Tonga health authorities believe that the mosquito borne dengue fever has claimed the lives of four children in the past fortnight.
Dr Seini Kupu, the acting chief medical officer of the public health division, says they are still waiting for confirmation on tests being carried out in New Zealand.
But she says the clinical presentation were like textbook examples of the signs and symptoms of dengue shock syndrome.
And Dr Kupu says there have been hundreds of recent hospital referrals for flu and viral conditions which they now believe is dengue.
She says they have stepped up campaigns to try ensure that breeding places for the mosquitoes are eliminated.
"particularly involving this community mobilization approach and actually around Tongatapu from last week up to now, we have been to almost every village, having these community meetings, and our health inspectors are out there with programs'"