Abstract
Objectives:
Cruise ship settings can facilitate transmission of respiratory infections. In March 2020, a COVID-19 outbreak occurred on the Grand Princess cruise ship. We describe the public health response, including a large-scale US federal quarantine intended to limit spread to communities not yet affected by COVID-19.
Methods:
All US residents and symptomatic people requiring hospitalization disembarked beginning on March 9 and were transported to designated US military bases for federal quarantine or to hospitals or alternate care sites for medical care. Foreign nationals remained on board (crew) or were repatriated (passengers). People under federal quarantine were monitored daily for symptoms and tested voluntarily for SARS-CoV-2 upon arrival, as tests became available, and if symptoms developed.
Results:
Of 3582 travelers (passengers and crew) on board, 2013 (56%) went to military bases, 59 (2%) went to hospitals or alternate care sites, 419 (12%) were repatriated, and the remainder (crew) quarantined on board. Overall, 1144 travelers (32%) were tested for SARS-CoV-2; of those, 155 (14%) had a positive test result. Among 2013 US residents quarantined, 1054 (52%) were tested. Of those, 115 (11%) had a positive test result, 37 (32%) of whom were symptomatic at testing. Proportions tested across bases ranged from 28% to 89%; test positivity ranged from 10% to 16%. Of 31 travelers hospitalized, the median (IQR) stay was 4 (4-9) nights, and 9 (29%) travelers died of SARS-CoV-2 complications.
Conclusions:
The Grand Princess outbreak was the first confirmed COVID-19 outbreak on a cruise ship in US waters. Multiagency public health responses allowed for isolation and quarantine, potentially helping to slow transmission into US communities. Ensuring that cruise ships have plans for communicable disease control and mitigation helps protect passenger and crew well-being.
Keywords: COVID-19, SARS-CoV-2, quarantine, cruise ship, outbreak
SARS-CoV-2 is a highly transmissible virus responsible for COVID-19, first confirmed in the United States on January 20, 2020, and declared a pandemic by the World Health Organization on March 1, 2020.1-4 Cruise ship environments can facilitate transmission of respiratory infections, including SARS-CoV-2, due to frequent close contact and shared airspaces of passengers and crew in dense indoor dining, entertainment, and recreational spaces. Outbreaks can also be sustained across multiple voyages by transmission among crew or passengers who remain on board.5-8
From February 11 through 21, 2020, the Grand Princess cruise ship sailed roundtrip from San Francisco, California, to Mexico (Voyage A) with 2489 passengers and 1108 crew on board (Figure 1). On February 21, 2020, the ship departed on a subsequent voyage to Hawaii (Voyage B) with 2471 passengers and 1111 crew, including 93 (4%) passengers and 1018 (92%) crew who had traveled on Voyage A. On March 3, 2020, the California Department of Public Health notified the Centers for Disease Control and Prevention (CDC) of a cluster of 5 California residents with COVID-19 symptoms, 1 confirmed to have died of SARS-CoV-2 infection, and all of whom had traveled on Grand Princess Voyage A. On March 4 and 5, 2020, while Voyage B was returning to San Francisco, the ship notified CDC about influenza-like illness among multiple passengers and crew. At that time, only 164 COVID-19 cases were known in the United States. 9 A CDC Epidemic Intelligence Service officer working with California’s Office of Emergency Services was deployed by helicopter to the ship on March 5, 2020, to collect specimens from 41 passengers and crew exhibiting influenza-like symptoms; 2 passengers and 19 crew had a positive test result for SARS-CoV-2. We describe the public health response to the COVID-19 outbreak among travelers of the Grand Princess, including SARS-CoV-2 testing aimed at identifying and isolating cases and a large federal quarantine intended to limit community spread at a time when few COVID-19 cases had been identified in the United States.
Figure 1.
Timeline of events during and after a COVID-19 outbreak on board the Grand Princess cruise ship, February–March 2020. Abbreviations: CDC, Centers for Disease Control and Prevention; USCG, United States Coast Guard.
Methods
Initial Onboard Response
Per the cruise line, large-group passenger activities were canceled on March 4, 2020. Passengers who had also sailed on Voyage A and people experiencing influenza-like symptoms or respiratory illness were asked to remain in their cabins for the duration of the voyage. 10 On March 5, 2020, a Captain of the Port Order was issued by the US Coast Guard, preventing the Grand Princess from docking in San Francisco until SARS-CoV-2 testing on board was completed and public health measures were implemented; all passengers were instructed to stay in their cabins. 11 A National Disaster Medical System assessment team of 8 people deployed by the Administration for Strategic Preparedness and Response boarded the Grand Princess via a US Coast Guard vessel 11 miles offshore and, with the ship’s medical staff, triaged the needs of ill passengers so they could be removed from the ship and transported to medical care in an orderly and timely fashion. On March 7, 2020, the ship was diverted to the Port of Oakland, California, where it docked on March 9, 2020.
