ROUND ROCK, Texas - A sixth person has been confirmed to have Legionnaires' disease after staying at the SpringHill Suites in Round Rock.

"Legionnaires' is a serious pneumonia," said Baylor Scott & White's Dr. Sam Deliberato. "About one out of every 10 cases can be deadly."

Williamson County and Cities Health District has been conducting tests on the hotel's water system. The hotel also hired a third party to test their waters. SpringHill Suites was shut down temporarily as a precaution.

"One of the common things that all the cases reported is that they spent time at the pool and the hot tub area," Williamson County and Cities Health District's Catherine Zettel Nalen explained. "But, really, until we get our water testing back, we can't confirm that."

Despite how rare and deadly Legionnaires' is, it's not contagious. Doctors say transmission is through water droplets from an infected water system.

The disease first manifests itself within a few days with flu-like symptoms, like a high fever, muscle aches and coughing. But a few days later, gastric issues like vomiting and diarrhea follow. The only way to know if you have Legionnaires' is by seeing your doctor for testing. Once diagnosed, it can be treated with antibiotics.

"This disease usually doesn't affect healthy people, it's older people and those who are immunocompromised," Nalen said. "This is a disease that's in the water system, so really, the cleanliness of the hotel is not going to lead you to suspect anything. This hotel was very well maintained. It was very clean."

SpringHill Suites is owned by Marriott. If you booked a reservation with SpringHill Suites in Round Rock, the hotel has been helping guests find reservations elsewhere.

The hotel spokeswoman said they hope to have the hotel re-opened by the end of the month, pending testing results.