The hunt for the origins of COVID-19 has gone dark in China, the victim of political infighting after a series of stalled and thwarted attempts to find the source of the virus that killed millions and paralyzed the world for months.

The Chinese government froze meaningful domestic and international efforts to trace the virus from the first weeks of the outbreak, despite statements supporting open scientific inquiry, an Associated Press investigation found. That pattern continues to this day, with labs closed, collaborations shattered, foreign scientists forced out and Chinese researchers barred from leaving the country.

The World Health Organization voiced alarm Thursday at the growing spread of H5N1 bird flu to new species, including humans, who face an "extraordinarily high" mortality rate.

"This remains I think an enormous concern," the UN health agency's chief scientist Jeremy Farrar told reporters in Geneva.

The World Health Organization on Thursday announced a new, catch-all terminology for pathogens that transmit through the air, erasing a distinction that caused dangerous confusion during the Covid pandemic.

During the Covid-19 crisis the standoff between experts arguing over whether the SARS-CoV-2 virus spread through droplets or through an aerosol mist proved a crucial public health challenge.

The number of new prostate cancer cases around the world will more than double over the next two decades as poorer countries catch up with the ageing of richer nations, according to a Lancet report published Thursday.

"Our findings suggest that the number of new cases annually will rise from 1.4 million in 2020 to 2.9 million by 2040," said the medical journal, based on a study of demographic changes.

A study that looked at how the immune system reacts to hot weather offers new insight into what's happening when the mercury rises.

Rio de Janeiro on Monday has declared a public health emergency because of an outbreak of mosquito-borne dengue fever, the city announced Monday, just days before Carnival celebrations kick off across Brazil.

The outbreak wasn't expected to derail Carnival, which officially starts Friday evening and runs until Feb. 14, but it has prompted a slew of special measures by the city in hopes of containing the illness.

According to Elon Musk, the first human received an implant from his computer-brain interface company Neuralink over the weekend.

In a Monday post on X, the platform formerly known as Twitter, Musk said that the patient received the implant the day prior and was "recovering well." He added that "initial results show promising neuron spike detection."

Winter is here, inflicting its usual array of symptoms — coughs, nasal congestion, fatigue and fever — and, this year, a new COVID-19 variant is dominating the scoreboard.

COVID-19 is leading hospital admissions among the respiratory viruses, according to the U.S. Centers for Disease Control and Prevention.

Face masks will be mandatory in hospitals and healthcare centers in Spain starting Wednesday due to a surge in respiratory illnesses, the Health Ministry said.

The new leftist minority coalition government is imposing the measure despite opposition from most of Spain's 17 autonomous regions.

France's National Assembly unanimously approved a bill to ban single-use, disposable electronic cigarettes, in an attempt to protect young people drawn to their flavors and mitigate the environmental impacts of the disposable products known as "puffs."

Lawmakers adopted the bill in a late-night vote on Monday by 104 in favor, zero against.