Chinese health officials are concerned that the global COVID-19 pandemic might boomerang back and hit China again for a second wave of mass infections.

The Daily Mail reported Li Lanjuan, a professor on Beijing’s team of coronavirus experts, is now “very worried that imported cases could trigger another large-scale epidemic” after a coronavirus case originating outside of China has resulted in a case of community spread.

The outlet interpreted Lanjuan’s comments from China’s state-run media, which reported health officials in China are now concerned that international travelers could ignite a second outbreak in the country.

“This requires us to continue to intensify our efforts and work tirelessly to prevent the coronavirus pneumonia epidemic from spreading in other cities,” the 73-year-old doctor said.

The doctor reportedly has spent the last 50 days helping to lead the campaign to rid Wuhan, the original epicenter of the outbreak, of the virus.

“[I am] very worried that imported cases could trigger another large-scale epidemic in our country,” she said.

“The mission in Wuhan has not been accomplished, and there are still many critical patients. Furthermore, I think the current situation in our country is very tough,” she told China’s state-run People’s Daily.

The Daily Mail reported China is prepared to take measures against travel after a person in Guangdong province became ill after coming into contact with someone who had recently returned from Turkey.

The international traveler, who is a Chinese citizen, was diagnosed with COVID-19, as was the person with whom she had contact.

Officials in Guangdong, in southeastern China, said the diagnosis was the first known case of a person spreading the virus in the country after being infected from outside of China.

The traveler, a 34-year-old woman described as Ms. Lin, returned to Guangdong on March 9 and did not show any symptoms of the virus.

She tested positive on March 21.

The woman had been in contact with a 54-year-old man who has also tested positive.

“Can we make every effort to guard our country and prevent another epidemic from happening? This is a tough challenge,” Lanjuan told state media.

As a result, the People’s Daily was advocating a mandatory 14-day quarantine for anyone who enters China from another country.

“Cases related to imported cases are the second-generation cases brought in from abroad. It means the close contacts of [the imported cases] have been transmitted and fallen ill,” the newspaper reported, according to the Daily Mail.

After originating in Wuhan, the capital of Hubei province, COVID-19 has now become a global pandemic.

China, though, has reported a significant decrease in both new cases and deaths in recent weeks.

According to the latest coronavirus numbers from Johns Hopkins, 16,411 people have died globally after contracting COVID-19.

The majority of those deaths have occurred outside of China.

Nearly 10,000 have died in Western Europe, with Italy being the hardest-hit country with 6,077 deaths reported as of Monday.