Three people have been isolated at the Murang'a General Hospital after they tested positive for cholera.
Murang'a County Health Director Winfred Kanyi said the cases were recorded on Friday and Saturday.
"The patients are in a stable condition," she told the Nation on the phone.
The director said officers from the public health department have been dispatched to areas where the victims come from to monitor the situation.
"Our team is on the ground to ensure the disease does not spread," she said.
The director urged locals to boil drinking water.