The future figure of “Venus de Milo”, is SARS-CoV-2 becoming a seasonal coronavirus in Japan?
(considerations of a working physician)
First, two figures were prepared for consideration.
The first is the number of individuals undergoing polymerase chain reaction (PCR) examination. “Fig. 1” shows a range that is fluctuating. It has increased approximately by 10 times compared with that at the rin Februaly to May 2020.
The second is the change in the trend of seasonal coronavirus in Japan. “Fig. 2” demonstrates monthly changes in the number of seasonal coronavirus cases. The peak occurs in January–February every year.
Fig. 3 shows the numbers of new positive cases (green) and deaths (red) caused by the new coronavirus (SARS-CoV-2) from March to November 2020. I think this graph is incomplete, similar to the arm of “Venus de Milo.”
Let us supplement the right hand of Venus. The mortality rate in Japan is 0.01–0.016. Thus, I estimated the missing affected number who may be present from the number of deaths. In fact, a large-scale PCR positive peaople was observed in February 2020 in Hokkaido, Japan, located in the north. I indicated the estimation in “Fig. 4.”
Less discussion was conducted about previous but major pandemics. My opinion is that we are fortunate to have undergone a pandemic without large-scale consequences.
Next, we should try to predict the future. “Fig. 5”, which is estimated from the current number of cases, is depicted by the left hand of Venus. If SARS-CoV-2 behaves like a seasonal coronavirus, many cases will appear in January–February 2021 over several periods, as shown in Fig. 2. The current number of cases is 1,500 people per day. Therefore, 3,000–5,000/day PCR positive individuals will apper.
This number will be smaller than the big first wave noted in the beginning of 2020. I have repeatedly reported such a possibility because of the cross-immunity of the seasonal coronavirus, despite the smaller damage inflicted on the Asia/Oceania region compared with the west. Additionally, herd immunity may contribute to this number. “Fig. 7” illustrates that Venus will become smaller and disappear.
“Fig. 6” indicates that the damage from SARS-CoV-2 was extremely less in comparison to that from the seasonal flu. Approximately 300,000 people are affected daily at its peak, and the death toll can exceed thousands per year.
Moreover, the Japanese media reported the “largest recorded number of positive cases ever” today and touted that “the terrible third wave had arrived.” In my opinion, this statement is wrong for two reasons. First, it does not consider the increase of approximately 10 times the number of individuals undergoing PCR examination. The second is the lack of perspective regarding the evolving behavior of SARS-COV-2 as a seasonal coronavirus.
Fig7 depicts the future image of “Venus.”My belief is that SARS-CoV-2 is becoming the fifth variation to the traditional four types of seasonal coronavirus.
4．Google COVID-19 感染予測（日本版）、
10．「雪まつり後に発症者急増 北海道、新型コロナ拡大」、日本経済新聞 2020/2/29
11．「GoToでコロナ感染131人 『拡大報告ない』と加藤氏 」東京新聞11月10日
19．「タイの民主化デモ、王宮へ数十メートルまで迫る 警察がバリケードと放水、緊迫高まる」Newsweek 11月9日
21．「PCRで検出できないSARS-CoV-2変異の可能性流行当初のPCR検査用のプライマーでは一部の変異株を見落とす」Lancet Infectious Disease誌から 日経メディカル