An outbreak of an unidentified gastrointestinal illness has struck the Queen Victoria Cruise, operated by Cunard Cruise Line, and has spread to affect a total of 154 people onboard, according to the U.S. Centers for Disease Control and Prevention (CDC).

The outbreak, which emerged during the voyage that departed from Fort Lauderdale, Florida on January 22, has resulted in 129 passengers and 25 crew members reporting symptoms such as vomiting and diarrhea. This represents an increase of 15 individuals since the illness was first reported on February 1. The Queen Victoria cruise ship is currently carrying 1,824 passengers and 967 crew members.

At present, the cause of the outbreak remains unknown, as the CDC's Vessel Sanitation Program is actively reviewing the ship's outbreak response and sanitation procedures. Cunard Cruise Line, in a statement to ABC News, confirmed that a number of guests aboard the Queen Victoria had fallen ill.

In response to the outbreak, the cruise line has heightened its cleaning and disinfection procedures in accordance with its outbreak prevention and response plan. Furthermore, ill passengers and crew members have been isolated, and both current and embarking passengers and crew have been informed about the situation aboard the ship.

Cunard Cruise Line stressed the effectiveness of their enhanced health and safety protocols in ensuring the well-being of all guests and crew members on board the Queen Victoria. It is hoped that these measures will help contain the outbreak and prevent further spread of the illness.

The CDC's Vessel Sanitation Program continues to monitor the situation closely, working in collaboration with Cunard Cruise Line to address the outbreak and conduct necessary investigations.

As the outbreak investigation unfolds, the Queen Victoria cruise ship remains under scrutiny, and efforts are being made to identify the source of the gastrointestinal illness to prevent future occurrences.