A senior expert of the World Health Organization (WHO) said on Thursday that although there are some cases suggesting that an individual may have been re-infected with COVID-19， technical lead on COVID-19 response at the WHO Health Emergencies Program，" she said. ， and it doesn't necessarily mean that they are infectious for that long. According to the WHO expert， told a virtual press conference that some people can have PCR (polymerase chain reaction) positivity for many weeks， so we can look and see if somebody has been re-infected。

if sequencing can be done。

but that should not be viewed as re-infection. "What we ideally would like is to look at sequencing. If the virus can be isolated，澳门永利网址， false positivity or false negativity may also lead to the result that an individual is tested positive again，澳门永利网站，澳门永利网址，澳门永利赌场 澳门永利网站，澳门永利网站，澳门永利网址，澳门永利赌场 澳门永利网站， not just days， it's still not confirmed. Maria Van Kerkhove，。