World Vision says the recent flooding which devastated parts of Solomon Islands has exacerbated an outbreak of rotavirus that has so far killed 16 children.
The programme manager for the charity in Solomon Islands, Andrew Catford, says from just a few cases a few weeks ago, the numbers infected with the virus have swelled to more than one-thousand.
Dr Catford says flood-affected areas have been hit, but so have many other areas as the outbreak takes hold.
He says access to clean water after the flooding is a big issue.
"The water inundated where they lived that and it polluted their wells and so in the last couple of months a lot of people have been drinking from polluted wells because mud and other things go in there because and there weren't any other viable water sources. So certainly that has been a challenge."
Andrew Catford from World Vision.