The United Nations children's support agency, UNICEF says people could be in evacuation centres on Guadalcanal for months yet, as Solomon Islands tries to recover from devastating floods almost a fortnight ago.
The executive director of UNICEF in New Zealand, Dennis McKinley, says the centres are struggling to cope, and with damage assessments of homes still to be carried out, there's no sign of people moving out soon.
Mr McKinley says the centres now have to cope with extra people after smaller centres were closed to allow children to return to school.
He says this has increased the threat of disease.
"There have been additional toilets and water supplies put in but it's still insufficient for the numbers, so we're seeing cases of diarrhoea, some cases of dengue fever and malaria, so it's definitely a problem having so many people in such close proximity."
However, Dennis McKinley, says reopening schools next week is a big step in helping a return to normality for the 26,000 affected children.