Disembarkation
From March 9 through 14, 2020, all passengers disembarked. Passengers were required to wear surgical masks while disembarking and maintain 6 feet between groups not traveling together. Passengers not identified as symptomatic on board disembarked via the central gangway; were screened for fever via noncontact thermometer reading; and were interviewed to assess self-reported symptoms of fever, shortness of breath, sore throat, or cough. Any passenger reporting symptoms during the interview or experiencing a temperature >100 °F was transferred to a separate tent for further assessment. Passengers identified by medical personnel on board as symptomatic disembarked via the forward gangway and were immediately assessed by dockside medical personnel (eFigure in the Supplement).
People who were mildly symptomatic (various COVID-19 signs/symptoms, no shortness of breath) were transported by ambulance to alternate care sites. 12 Anyone with more than mild symptoms was transported to a local hospital for evaluation. People who had a positive test result for SARS-CoV-2 but were discharged from the hospital were transported to an alternate care site to complete their isolation. US residents who were asymptomatic were transported by bus or plane, depending on distance from the port, to 1 of 4 military bases (Bases A-D) to begin a 14-day federal quarantine. People were required to wear face masks and maintain distance while on the bus or plane to mitigate potential transmission during transport.
Foreign national passengers were repatriated via private charter flights. Most crew were foreign nationals and could not be housed at US military bases. Once all passengers disembarked, the ship was disinfected, and remaining crew stayed on board in separate cabins for a 14-day quarantine. Essential crew were permitted to move about the ship while masked to operate the vessel. Crew remaining on board were monitored for symptoms and tested. Crew with positive test results were isolated, and medical treatment was provided on board unless hospitalization was required.
US Federal Isolation and Quarantine Orders
US residents who were asymptomatic and had not tested positive for SARS-CoV-2 were issued federal quarantine orders upon arrival at the military bases. These people remained in quarantine until 1 of the following occurred: (1) they completed a 14-day period following their last known exposure; (2) they were released to the supervision of a state or local jurisdiction; (3) they had a positive test result and were issued isolation orders; or (4) federal quarantine was rescinded on March 23, 2020. Any person with a positive SARS-CoV-2 test result was issued federal isolation orders. At the initiation of this response, release from isolation required 2 consecutive negative sets (nasopharyngeal and oropharyngeal) of real-time reverse transcriptase–polymerase chain reaction tests; subsequently, time-based criteria were developed according to time since illness onset and symptom resolution.
US Resident Medical Care, Testing, and Arrival at Quarantine
US residents were screened for COVID-19 symptoms before boarding transportation and again upon arrival at military bases. During quarantine, people were monitored daily for symptoms and advised to report any new symptoms when they occurred. Medical care was available 24 hours daily. From March 13 through 19, 2020, voluntary SARS-CoV-2 testing was conducted at the bases when those quarantined requested it or they became symptomatic. After informed consent was obtained, specimens were collected using nasopharyngeal swabs and tested by real-time reverse transcriptase–polymerase chain reaction. Most samples were sent to LabCorp; public health and clinical laboratories provided additional testing support as needed. Close contacts to people who had a positive test result (eg, family members quarantining in the same room as the infected person) and remained on base were tested and separated from others while awaiting results.
Data Management and Statistical Analysis
We obtained demographic data (age, county, state, country of residence) and crew or passenger classification from Voyage A and B manifests. Manifests were linked by name and date of birth to identify people who had traveled on both voyages. We obtained SARS-CoV-2 test results from laboratory reports sent electronically to the California Department of Public Health’s disease reporting system or directly to quarantine or isolation sites. We compiled symptom and hospitalization data from several data sources, including paper logs, electronic records maintained by federal response teams, and hospital discharge data, where available.
We calculated SARS-CoV-2 positivity rates for people tested on Voyage B and people tested at all bases combined. Due to limited data, we restricted analysis of symptoms to Bases A, B, and D in aggregate and Base B individually because its high testing proportion minimized potential bias toward preferential testing of older or symptomatic people. For Base B, we calculated the risk ratio (RR) of having a positive SARS-CoV-2 test result or being hospitalized, stratified by sex (female, male) and age (<70, 70-79, or ≥80 y).
