1. ECDC COVID-19 European Center for Disease Prevention and Control 2020. Available online: https://www.ecdc.europa.eu/en/covid-19-pandemic (last accessed on April 2, 2020)
2. WHO Coronavirus disease 2019 (COVID-19) Situation Report—73 World Health Organisation 2020. Available online: https://www.who.int/docs/default-source/coronaviruse/situation-reports/20200402-sitrep-73-covid-19.pdf?sfvrsn=5ae25bc7_2
3. Johns Hopkins University Coronavirus Resouce Center. Johns Hopkins Center for Systems Science and Engineering 2020. Available online: https://coronavirus.jhu.edu/#covid-19-basics (last accessed on April 2, 2020)
4. RKI Coronavirus SARS-CoV-2—dedicated homepage of the Robert Koch-Institute, Berlin, Germany 2020. Available online: https://www.rki.de/DE/Content/InfAZ/N/Neuartiges_Coronavirus/nCoV_node.html (last accessed on April 2, 2020)
5. WHO Team Modes of transmission of virus causing COVID-19:implications for IPC precaution recommendations World Health Organisation—Department of Communication 2020. Available online: WHO Reference Number: WHO/2019-nCoV/Sci_Brief/Transmission_modes/2020.2 (last accessed on April 2, 2020)