German Chancellor Angela Merkel explained at a press conference last week how important the reproduction rate of the coronavirus is in controlling the epidemic, and how small increases could cause the health system to collapse in a short time. What Chancellor Merkel did in her press conference was an exemplary use of basic mathematics to convey to the public how little room for manoeuvre the epidemic leaves, and the need to act with extreme caution. One tends to think that this kind of mathematical explanation should be within the reach of any politician with a high school diploma, although one need only look at the appearances of other national and international leaders to realise that this is perhaps too much to assume. Chancellor Merkel’s fluency with her mathematical explanations must have had something to do with her degree in physics and her doctorate in quantum chemistry.
Merkel explained that the flattening of the epidemic curve in Germany is due to the fact that the reproduction rate, the average number of infections caused by each infected person in the course of the infection, now stands at 1. But she warned that if it were raised to 1.1, intensive care units would be overcrowded in Germany in October; if it were raised to 1.2 (just 20% higher than the current situation, Merkel warned), overcrowding would come in July, and in June if it were raised to 1.3. “So you can see how little margin we have,” and, quoting the mayor of Hamburg, Merkel said:
Because we walk on thin ice,
And she added: “We have to be cautious and not be overconfident.
You can see the full explanation here:
Los alemanes llevan haciendo tests masivamente desde que tuvieron el primer caso, para detectar temprano a los posibles infectados. Así han podido controlar la epidemia hasta ahora y pueden saber con bastante seguridad el ratio de infección, que además es una ratio baja porque hacen muchos tests, incluso a asintomáticos.
En España es imposible saber esa ratio porque se han hecho pocos tests, sólo a personas que ya tenían síntomas (y no a todas) y a sus familias (no siempre). Pero no se han hecho tests exhaustivamente a otros cercanos a los contagiados, y mucho menos aleatoriamente a la población en general.
Así que si los alemanes andan sobre hielo fino, aquí andamos sobre papel de fumar y cualquier medida que tomen los políticos para “desescalar” será más una decisión a ciegas que basada en datos fiables.