Ethics
A human subjects advisor for CDC’s National Center for Emerging and Zoonotic Infectious Diseases reviewed this analysis and determined it to be a nonresearch public health response activity.
Results
Of 3582 travelers on board Voyage B, 2052 (57%) were US resident passengers from 45 states; 419 (12%) were foreign national passengers from 16 countries; and 1111 (31%) were crew from 45 countries, including 12 from the United States (Figure 2).
Figure 2.
Public health management of travelers on board the Grand Princess cruise ship Voyage B during a COVID-19 outbreak, after docking in Oakland, California, March 2020.
Of 2064 US resident travelers on board Voyage B (2052 passengers, 12 crew), 968 (47%) were California residents and 1142 (55%) were female (Table 1). The median (IQR) age was 68 (61-75) years. Nearly all US resident travelers (n = 2013; 98%) were asymptomatic at disembarkation and transported to federal quarantine at Base A (n = 875), Base B (n = 490), Base C (n = 149), or Base D (n = 499). Of those with symptoms, 2 US resident travelers were airlifted off the ship to a hospital prior to docking at the Port of Oakland; 39 US resident travelers reporting symptoms at disembarkation were taken to local hospitals (n = 9) or an alternate care site (n = 29); and 1 US resident traveler was permitted to return home for isolation, upon agreement to remain under health department supervision. Two US resident travelers disembarked during a Hawaii port visit before the ship reached California. Information on the disembarkation port was not available for 8 US resident passengers on the manifest (Figure 2).
Table 1.
Demographic characteristics, geographic distribution, and SARS-CoV-2 testing outcomes among US residents who traveled on the Grand Princess Voyage B a during a COVID-19 outbreak on board, March 2020
| Grand Princess US residents by disembarkation site, no. (%) | ||||||
|---|---|---|---|---|---|---|
| Characteristic | Total b | Base A | Base B | Base C | Base D | Nonquarantine Sites c |
| Overall | 2064 | 875 | 490 | 149 | 499 | 41 |
| Sex d | ||||||
| Female | 1142 (55) | 482 (55) | 278 (57) | 79 (53) | 274 (55) | 23 (56) |
| Male | 922 (45) | 393 (45) | 212 (43) | 70 (47) | 225 (45) | 18 (44) |
| Age, y, median (IQR) | 68 (61-75) | 70 (62-76) | 68 (62-74) | 67 (61-73) | 67 (60-73) | 67 (61-69) |
| By regiond,e | ||||||
| West | 1328 (64) | 830 (95) | 394 (80) | 3 (2) | 70 (14) | 24 (57) |
| Midwest | 270 (13) | 21 (2) | 70 (14) | 59 (40) | 111 (22) | 9 (23) |
| South | 332 (16) | 14 (2) | 21 (4) | 85 (57) | 207 (41) | 4 (10) |
| Northeast | 132 (6) | 9 (1) | 5 (1) | 2 (1) | 111 (22) | 4 (10) |
| Unknown | 2 | 1 | 0 | 0 | 0 | 0 |
| California residents by region of residenced,f | ||||||
| Northern | 48 (5) | 42 (5) | 4 (3) | — | — | 2 (20) |
| Sacramento | 241 (25) | 228 (28) | 7 (5) | — | — | 3 (30) |
| San Francisco Bay Area | 546 (56) | 469 (58) | 74 (54) | — | — | 1 (10) |
| Central Coast | 19 (2) | 7 (1) | 10 (7) | — | — | 2 (20) |
| Central Inland | 90 (9) | 60 (7) | 29 (21) | — | — | 1 (10) |
| Southern | 23 (2) | 10 (1) | 12 (9) | — | — | 1 (10) |
| Unknown | 1 | 0 | 1 | — | — | 0 |
| All regions | 968 | 816 | 137 | — | — | 10 |
| SARS-CoV-2 travelers tested | ||||||
| Overall | 1099 (53) | 410 (47) | 436 (89) | 67 (45) | 141 (28) | 38 (93) |
| Positive test result | 124 (11) | 40 (10) | 46 (11) | 6 (9) | 23 (16) | 9 (24) |
Voyage B (February 21–March 9, 2020): 2471 passengers and 1111 crew. Of 2064 US resident travelers, 2052 were passengers and 12 were crew.
