Tokyo Marathon PCR Testing Found 108 Positive Cases Pre-Race, No Link to Post-Race Clusters

As part of the countermeasures established by the Tokyo Marathon Foundation to ensure the safety of participants by preventing clusters of new coronavirus infections at the 2021 Tokyo Marathon held on Sunday, Mar. 6, 2022, the TMF established a countermeasure review committee and study group to develop effective measures for dealing with infectious disease risk for the purpose of conducting a safe and secure event. A summary of the results from PCR testing done on runners before the race by event medical partners F Medical Equipment Co., Ltd. and Tokyo TMS Clinic are as follows. The complete report is linked at the bottom.

Of 19.527 tests conducted on runners in the three days prior to the race, 108 positive cases were discovered, a positivity rate of 0.55%. No defective tests were discovered. None of the participants who tested positive had temperatures measured at 37.5˚C or higher when they came to runner check-in at the event expo. In telephone interviews Tokyo TMS Clinic doctors found that while the majority were asymptomatic, 35 exhibited some symptoms such as sore throat or fever, including 11 who developed symptoms after having submitted their test samples. The asymptomatic numbers included people who were close contacts and those who had gone through quarantine following infection but still tested positive for the virus.

On race day, Mar. 6, the city of Tokyo as a whole recorded 9,282 new cases, with a 7-day average of 10,995 and a positivity rate of 32.8%. For the week from Feb. 28 to Mar. 6, of 79,479 tests conducted the number of positive cases was 4,845, a suspected positive rate of 6.1%. This was in line with rates of 5 to 7% in the 10 days before the race at testing conducted at Tokyo TMS Clinic. 

Among the 19,188 who started the marathon, none recorded temperatures of 37.5˚C or higher on race day. In post-race monitoring during the period from Mar. 7 to 20, two new positive cases were found in subsequent PCR testing, indicating that no cluster infections occurred at the event and that there had been no false negatives among those tested pre-race. 

This was the first attempt in Japan to conduct the same PCR test on all participants in a large-scale event, and in the midst of other measures such as body temperature and physical condition self-monitoring designed to slow the spread of the sixth wave of infections, it was demonstrated that these measures alone are insufficient for preventing the participation of roughly 100 infected people in a field of 20,000. At the same time, it was confirmed that effective testing protocols based on science can make it possible to safely stage a large event with 20,000 people.

The 2023 Tokyo Marathon scheduled for Sunday, Mar. 5, 2023 will likewise be held in a safe and secure way based on the knowledge and practices gained from the 2021 race. Applications will open in mid-July, 2022.

source articles:

https://www.marathon.tokyo/news/detail/news_002569.html

https://www.marathon.tokyo/news/detail/images/20220707_pcrtest_report.pdf

translated and edited by Brett Larner