In conclusion, this review indicates that PICU survivors and their parents may have substantial physical and psychological sequelae interacting with QoL. Because of longer life expectancy, longer follow-up time is warranted, emphasising the consequences for health care in children. We believe that paediatric intensivists and psychologists should be involved as core members of follow-up teams. An evaluation of Comparative Genome Sequencing (CGS) by comparing two previously-sequenced bacterial genomes BACKGROUND: With the development of new technology, it has recently become practical to resequence the genome of a bacterium after experimental manipulation. It is critical though to know the accuracy of the technique used, and to establish confidence that all of the mutations were detected. RESULTS: In order to evaluate the accuracy of genome resequencing using the microarray-based Comparative Genome Sequencing service provided by Nimblegen Systems Inc., we resequenced the E. coli strain W3110 Kohara using MG1655 as a reference, both of which have been completely sequenced using traditional sequencing methods. CGS detected 7 of 8 small sequence differences, one large deletion, and 9 of 12 IS element insertions present in W3110, but did not detect a large chromosomal inversion. In addition, we confirmed that CGS also detected 2 SNPs, one deletion and 7 IS element insertions that are not present in the genome sequence, which we attribute to changes that occurred after the creation of the W3110 lambda clone library. The false positive rate for SNPs was one per 244 Kb of genome sequence. CONCLUSION: CGS is an effective way to detect multiple mutations present in one bacterium relative to another, and while highly cost-effective, is prone to certain errors. Mutations occurring in repeated sequences or in sequences with a high degree of secondary structure may go undetected. It is also critical to follow up on regions of interest in which SNPs were not called because they often indicate deletions or IS element insertions. Genome resequencing is the determination of a genome sequence using an already established genome sequence as a reference. In hybridization-based resequencing, the reference is necessary for the generation of microarray probes and for signal normalization. In other types of resequencing the reference is used as a scaffold for the assembly of short sequence reads. The genome to be rese-quenced must be substantially similar to the reference; otherwise the reference looses its effectiveness.