Of 2064 US resident travelers, 8 had unknown initial disembarkation location, and 2 were known to have disembarked at a prior port of call.
Nonquarantine sites include travelers taken directly from the ship to a hospital, alternate care site, or home isolation.
Percentages may not add to 100 because of rounding.
West: Alaska, Arizona, California, Colorado, Hawaii, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, Wyoming. Midwest: Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, South Dakota, Wisconsin. Northeast: Connecticut, Delaware, Maine, Maryland, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Vermont. South: Alabama, Arkansas, Florida, Georgia, Kentucky, Louisiana, Mississippi, North Carolina, Oklahoma, South Carolina, Tennessee, Texas, Virginia, West Virginia.
Northern counties: Butte, Colusa, Del Norte, Glenn, Humboldt, Lake, Lassen, Mendocino, Modoc, Nevada, Plumas, Shasta, Sierra, Siskiyou, Sutter, Tehama, Trinity, Yuba. Sacramento counties: El Dorado, Placer, Sacramento, Yolo. San Francisco Bay Area counties: Alameda, Berkeley, Contra Costa, Marin, Napa, San Francisco, San Mateo, Santa Clara, Solano, Sonoma. Central Coast counties: Monterey, San Luis Obispo, Santa Barbara, Santa Cruz, Ventura. Central Inland: Alpine, Amador, Calaveras, Fresno, Inyo, Kern, Kings, Madera, Mariposa, Merced, Mono, San Benito, San Joaquin, Stanislaus, Tulare, Tuolumne. Southern counties: Imperial, Long Beach, Los Angeles, Orange, Pasadena, Riverside, San Bernardino, San Diego.
Two foreign national passengers were taken to an alternate care site; all others were repatriated. Of the 1099 foreign national crew, 19 were among those identified as having SARS-CoV-2 infection on March 5, 2020, and were transferred to an alternate care site; another 9 foreign national crew later developed symptoms and were transferred to an alternate care site (n = 8) or hospital (n = 1). All remaining foreign national crew completed a 14-day quarantine on board (Figure 2).
SARS-CoV-2 Testing
Overall, 1144 of 3582 travelers (32%) on Voyage B were tested for SARS-CoV-2 during the response; of those, 155 (14%) had a positive test result (Table 2). Among those tested, the median (IQR) age was 68 (61-74) years, and 617 (54%) were female. Among 1093 passengers tested, 124 (11%) had a positive test result for SARS-CoV-2. Of 93 passengers who traveled on Voyages A and B, 33 (35%) were tested (all with negative results), 28 (30%) were not tested, and 32 (34%) had unknown testing information. Among 1111 crew, 45 (4%) were tested, of whom 31 (69%) had a positive test result. Among those 31 crew were the 19 crew who had a positive test result for SARS-CoV-2 on March 5, plus 12 crew who had a positive test result at an alternate care site (n = 3), at a hospital (n = 1), or on board after docking (n = 8). Of 31 crew with a positive test result, 29 (94%) had traveled on Voyages A and B.
Table 2.
SARS-CoV-2 test results among travelers of Grand Princess Voyage B, March 2020
| Travelers, no. (%) | |||
|---|---|---|---|
| Measure | Total | Crew | Passengers |
| On the Grand Princess Voyage B | 3582 | 1111 | 2471 a |
| Tested for SARS-CoV-2 b | 1144 (32) | 45 (4) | 1093 (44) |
| Positive result | 155 (14) | 31 (69) | 124 (11) |
| Negative result | 984 (86) | 14 (31) | 964 (88) |
| Invalid, indeterminate, or unknown result | 5 | 0 | 5 |
| Those testing positive who traveled on Voyages A and B c | 29 (19) | 29 (94) | 0 |
2471 passengers included 2458 passengers on the manifest and 13 additional people not identified on the manifest but who disembarked to quarantine or isolation sites.
All tests were performed with real-time reverse transcriptase–polymerase chain reaction.
93 passengers and 1018 crew traveled on Voyage A (February 11-21, 2020) and Voyage B (February 21–March 9, 2020).
Among 2013 US resident travelers federally quarantined on bases, 1054 (52%) were tested for SARS-CoV-2; of those, 115 (11%) had a positive test result. The proportion tested at each base ranged from 28% to 89%; test positivity ranged from 10% to 16% (Table 1). All 29 US resident travelers who disembarked to an alternate care site were tested; 5 (17%) had a positive test result. Of 9 travelers who went to a hospital directly from the ship after docking, 6 were tested and 3 had a positive test result.
