Passengers and crew who travelled on several cruise ships during the 2019–20 coronavirus pandemic were found to be infected with the novel SARS-CoV-2 virus that caused the pandemic. Although most ships involved did not have substantial spread of the disease, on the British-registered Diamond Princess, there was substantial spread of the virus amongst the passengers and crew. The ship was quarantined in February 2020 for nearly a month with about 3,700 passengers and crew on board; around 700 people were infected in the incident, and seven died.
The crisis management team of the German federal government said on 4 March 2020, following several actual and suspected outbreaks on cruise ships, "The Federal Foreign Office has included in its travel advice that there is an increased risk of quarantine on cruise ships." On 11 March 2020, Viking Cruises suspended operations for its 79-vessel fleet until the end of April, cancelling all ocean and river cruises, after it was revealed that a passenger on a cruise in Cambodia had been exposed to the virus while in transit via plane, placing at least 28 other passengers in quarantine. Similarly, on 12 March, Princess Cruises, owner of virus-stricken ships Diamond Princess and Grand Princess, suspended operations for all future cruises on its 18-ship fleet for 60 days. The Federal Transport Minister of Canada announced on 13 March that ships carrying more than 500 people cannot dock in Canada through 1 July 2020.
SARS-CoV-2 was confirmed on 4 February 2020 to have spread within Diamond Princess during cruise M003, which had departed on 20 January 2020 from Yokohama (in Tokyo Bay near Tokyo) for a round trip. By the time passengers disembarked into quarantine the number of confirmed cases on the ship was more than in most countries.
On 20 January 2020, an 80-year-old passenger from Hong Kong, China, embarked in Yokohama, and disembarked in Hong Kong on 25 January. On 1 February, six days after leaving the ship, he visited a Hong Kong hospital, where he tested positive for SARS-CoV-2. The ship was due to depart Yokohama for its next cruise on 4 February, but announced a delay the same day to allow Japanese authorities to screen and test passengers and crew still on board. On 4 February, the authorities announced positive test results for SARS-CoV-2 for ten people on board, the cancellation of the cruise, and that the ship was entering quarantine.
A total of 3,700 passengers and crew were quarantined by the Japanese Ministry of Health, Labour and Welfare for what was expected to be a 14-day period, off the Port of Yokohama. On 7 February, the total number of people on board with confirmed SARS-CoV-2 infections grew to 61. Another 3 cases were detected on 8 February, bringing the total to 64. On 9 February 6 cases were detected, while another 65 were detected on 10 February, bringing the total to 135.
On 11 February, 39 more people tested positive for the virus, including one quarantine officer, bringing the total to 174. Passengers with confirmed cases were reported to be taken ashore for treatment. On 13 February, 44 more people tested positive for the virus, bringing the total to 218. On 15 February 67 more people were reported to be infected, bringing the total to 285. On 16 February 70 more people were reported to be infected, bringing the total to 355. The next day on 17 February, the Ministry of Health, Labour and Welfare confirmed 99 more cases, raising the total to 454, 33 of whom were crew members; on 18 February, another 88 cases were confirmed, bringing the total to 542.
Kentaro Iwata, an infectious diseases expert at Kobe University who visited the ship, strongly criticised the management of the situation in two widely circulated YouTube videos published on 18 February. He called Diamond Princess a "COVID-19 mill". He said that the areas possibly contaminated by the virus were not in any way separated from virus-free areas, there were numerous lapses in infection control measures, and that there was no professional in charge of infection prevention—the bureaucrats were in charge of everything. Japanese officials denied the accusations. While the U.S. Centers for Disease Control and Prevention commended the efforts to institute quarantine measures, their assessment was that it may have not been sufficient to prevent transmission among people on the ship.Anthony Fauci, director of the U.S. National Institute of Allergy and Infectious Diseases, said that the quarantine process had failed. A day later, Yoshihiro Takayama, an acquaintance of Iwata and a doctor working on Diamond Princess, pointed out what he described as errors in Iwata's description of the situation in a Facebook post that went viral. The next day on 20 February, Iwata removed his videos and apologised to those involved, but still insisted the situation on the ship had been chaotic.
