While the Centers for Disease Control and Prevention (CDC) have yet to call the etiology of what had sickened hundreds of passengers and crew on board the Royal Caribbean Oasis of the Seas, the outbreak tally of people with gastrointestinal illness symptoms continues to rise.

Public domain image/Maryland Pride
Public domain image/Maryland Pride

As of Saturday, federal health officials now put the count at nearly 600 people. This is broken down as follows: 561 of 6,285 (8.91%) passengers and 31 of 2,169 (1.45%) crew, for a total of 592.

The ship returned to it’s home port in Port Canaveral yesterday, one day early from the scheduled return.

While not confirmed, health officials believe the cause of the outbreak is norovirus.

WATCH: Space Coast Daily video of passengers disembarking

Norovirus is a highly contagious viral illness that often goes by other names, such as viral gastroenteritis, stomach flu, and food poisoning.

The symptoms include nauseavomitingdiarrhea, and some stomach cramping. Sometimes people additionally have a low-grade fever, chills,headache, muscle aches, and a general sense of tiredness. The illness often begins suddenly, and the infected person may feel very sick. In most people, the illness is self-limiting with symptoms lasting for about 1 or 2 days. In general, children experience more vomiting than adults do.

Norovirus is spread person to person particularly in crowded, closed places. Norovirus is typically spread through contaminated food and water, touching surfaces or objects contaminated with norovirus and then putting your hand or fingers in your mouth and close contact with someone who is vomiting or has diarrhea.

Norovirus causes more than 20 million illnesses annually in the US, and it is the leading cause of gastroenteritis outbreaks in the United States.

Passengers did get a refund plus $200 credit per room to accommodate their travels back home.