Symptoms
Of 109 travelers at Bases A, B, and D with a positive test result, 31 (28%) reported COVID-19 symptoms at specimen collection. Six others who initially had a negative test result subsequently developed symptoms and had a positive test result for SARS-CoV-2. Of these 37 (34%) travelers who were symptomatic, 17 (46%) were female and the median (IQR) age was 74 (69-80) years. Symptoms included fever (n = 13; 35%), cough (n = 13; 35%), weakness (n = 7; 19%), chills (n = 6; 16%), shortness of breath (n = 6; 16%), and fatigue (n = 3; 8%). The median (IQR) number of days from arrival at the base to symptom onset was 2 (0-4.5) days.
Hospitalizations
Of 31 travelers taken to hospitals, 26 (84%) had a positive test result for SARS-CoV-2, 3 (10%) had a negative test result, and 2 had unavailable results. The median (IQR) length of hospitalization was 4 (4-9) nights. Of 31 hospitalized patients, 9 (29%) died of COVID-19 complications; all 9 were male (8 passengers, 1 crew).
Base B
Of 490 travelers at Base B, 57% were female and the median (IQR) age was 68 (62-74) years. Of 436 (89%) travelers tested, 46 (11%) had a positive test result. Of those 46 travelers, 38 (83%) reported no symptoms at specimen collection. Travelers aged ≥80 years were twice as likely as those aged <80 years to have a positive test result (RR = 2.5; 95% CI, 1.3-4.7). Males and females were equally likely to have a positive test result (RR = 1.2; 95% CI, 0.7-2.0). Hospitalization was 4 times more likely among those aged ≥80 years (RR = 4.89; 95% CI, 1.08-22.13) and those aged 70 to 79 years (RR = 4.40; 95% CI, 1.02-18.93) than among those aged <70 years.
Discussion
Quarantine and isolation are public health strategies for limiting the spread of certain communicable diseases and are authorized in the United States by executive order of the president.13,14 Prior to COVID-19, the 1918-1919 influenza pandemic was the last time that a large-scale federal quarantine response was implemented in the United States.15-17 The Grand Princess outbreak was the first cruise ship with a COVID-19 outbreak identified in US waters, occurring on the heels of the Diamond Princess outbreak in Japan. 6 The Grand Princess response was a collaboration across federal, state, and local entities to coordinate, triage, disembark, transport, quarantine, track, test, isolate, medically care for, and repatriate passengers and crew (Supplement) and was implemented at a scale not attempted for more than a century. More than 2000 US residents from 45 states who were asymptomatic were federally quarantined on 4 US military bases in 3 states.
The overall 14% positivity among tested travelers of Voyage B reflects the ease of transmission of viral respiratory pathogens on cruise ships; however, this rate is likely underestimated. A high proportion of passengers, particularly those asymptomatic, declined voluntary SARS-CoV-2 testing. At Base B, where 89% of people were tested, testing positivity was high at 11%; <50% of passengers at the other bases opted to test. In contrast, Diamond Princess travelers were tested on the basis of decisions by the government of Japan, with a 19% SARS-CoV-2 attack rate among those tested.6,18,19 Some US passengers on Voyage B disembarked before the ship docked in Oakland or returned by charter flights to their home states before testing began. Testing of crew was limited, yet a high proportion of symptomatic crew had a positive test result for SARS-CoV-2, suggesting the need for (1) control measures that prevent prolonged transmission across voyages or exposures in dense living and work areas and (2) systems to track crew disembarking to other vessels. Testing was not conducted in the United States for repatriated passengers, and results of testing upon repatriation were not available.
Infections among Voyage A travelers may have contributed to SARS-CoV-2 spread on Voyage B. While testing data were limited and test results were negative for passengers who traveled on both Grand Princess voyages, 94% of crew with a positive test result had traveled on both trips. A genomic survey of SARS-CoV-2–positive specimens obtained from 11 Grand Princess passengers (3 from Voyage A who developed symptoms after returning to their home country and 8 from Voyage B) and phylogenic analysis found that all were part of the WA1 lineage, possibly indicating association of SARS-CoV-2 infection on Voyages A and B. 20
Analyses of Base B data found that people aged ≥80 years were more likely to have a positive test result than people aged <80 years, despite a higher overall testing rate, and 34% of people positive for SARS-CoV-2 at Bases A, B, and D were symptomatic at specimen collection. This finding was consistent with studies that found high rates of asymptomatic infections in skilled nursing facilities and studies of the Diamond Princess.4,21-27 Inconsistent frequency of symptom assessment and lack of systematic data collection made it difficult to describe true symptom prevalence, resulting in likely overestimation of the Grand Princess COVID-19 death rate (9 of 155; 5.8%), given undetected asymptomatic or mild infections and voluntary testing. Data were not available on whether people who were positive with SARS-CoV-2 and asymptomatic at testing subsequently developed symptoms or remained asymptomatic throughout their infection.
