# Utrecht mathematician is going to calculate Dutch exit strategy

What happens when young people are once again allowed to come into contact? Or when we decide to re-open primary schools? Will the number of infections increase to the point that we exceed the capacity of our intensive care facilities? Mathematician Martin Bootsma has modelled the various options available to find the optimal scenario for The Netherlands: maximum freedom of movement without exacerbating the peaks in intensive care departments. His project recently received funding from the Netherlands eScience Center.

## Hands full

At the moment, Martin Bootsma is working full-time on the coronavirus crisis. Well, full-time might be an understatement: he works from 20:00 to 24:00 at night, because like so many others he has his hands full with his children during the day. Together with his colleagues at the UMCU, he studies the degree to which the Dutch government can relax the limitations on contact between people. Bootsma earned his PhD on modelling infectious diseases. His work usually focuses on studying the spread of antibiotics resistance in hospitals.

Many mathematical models that predict the spread of the virus, do not take into account the differences between countries and regions.

## ‘Curse of locality’

Bootsma is working on the development of a model specific to the Netherlands. This is important because the way in which the virus spreads is related to local circumstances, such as social norms and customs and the way in which the population moves during the day. There are many mathematical models that predict the spread of the virus, but those suffer from the curse of locality: they do not take into account these kinds of differences between countries and regions.

## Interesting problem

The Covid-19 outbreak is an interesting problem from a scientific perspective, and it is an excellent example of the social relevance of his field, says Bootsma. Bootsma creates models that combine many parameters in a variety of ways, such as age categories, gender, degree of contact and average length of stay in intensive care.

Relevant formulas used by Martin Bootsma in his models

## Multidisciplinary challenge

These models are very large and present a complicated problem. The calculations that the model produces are too specialist even for Bootsma, so he has called on the assistance of colleagues who have special knowledge of optimal scenarios. This is a good indication of the complexity of the problem that we currently face in the coronavirus crisis; even the mathematics involved is a multidisciplinary challenge.

## International cooperation

Mathematicians all over the world are working on the spread of the coronavirus. Some look at the spread in general, while others, like Bootsma, look at the spread within a country or region. They share their results as quickly as they are produced, even before the peer reviews, because otherwise the process would take too long. For example, via the platform medrxiv.org. There are already about 1800 corona-related preprints available.