A preliminary report based on the first 184 cases by Japan's National Institute of Infectious Diseases (NIID) estimated that most of the transmission on the ship had occurred before the quarantine. The cruise line, Princess Cruises had first assumed there was only minimal risk and had initiated only the lowest-level protocols for outbreaks before the quarantine. By 27 February, at least 150 of the crew members had tested positive for the virus. Dr. Norio Ohmagari, top government adviser and director of Japan's Disease Control and Prevention Center admitted that the quarantine process might not have been perfect. A crew member reported that many of the crew had been expected to still work and interact with passengers even under the quarantine. Princess Cruises stated that Japan's ministry of health was the lead authority defining and executing quarantine protocols, yet Japan's ministry of foreign affairs stated that a criteria of behavior was presented but the ultimate responsibility for safe environment rested with the ship operator.
By 1 March, all passengers and crew members had disembarked from the ship. On 8 March, an Indonesian, one of the former crew member of Diamond Princess had tested positive for SARS-CoV-2 during the mandatory quarantine period in Indonesia.
Two passengers died on 20 February and a third on 23 February, all three Japanese citizens in their 80s. A fourth passenger, an elderly Japanese man, was reported on 25 February to have died. The fifth fatality, a British national in his 70s, died on 28 February. A 78-year-old Australian national, who was evacuated from the ship, died on 1 March in Australia, making him the sixth. A Hong Kong national from the ship died on 6 March, making him the seventh coronavirus-related death from the ship.
Cruise ship World Dream (registered in the Bahamas, operated by Dream Cruises) had three passengers confirmed to have been infected by SARS-CoV-2 who were aboard during the early part of the outbreak, from 19 to 24 January 2020. On 5 February 2020, all 3,800 World Dream passengers and crew were put under quarantine on board the ship at Hong Kong's Kai Tak Cruise Terminal after Taiwan blocked its port of call in Kaohsiung.
The quarantine was lifted on 9 February 2020 after all 1,800 crew members tested negative for the virus. The majority of the passengers were not tested as they had had no contact with the infected Chinese passengers who had been on the ship during 19–24 January.
MS Westerdam pictured on 24 November 2015
In February 2020, Netherlands' ship MS Westerdam, departing after a stop in Hong Kong on 1 February, was not allowed to call in the Philippines, Japan, and Guam over concerns regarding coronavirus infections. After initially receiving approval on 10 February to let the passengers disembark in Thailand, as the ship was heading to Laem Chabang port near Bangkok, permission to dock was refused the next day. However, the ship was still maintaining its course to Bangkok and at around 10:30 am CET on 11 February, Westerdam sailed around the southern tip of Vietnam. According to Flip Knibbe, a Dutch passenger on the ship, all the passengers had their temperatures checked a second time. Speaking to NOS on 11 February, Knibbe said "Dit schip is virusvrij": 'This ship is virus-free'. Unlike Diamond Princess, those on board were not in quarantine. Everyone could move freely, shops and restaurants were open and the entertainment programme continued.
After Westerdam was refused at several points of call, on 13 February, the ship was allowed to dock in Sihanoukville, Cambodia. At this point, only the 20 passengers who reported feeling ill were tested, and all of them tested negative.
On 15 February, Malaysia reported that an 83-year-old US citizen who disembarked from Westerdam and flew into Malaysia on 14 February had tested positive for SARS-CoV-2. In a second test, requested both by the Holland America Line and Cambodian authorities the woman tested positive again. Despite these findings, Cambodian Prime Minister Hun Sen visited the ship, discouraged use of masks, and encouraged the passengers to tour the city, sparking concerns that another spoke was being added to the contagion network. Further cruise passengers were denied entry to Malaysia from Cambodia as a result.
