Higher than expected rates of some infections were found in cancer patients at Glasgow’s children’s hospital in 2017, a report has said.
Health Protection Scotland said there was an upturn in “gram-negative” bacteria over a 10-month period.
This came a year before cancer wards were closed because of a link to contaminated water.
The mother of Milly Main said she was “100%” certain contaminated water caused her daughter’s fatal infection.
The 10-year-old died in August 2017 after treatment for leukaemia at the Royal Hospital for Children (RHC).
Stenotrophomonas maltophilia, a form of “gram-negative” bacterium found in water, soil and plants, was listed on her death certificate.
NHS Greater Glasgow and Clyde (NHSGGC) insisted it was impossible to determine the source of Milly’s infection, and those of other children, because there was no requirement to test the water supply at the time.
The Health Protection Scotland report reviewed rates of blood infection data from 2015 to 2019.
It said there was “no single point” of exposure as a source of infections.
The Health Protection Scotland analysis said that over the four-year period blood data for the Royal Hospital for Children was “broadly consistent” with other large children’s hospitals in Scotland.
However, the report pointed to periods when there had been a detectable rise in certain bacteria groupings.
It said the gram-negative group saw an “upward shift” in rates between March and December 2017, with the upper warning limit breached in August 2017, March 2018, May 2018 and September 2019.
The Royal Hospital for Children is part of the £842m Queen Elizabeth University Hospital complex which opened in June 2015.
Two cancer wards at the children’s hospital were closed in October 2018 amid concern about infections and investigation of water supply issues. Patients were moved to wards 6A and 4B at the adult hospital.
Last month, Health Protection Scotland was asked to review all NHS Greater Glasgow and Clyde’s child cancer blood data.
The analysis compared the overall Glasgow children’s hospital blood culture data with Scotland’s two other large paediatric hospitals.
It found the Glasgow complex was higher for “environmental including Enteric (ENT) group” but lower for the gram-positive group. There was no difference in the gram-negative group or environmental group.
However, the report did identify periods when the rates for infection increased.
The Health Protection Scotland report concluded that the data did “not provide evidence of a single point of exposure causing bloodstream infections”.
It said the current restrictions on some wards should be reconsidered but risks should be continually monitored.
An independent review is examining water contamination and other problems at the QEUH campus and will be published in the spring.
A separate public inquiry, which will examine safety and wellbeing issues at the QEUH and the new children’s hospital in Edinburgh, is also expected to look at water contamination.