The United States health agency, the Centres for Disease Control and Prevention, has issued a warning to travellers about the threat in Samoa from chikungunya.
Earlier this week the Samoa Ministry of Health said the mosquito borne disease is now affecting all of the country.
It says there are more than 2,500 confirmed cases.
The CDC says for the first time, chikungunya is being locally transmitted in Samoa.
It says travellers to Samoa, especially those with underlying medical conditions, should take precautions to protect themselves from mosquito bites.