On 22 February, after treatment with antiviral medications that were speculated to have an effect against COVID-19, the woman's medical condition improved and she was tested negative for SARS-CoV-2 presence. The United States Centers for Disease Control and Prevention (CDC) initially stated that the woman had never been infected by SARS-CoV-2, but withdrew the claim, clarifying that the CDC "[has] no visibility on whether the initial test of the woman was anything other than positive". Due to possible background politics, it is uncertain whether these results were a false negative, or whether the passenger cleared the virus from her system after 72 hours of intensive treatment.
Public health officials from Placer County, California reported that an elderly resident with underlying health conditions who had died on 4 March 2020 had tested positive for SARS-CoV-2 after returning from a cruise from San Francisco to Mexico and back on Grand Princess between 11 and 21 February. This marked the first death in California attributable to the virus. The source of the new case's infection appeared to be the same as that of a resident of Sonoma County who tested positive on 2 March and who was also aboard Grand Princess on the same dates.
Consequently, Princess Cruises, the owner and operator of Grand Princess, working with the Centers for Disease Control and Prevention (CDC), the government of California, and public health officials in San Francisco, terminated a port call in Ensenada, Mexico planned for 5 March and ordered the ship to return to San Francisco over concerns about the potential for an outbreak on board.
After Grand Princess docked in San Francisco on 21 February 62 passengers who had been on the previous cruise to Mexico reboarded the ship as it set sail for Hawaii, making stops at Kauai, Oahu, Maui, and Hilo (on the Big Island) between 26 and 29 February. These passengers, who may have made been exposed to the same environment as were the Placer or Sonoma County cases during the previous cruise, were quarantined in their own on-board staterooms on 4 March by order of the CDC. In addition, eleven passengers and ten crew members were exhibiting potential symptoms, and Grand Princess was ordered by the government of California to remain offshore while the California National Guard's 129th Rescue Wing airlifted test kits by helicopter to the ship.
On 5 March, Princess Cruises confirmed that there were 3,533 people on board the ship—2,422 passengers and 1,111 crew members—representing 54 nationalities in total.
On 6 March, U.S. Vice PresidentMike Pence announced that of the 46 tests run on selected passengers and crew members on Grand Princess, 19 crew members and two passengers had tested positive, 24 had tested negative, and one test was inconclusive. Pence announced at a White House Coronavirus Task Force briefing that the ship would be brought to a non-commercial port, and that everyone on the ship would be tested and quarantined as necessary. On 6 March, President Trump said that, despite what experts told him about limiting the spread of COVID-19, he wanted those on board Grand Princess to stay on the ship so that they would not be counted as American cases, which would otherwise "double because of one ship that wasn't our fault."
On 7 March, Princess Cruises confirmed that Grand Princess was still at sea roughly 50 miles (80 km) from San Francisco, and that it was scheduled to dock in Oakland on 9 March, with its passengers to be transferred to facilities on land while the crew would be quarantined and treated on board. The United States Coast Guard had airlifted supplies, including personal protective equipment, to the ship, and had medivacked a critically ill passenger and his travel companion for treatment unrelated to COVID-19.
On 9 March, the ship docked at the Port of Oakland and passengers started disembarking. More than 3,000 people on board were to be quarantined, with passengers at land facilities and the crew on board. As of 22:00, 407 people had disembarked.
Princess Cruises confirmed on 10 March that 1,406 people had disembarked from Grand Princess, increasing to 2,042 on 12 March.
California: The Sonoma County Department of Health confirmed that a former passenger of Grand Princess, on the cruise from San Francisco to Mexico, was a (presumptive) case.
California: Placer County officials confirmed that a former passenger of Grand Princess, also on the cruise from San Francisco to Mexico, was a (presumptive) case. Officials confirmed the next day that the passenger had died.