With 164 known cases in the United States at the time of the Grand Princess outbreak, the early response focused on containment to prevent introduction and spread of SARS-CoV-2 from returning cruise passengers. 9 Most US residents from Voyage B who did not have symptoms or who did not have a positive test result remained on bases for quarantine; however, some states chartered flights home for their residents, with state health departments assuming responsibility for ensuring that people completed a 14-day home quarantine. On March 23, 2020, CDC rescinded the federal quarantine order for Grand Princess travelers, releasing people from quarantine at the bases. By end of March 2020, US public health strategy was shifting from containment to mitigation, with multiple states issuing shelter-in-place orders. 28
With early transmission dynamics indicating a reproduction number of 2 new infections for every 1 person with COVID-19, disembarkation of at least 115 US people who were positive with SARS-CoV-2 from the Grand Princess would have resulted in numerous new infections across the country at a time when community transmission in the United States was thought to be low.2,29,30 Timely isolation of cases combined with testing and quarantine of exposed people may have prevented transmission; however, this required substantial investment of federal, state, and local public health resources. This outbreak also occurred during a period of particularly high uncertainty about the potential spread of SARS-CoV-2, the morbidity and mortality associated with COVID-19, and the occurrence of asymptomatic infections. Under these circumstances, navigating the least restrictive measures while protecting the general public’s health was a challenging, sensitive endeavor with limited real-time opportunity for robust assessment of effectiveness in a rapidly changing pandemic. The mass quarantine approach was discontinued after the Grand Princess response when it became clear that SARS-CoV-2 was spreading on multiple ships destined for US ports. Instead, CDC focused on safer options to return cruise travelers to their places of residence and recommended that people avoid cruise travel.31,32 On March 14, 2020, CDC issued a nationwide No Sail Order that suspended passenger operations on cruise ships in US waters. 33 Several reports describe the potential effect of different strategies for reducing cruise-related SARS-CoV-2 transmission early in the pandemic, including 1-time screening versus repeat testing, symptom monitoring, reduced ship capacity, and quarantine and isolation policies.5,34-37
Conclusion
While COVID-19 is no longer a public health emergency, transmission of viral respiratory pathogens, including SARS-CoV-2, influenza, and respiratory syncytial viruses, remains a risk onboard cruise ships. Ensuring that cruise ships have communicable disease control plans with mitigation measures, including vaccine promotion, testing and treatment capacity, and logistics for isolation and quarantine, can help protect the safety and health of people on board.
Supplemental Material
Supplemental material, sj-docx-2-phr-10.1177_00333549251321762 for Public Health Response to COVID-19 Among Travelers Disembarked From the Grand Princess Cruise Ship, March 2020 by Rilene A. Chew Ng, Maureen Fonseca-Ford, Cindy R. Friedman, Kara Tardivel, Stefanie White, Ryan Murphy, Lyle R. Petersen, Kathleen Attfield, William A. Bower, Erin L. Murray, Seema Jain, Mariel Marlow, William Wheeler, Lauren J. Stockman, Paul Mead, Nicki T. Pesik, Dale Rose, Paul J. Weidle, Adam Readhead, Debra A. Wadford, Aimee Treffiletti, Jonathon R. Bartlett, Jeanne Eckes-Roper, John T. Redd, Joanna J. Regan, Lisa Rotz, Joaquin Rueda, Deborah Dee, Deniz Dominguez, Tamara Hennessy-Burt, Allison Jacobsen, Martin S. Cetron, Clive Brown, Leah Moriarty, Shannon M. Casillas, Paige A. Armstrong and Ryan T. Novak in Public Health Reports
