American Samoan health officials are analysing whether there's been a rise in dengue fever caused by mosquitos breeding in debris left over from the tsunami.
Public Health Emergency Preparedness programme director Siitia Soliai-Lemusu says the LBJ hospital has seen several patients with dengue fever in the past three weeks.
But she says she can't confirm whether the cases were caused by rising mosquito populations breeding in water holes in washed-up debris.
"Stagnant water is where the mosquito would most likely reproduce and so having these scrap metals around and even the containers, tyres, these can harbour stagnant water."
Siitia Soliai-Lemusu says a team of epidemiologists will consider medical assessments made shortly after the tsunami and follow-up data that will be gathered this weekend.
She says the results will reveal any outbreaks of disease.