Alberta: Alberta reported its first presumptive case, a woman in her 50s who lives in the Calgary area, was on board Grand Princess and returned to Alberta on 21 February.
Placer County: Officials reported an additional three presumptive positive cases, with all three having travelled on the same cruise on the same dates.
Sonoma County: Health officials announced another positive presumptive case who was a passenger on the same cruise between 11 and 21 February.
Sunnyvale: Department of Public Safety officers reported that they performed CPR on an unconscious 72-year-old patient who was not breathing, but were ultimately unsuccessful in reviving him. After the man died, a family member informed officials that the victim had been a passenger on Grand Princess with two other people currently suspected of being infected.
Nevada: The Washoe County Health District announced that a presumptive positive patient, a male in his 50s, has been linked to Grand Princess. He is currently in stable condition and self-isolating at home. Out of an abundance of caution, an elementary school in Reno has been closed because one of the man's family members is a student there.
Ontario: Health officials confirmed that two new cases, a married man and woman in their 60s, were aboard Grand Princess from 11–21 February and returned to Canada on 28 February.
Alameda County: Officials confirmed that a former passenger of Grand Princess, an older patient with underlying health problems, has tested positive. The former passenger was on the ship during the trip to Mexico from 11–21 February 2020. The patient is currently hospitalised and family members have been quarantined.
Contra Costa County: Health officials announced that two new cases have been identified, with both having travelled on the same cruise on the same dates.
Marin County: The health department announced that two Marin County residents that were on the cruise and displayed symptoms have also been tested, but Governor Gavin Newsom has prioritised the testing of the passengers currently aboard Grand Princess, and all the tests are going through the same lab.
Hawaii: Governor David Ige announced the state's first case, a male Oahu resident who was a passenger on Grand Princess. Although the ship stopped in Hawaii in late February, the man disembarked Grand Princess in Mexico earlier in February (before it returned in San Francisco on 21 February) and flew back home to Honolulu from Mexico.
Illinois: The Illinois and Chicago public-health departments announced that a former passenger of Grand Princess tested (presumptive) positive. The passenger, a woman in her 50s, had travelled on the same cruise to Mexico, and disembarked at San Francisco on 21 February. She was hospitalised and isolated in stable condition. She is a special education assistant in the Chicago public school system, and the school where she worked was to be closed the following week, with all at-risk staff requested to self-quarantine for 14 days.
Utah: The Department of Health confirmed that the first (presumptive) case in Utah is a former passenger of Grand Princess living in Davis County.
British Columbia: Health officials announced that two cases are former passengers of Grand Princess. Both in their 60s, the two patients rode the ship to Mexico and back to California.
Fresno County: Officials confirmed that a former passenger of Grand Princess had tested positive. The former passenger was on the ship during the trip to Mexico from 11–21 February 2020. The family of the patient is reported to be self-monitoring.
A Taiwanese-American tourist, who had been a passenger on a Nile River cruise ship variously known as MS River Anuket or Asara, discovered that she was positive for SARS-CoV-2 after she returned to Taiwan. World Health Organization officials informed Egyptian authorities of the situation, and all crew members and 150 passengers aboard the cruise ship were tested for SARS-CoV-2. On 7 March 2020, health authorities announced that 45 people on board had tested positive despite being asymptomatic, and that the ship had been placed in quarantine at a dock in Luxor.
On 13 March 2020, five passengers tested positive for the COVID-19 virus aboard MS Braemar. As a result, the ship was denied entry into its destination, the Bahamas. The infected patients were discovered after a former passenger of the cruise tested positive in the Canadian province of Alberta. The infected passenger disembarked off the cruise in Kingston, Jamaica, but it is currently unknown where they contracted the disease.
Sint Maarten also denied a request from the cruise to allow passengers to fly out.
AIDAaura: The German cruise ship AIDAaura, with about 1,200 people on board, was held on 3 March 2020 in the harbour of Haugesund, Norway, while two asymptomatic German passengers were tested who had been in contact with a person who subsequently developed COVID-19; their test results were negative.