Supplemental material, sj-docx-3-phr-10.1177_00333549251321762 for Public Health Response to COVID-19 Among Travelers Disembarked From the Grand Princess Cruise Ship, March 2020 by Rilene A. Chew Ng, Maureen Fonseca-Ford, Cindy R. Friedman, Kara Tardivel, Stefanie White, Ryan Murphy, Lyle R. Petersen, Kathleen Attfield, William A. Bower, Erin L. Murray, Seema Jain, Mariel Marlow, William Wheeler, Lauren J. Stockman, Paul Mead, Nicki T. Pesik, Dale Rose, Paul J. Weidle, Adam Readhead, Debra A. Wadford, Aimee Treffiletti, Jonathon R. Bartlett, Jeanne Eckes-Roper, John T. Redd, Joanna J. Regan, Lisa Rotz, Joaquin Rueda, Deborah Dee, Deniz Dominguez, Tamara Hennessy-Burt, Allison Jacobsen, Martin S. Cetron, Clive Brown, Leah Moriarty, Shannon M. Casillas, Paige A. Armstrong and Ryan T. Novak in Public Health Reports
Supplemental material, sj-jpg-1-phr-10.1177_00333549251321762 for Public Health Response to COVID-19 Among Travelers Disembarked From the Grand Princess Cruise Ship, March 2020 by Rilene A. Chew Ng, Maureen Fonseca-Ford, Cindy R. Friedman, Kara Tardivel, Stefanie White, Ryan Murphy, Lyle R. Petersen, Kathleen Attfield, William A. Bower, Erin L. Murray, Seema Jain, Mariel Marlow, William Wheeler, Lauren J. Stockman, Paul Mead, Nicki T. Pesik, Dale Rose, Paul J. Weidle, Adam Readhead, Debra A. Wadford, Aimee Treffiletti, Jonathon R. Bartlett, Jeanne Eckes-Roper, John T. Redd, Joanna J. Regan, Lisa Rotz, Joaquin Rueda, Deborah Dee, Deniz Dominguez, Tamara Hennessy-Burt, Allison Jacobsen, Martin S. Cetron, Clive Brown, Leah Moriarty, Shannon M. Casillas, Paige A. Armstrong and Ryan T. Novak in Public Health Reports
Acknowledgments
We recognize the many agencies involved in this effort: Grand Princess crew members; California Department of Public Health COVID-19 Team; California Department of Public Health Viral and Rickettsial Diseases Laboratory staff; Centers for Disease Control and Prevention Grand Princess Response Team; Division of Global Migration Health; Administration for Strategic Preparedness and Response and personnel of Incident Management Teams 1, 2, 4, 5, and 8; Office of the National Disaster Medical System and members of the Disaster Medical Assistance Teams and Incident Management Team; Federal Emergency Management Agency Region IX; Bothell Community Emergency Response Team; California Office of Emergency Services; California Emergency Medical Services Authority; CAL FIRE Incident Management Team; Port of Oakland; Oakland Fire Department; Oakland Police Department; Princess Cruises; Holland America Group health services; Alameda County, California; Placer County, California; San Diego County, California; San Mateo County, California; California State Parks; staff of local health care facilities who accepted disembarked patients; US Coast Guard; US Customs and Border Protection; US Department of State; and US Marshalls Service. We also thank individual members of the aforementioned agencies for their contributions, including Brooke Bergman, Martin Cilnis, Joseph Engeda, Kristen Finch, Deanna Fink, Varsha Hampole, Emily Han, Sana Khan, Genevieve Kray, Tisha Mitsunaga, Lauren Nelson, Kyle Rizzo, Sarah Rutschmann, Kayla Saadeh, Robert Snyder, James Watt, Cynthia Yen, Carla DeSisto, Onalee Grady-Erickson, Bradley Nelson, Danielle Gilliard, Brad J. Biggerstaff, Erica Pan, Pamela Evans, Steve Formanski, Eduardo Cua, Joseph Lamana, Ken Sturrock, Tom Bowman, Mark Libby, Anthony Voirin, Mick Cote, Casey Barton Behravesh, Zach Braden, Stefanie Bolas, Victoria Chu, David Daigle, William J. (Joe) Gregg, Jefferson Jones, Melissa Kadzik, Eric Kasowski, Brett Petersen, Adam Kramer, Chad Martin, Oren Mayer, Troy Ritter, Paul Smith, Beth Wittry, Chris de la Motte Hurst, Amber Stolp, Brian Maskery, Eileen Bosso, Terry Comans, Nicole Cohen, Sara J. Vagi, Jonathan White, Shelby Cash, Dawn Pepin, Ken Rose, Jennifer Buigut, Hannah Lofgren, Naayab Ladak, Christopher Perdue, Luis O. Rodriguez, Laura Annetta, James Miller, Adam Lofton, and Erin Kincaid.
