Testing for COVID-19 at travel clinics in Japan.

To the Editor.

The coronavirus disease 2019 (COVID-19) pandemic has led many countries to take public health measures, including travel restrictions, to prevent the spread of infection. The World Tourism Organization estimates international tourism could fall by 60–80% in 2020. As of the end of May, 182 countries had placed some immigration restrictions on travellers from Japan, and the number of departures in April had decreased by 99.8% compared with last year. The number of travel consultations at travel clinics has also dramatically fallen. At our facility, Japan’s largest travel clinic, the number of vaccinations in April decreased from 1336 last year to 250.

Some countries are now resuming traffic to neighbouring countries, and the accepting countries should take comprehensive measures to prevent importing COVID-19. One such action is the need for travellers to submit a certificate confirming the evaluation of infectiousness immediately before travelling. Our travel clinic has started a medical assessment service, including real-time polymerase chain reaction (PCR) testing, to issue certificates to travellers who are required to undergo pre-travel evaluation. The in-house PCR test is performed on the specimens acquired from the nasopharyngeal swab. The test itself costs 22 000 yen (about USD 205), including tax, and we issue the certificate 1 day after the assessment, similar to the service started recently for travellers at Vienna International Airport. Here, we report precautionary measures and key issues related to providing this service.

Because pre-travel consultation is a service for healthy people, we need to prevent infection within the clinic. So, we use a screening sheet to check overseas travel history within 2 weeks, contact history with COVID-19 patients, clinical symptoms and body temperature before the consultation. Also, the person performing the test wears appropriate personal protective equipment. We must also act on the returned test results, including considering the possibility of false-positive results and reporting of any asymptomatic carriers of severe acute respiratory syndrome coronavirus 2 (SARS-COV-2). So, we inform examinees in advance that should their test results be positive, this information will be shared with the public health centre under the Infectious Disease Act, and necessary measures such as isolation will be implemented. We also advise against unnecessary outings and contact with many people until we confirm a negative result. Finally, we prioritize testing in confirmed or suspected COVID-19 cases, so sufficient testing capabilities are needed to complete pre-travel testing. Aside from PCR testing, an approved rapid antigen test for SARS-CoV-2 (ESPLINE® SARS-CoV-2, Fujirebio Inc.) is available. This antigen test seems a useful option for travellers because it is cheaper than PCR, and the results are returned quickly. However, because of insufficient sensitivity, at around 80% for measurement of ≥100 RNA copies/ml, additional PCR testing is needed for a negative result according to the guideline. So, it is not suitable for travellers with a very low pre-test probability of infection.

It is necessary to continue taking measures against COVID-19. As economic activities and overseas travel resume, the role of PCR testing in the pre-travel evaluation will become even more critical. As countries around the world strive to minimize their impact on the COVID-19 pandemic, this test required by destination countries provides high adherence to pre-travel health advice. It may also be an opportunity to provide other general knowledge and vaccinations needed to enhance international travellers’ safety. So, it is a matter of urgency that the capacity of the healthcare system is expanded to meet the testing needs of travellers.