AIDAmira: Six passengers on the ship have been isolated, after flying on a plane with a sailor who later tested positive with the virus. More than 1,700 are now trapped on the cruise, docked at Cape Town. 
Carnival Panorama: On 7 March 2020, the Centers for Disease Control and Prevention (CDC) halted passengers disembarking from the cruise ship Carnival Panorama docked at Long Beach Cruise Terminal in California when a female passenger was reported to be sick. The sick passenger was transported to a hospital to be tested, and all passengers were held on board the ship pending test results. The test came back negative late that evening, and disembarkation was scheduled to resume the next morning.Carnival Panorama was returning from a trip to Mexico with scheduled stops at Cabo San Lucas, Mazatlán and Puerto Vallarta, which were also scheduled stops for Grand Princess during the previous month.
Costa Fortuna: The Italian cruise ship Costa Fortuna attempted to dock at Phuket, Thailand, on 6 March 2020, but was denied by Thai officials because it was carrying passengers who had left Italy within the past two weeks. On 7 March, the ship attempted to dock at Penang in northern Malaysia, but was denied pursuant to a complete ban on cruise ships.
Costa Magica: On 12 March, two passengers were reported to be tested positively for COVID-19 while quarantined in Martinique. The ship with 3,300 people on board had been disallowed entry in several sea ports including in Grenada, Tobago, Barbados and Saint Lucia, due to over 300 Italian nationals on board.
Costa Serena: Fifteen passengers aboard Costa Serena on 24 January were suspected to have SARS-CoV-2. The ship arrived at its destination, Tianjin, China, on 25 January. With 17 suspected cases, and 146 (of 3,706) passengers from Hubei province where the disease originated, an emergency was declared. The cruise ship was locked down for 19 hours before the passengers were allowed to disembark; no confirmed cases were found.
Costa Smeralda: In January, Costa Smeralda and her 6,000 passengers were quarantined at the port of Civitavecchia in Rome, Italy, following two suspected cases. A spokesperson from Costa Cruises stated that a 54-year-old woman aboard the ship was suffering from a fever and that she and her husband were both being tested. They were found to be uninfected, and passengers were allowed to go on shore the next day.
Golden Princess: At least three passengers have been quarantined by the ship's doctor, according to local health officials. It is en route for Melbourne.
MS Monarch: On 14 March, Panama repatriated 1,504 Colombian tourists from the cruise ship Monarch. Since the port of Cartagena, Colombia is closed, the people have to fly from Colón, Panama. About 300 people were still waiting to buy tickets.
Regal Princess: On 7 March, two crew members of Regal Princess were tested and the docking of the ship at Port Everglades in Fort Lauderdale, Florida, was delayed for about a day while waiting for test results. The tests were negative, and the crew did not have respiratory complications, so the ship was allowed to dock.
Royal Princess: As a crew member from Grand Princess had transferred to Royal Princess fifteen days earlier, the CDC issued a "no-sail order" for Royal Princess on 8 March 2020, prompting Princess Cruises to cancel the ship's seven-day cruise to Mexico before it departed Los Angeles.
Silver Shadow: Silversea Cruises ship Silver Shadow was blocked from disembarking its 608 passengers and crew at the port of Recife in Brazil, as a 78-year old Canadian aboard had been suspected of having the virus. Two passengers were later medically disembarked, and one of them tested positive for the virus.
Sun Princess: Princess Cruises ship Sun Princess was not allowed to dock at a port in Madagascar on 13 February 2020. as it had visited Thailand less than 14 days before. The ship docked at the French island of Réunion on 1 March, but passengers were met by a crowd of about 30 who insisted that the passengers be tested and tried to prevent them from leaving the port area. Objects were thrown at passengers, and the police deployed tear gas. Princess Cruises said that there was no evidence of SARS-CoV-2 on the ship.