It is already known that some children who have had such illnesses can experience deficits in IQ, memory and attention in three to six months after recovery.
However, a new study, commissioned by the Meningitis Research Foundation (MRF) and published this month, warns that these problems persist after even a year and must be better recognised and addressed.
It also suggests persistent problems with children's academic performance as reported by teachers – although says further research is needed into this part of the findings.
Dr Lorraine Als, a research psychologist at Imperial College London, who was funded by the MRF to carry out the research, said: "In spite of significant improvements in measures of memory, there was little change in IQ and visual attention at 12 months compared to three to six months after illness.
"This is one of the first studies measuring these outcomes over time in children that have been critically ill and certainly indicates that these problems need to be recognised and addressed."
Chris Head, chief executive at the MRF, added: "This research shows the long-lasting impact that critical illnesses such as meningitis can have on children. Often the impact on IQ, memory and attention only comes to light many years after children have recovered from the initial illness, when they start at nursery or school. This research provides evidence for parents with school-aged children who are struggling and highlights the need for all children who have had meningitis to be closely monitored as they get older."
The MRF provides support and information for those affected by meningitis and related infections. Alongside the Meningitis Trust, the MRF recently developed new resources for parents of children who have recovered from meningitis and septicaemia, containing information both about managing the physical after-effects and the potential for longer term impacts at school.
For more information, visit www.meningitis.org/recovery
The research study was published in the journal Critical Care Medicine.