T**********e
发帖数: 29576 | 1 COVID antibody test in German town shows 15 percent infection rate
This morning we have some data giving a little more insight into the great
unknown of the coronavirus pandemic: just how widely among the population
has SARS-CoV-2 — the virus which causes COVID-19 — spread among the
general population. A team at the University of Bonn has tested a randomized
sample of 1,000 residents of the town of Gangelt in the north-west of the
country, one of the epicenters of the outbreak in Germany. The study found
that two percent of the population currently had the virus and that 14
percent were carrying antibodies suggesting that they had already been
infected — whether or not they experienced any symptoms. Eliminating an
overlap between the two groups, the team concluded that 15 percent of the
town have been infected with the virus.
This number matters hugely because it tells us what we need to know in order
to judge how deadly the virus is and also how easily it spreads. It tells
us, ultimately, how useful the methods are that we are employing in order to
combat the virus. As explained here before, the question of how many people
already have the infection is at the heart of a debate between
epidemiologists at the Imperial College and Oxford university.
Two weeks ago, the latter published modeling claiming that up to half the UK
population might already have been infected with the virus — a level of
infection which would mean that lockdown may be the wrong approach, as we
would already have achieved a state of herd immunity, preventing the further
spread of the disease.
The Gangelt study does not provide support for the idea that half of the
population of Britain, or any other country, has been infected with the
virus. But for a town to have an infection rate of 15 percent suggests that
the virus had spread a lot further than many believed. Neil Ferguson, who
leads the Imperial team, told the FT this week that he believes between
three and five percent of the UK population has already been infected.
Data from coronavirus deaths in Gangelt suggests an infection mortality rate
of 0.37 percent, significantly below the 0.9 percent which Imperial College
has estimated, or the 0.66 percent found in a revised study last week.
The 15 percent figure from Gangelt is interesting because it matches two
previous studies. Firstly, there was the accidental experiment of the cruise
ship the Diamond Princess, which inadvertently became a floating laboratory
when a passenger showing symptoms of COVID-19 boarded on January 20 and
remained in the ship, spreading the virus, for five days. The ship was
eventually quarantined on February 3 and all its 3,711 passengers tested for
the virus. It turned out the 634 of them — 17 percent — had been infected
, many of them without symptoms. The mortality rate on the vessel was 1.2
percent — although, inevitably being a cruise ship, it was a relatively
elderly cohort.
We gained another insight into SARS-CoV-2 from a Chinese study into 391
cases of COVID-19 in the southern Chinese city of Shenzhen. In this case,
scientists tested everyone who shared a household with people who were found
to be suffering from the disease. It turned out 15 percent of this group
had gone on to be infected with SARS-CoV-2 themselves. Again, many showed no
symptoms.
Obviously these are all small-scale studies and none of them are deliberate
experiments to see how far SARS-CoV-2 will spread if it is allowed to ‘rip
through’ a population. But they do raise the question: is there a ceiling
on the number of people who are prone to be infected with the disease? Do
many of us have some kind of natural protection against infection? Would it
ever spread among more than about one in six of us?
The British government has based its planning and policy for COVID-19 on the
assumption that if the virus was allowed to spread unchecked it would
eventually infect 80 percent of the population. That is a figure that seems
to have been borrowed from planning for a flu pandemic, but that doesn’t
necessarily mean it applies to this virus. The sooner we have the results of
more studies like that at Gangelt, the better a picture we have and the
sooner we will be able to plot a path out of lockdown.
http://spectator.us/covid-antibody-test-german-town-shows-15-percent-infection-rate/ | L*********4
发帖数: 883 | 2 这个说不清吧。代数还不够。公主号只有几代。Gangelt代数也没有很多。
死亡率是个好消息，可能算上无症状确实有可能是一个0.4%死亡率的病。关键是不知道
到底有多少只是对其它的“感冒冠状病毒”免疫。
randomized
【在 T**********e 的大作中提到】
: COVID antibody test in German town shows 15 percent infection rate
: This morning we have some data giving a little more insight into the great
: unknown of the coronavirus pandemic: just how widely among the population
: has SARS-CoV-2 — the virus which causes COVID-19 — spread among the
: general population. A team at the University of Bonn has tested a randomized
: sample of 1,000 residents of the town of Gangelt in the north-west of the
: country, one of the epicenters of the outbreak in Germany. The study found
: that two percent of the population currently had the virus and that 14
: percent were carrying antibodies suggesting that they had already been
: infected — whether or not they experienced any symptoms. Eliminating an
| T**********e
发帖数: 29576 | 3 现在最主要问题是弄清楚为啥有人无症状有人几天死，那些大数据怎么没出来发挥一下。
: 这个说不清吧。代数还不够。公主号只有几代。Gangelt代数也没有很多。
: 死亡率是个好消息，可能算上无症状确实有可能是一个0.4%死亡率的病。关键是
不知道
: 到底有多少只是对其它的“感冒冠状病毒”免疫。
: randomized
【在 L*********4 的大作中提到】
: 这个说不清吧。代数还不够。公主号只有几代。Gangelt代数也没有很多。
: 死亡率是个好消息，可能算上无症状确实有可能是一个0.4%死亡率的病。关键是不知道
: 到底有多少只是对其它的“感冒冠状病毒”免疫。
:
: randomized
|
|
