Women in Tonga are facing a nervous wait as they wait to find out if the Zika virus is going to cause birth defects.

Tonga's Public Health Chief Medical Officer Dr Reynold Ofanoa has announced there are 549 people confirmed through symptoms to have the virus - including five who have tested positive for it via a blood test.

Mary Fonua, managing editor of Tongan news service Matangi Tonga Online, said there have been no confirmed cases of deformities yet, but it's still early days.

"We don't know if that's gonna happen with this outbreak and that's the tragedy I think because of what we're seeing in Brazil with the deformed babies."

She said pregnant women in Tonga are "extremely anxious" because it's practically impossible to avoid mosquitos in the tropical country.

Authorities may also need to start looking at support for their mental well-being and how they could provide reassurance to pregnant women, Fonua said.

"Do they have to have their entire pregnancy in the state of not knowing? Perhaps that's the way it has to be, but what can we do to reduce their levels of anxiety?"

Tonga is in desperate need of simple resources to help contain the virus - journalists say what's been given so far from neighbouring countries won't go far enough, and simple measures such as units that catch and kill mosquitos in the home would help a lot.

"It seems to me if somebody could get some of those units, it would provide a lot of protection around households so that's one method - it's known but it's not available," Fonua said.