One staff member died on Tuesday when the disease broke out at hospital.
City Hall confirmed outbreak of the disease in Nairobi County on March 20.
The county government alerted all referral hospitals within the Nairobi metropolitan area to reactivate cholera treatment units.
The number of The Nairobi Hospital staff infected with cholera has risen to 52.
The hospital’s communication officer Tom Simba on Thursday said the number rose after the management examined all the staff who were on duty on Tuesday, the day the outbreak was first reported.
