Table 1.

Strategy used for the search conducted in MEDLINE (via PubMed).

Search number	Facet	Search terms	Search results (July 24, 2020)
1	Identify articles on NPIsa of contact tracing used alone or in combination with other NPIs	(contact tracing[title] OR case finding[title] OR identify contacts[title]or detect case*[title] OR early detection[title] OR “contact tracing” [MeSH][title]) OR (non-pharmaceutical intervention* AND contact tracing)	17,896
2	Identify articles on viral epidemics or pandemics with a focus on COVID-19	covid19[tiab] OR covid-19[tiab] OR severe acute respiratory syndrome coronavirus 2 or SARS-COV-2 OR 2019-nCoV OR novel coronavirus OR “COVID-19”[Supplementary Concept] OR viral epidemic[tiab] OR viral pandemic[tiab] OR influenza[tiab] or flu[tiab]	140,427
3	Identify effectiveness outcomes	effective* OR efficacy OR effectiveness	8,348,810
4	Identify contact tracing effectiveness studies in viral epidemics or pandemics	#1 AND #2 AND #3	122

^aNPI: nonpharmaceutical intervention.