Eight additional sailors aboard the USS Theodore Roosevelt have tested positive a second time for the coronavirus, according to multiplereports.
The news comes after Navy officials confirmed earlier this week that five other sailors serving aboard the aircraft carrier also appear to have been infected again.
The sailors had all previously tested positive for the virus and gone through at least two weeks of isolation. They all had to test negative twice before being admitted back to the ship.
But on Saturday, a Navy official confirmed that eight sailors had again tested positive, The Associated Press reported.
Some of the 13 sailors who have now tested positive for a second time reported symptoms to the medical crew, CNN reported.
However, the outlet noted that the testing accuracy has been questioned. In some cases, extremely low levels of the virus may be detected in patients who were previously infected but had recovered from the diease.
A coronavirus outbreak on the Roosevelt earlier this year infected 1,000 sailors. More than 4,000 sailors of the Roosevelts near 5,000-person crew were taken off the ship to quarantine at Naval Base Guam or hotels around Guam.
Last month, the Navy started returning sailors to the aircraft carrier who had tested negative two consecutive times.