Leaders in global health and the U.S. claim that China is not disclosing enough information on the local spread of COVID-19, leaving the rest of the world in the dark about the scope and severity of the current wave of infection in the most populous nation on Earth.

On Wednesday, a U.S. federal health official told reporters on a conference call that the Biden administration had very little knowledge of the amount of new COVID cases, hospitalizations, and particularly deaths in China.

The official claimed that because testing and casing reporting have declined nationwide, it is challenging to estimate the true infection prevalence.

According to a statement issued by the U.S. Centers for Disease Control and Prevention on Wednesday, China's lack of transparency may delay the detection of new COVID variants that represent a harm to public health. The CDC says China shares extremely few genetic sequences used to identify such variations.

The CDC announced additional testing criteria for airline passengers flying from China on Wednesday. All passengers, regardless of nationality or vaccination status, must be tested for COVID no later than two days before their journey to the United States, and a negative result must be shown to the airline before departure. The requirements take effect on Jan. 5.

The World Health Organization has additionally urged China to divulge greater details regarding what is happening locally as the illness spreads.

"WHO is very concerned over the evolving situation in China with increasing reports of severe disease," Dr. Tedros Adhanom Ghebreyesus, the head of the global health agency, said in a press briefing in Geneva last week.

A significant section of the population lacks immunity to the extremely contagious Omicron strains as a result of China's zero-COVID policy, which tried to eradicate outbreaks through drastic measures, the official said.

The Biden administration believes that as a result, a significant number of people will become sick in China rather fast.

"What we're concerned about is a new variant that may emerge actually in China," the official said. "With so many people in China being affected in a short period of time there is a chance, a probability that a new variant may emerge."

According to a statement issued this week by GISAID, a public database located in Germany, the most recent genome sequencing data released by Chinese health officials reveals that COVID variations circulating in the country are similar to those known elsewhere in the globe.

China has sequenced and shared 412 COVID cases with GISAID in the last 180 days, compared to more than 576,000 supplied by the US. China's health authorities revealed less than 1% of reported and sequenced COVID cases, whereas the U.S. shared more than 4% and the U.K. approximately 12%.