The World Health Organisation in Solomon Islands says four new cases of dengue fever were detected in Gizo on Wednesday while there are now over 300 suspected cases of the illness in Honiara.
Country Representative Dr Juliet Fleischl says surveillance has increased since January when clinics noticed an increase in the number of people attending clinics with dengue symptoms such as high fever.
She says earlier this week teams visited Malaita and Guadalcanal as part of a step up in training and surveillance and there were no cases found in either province.
Dr Fleischl is asking for the public to help limit the outbreak by clearing water from around their homes where the mosquito carriers breed, as well as using insect repellent and bed nets.
She says the increase in cases is related to more surveillance.
"The initial outbreak was recognised in early 2013. There are now over 300 suspected dengue cases reported in Honiara. And yesterday four new cases were reported in Gizo. This is not an explosive outbreak."
Dr Fleischl says the WHO is also working with the Honiara City Council to make sure rubbish and breeding sites are cleared.