Can the bird become in the air?

At the beginning of February 2020, China closed over 50 million people, hoping that it would make it challenging to spread the modern Coronavirus. At that time, no one knew exactly how to spread, but Lidia Morawska, an air quality expert at Queensland University of Technology in Australia, did not like the tips that were found.

It seemed to her as if coronavirus spread in the air, moved by drops exhaled by infected. If it were true, standard measures, such as disinfecting surfaces and will remain a few feet from people with symptoms, it is not enough to avoid infection.

Dr. Morawska and her colleague, Junji Cao from Chinese Academy of Sciences in Beijing, developed a terrible warning. Ignoring the spread of the virus in the air, they wrote would lead to many other infections. But when scientists sent their commentary on medical magazines, they were rejected over and over again.

“Nobody would listen,” said Dr. Morawska.

The World Health Organization took the official recognition that Covid spread in the air. Now, five years after Dr. Morawska began to sound the alarm, scientists pay more attention to how Other diseases It can also spread in the air. At the top of their list there is a bird flu.

Last year, Centers for Disease Control was recorded 66 people in the United States who were infected with a strain of bird flu called H5N1. Some of them probably got ailing, dealing with birds burdened with viruses. In March, the Department of Agriculture discovered cows, which were also infected with H5N1 and that the animals could pass the virus to people – perhaps by droplets splashed from the milking of the machines.

If the bird gains the ability to spread from person to person, it can produce another pandemic. So some flu experts follow changes that could create a virus airborneDrifting in compact drops through hospitals, restaurants and other common spaces in which his subsequent victims could inhale.

“Having this evidence is really crucial in advance so that we do not end in the same situation when Covid appeared, where everyone tried to find out how the virus was passed on,” said Kristen K. Coleman, an infectious- Infectious- disease expert at the University of Maryland.

Scientists are arguing about how flu viruses have been spreading for over a century. In 1918, a variety of flu called H1N1 swept the world and killed over 50 million people. Some American cities treated this as a disease in the air, demanding masks in public windows and opening windows in schools. But many public health experts remained convinced that the flu was spread mainly by direct contact, such as touching the polluted door knob or sneezing or touched.

H5N1 came to airy for the first time in 1996when it was detected in wild birds in China. The virus infected its digestive tract and spread through the feces. Over the years, the virus spread to millions of chickens and other breeding birds. Hundreds of people also got ailing, mainly from dealing with ailing animals. These victims have developed H5N1 infections in their lungs, which were often fatal. But the virus could not easily move from one person to another.

The threat of H5N1 Bottling in human populations prompted scientists to carefully look at how influenza viruses spread. In one experiment, Sander Herfst, a virologist from Erasmus University Rotterdam in the Netherlands, and his colleagues checked whether H5N1 could spread between ferrets in cages placed four inches from each other.

“Animals cannot touch each other, they cannot lick,” said Dr. Herfst. “So the only way to transmit is air.”

When Dr. Herfst and his colleagues plundered the H5N1 viruses in Ferref’s nostril, developed lung infections. They did not spread viruses to robust ferrets in other cages.

But Dr. Herfst and his colleagues discovered that several mutations allowed H5N1 to become in the air. Genetically modified viruses that carried these mutations spread from one frame to the other in three of the four attempts, causing robust fret diseases.

When the scientists shared these results in 2012, an intensive debate was crashed on whether scientists should deliberately try to produce viruses that can start a modern pandemic. Nevertheless, other scientists continued the research to find out how these mutations allowed the influenza spread in the air.

Some studies suggest that viruses become more stable, so they can endure a journey in the air inside the drop. When the next mammal inhales a drop, some mutations allow viruses to slam the cells in the upper respiratory tract of the animal. And other mutations may allow the virus to develop at a cold temperature of the respiratory tract, creating many modern viruses that can then be exhaled.

Tracking flu among people turned out to be more challenging, despite the fact that more or less billion people Get the seasonal flu each year. But some studies indicated the transmission in the air. In 2018, scientists recruited patients with flu and he told them to breathe Corner -shaped sampler. Thirty -nine percent of compact drops that they exhaled, carried live flu viruses.

Despite these discoveries, exactly how the flu spreads in the air is still unclear. Scientists cannot offer a precise number of influenza cases caused by spreading in the air compared to a contaminated surface like a handle.

“There is really a lack of very basic knowledge,” said Dr. Herfst.

During last year’s flu season Dr. Coleman and her colleagues led people to the flu at the Hotel in Baltimore. Unwell volunteers spent time in a room with robust people, playing games and talking together.

Dr. Coleman and her colleagues gathered flu viruses hovering around the room. But none of the uninfected volunteers got ailing, so scientists could not compare how often flu infect people in the air, unlike brief -range coughing or on viral surfaces.

“It’s difficult to imitate real life,” said Dr. Coleman.

While Dr. Coleman and her colleagues are trying to throw away the spread of flu, the bird flu infects more and more animals in the United States. Even cats are infected, maybe drinking raw milk or eat raw animal food.

Some flu experts are afraid that H5N1 is gaining some of the mutations required to travel in the air. The virus isolated from a dairy employee in Texas had a mutation that can speed up his replication in the respiratory tract. When Dr. Herfst and his colleagues sprayed Ferrets with air droplets carrying Texas virus, 30 percent of animals have developed infections.

“Laboratories in the United States and around the world believe whether these viruses are approaching something that can be very perilous to people,” said Dr. Herfst.

It was impossible to predict when – and even if – influenza bird viruses gain additional mutations necessary for quick spread from person to person, said Seem Lakdawala, a virologist from Emory University. But when the virus goes crazy on farms and so many people get infected, the chances of evolution in the air grow.

“The shocking me that we allow nature to conduct this experiment,” said Dr. Lakdawala.