WASHINGTON (NYTIMES) – Officials at the US Centres for Disease Control and Prevention on Friday (June 10) pushed back against the idea that the monkeypox virus can spread through the air, saying the virus is usually transmitted through direct physical contact with sores or contaminated materials from a patient.
The virus may also be transmitted by respiratory droplets expelled by an infected patient who comes into physical contact with another person, they said. But it cannot linger in the air over long distances.
Experts on airborne transmission of viruses did not disagree, but some said the agency had not fully considered the possibility that respiratory droplets, large or small, could be inhaled at a shorter distance from a patient.
The World Health Organisation (WHO) and several experts have said that although “short-range” airborne transmission of monkeypox appears to be uncommon, it is possible and warrants precautions. Britain also includes monkeypox on its list of “high-consequence infectious diseases” that can spread through the air.
“Airborne transmission may not be the dominant route of transmission, nor very efficient, but it could still occur,” said Linsey Marr, an expert on airborne viruses at Virginia Tech.
“I think the WHO has it right, and the CDC’s message is misleading,” she added.
In the United States, the monkeypox outbreak has swelled to 45 cases in 15 states and the District of Columbia, CDC officials said at a news conference.
The global tally has risen swiftly since May 13, when the first case was reported, to more than 1,450. At least 1,500 cases are still under investigation.
Historically, people with monkeypox have reported flu-like symptoms before a characteristic rash appears. But some patients in the current outbreak have developed the rash first, and some have not had these symptoms at all, Dr Rochelle Walensky, the CDC’s director, said on Friday.
No deaths have yet been recorded in the current outbreak, she said.
Questions about airborne transmission of the monkeypox virus are important because the answers, in turn, will bear on recommendations for masking, ventilation and other protective measures should the outbreak continue to grow.
The CDC said on Thursday that monkeypox “is not known to linger in the air and is not transmitted during short periods of shared airspace.”
The statement followed a New York Times article on Tuesday in which scientists described uncertainties about transmission of the virus.
“What we do know is that those diagnosed with monkeypox in this current outbreak described close, sustained physical contact with other people who were infected with the virus,” Dr Walensky said on Friday. “This is consistent with what we’ve seen in prior outbreaks and what we know from decades of studying this virus and closely related viruses.”