A 22-year-old man and a three-year-old boy who traveled to Vietnam from China’s Wuhang City, where the pneumonia outbreak started in late December, were part of a tour group. Their temperatures were high and both were quarantined right after landing at the Da Nang Airport.

The boy’s temperature came down shortly after he was quarantined. He was then allowed to enter Vietnam and his health has been normal since.

For the young man, tests at the Oxford University Clinical Research Unit (OUCRU) in Vietnam that operates within the Hospital for Tropical Diseases Ho Chi Minh City, showed that he was not infected with the pneumonia virus that has spread across China since December.

Nguyen Tien Hong, deputy director of Da Nang’s health department, said the man, who was not named, only had a normal viral infection. He’d had a normal viral infection and returned to China Saturday’s night.

The throat swabs and blood serum samples of the two were first sent to the Nha Trang Pasteur Institute to determine the cause of the fever.

Test results from the institute also confirmed both were not infected with the pneumonia virus.

However, local health authorities transferred the blood sample of the 22-year-old to the OUCRU to test for the NCoV, a new strain of coronavirus, which has been identified as the cause for the ongoing outbreak that has killed two Chinese in Wuhang so far.

WHO, China and other countries are trying to prevent further spread of the virus ahead of the Lunar New Year holidays next week, when many of the 1.4 billion Chinese citizens will travel abroad.

Vietnam has not detected any infection so far. The two Chinese tourists are the first case of foreigners entering Vietnam with a fever since the outbreak started.

Airports in Hanoi, Ho Chi Minh City and Khanh Hoa Province, a major destination for Chinese tourists, have installed equipment to monitor passengers’ body temperature on arrival.