From your same study
So I am not sure if you are for or against masks
Also with regards to asymptomatic patients, I think you guys are getting confused. Asymptomatic patients are patients who show absolutely no symptoms and will not have any symptoms (ever) of COVID although actually being positive for COVID. these patients are very rare since most people who contract COVID will be "presymptomatic" that is may not be showing any symptoms but will get symptoms later on (the symptoms may be mild but they will still get them).
The reason why it is hard to verify if asymptomatic patients can transmit the disease is due to the lack of numbers of actual cases of true asymptomatic patients to actually do the studies on. As an example this study is based on contact tracing and information based solely on one patient (patient A), also I am not sure that this patient was actually true asymptomatic and I think she was presymptomatic because of
shortness of breath is a symptom of COVID - although they may have disregarded it due to her having problems for 16 years however it does not rule out that the worsening of the symptoms were due to COVID.
Thanks for taking the time for the analysis.
As for the the lady in the study. To quote she was positive " Nevertheless, the patient's nasopharyngeal swab tested positive for SARS-CoV-2 by real-time Reverse Transcription-Polymerase Chain Reaction (RT-PCR). She was immediately admitted to quarantine ward in infectious department. " So weather she was "presymptomatic" or "asymptomatic" still is a factor in the spread, or lack thereof. The the question is, what reliable evidence do we have for each class of person? As when do we define someone as "presymptomatic" or "asymptomatic" and how is this contrasted to the symptomatic carriers.
Second point form the study: "Case A and her brother both denied visiting Wuhan (the epidemic area in China) and any contact with COVID-19 patients. They wore masks all the time except at meals and drinking. How she became infected was unknown. "
From what I can see on the internet, everyone in China were already wearing masks. if everyone is wearing masks how come people get infected? Same thing in South Africa, Since we went to Lock down level 4, you could not enter the workplace or go to the shops without wearing a mask, yet our numbers continue to go up consistently.
Furthermore to this point, it is noted in the stydy that N95 masks were in use ' It is noteworthy that all personnel working in ED must take medical protection – namely, using N95 mask, putting on isolation gown and wearing goggle. " However, the use of a N95 mask is not the same as a cloth mask. See study
https://bmjopen.bmj.com/content/5/4/e006577
to quote "
Results The rates of all infection outcomes were highest in the cloth mask arm, with the rate of ILI statistically significantly higher in the cloth mask arm (relative risk (RR)=13.00, 95% CI 1.69 to 100.07) compared with the medical mask arm. Cloth masks also had significantly higher rates of ILI compared with the control arm. An analysis by mask use showed ILI (RR=6.64, 95% CI 1.45 to 28.65) and laboratory-confirmed virus (RR=1.72, 95% CI 1.01 to 2.94) were significantly higher in the cloth masks group compared with the medical masks group. Penetration of cloth masks by particles was almost 97% and medical masks 44%. "
So I get the rational that to prevent the spread you limit spit and coughs with a mask. And people have been buying and making masks like crazy since news broke, yet the infections continue to climb.