Fresh, preliminary research suggests that people who have an infection with SARS-CoV-2 are more likely to pass on the virus during the first week after contracting it.
Since January, when the World Health Organization (WHO) announced a global public health emergency for the latest coronavirus epidemic, international experts have been continuing to work the virus.
The main aim is to learn enough about SARS-CoV-2 to allow specialists to establish the most effective strategies for prevention and containment.
While much remains unknown, research on the new coronavirus has progressed rapidly.
One of the most recent studies— undertaken by researchers from Munich’s Bundeswehr Institute of Microbiology, the Klinikum München-Schwabing, the Charité Universitätsmedizin Berlin, and LMU Munich University Hospital, all in Germany— claims to have found out when the virus is at its most contagious.
The new study has not yet been published in a peer-reviewed journal, which means that it has not yet been tested by outside experts for quality and accuracy.
However, its authors have made a preprint of the research paper available online. First author of the paper is Roman Wölfel, Ph.D., of the Bundeswehr Microbiology Institute.
Findings may have impact on care strategy
The researchers analyzed various samples we collected from nine individuals who had contracted SARS-CoV-2 to find out how likely the virus was to spread at different stages of an infection, and through what mediums.
These were all people seeking diagnosis and treatment who had visited a hospital in Munich, and they all had mild symptoms. All of these people were young and middle-aged adults who had no serious underlying problems of health.
The researchers studied samples of saliva and mucus, as well as samples of blood, urine, and stool collected at various stages of the infection. They checked each of them to see if the virus was present, and if it could get further infection.
Samples from the throats of the patients showed that the virus was the most contagious during the first week after it was contracted by the human. That was the case for samples of 16.66 percent of throat swabs and 83.33 percent of sputum (saliva and mucus).
The researchers were unable to distinguish the virus from a person’s exposure to the virus in samples this they obtained after the 8th day.
While there were no signs of virus in the blood and urine samples, stool samples yielded viral RNA.
The researchers, however, were unable to establish a viral culture from the RNA virus found in stool, which means that this may be an unlikely source of infection.
“The prolonged viral sputum shedding is important not only for the control of hospital infections but also for the management of discharge,” the researchers write.
Based on their results, they say that medical professionals may be able to avoid shortages in hospital beds by immediately discharging patients from the hospital and advise on self-isolation.
They note that:
“In a situation characterized by limited capacity of hospital beds in infectious diseases wards, there is pressure for early discharge following treatment. Based on the present findings, early discharge with ensuing home isolation could be chosen for patients who are beyond day 10 of symptoms […]”