Many who’ve had a nasal Covid-19 test performed on themselves have described it as feeling like that swab got as far back as their brains. If done correctly, the swab is angled parallel to the floor, all the way to the back of the nose, and the swab is rubbed on an area called the nasopharynx. The actual term is a nasopharyngeal swab, not nasal swab, because it’s the nasopharynx that contains the highest possible viral load to best determine an active Covid-19 infection. The distance from the average nasal tip to the nasopharynx is close to 6 inches. So if it feels like there’s a half a foot being stuck up your nose, well, you’re not so far off.
The Centers for Disease Control and Prevention (CDC) quietly changed its guidance on Monday to now say that asymptomatic people do not need to be tested for coronavirus, even if they have been in close contact with an infected person.
The agency made the move by updating its website but did not make any public announcement or explain the reasoning behind the major revision.
The guidance now states: “If you have been in close contact (within 6 feet) of a person with a COVID-19 infection for at least 15 minutes but do not have symptoms: You do not necessarily need a test unless you are a vulnerable individual or your health care provider or State or local public health officials recommend you take one.”
There are two generally available types of Covid-19 tests. The first, and most commonly used so far, is a PCR test, which is short for polymerase chain reaction.
It’s a molecular test, meaning it searches for the virus’s genetic material in a nasal swab or saliva sample, and it is often processed in a highly complex laboratory. There are two ways to collect a nasal sample: from the inside of a nostril, or from the back of the nose and throat. The second way, called a nasopharyngeal swab, requires a professional to probe more deeply into the nasal cavity to get the sample. Some testing sites may ask you to swab your nose or cheek yourself, or spit into a tube. Each of these collection methods creates a sample that can be analyzed with a PCR test.
Antigen tests, which search the sample for viral proteins instead of the virus’s genetic code, are becoming more widespread in the U.S. Right now, antigen tests are typically offered at doctor’s offices, nursing homes, schools and other congregate settings where groups of people need testing fast.
The Centers for Disease Control and Prevention has ordered that all travelers flying to the U.S. from abroad will have to show proof of negative Covid-19 tests before boarding their flight starting Jan. 26. The CDC said preflight testing is necessary as Covid-19 cases continue to soar and new, more contagious strains of the virus emerge around the world.