Cairns dengue outbreak spreads

An outbreak of dengue fever in the tropical north Queensland city of Cairns has spread to a third suburb.

A ninth case of the mosquito-borne virus was confirmed in the suburb of Mooroobool on Monday afternoon, health authorities say.

Eight others have contracted the virus in Edmonton and Trinity Beach this wet season.

Director of Tropical Public Health Services Dr Richard Gair warned residents to be extra vigilant to stop the spread of the virus which can cause fever, severe headaches, vomiting and diarrhoea.

"These confirmed cases show we can't be complacent, and only a small amount of water can make areas perfect breeding grounds for mosquitoes," he said.

Dengue mosquitoes breed in urban areas and bite during the day.

Last dengue season 136 people were infected with the virus in Cairns.