Category Archives: Community

“Coronaviren sind Cluster-Champions”

Die Zeit: Christian Drosten hält zweite Infektionswelle für vermeidbar. “Mit dem aktuellen Wissen über das Virus könnte Deutschland einem zweiten Shutdown entgehen. Vorbild dafür ist laut dem Virologen Christian Drosten Japans Strategie.”

“Der Virologe Christian Drosten sieht eine Chance, dass Deutschland auch ohne Impfstoff glimpflich durch die Corona-Pandemie dieses Jahr kommt. “Vielleicht entgehen wir einem zweiten Shutdown”, sagte er dem Spiegel. Es gebe jetzt eine theoretische Möglichkeit, dass die Deutschen ohne zweite Welle durchkommen. Dafür sei es nötig, bei den jetzigen Maßnahmen nachzujustieren, sagte Drosten dazu im NDR-Podcast.

Ähnlich äußerte sich der Bonner Virologe Hendrik Streeck. Er glaube nicht, dass Deutschland eine gewaltige zweite Corona-Welle erleben werde, sagte Streeck den Zeitungen des Redaktionsnetzwerks Deutschland. Er vermute aber, dass es immer wieder lokale Ausbrüche geben werde. “Das wird vielleicht im Herbst auch vermehrt und überraschend geschehen – aber ich glaube nicht, dass wir eine zweite Welle sehen werden, die uns regelrecht überschwemmt und überfordert”. Er rate dazu, sich bei den Schutzmaßnahmen vor allem auf Großveranstaltungen zu fokussieren. “Die zu unterbinden, scheint am ehesten was gebracht zu haben.””

Die Zeit: Jeder könnte Superspreader sein. “Konzert, Fußballspiel, Zumbakurs: Es sind solche Events, auf denen Einzelne viele anstecken. Die meisten Covid-Patienten infizieren niemanden. Und das ist entscheidend. Eine Analyse von Kai Kupferschmidt”.

“In gewisser Weise ist die Rolle von Superspreading Events eine gute Nachricht, sagt Jamie Lloyd-Smith [Biophysiker an der University of California, Los Angeles]. “Wenn man vorhersagen kann, unter welchen Umständen es zu solchen Ereignissen kommt, dann lässt sich mathematisch zeigen, dass man die Ausbreitung der Krankheit wirklich sehr schnell aufhalten kann”, sagt er. Das ist allerdings leichter gesagt als getan, denn die Wissenschaft versteht Superspreading Events bislang kaum. Das liegt auch daran, dass dabei mindestens drei verschiedene Ebenen zusammenspielen: das Virus, der Infizierte und sein Umfeld.”

“A Robust Public Health Care System”

The New York Times: A German Exception? Why the Country’s Coronavirus Death Rate Is Low. “The pandemic has hit Germany hard, with more than 92,000 people infected. But the percentage of fatal cases has been remarkably low compared to those in many neighboring countries.”

“All across Germany, hospitals have expanded their intensive care capacities. And they started from a high level. In January, Germany had some 28,000 intensive care beds equipped with ventilators, or 34 per 100,000 people. By comparison, that rate is 12 in Italy and 7 in the Netherlands.

By now, there are 40,000 intensive care beds available in Germany.

Some experts are cautiously optimistic that social distancing measures might be flattening the curve enough for Germany’s health care system to weather the pandemic without producing a scarcity of lifesaving equipment like ventilators.

“It is important that we have guidelines for doctors on how to practice triage between patients if they have to,” Professor Streeck said. “But I hope we will never need to use them.”

The time it takes for the number of infections to double has slowed to about eight days. If it slows a little more, to between 12 and 14 days, Professor Herold said, the models suggest that triage could be avoided.

“The curve is beginning to flatten,” she said.”

Different ways to model a pandemic

Numberphile: The Coronavirus Curve. (YouTube, 22:17min) “Ben Sparks explains (and codes) the so-called SIR Model being used to predict the spread of coronavirus (COVID-19).”

I played along at home and created my own version with Geogebra, but you can also find Ben Sparks’s version here: SIR Model.

Be sure to also check out the links in the description of the video.

3Blue1Brown: Simulating an epidemic. (YouTube, 23:11min)

“While here we looked at what you might call an “agent-based” SIR model, if you want to see what it looks like as a set of differential equations, Ben Sparks just did a lovely video on the topic over at Numberphile [see above].

There are a few reasons I like the agent-based model here, for demo purposes at least. It’s a bit easier to understand for those who are not comfortable yet with ODEs, for one. It also conveys how things are not deterministic; no real-world curve will look as smooth as the differential equations. It also makes it way easier to ask questions and bake other assumptions into the model. Introducing things like travel or community centers into the differential equations would get very hairy very quickly. For those who want to go much more deeply into this, the Institute for Disease Modeling has a lot of models free for people to look at and play with.”

“Look to your backyard and recreate there”

The Washington Post: Thousands are crowding into free national parks. And workers are terrified of coronavirus.. “A park ranger at Grand Canyon National Park had 600 close contacts with visitors in a single day, greatly increasing his exposure to infection, according to a staff member at the attraction.”

“Two days before he cursed a supervisor and quit the National Park Service job he loved, Dustin Stone arrived to work in a foul mood. A decision by Interior Secretary David Bernhardt to keep national park sites open despite the coronavirus outbreak left him angry and in disbelief.
The virus hasn’t reached Skagway, a tiny town on the Alaskan panhandle where Stone lives and worked at the Klondike Gold Rush National Historical Park. But if it does, he said, it could be a disaster. “I’ve lived here year-round through eight flu seasons, and I’ve seen how quickly an infection can spread,” he said. “When one of us gets sick, most of us get sick.” There’s no full-time doctor and no hospital in Skagway. A single community health clinic has a registered nurse and assistants.
[…]
“This is a political game being played with people’s lives by leadership at the highest levels of the Department of Interior, and, I believe, the White House,” Stone said. “President Trump is the one who announced the fee waiver. I don’t think he knows what a national park is. I would be so surprised if Donald Trump ever set foot in a national park.””