SHAH ALAM - Some patients with Covid Omicron variant may still shed virus on day nine and ten, said an expert.
Dr Wes Ely from Critical Illness, Brain dysfunction and Survivorship (CIBS) Research Center at Vanderblit University said Omicron variant has rapid onset symptoms and high transmissibility which is contagious.
"This is incredibly contagious and that's why so many of you testing at home are experiencing Covid-19 positive right now," he said in a video through his TikTok account.
Ely added Center for Disease Control and Prevention (CDC) had six months ago changed the mandatory isolation policy from 10 to five days after the first test of Covid-19 and an additional five days of masking.
"But what if 25 percent of individuals are still shedding Omicron virus at day nine and 10," Ely said.
"That's what we learned in the New England journal where half of the patients were still shedding at day five and 25 percent of patients were still shedding at day nine," he said.
"This is really significant because when we go out of isolation, when we cough or breath, we are eventually shedding the virus to people around us who could catch Covid-19.
"So you have to decide where are you in term of your choices, in terms of how long you stay isolated after you test for Omicron," he added.
Commenting further, Ely also said that vaccination helps to prevent the virus from getting into worst scenario.
"The vaccination works, it helps you to not get hospitalised. The vaccination doesn't stop you from getting infected but it stops you from getting sick enough to get admitted," he said.
Wes also urged public to carry out rapid antigen test and warned public as the virus might start replicating in the body and it do now show any symptoms.
"Make some choices about what you choose in terms of isolating versus masking.
"If you take Paxlovid or some other antiviral and stop the medication on day five, as prescribed, be aware that many people are getting Paxlovid rebound where you start shedding virus again.
"The virus start replicating in your body and you may not even be symptomatic with that, you won't know until you do a rapid antigen test on yourself," he added.
Meanwhile a data from Japan shows patients with the Omicron variant of Covid-19 shed virus for longer after symptoms emerge, potentially jeopardising hopes that the period of isolation for people testing positive could be shortened.
Preliminary data from the National Institute of Infectious Diseases which conducts disease surveillance in Japan suggest that the amount of viral RNA is highest three to six days after diagnosis or symptom onset.
The isolation period for people testing positive for Covid-19 was recently cut from 10 days to seven in England if two lateral flow tests returned negative results on days six and seven.
Similar cuts to isolation have followed in Scotland, Wales, and Northern Ireland.
Professor in medicine at University of East Anglia Paul Hunter said that the latest Japanese data 'muddy the waters.'
"I’m still working my way through the evidence for and against given that the Japanese study has now shifted the balance,” he said.
Previous studies suggest that the peak transmission period for people with other variants was between two days before symptoms emerged and three days afterward, with virus shedding peaking on or before symptom onset.
The Japanese study suggests that with omicron, the peak of virus shedding may be two or three days later, Hunter said.