Viral Shedding Peaks – BEFORE Symptoms!

By Shlomo Maital

The late Li Wenliang, China’s hero doctor who warned us

   A very large number of research papers are now emerging from China, by Chinese scientists and scholars, related to biology, medicine, education, and other areas. China is sharing with the world what it has learned.

   Yesterday’s Nature Medicine features a very important article by a large group of Chinese researchers, which shows this:

     “We report temporal patterns of viral shedding in 94 patients with laboratory-confirmed COVID-19 and modeled COVID-19 infectiousness profiles from a separate sample of 77 infector–infectee transmission pairs.

     We observed the highest viral load in throat swabs at the time of symptom onset, and inferred that infectiousness peaked on or before symptom onset. We estimated that 44% (95% confidence interval, 25–69%) of secondary cases were infected during the index cases’ pre-symptomatic stage, in settings with substantial household clustering, active case finding and quarantine outside the home. Disease control measures should be adjusted to account for probable substantial presymptomatic transmission.”

   Meaning?   Three rather scary words: substantial pre-symptomatic transmission. We spread the coronavirus even before we feel symptoms.

     This is why social distancing will need to be enforced for quite some time, until tests are widely available and can provide results within hours. If you have no symptoms, then anybody can be a carrier and spreader. Anybody.

     Finally, we are learning about this insidious enemy – is anyone expressing some gratitude to the Chinese for sharing?

         Well, a small gesture – here are the names of the researchers who co-authored this paper: Xi He, Eric H. Y. Lau, Peng Wu, Xilong Deng, Jian Wang, Xinxin Hao, Yiu Chung Lau, Jessica Y. Wong, Yujuan Guan, Xinghua Tan, Xiaoneng Mo, Yanqing Chen, Baolin Liao, Weilie Chen, Fengyu Hu, Qing Zhang, Mingqiu Zhong, Yanrong Wu, Lingzhai Zhao, Fuchun Zhang, Benjamin J. Cowling, Fang Li & Gabriel M. Leung