Healthcare workers transport a patient on a stretcher into an ambulance at Life Care Center of Kirkland on Saturday in Kirkland, Washington. Dozens of staff and residents at Life Care Center of Kirkland are reportedly exhibiting coronavirus-like symptoms with two confirmed cases of COVID-19 so far. Photo: AFP

The US might have failed to identify illnesses of different causes, experts said considering the outbreaks of influenza and vaping-related illnesses in the country. Some have connected the cases with novel coronavirus.

A total of 74 cases of the COVID-19 have been confirmed in the US by Monday morning, with one death. On Sunday, the US announced a "radical expansion" on coronavirus testing, Reuters reported.

However, some experts have been doubting if the COVID-19 cases have been mixed among respiratory illnesses which have similar symptoms, including a mysterious e-cigarette-caused lung disease, in the US without being tested out.

"There must be a possibility," Yang Zhanqiu, deputy director of the pathogen biology department at Wuhan University, told the Global Times on Sunday.

"If the US does not look back to detect the novel coronavirus on the influenza patients of last year, the question could not be answered," he said.

The situation might exist that some pneumonia cases of unclear causes are not identified on time, Zhou Zijun, a professor at Peking University's School of Public Health, told the Global Times. "At least, there should be further investigation and research when mysterious illness occurs."

"The US had not tested [for the novel coronavirus], so it could not be excepted," Zhi Xiuyi, director of the Beijing United Family Hospital (BJU) Lung Cancer Center, told the Global Times on Sunday.

Due to reasons like a lack of kits and low awareness, testing for virus has not been promoted in the US, which was also the same situation in other countries like China and Japan, he noted.

Zhi noted that China's experience, recognition and data of the COVID-19 in the past weeks could be shared on international platforms.

Studies on genome sequence have found that the virus might have been spreading in the US for about six weeks through other people in communities, according to Trevor Bedford, an associate professor at the Fred Hutchinson Cancer Research Center and the University of Washington, the New York Times reported Sunday.

A mysterious lung injury outbreak in the US, which is claimed to be associated with e-cigarette, or vaping, has affected 2,807 people and caused 68 deaths as of February 18. 

It has been named e-cigarette, or vaping, product use-associated lung injury, or EVALI. The outbreak saw a sharp increase in August 2019 and peaked in September 2019. EVALI patients have been declining, according to the CDC. 

The EVALI and other respiratory viruses share similar symptoms, including shortness of breath, night sweats, low oxygen levels, and hazy spots on a lung X-ray, statnews.com reported, quoting experts, who mentioned the difficulty to "tease apart a bad flu case and a vaping case."

The symptoms also resemble those caused by the COVID-19.

Zhi, also vice president of the Chinese Association on Tobacco Control, questioned the sudden death cases of vaping, implying there might be other causes. He said that it is possible that those who died of vaping could also be affected by flu or coronavirus and called for studies.

"The US, as a big country, should also take the responsibility to pay more awareness on the prevention," Zhi said.

At least 190,362 people have been tested positive for influenza in this flu season that started October 2019 in the US, according to the US' Centers for Disease Control and Prevention. The agency estimated illnesses caused by flu has killed 18,000 to 46,000 people.

The WHO has raised the risk assessment of the COVID-19 to "very high" across the world on Friday.