Photo by Adobe Stock
A University of Maryland researcher who helped influence guidelines on masking and other measures nationwide to limit the spread of COVID-19 joined fellow experts on Thursday in publishing a new report designed to standardize how the medical and scientific fields communicate about transmission of respiratory viruses.
Released by the World Health Organization, the report aims to combat the misinformation that spread rapidly during the pandemic and sometimes cost people their health—or lives.
“The report corrects a number of misconceptions and misunderstandings that were major problems earlier in the COVID-19 pandemic,” said Dr. Donald Milton, a School of Public Health environmental health professor and leading authority on respiratory virus transmission. “It is important to have clear terminology and a shared understanding as a basis for developing effective policy to prevent infection and control pandemics.
Milton was instrumental in convincing health authorities to take precautions against viruses that remain suspended in the air for minutes or longer, even though conventional wisdom at the beginning of the pandemic was oriented toward avoiding germs on surfaces and in virus-containing particles directly sprayed by sneezes or coughs.
The new report proposes “airborne transmission/inhalation” as the standardized term for infectious respiratory particles emitted into the air and breathed in. This term applies regardless of whether particles capable of infecting others travel a few feet or many yards from the infected person.
When infectious respiratory particles follow a direct spray trajectory over a short distance through the air to the mouth, nose or eyes of another individual, the report proposes using the term “direct deposition.” Because “aerosol” and “droplet” were widely misunderstood by some practitioners and officials, these terms were avoided in the new report.
“The report states clearly that the risk of airborne/inhalation transmission is greatest close to an infected person,” Milton said.
He noted that a great deal of work is still needed to reach scientific consensus on the relative importance of each mode of transmission for specific infectious agents.
“They require very different controls to protect health care workers and other high-risk people,” Milton said. “How this report is translated into infection prevention and control policy will be critical—that work lies ahead. Acknowledging that airborne/inhalation and direct deposition transmission are very different, as described in the body of the report, could be a first step toward new and more effective policies.”
-- By Sumaya Abdel Motagaly '26