The fast-spreading illness has had a limited impact on Vietnam thus far, but doctors are concerned that this could change.

A mysterious coronavirus which originated in Wuhan, China has infected over 7,700 people worldwide, with the vast majority in China, according to the latest post from the New York Times' live tracker of the outbreak.

The virus, causing respiratory symptoms such as coughing and pneumonia, has killed 170 people, all in China, while confirmed infections have been reported in Thailand, Hong Kong, the United States, Taiwan, Australia, Macau, Singapore, South Korea, Malaysia, Japan, France, Germany, Canada, Vietnam, Nepal, Cambodia and the United Arab Emirates.

Last Thursday, January 23, two Chinese men were admitted to Cho Ray Hospital in Saigon with symptoms similar to those of the coronavirus, and were quarantined after they tested positive, VnExpress reports. The son has since fully recovered from the sickness, while Ding is still in quarantine at Cho Ray with stable conditions.

Li Ding, 66, and his son Li Zichao, 28, are Vietnam's first confirmed cases of the coronavirus, which is shortened to nCoV. Ding had flown from Wuhan to Nha Trang, where Zichao, who lives in Long An Province, met him before traveling around Vietnam. The family's mother also traveled with them, but is asymptomatic.

South China Morning Post reports that nine Vietnamese doctors, some from Cho Ray Hospital, published a letter in the New England Journal of Medicine on Tuesday highlighting concerns of human-to-human transmission of nCov within Vietnam.

As Zichao had not visited China before meeting his father in Nha Trang, it is likely that he caught the virus from his family member, the doctors surmise in the document.

In the letter, the doctors write that "sequencing of strains from the two patients to ascertain the transmission of 2019-nCoV from the father to son has not been performed." Such an incident would be considered second-generation transmission, a worrying step in any outbreak. "A total of 28 close contacts have been identified, and symptoms of an upper respiratory infection have not developed in any of them," the letter adds.

Meanwhile, on Wednesday the Vietnam National Administration of Tourism suggested that travel companies in Vietnam halt transportation to and from areas impacted by nCoV.

According to VnExpress, some businesses in Da Nang, Khanh Hoa Province and Lao Cai Province — all popular destinations for Chinese tourists — have stopped serving mainland visitors, while tourist visas will not be granted to Chinese citizens from regions with confirmed infections.

Tuoi Tre reports that face masks are in high demand in Saigon, with some pharmacies seeing huge surges in sales of the items as people look to ward off potential infection.

[Top photo: Li Zichao (left) at Cho Ray Hospital/TVTS Online]