case of food and water poisoning.
On April 3, the school was shut down by public health officers in Kakamega after more than 500 were infected by the bacteria.
Kakamega Senator Boni Khalwale on Thursday warned parents against taking their children back to school.
"I am disheartened to report that the situation on the ground has not changed, and I wish to advise parents of this great institution not to take their children back to school until the requisite changes are made," he said.
Khalwale, who had visited the school to assess the situation, said the food storage area was still full of rotten foodstuff.
The school is scheduled for reopening early next month.
The senator faulted the school for not taking precautionary steps to get cleaner water or purify the water it uses from a local river.
"The Ministry of Education and the Teachers Service Commission accordingly stand accused of failing to take any single action against the School Principal, BOM, and other officers who, through sheer negligence, deliberate greed or incompetence, are responsible for the current life-threatening mess at Mukumu Girls," he added.