Footnotes
The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding: The authors received no financial support for the research, authorship, and/or publication of this article.
Disclaimer: The findings and conclusions of this article are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention or the US Department of Health and Human Services.
ORCID iDs: Rilene A. Chew Ng, DrPH 
https://orcid.org/0000-0002-8394-1900
Maureen Fonseca-Ford, MPH
https://orcid.org/0000-0002-4730-7259
Adam Readhead, PhD, MPH
https://orcid.org/0000-0003-3186-9027
Lisa Rotz, MD
https://orcid.org/0000-0002-9936-7325
Data Availability Statement: Data underlying this article cannot be shared publicly, due to the privacy of people involved in this public health response. The data may be shared on reasonable request to the corresponding author.
Supplemental Material: Supplemental material for this article is available online. The authors have provided these supplemental materials to give readers additional information about their work. These materials have not been edited or formatted by Public Health Reports’s scientific editors and, thus, may not conform to the guidelines of the AMA Manual of Style, 11th Edition.
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Supplementary Materials
Supplemental material, sj-docx-2-phr-10.1177_00333549251321762 for Public Health Response to COVID-19 Among Travelers Disembarked From the Grand Princess Cruise Ship, March 2020 by Rilene A. Chew Ng, Maureen Fonseca-Ford, Cindy R. Friedman, Kara Tardivel, Stefanie White, Ryan Murphy, Lyle R. Petersen, Kathleen Attfield, William A. Bower, Erin L. Murray, Seema Jain, Mariel Marlow, William Wheeler, Lauren J. Stockman, Paul Mead, Nicki T. Pesik, Dale Rose, Paul J. Weidle, Adam Readhead, Debra A. Wadford, Aimee Treffiletti, Jonathon R. Bartlett, Jeanne Eckes-Roper, John T. Redd, Joanna J. Regan, Lisa Rotz, Joaquin Rueda, Deborah Dee, Deniz Dominguez, Tamara Hennessy-Burt, Allison Jacobsen, Martin S. Cetron, Clive Brown, Leah Moriarty, Shannon M. Casillas, Paige A. Armstrong and Ryan T. Novak in Public Health Reports
Supplemental material, sj-docx-3-phr-10.1177_00333549251321762 for Public Health Response to COVID-19 Among Travelers Disembarked From the Grand Princess Cruise Ship, March 2020 by Rilene A. Chew Ng, Maureen Fonseca-Ford, Cindy R. Friedman, Kara Tardivel, Stefanie White, Ryan Murphy, Lyle R. Petersen, Kathleen Attfield, William A. Bower, Erin L. Murray, Seema Jain, Mariel Marlow, William Wheeler, Lauren J. Stockman, Paul Mead, Nicki T. Pesik, Dale Rose, Paul J. Weidle, Adam Readhead, Debra A. Wadford, Aimee Treffiletti, Jonathon R. Bartlett, Jeanne Eckes-Roper, John T. Redd, Joanna J. Regan, Lisa Rotz, Joaquin Rueda, Deborah Dee, Deniz Dominguez, Tamara Hennessy-Burt, Allison Jacobsen, Martin S. Cetron, Clive Brown, Leah Moriarty, Shannon M. Casillas, Paige A. Armstrong and Ryan T. Novak in Public Health Reports
Supplemental material, sj-jpg-1-phr-10.1177_00333549251321762 for Public Health Response to COVID-19 Among Travelers Disembarked From the Grand Princess Cruise Ship, March 2020 by Rilene A. Chew Ng, Maureen Fonseca-Ford, Cindy R. Friedman, Kara Tardivel, Stefanie White, Ryan Murphy, Lyle R. Petersen, Kathleen Attfield, William A. Bower, Erin L. Murray, Seema Jain, Mariel Marlow, William Wheeler, Lauren J. Stockman, Paul Mead, Nicki T. Pesik, Dale Rose, Paul J. Weidle, Adam Readhead, Debra A. Wadford, Aimee Treffiletti, Jonathon R. Bartlett, Jeanne Eckes-Roper, John T. Redd, Joanna J. Regan, Lisa Rotz, Joaquin Rueda, Deborah Dee, Deniz Dominguez, Tamara Hennessy-Burt, Allison Jacobsen, Martin S. Cetron, Clive Brown, Leah Moriarty, Shannon M. Casillas, Paige A. Armstrong and Ryan T. Novak in Public Health Reports