Asymptomatic patients are carriers of the virus causing Covid-19 that do not display characteristic symptoms. All infected people are initially symptom-free for a period, but this duration varies. However, some infections are so mild, there are no signs at all. Chinese researchers investigated SARS-CoV-2 survival in asymptomatic patients and discovered this lasts longer than they expected.
SARS-CoV-2 Survival in Asymptomatic Patients in China
Xiquan Yan, Xiaotong Han, Yong Fan, Zhixiong Fang, Da Long and Yimin Zhu investigated carriers without symptoms at three hospitals. These health care facilities are all in Hunan Province where the Covid-19 outbreak began. They based their study on respiratory samples taken every one-to-two days from 24 Covid-19 patients.
First, the researchers tested the patients until they registered negative for the virus on two successive days. Their study of SARS-CoV-2 survival in asymptomatic patients revealed the mean time from infection to continuous negativity was 22 days. Moreover, one asymptomatic patient carried the virus for 32 days, but took 13 days before registering positive.
What Could This Mean for Isolation After Positive Contact?
The researchers relied on standard hospital testing protocols because they had limited resources. Hence they were unable to confirm their findings using viral culture. Therefore, they recommend further research, following what they believe is the first comprehensive study according to a Biomed Central report.
This ground-breaking study appears to confirm two underlying facts. In the first instance, asymptomatic contacts may need to self-isolate for longer than fourteen days. And secondly, they may require more intensive testing to definitively rule out the possibility of an infection concealed by a lack of symptoms.
The researchers conclude distancing, testing and effective quarantine measures remain paramount. For without them the prevention of SARS-CoV-2 infection would continue to prove challenging although they did stop it in China.
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