Chat about Novel Coronavirus - 2019-nCoV - COVID-19

Table 6 in the appendix has the breakdown by region, the central region (Madrid, Castilla-La Mancha and Castilla y León) were the hotspot provinces:

https://www.thelancet.com/cms/10.1016/S0140-6736(20)31483-5/attachment/25c80941-a8c5-470e-a6a8-fde7397b9547/mmc1.pdf

From the paper discussion section:

The findings from this nationwide seroprevalence study for SARS-CoV-2 indicate that the prevalence of IgG antibodies against this coronavirus is around 5% in Spain. Because the study was designed to obtain representative data at both national and provincial level, we were able to observe marked regional differences between the centre of Spain and the outskirts that generally match the surveillance data.2 The prevalence in hotspot areas such as Madrid is more than five times higher than that observed in low-risk regions such as most provinces along the coasts.