The Taiwan Taoyuan International Airport COVID-19 cluster, also known as the Taoyuan Airport cluster, was a cluster of COVID-19 infections that began on 2 January 2022 at Taiwan Taoyuan International Airport in Taoyuan City, Taiwan. On 3 January, the announced that a parking lot cleaner at the airport had tested positive for COVID-19; the case had previously operated a stall at . The following day, after the number of linked infections increased to four, the Central Epidemic Command Center (CECC) immediately established a forward command post at the airport in response. As of 23 February, a total of 789 people had been confirmed in connection with the cluster, including cleaners, epidemic-prevention taxi drivers, airport security personnel, members of the Golden Voice Singing Club, baggage cart workers, home-care workers, electronics factory employees, bank employees, restaurant staff and customers, teachers and students, motorcycle shop workers, factory workers, their household contacts, and cases identified through expanded contact tracing. The ages of those infected ranged from under five years old to over seventy.

Course of events

Early cases

During the COVID-19 pandemic in Taiwan, airports were regarded as high-risk areas. Cleaning services at Taiwan Taoyuan International Airport were provided by Shin Shih Security Services.On 2 January, a Taiwanese woman in her 40s who worked as a cleaner in the airport's epidemic-prevention vehicle parking area developed fever and cough symptoms. She tested positive for COVID-19 the following day, with a Ct value of only 11. The CECC announced the locally transmitted case that evening. She had no recent travel history and had received two doses of the Oxford–AstraZeneca COVID-19 vaccine. On the mornings of 30 and 31 December, during the New Year's holiday period, she had operated a stall at Zhongzhen Market in Zhongli District, Taoyuan City. The Taoyuan Department of Health urgently tested her six household members, all of whom returned negative results.

On the afternoon of 4 January, the CECC officially announced four new local cases. They included three cleaners working in the parking area of Taiwan Taoyuan International Airport (Cases 17230, 17238, and 17239) and one epidemic-prevention taxi driver (Case 17240). Case 17230 was preliminarily identified as being infected with the Omicron variant of SARS-CoV-2, while Case 17239 developed symptoms on 1 January and had a Ct value of approximately 24. Case 17240 developed symptoms on 1 January and had transported passengers infected with the Omicron variant on 26 and 31 December. He became the first epidemic-prevention taxi driver in Taiwan to test positive.That afternoon Lin Yu-chang, Mayor of Keelung, stated that Case 17240 rented residences in both Keelung and Taoyuan and lived with a friend in Keelung, who was subsequently placed under home quarantine and tested. That evening, the Keelung City Government announced that the test result was negative.

On the morning of 5 January, Cheng Wen-tsan, Mayor of Taoyuan, announced at an epidemic-prevention meeting that another cleaner employed by Reliance Group had tested positive. In the afternoon, the CECC officially announced one new local case, a Taiwanese woman in her 50s (Case 17266) who worked as a cleaner at Taiwan Taoyuan International Airport.She had received two doses of the Moderna COVID-19 vaccine and worked at the same workplace as Cases 17230, 17238, and 17239, and had commuted with them on the same shuttle route. She developed cough and throat discomfort on 3 January and tested positive through self-testing, with a Ct value of 16. On the same day, the CECC announced that genomic sequencing had confirmed that Case 17240 was infected with the Omicron variant. In addition, an imported case previously announced on 2 January (Case 17181) was reclassified as a locally transmitted case after epidemiological investigation determined that it was linked to Case 16941. That evening, the CECC announced three additional confirmed cases, all night-shift cleaners employed by Reliance Group through subcontracting, who had been identified through expanded testing. Their overlapping exposure was mainly associated with the employee shuttle bus used after work.

Increase in cases Secondary clusterConfirmed casesAirport cleaners, security personnel, and Golden Voice Singing Club-related cases26Airport baggage cart workers and home-care workers-related cases22Union Bank Jianxing Branch-related cases23Xi Di Restaurant-related cases165Others690 (674)Total926 (910)

Daily trend of case increases and decreases

Distribution of cumulative domestic COVID-19 cases in Taiwan

Data cover the period from 1 January to 14 May 2022, with a cumulative total of 763,049 confirmed cases. Location (city/county)Cumulative casesNew Taipei City268,616Taipei City143,162Taoyuan City124,154Taichung City41,552Kaohsiung City35,783Keelung City27,713Tainan City22,153Yilan County15,607Hsinchu County14,621Hualien County12,976Pingtung County10,757Changhua County9,892Miaoli County6,401Yunlin County6,359Nantou County3,739Taitung County3,726Chiayi County3,333Chiayi City2,206Hsinchu City1,187Penghu County772Kinmen County564Lienchiang County181 Note: Data are compiled from statistics provided by the National Center for High-performance Computing. Figures are subject to rolling adjustments due to differences in data retrieval times and the reassignment of case records between jurisdictions.

