Large-scale testing of the population is a key tool to limit the spread of the disease. Governments must set up massive test programmes and, to contain new virus clusters, they must test often and test quickly.
Standard PCR test kits work by taking a swab with a sample of saliva from a person, and looking for viral RNA on the swab. For the virus's RNA to be identifiable, it must first be transformed into DNA (i.e., it must go from single to double helix) and then replicated, so that it reaches detectable quantities. Laboratories need reagents to carry out the steps of this procedure.
During the COVID-19 pandemic, reagents availability has been a major bottleneck to increase test capacity. We show that we can optimise two decisions which lead to a noticeable increase in capacity:
- How to allocate reagents to the laboratories, and
- whether to send swabs collected in one region to labs in other regions.
We use the Italian healthcare system as a case study. The healthcare system in Italy is organised on a regional basis and cross-regional collaboration isn't as developed as it could. We argue that this results in missed optimisation opportunities, and we provide some data to support this hypothesis.
In this case study, we first report data provided by Italy's Civil Defence Department for the first thirteen days of April.
The following map shows how many swabs each region tested, over the whole period.
The chart below shows the total number of swabs tested in Italy, day by day.
The following dashboard shows the increase in test capacity when applying optimisation techniques. We consider four scenarios:
- A central authority organises the distribution of reagents to the laboratories; swabs collected in one region are still assigned to labs in the same region.
- As in scenario 1, but swabs can also be assigned to out-of-region labs, as long as they are within 100Km from an in-region laboratory.
- As in scenario 2, but allowing a radius of 200Km, which still allows swabs to be transported within a few hours.
- As in scenario 2, but allowing a radius of 400Km, which allows for overnight transport of swabs. Sardinia is an exception, as overnight transport wouldn't be feasible.
Use the slider below to choose the model:
The following map shows how Italian laboratories can test each other's swabs under the assumptions of the current model. If there is a line between two labs, they can transfer swabs among themselves, effectively sharing their capacities.
In dark red, the swabs tested, day by day, in Italy during the period 01-13 April, 2020. In light red, how many swabs could have been tested, if optimising the assignment of reagents and swabs, using the optimisation model.