The Tonga women's rugby side has been put in quarantine for 18 days, forcing it to withdraw from the Oceania championships and miss out on a chance to qualify for the World Cup.
The players have been isolated following an outbreak of measles, which has also closed schools and a crackdown on public gatherings.
In Tonga, the ministry of health last week said an outbreak of measles in the country occurred following the return of a squad of Tongan rugby players from New Zealand and 251 confirmed or suspected cases were identified.
Australia A was due to play Tonga in the opening match earlier this week, but will instead start the tournament with a clash against the Black Ferns development side on Friday.
Tonga's women were to take part in the two-week tournament in Fiji, which are qualifiers for the 2021 women's World Cup, but the decision to quarantine the team was made by the Fiji Ministry of Health and the World Health Organisation.
"Based on the knowledge of the pattern of test results seen for measles cases amongst young adults in Tonga, we've advised the Tongan Women's team that they must be quarantined for the stated period," Dr. Aalisha Sahukan, from Fiji's Ministry of Health, said in a statement.
"There's a risk that the teams they play against and any other people they come into contact with during the infectious period of the disease could be exposed and develop the disease.
"And those who potentially develop the disease could spread it to other people in Fiji, and overseas when the national teams return home."
ACT Brumbies lock Michaela Leonard will captain Australia A, while Sammie Wood, Remi Wilton and Grace Kemp are on the bench.