A husband and wife vacationing in Fiji died within days of each other from a mysterious illness, according to news reports.

The Texas couple, Michelle and David Paul, arrived in Fiji around May 22, according to NBC News.

Although the Pauls were in good health before leaving, they soon began experiencing odd symptoms, including vomiting, diarrhea and numb hands, NBC reported.

Both husband and wife were initially treated at a local hospital before being released. But their condition grew worse, and on May 25, Michelle Paul's family received the news that she had died. The family was also told that David Paul was in critical condition and the hospital planned to transfer him to Australia for treatment, but he died before this could happen. [27 Devastating Infectious Diseases]

According to the couple's family, there is some indication that the couple may have contracted some type of virus, ABC News reported. "They knew something was going on in their [bodies]," Tracey Calanog, Michelle Paul's sister-in-law, told ABC.

Their deaths are being investigated by Fiji's Ministry of Health and Medical Services.

"Although they were provided medical treatment as standard of care, their illnesses progressively worsened and despite best efforts, they died within a few days of each other," Fiji's Ministry of Health said in a statement.

To help with the investigation, the U.S. Centers for Disease Control and Prevention said it will be testing specimens from the couple.

Originally published on Live Science.