When Deschutes County’s head doctor looks around the community and sees people not wearing face coverings indoors, he’s dismayed.

He knows the research. He knows the data. He knows wearing a mask or face covering during the COVID-19 pandemic will be a necessary accessory until a vaccine is developed. Coupled with the use of hand-washing and maintaining a 6-foot physical distance, the spread of the virus can be contained.

It’s a question of maintaining that social contract where people protect each other because wearing a mask protects others, said Dr. George Conway, Deschutes County Health Services director.

“A mask contains a cough or a sneeze, and in case you have the virus and aren’t aware of it, it contains that, too,” Conway said. “A mask protects the general population and keeps down the rate of infection and is particularly effective for the vulnerable population, the older people.”

In fact, studies show that wearing a tightly woven fabric mask or a paper mask can cut down the transmission of respiratory illnesses, according to the Institute of Health Metrics and Evaluation, a global health research center at the University of Washington.

Earlier this month, the institute looked at the results of 20 studies on masks. It didn’t matter if the mask was medical-grade or a home-made cloth mask, a facial covering reduced the risk of respiratory illnesses like COVID-19 by a third or more.

Using a mask, hand-washing and maintaining a 6-foot physical distance are low-tech ways that can thwart an infection spike until a vaccine can be developed. Until then, every protest, every choir practice, every large or small gathering poses a risk of spreading COVID-19.

“What keeps me up at night is just how precarious we are,” said Mike Johnson, St. Charles Health System data scientist. “We don’t have the numbers (of cases in Deschutes County) because we’ve done well mitigating the transmission. We’ve been very good at containing it.”

On Friday, the Oregon Health Authority looked at disease models to project how many COVID-19 cases could occur. Key among the findings is that aggressive community interventions were effective in lowering the number of COVID-19 transmissions because since reopening on May 15, there have been more positive cases.

On Wednesday, Gov. Kate Brown made mask wearing a requirement indoors in counties where the number of confirmed or suspected cases has been high. Those counties — Multnomah, Washington, Clackamas, Marion, Polk, Hood River and Lincoln — must follow the order requiring a mask indoors for customers as well as workers. There are exceptions for children under age 12 and for people with medical conditions.

At the moment there are no penalties enforcing the guidelines in these counties. The governor recommends that businesses offer free masks to those without.

On Friday, Washington began requiring face coverings for any indoor or outdoor activities statewide when a 6-foot physical distance cannot be maintained, following in California’s footsteps. Violators could face misdemeanor charges, but authorities will first attempt to educate rather than cite, according to the Washington governor’s website.

For Oregon, Washington and California, the goal is to encourage more mask use. A study by the University of Washington showed that 79% of those surveyed said they sometimes or all the time wore a mask, and 21% said they never wore one.

“Typically, there’s a little bit of spray, particularly if you’re shouting or sneezing or coughing,” Conway said. “A strong singer can project mucus particles up to 12 feet away. For normal people, it’s a 6-feet range.”

For Oregon, Washington and California, the mask requirements are for the indefinite future.

“Our office selected the counties included in Oregon’s face coverings requirement for indoor public spaces based on the COVID-19 situations in those counties and the recommendations of health experts,” said Charles Boyle, a deputy communications director for Brown. “We strongly recommend that all Oregonians wear face coverings in public, both indoors and outdoors, especially when 6 feet of distance from other individuals cannot be maintained.

“We’re all in this together.”

When combined with hand-washing and physical distance, these measures work to combat the spread, public health officials say. They become particularly important as up to 40% of those testing positive don’t show any symptoms of COVID-19.

Increasing mask use could also help with the current spate of spikes in the number of positive test results in Oregon.

On Wednesday, the Oregon Health Authority reported that for four weeks in a row, newly reported COVID-19 cases increased over the previous week.

During the week of June 15-21, the health authority recorded 1,263 new cases of COVID-19 infection, a 40% increase from the previous week’s total of 898 new cases.

Increasing mask use could temper, or help prevent, a second wave of the pandemic, University of Washington researchers concluded.

“This virus is so sensitive,” Johnson said. “Without any measures in place, the virus can double every 6.2 days. It will spread throughout the population in a matter of two months if we don’t do anything.

“If we get too relaxed it can grow without bounds until we finally say to ourselves that we have to take measures.”