SARS-CoV-2-Transmission is longer than accepted

Many of the new Coronavirus SARS-CoV-2 Infected develop no symptoms at all, but you can still have the Virus. In a recent study, it was now clear that the risk of Transmission was underestimated due to asymptomatic Infected so far, apparently significantly. In addition, the incubation time among young people is apparently much longer than the previously assumed maximum of 14 days.

“Younger adults remain at an infection with the new Coronavirus SARS-CoV-2 is often asymptomatic, but they have the same amount of virus in the swabs, such as symptomatic patients”, reports the German Ärzteblatt of the study results, the research team from South Korea. The study also brought surprising new insights about the incubation period or the period of Infectivity. Were published the results of the study in the journal JAMA Internal Medicine.

303 positive tested persons were examined

The South Korean research team from the Soonchunhyang University College of Medicine has taken into account in the cohort study of 303 patients with SARS-CoV-2 infection in a community treatment centre in South Korea under quarantine. The Participants were 110 (36,3%) as of the date of Isolation of asymptomatic and 21 of them developed during the period of quarantine symptoms. On the basis of 1.886 smears from the nasopharynx of the Participants, the researchers investigated the viral load. The proof of the so-called Polymerase chain reaction was carried out.

The Participants were on average 25 years old, 201 were women and 102 men. Only 12 participants suffered from pre-existing conditions – ten high blood pressure, a Person with cancer and Asthma had. 193 participants showed already at the beginning of the period of quarantine symptoms, the Rest was initially asymptomatic, 21 of them developed however in the following symptoms.

15 days until the first symptoms

In these “pre-symptomatic patients 15 days (interquartile range 13-20 days) passed before the first symptoms occurred,” reports the German Ärzteblatt of the study results. This indicates that the incubation time, which indicated, for example, the Robert Koch Institute with an average of five to six days and a maximum of 14 days, may, at least in the case of young people, significantly longer than previously thought.

Viral load comparable to the high

From the published results, Further, show that, in the case of asymptomatic individuals the same viral load in the swabs was obtained as in the case of symptomatic Participants. In addition, in the sputum examinations have decreased the concentration of Virus in the asymptomatic Participants, even more slowly, reports the German Ärzteblatt. Based on the viral load and the Infectivity of the two groups could be similar.

However, cough belong to the most common symptoms of the disease, and this increased the risk of Transmission, so the doctors sheet more. By coughing the symptomatic individuals could make more virus, and therefore, more people to infect.

Virus long remain undetectable

The South Korean researchers were able to demonstrate, moreover, that the infection persists for a relatively long time. In the case of the Participating 29.6% of pre-symptomatic or symptomatic individuals and 33.7% of asymptomatic persons with no virus detection in the smear be after 14 days, only been and after 21 days, the proportion was still only 69,9% and 75,2%, according to the research team. Overall, the new evidence that has been underestimated, the transmission duration and the risk of Transmission by asymptomatic Infected so far, speak clearly. (fp)

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