2 METHODOLOGY FOR RETRIEVAL OF THE EVIDENCE
To provide hints and hypothesis about the possibilities of ticks to transmit SARS-CoV-2, the evidence within a systematic review was captured. The considered evidence was the 1st January 1970 to the 1st June 2020. Medline; Scopus; EMBASE; Google Scholar, Scifinder and the WHO Institutional Repository databases were analysed. Information sharing was achieved by using variations of the following search strategy:
Transmission: “coronavirus/ Runde coronavirus-like transmitted by ticks” or “SARS-CoV transmitted by ticks” or “SARS-CoV-2 transmitted by ticks” or “Covid-19 transmitted by ticks”.
Structure: “coronavirus/ Runde coronavirus-like structure ticks” or “SARS-CoV structure ticks” or “SARS-CoV-2 structure ticks” or “Covid-19 structure ticks”.
Host range: “coronavirus/ Runde coronavirus-like host range ticks” or “SARS-CoV host range ticks” or “SARS-CoV-2 host range ticks” or “Covid-19 host range ticks”.
Distribution: “coronavirus/ Runde coronavirus-like distribution ticks” or “SARS-CoV distribution ticks” or “SARS-CoV-2 distribution ticks” or “Covid-19 distribution ticks”.
Cross-referencing was done to find extra studies meeting the inclusion criteria. The published articles were evaluated by reading the full text. The Integrated quality criteria for review of multiple study designs (ICROMS) scoring system was used to assess the standard of articles (Zingg et al., 2016). The standard of appropriate studies was ranked as ‘low’, ‘moderate’ or ‘high’. The hypothesis was then formulated based on the appropriate evidence of each study.