SeattleWith each new day of the growing coronavirus pandemic, a chief concern is how to keep the rate of transmission down.

Humans are both reservoirs where the virus thrives and causes destruction, and also the main spreaders of the disease. Once human carriers contaminate objects—known to medical professionals as fomites—there’s a new challenge of cleaning surfaces and washing hands to stymie the spread of the coronavirus.

Even with such precautions, those who are most vulnerable—people who are older or have underlying health conditions—are advised to take extra care. But research on the coronavirus outbreak and past epidemics indicates it’s even harder to prevent transmission among people in certain jobs and those experiencing homelessness and poverty.

The lessons learned in early epicenters, such