Norovirus outbreak sickens 125 on Princess Cruises ship Ruby Princess

Outbreak on the Ruby Princess

The Ruby Princess departed San Francisco on 12 June for a 20-day round-trip cruise to Alaska and Canada with 3,032 passengers and 1,144 crew. During the voyage, passengers and crew began reporting symptoms of nausea, vomiting, diarrhoea and abdominal cramps. The US Centers for Disease Control and Prevention (CDC) was notified on 28 June after the number of sick individuals exceeded the 3% reporting threshold. By the time the ship returned to San Francisco on 2 July, 125 people had fallen ill: 102 passengers and 23 crew members.

Norovirus and cruise ships

Norovirus is a highly contagious gastrointestinal virus that spreads through contaminated food, water, surfaces and direct contact with infected persons. It can also transmit via airborne particles during vomiting. The confined, shared spaces of a cruise ship create conditions where the virus can move quickly. Symptoms typically appear 12 to 48 hours after exposure and last 12 to 60 hours, resolving within one to two days. While rarely dangerous for healthy adults, the illness causes acute discomfort and can lead to dehydration.

The Vessel Sanitation Program is monitoring the situation remotely, reviewing the outbreak response and sanitation procedures implemented by the ship.

A pattern in 2026

The Ruby Princess outbreak is the third norovirus incident on a Princess Cruises ship this year. In March, the Star Princess reported 193 cases (141 passengers, 52 crew). In May, the Caribbean Princess recorded 160 cases (145 passengers, 15 crew). Across the cruise industry, the CDC has tracked seven gastrointestinal outbreaks since the start of 2026, five of which were confirmed as norovirus.

Response and sanitation

Princess Cruises activated its outbreak protocols: symptomatic individuals were isolated, cleaning and disinfection were intensified, and samples were collected for analysis. The CDC monitored the situation remotely until the ship docked. Before its next sailing, the Ruby Princess will undergo a thorough disinfection, the company said.