The health board is investigating any potential links to the hospital environment and stressed it is taking "a very precautionary approach".
Patients are still being treated as normal but some procedures may be relocated and delays in treatment for a small number of patients may occur.
An NHS Grampian spokesman said: "We have identified a small number of unusual infections in patients treated at RACH.
"While we investigate the causes of this - and whether or not there is a link to the hospital environment - we are taking a very
"This means we are changing some of our processes in theatres and considering the relocation of some procedures.
"This may lead to a delay for a very small number of patients, for which we apologise. We are communicating directly with both patients and staff about this. RACH continues to admit and treat patients as normal."
The RACH is the main hospital for children up to the age of 16, with parents and kids often travelling from across Aberdeen, Aberdeenshire and Moray.
It provides a comprehensive range of paediatric services, covering all aspects of inpatient, outpatient and day-case care.
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