A Health Ministry official said on Monday that the Japanese national who tested positive for the novel coronavirus upon his return from a trip to Indonesia was "not a case of COVID-19".

Secretary Achmad Yurianto of the Health Ministry's disease control and prevention directorate general said that according to Japanese authorities, the man was infected with “Severe Acute Respiratory Syndrome coronavirus 2" – or SARS-CoV-2 – and insisted that SARS-CoV-2 was different from COVID-19.

“There [in Japan], he was diagnosed by doctors to have been infected with SARS coronavirus type 2,” Yurianto told The Jakarta Post on Monday.

When the Post asked Yurianto to elaborate on his insistence that the Japanese man did not have COVID-19 despite testing positive for SARS-CoV-2, he maintained his earlier statement.

In an earlier interview with kompas.com, Yurianto claimed that coronavirus disease 2019, officially named COVID-19, was different from SARS-CoV-2.

"What we have now is a COVID-19 epidemic. There are experts saying that COVID-19 is different from SARS CoV-2, and that the differences reach 70 percent,” he said.

Yurianto said he believed that the two were different because in dealing with Indonesian crew members of the Diamond Princess cruise ship, Japan had consistently referred to their illness as COVID-19 rather than saying that they had tested positive for SARS-CoV-2.

The International Committee on Taxonomy of Viruses (ICTV), which is responsible for naming and classifying new viruses, announced on Feb. 11 that the virus that causes COVID-19 (coronavirus disease 2019) "has been named 'severe acute respiratory syndrome coronavirus 2' (SARS-CoV-2)".

The World Health Organization has also published a special webpage on naming the new coronavirus, which states that "the virus responsible for COVID-19" is named "severe acute respiratory syndrome coronavirus 2

(SARS-CoV-2)". The subsequent section has the subheading "Why do the virus and the disease have different names?", and provides a clear explanation.

On Feb. 22, the Tokyo Metropolitan Government announced that the Japanese man was a Tokyo resident in his 60s. In related news published the same day, national broadcaster NHK reported that the man was diagnosed on Feb. 19 upon his return from a family vacation in Indonesia, but did not specify the local destination. It also said that he had gone to a medical facility on Feb. 12 with "cold-like symptoms".

Read also: BREAKING: Japanese man tests positive for COVID-19 after Indonesia visit: Report

Yurianto said that while the man was in Indonesia, he had only visited Bali and had not shown any symptoms of COVID-19.

Meanwhile, Omni Hospital Pulomas vaccinologist Dirga Sakti Rambe said that similar cases could be going undetected, as several cases had been reported of people infected with SARS-CoV-2 who had not shown any symptoms of COVID-19.

“[Asymptomatic] cases like this would not be detected at any airport around the world. This is what makes COVID-19 management difficult,” Dirga told the Post.

Although ports of entry like airports should check the temperature of passengers according to guidance from the WHO, cases of infection could still miss detection, he said.

“This is not the fault of the airport’s detection system, but the character of this disease. It is getting harder to control the outbreak because of asymptomatic transmission,” said Dirga. “That’s why it must be followed up, where he went, etc. Ideally, we should be tracking his [close] contacts.”

On Monday, NHK reported that the Tokyo government had identified around 80 people as the man's close contacts and instructed them to remain at home in self-quarantine, and that it was continuing to surveil their condition.