Death cases (domestic cases) On 15 February, following postmortem epidemiological investigations, the Central Epidemic Command Center announced one additional death case on the same day. The deceased (Case 18138) was a Taiwanese woman in her 80s from northern Taiwan with a history of chronic illnesses. Due to medical needs, she had been admitted for isolation on 10 January. She tested positive before completing her isolation period on 19 January and was confirmed with COVID-19 on 20 January, after which she remained in isolation and received treatment. She died on 4 February. The case was identified as a contact related to Case 17368, which was associated with the Golden Voice Singing Club cluster.

Prevention measures

Central Epidemic Command Center On the afternoon of 4 January, in response to four locally transmitted cases in Taoyuan City, Minister of Health and Welfare and CECC commander Chen Shih-chung announced that enhanced epidemic prevention measures would be implemented in Taoyuan City from that day until 17 January. Residents were required to wear masks at all times when outside, with mask removal permitted only while eating or drinking; all other exemptions were suspended. Airport prevention measures were also strengthened, with epidemic-prevention taxi drivers required to undergo deep-throat saliva PCR testing every three days, airport staff required to take rapid tests once a week, and symptomatic individuals required to immediately undergo deep-throat saliva or nasopharyngeal PCR testing.

At around 4 p.m., Chen and deputy head of the medical response team traveled to the Taoyuan International Airport emergency response center to receive briefings from relevant agencies. They then inspected the passenger arrival procedures within the restricted area, reviewed epidemic prevention operations, and visited the epidemic-prevention taxi stand to thank drivers for their efforts.

Chen paid particular attention to coordination between the CECC and Taoyuan International Airport, and expressed hope that the airport's experience could be applied to other international airports handling arriving passengers. That evening, the CECC officially classified the outbreak as a cluster and approved the establishment of a forward command post at Taoyuan International Airport to contain the outbreak. Wang Pi-sheng was placed in charge of coordinating epidemic control efforts. The forward command post subsequently focused on three tasks: evaluating on-site operations, assessing risks along arrival routes, and implementing rapid screening. Initially, the CECC suspected two possible transmission routes, including infection through shared toilet facilities and cleaning activities. Chen emphasized that cleaners, epidemic-prevention taxi drivers, and hotel staff were frontline workers bearing risks in the same manner as healthcare personnel and should not be regarded as failures in epidemic prevention.

However, after several cases emerged among people who had no direct workplace or shuttle bus contact, Chen acknowledged that the situation was more complicated and suggested that multiple waves of transmission might already have occurred. Wang identified the toilets near baggage carousel No. 6 and the P3 parking lot toilets as possible sources of infection. On 6 January, Chen stated that the Omicron variant had already entered the local community and admitted that the expanding cluster had made the situation somewhat tense. On 7 January, he acknowledged that community transmission had occurred but said that, because the chain of transmission remained traceable, epidemic alert levels would not be raised. Wang also suggested that a comprehensive review of airport-wide testing might be necessary.

Taoyuan International Airport On the afternoon of 3 January, Taoyuan International Airport Corporation received notification that an employee of a contracted cleaning company had tested positive. The company immediately expanded contact tracing and carried out extensive disinfection in areas where the employee had worked. Hundreds of epidemic-prevention taxi drivers were recalled for testing and were required to test negative before returning to service. The cleaning company identified 26 close contacts.

At 9 a.m. on 4 January, the of the Republic of China Army was deployed to Taoyuan International Airport to conduct another round of deep disinfection, focusing on , the P3 parking lot, taxi driver rest areas, toilets, and elevators. The airport corporation simultaneously disinfected the terminals. Beginning at 11 a.m., recalled epidemic-prevention taxi drivers underwent screening, which was completed by 12:30 p.m.

That afternoon, Taoyuan International Airport Corporation arranged large-scale testing for airport employees and employees of the Reliance Group, including 878 cleaning workers. No additional infections were found among contacts of the parking lot cleaners.

At 9 a.m. on 5 January, Wang Pi-sheng convened the first meeting of the forward command post and stated that passenger arrival routes would largely remain unchanged, though certain procedures would be adjusted and improved.Epidemic-prevention taxi drivers were provided with additional protective gowns and upgraded equipment.The command post also required enhanced testing procedures for airport personnel and epidemic-prevention taxi fleets, with representatives from Taoyuan International Airport and northern regional hospitals under the Taiwan Centers for Disease Control planning implementation. Taipei Songshan Airport and Kaohsiung International Airport adopted similar measures.

Testing of airport personnel was completed on the same day and follow-up monitoring continued. On 6 January, all 93 night-shift terminal cleaning staff employed by the contractor were transferred to centralized quarantine facilities. Employees not placed in quarantine were required to undergo rapid tests and all personnel were scheduled for PCR testing on 8 January. Apart from the seven cleaners who tested positive, all other employees tested negative. In response to the continuing infections, Reliance Group announced that it would strengthen four epidemic prevention measures. The forward command post also reviewed shuttle bus arrangements and required real-name registration and fixed seating assignments.

Community prevention

Taoyuan City