The United States is closing in on the somber milestone of 200,000 deaths from Covid-19 as more than half of states are reporting a rise in cases.
The climb comes after many states had seen case numbers decline following a summer resurgence of infections.
Among the states reporting more new cases in the last seven days are Wisconsin, Idaho, South Dakota, Iowa and Kansas, all of which are also reporting test positivity rates above 15%.
The test positivity rate is the percentage of all tests given that come back positive for coronavirus.
The World Health Organization (WHO) advised governments in May that positivity rates should hold steady at 5% or lower for at least two weeks before businesses reopen. A total of 27 states and Puerto Rico have rates above that level, according to JHU.
But some states are still seeing improvements. Maine, Vermont, Massachusetts and New York all have positivity rates below 1%, and Delaware, Hawaii, Louisiana, Michigan, South Carolina and Vermont are all reporting fewer cases than last week.
Updated guidance from the US Centers for Disease Control and Prevention says the coronavirus can be commonly spread through viral particles in the air.
The guidance previously said Covid-19 was mainly thought to spread between people within 6 feet of one another and through respiratory droplets “produced when an infected person coughs, sneezes or talks.”
The guidance, updated on Friday, still says Covid-19 is commonly spread between people in close contact with one another. But it also says the virus is known to spread through respiratory droplets “produced when an infected person coughs, sneezes, sings, talks or breathes.”
Infection can occur if the particles are inhaled “into the nose, mouth, airways, and lungs,” the guidance says.
“There is growing evidence that droplets and airborne particles can remain suspended in the air and be breathed in by others, and travel distances beyond 6 feet (for example, during choir practice, in restaurants, or in fitness classes),” the page now says. “In general, indoor environments without good ventilation increase this risk.”
Donald Milton, a professor of environmental health at the University of Maryland who studies how viruses are transmitted, told CNN the CDC’s new language was a “major improvement.”