You can test negative for coronavirus despite having the virus, a top virologist has warned.
Appearing on The Jeremy Vine Show, Dr Chris Smith addressed a caller's concerns after her daughter-in-law was hospitalised with numerous symptoms but tested negative for COVID-19.
Julie from Kent said that her relative was in hospital last night with suspected coronavirus.
She said: "She had every symptom going and even the new ones now and they did a test on her and it came back negative. And I just wondered how that could be? Have they mixed the tests up or should she go and have another test when she's feeling better?"
He replied: "I'm really glad you answered this question and it highlights a really good point that no test is a perfect test.
"The way we're testing for the virus is taking nose and throat swabs which collect samples at the back of the throat and and we extract from those genetic information.
"If there's a virus there, we can extract genetic information which we then look for. But the virus doesn't grow very well in the nose and throat, it grows best in the lungs and possibly in the intestines.
"So the amount of virus in the throat is actually quite low and it's easy to miss.
"So sometimes although you can have the virus, you can have all of the symptoms, you may sometimes nevertheless test negative. I have actually seen some patients where we have tested them negative and then we've got subsequent samples in their lungs and they've been very very strongly positive.
"So it's not a given and we must be very cautious about interpreting those results. If she's got those symptoms, she could nevertheless have this disorder - a negative test doesn't mean she hasn't.
"She should probably still take precautions."
*The Jeremy Vine Show airs weekdays at 9.15am on Channel 5
