A dangerous common feature* — Numbers aren’t real!!
From the over 400 cities' data we have collected, we found one particular dangerous feature. When there are only a very small number of confirmed cases reported consecutively over a period of more than two weeks, there will always be severe outbreak soon! This dangerous feature was observed in many Chinese cities, which may be caused by late reporting or unwillingness to report or perform tests. From a scientific viewpoint, this feature is dangerous because the incubation period of the virus is about two weeks, and if a city reported only a small number of cases for more than two weeks, then people were likely not to pay serious attention and the government might not be taking any action for political or administrative reasons. Then, the virus would have spread almost unnoticed and unobstructed, and many became sick but did not realise it was coronavirus until the hospital and medical system started to feel the pressure. Then, tests were performed and the number of confirmed cases surged.
We observe this same feature recently in Aichi, Hokkaido and Kanagawa in Japan and also in India. Thus, we should NOT make decision on travel (or further tightening border control) based only on the number of confirmed cases in some specific cities or regions. Numbers are always late indications! The reason is that "confirmed cases" are those reported only, and hence are subject to the ability and willingness of the city/country to perform tests. For instance, as of March 9, 2020, South Korea tested 214,144 individuals (4,099 per million); Hong Kong tested 16,000 (2,134 per million); Japan tested 9,600 (76 per million); and US only 8,544 (26 per million).
As we know, Wuhan was the first of this dangerous category:
Obviously, from early December 2019 to January 24, 2020, the virus has been spreading freely in Wuhan. The situation was doomed in early January! Numbers began to be reported after January 24, and soared! But these numbers could actually be the cases way way back!
Click here to see more details of COVID-19 testing by countries.
For Japan, as of March 8, 2020, the self-reported cases (from people returning from overseas to Japan 歸國者 and people with close contact with infected individuals 接觸者) are more than 130,000, but the authorites have only tested 3,505 of these people, which is just 2.6%! The number of confirmed cases is thus consistently small!
Imported cases as the dominant source
In Hong Kong (and much of China now), “imported" cases have begun to replace local cases as the dominant source of infected cases, as of March 13, 2020. In the past one week, 9 cases from an Eygptian tour and 5 cases related to an Indian tour are reported. This clearly reflects that the situation in Eygpt and India may not be what would be normally expected from the numbers! However, this could be just the tip of the iceberg.
Hong Kong Government’s announcement (on March 13) regarding restriction of entry to Hong Kong, shown on the left, has purely based on the number of infected cases in a country or region. This could be misleading to some members of the public and surely does not help them with their travel decisions! The public should be advised not to take this list as the only list of countries or regions to be avoided, and that visiting other countries or regions also has significant risk!
*Our findings are based on data provided by official source from the respective countries.