Samoa's Ministry of Health says nearly 100 people have now been affected by a mystery virus.

Two people have also died from but authorities still aren't exactly sure what the virus is.

Samoan Ministry of Health's Dr Saaine Vaai told Pacific Beat patients are showing signs of two separate illnesses.

"Well initially we thought we were seeing acute fever and rash, which is one of the things we do look for," she said.

"But as of Saturday we did get the confirmation of some of the specimens that we sent out for chikungunya.

"We're still waiting for other specimen confirmation."

In neighbouring American Samoa there have been more than 300 confirmed cases of chikungunya and authorities say a traveller between the two countries brought some strain of the virus to Samoa.

Dr Vaai says a public campaign to raise awareness about the outbreak and educate people about precautions to take has begun.

"This is the first time that we've have had this virus in the country and we are working with experts from WHO (World Health Organisation) and the Secretariat of the Pacific Community to control it," she said.

Officials say five people have been admitted to hospital with symptoms of the virus.