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Data

Tests conducted per new confirmed case of COVID-19

What you should know about this indicator

  • Testing is a key tool for identifying infections, guiding treatment, isolating positive cases, tracing contacts, and allocating healthcare resources.
  • The number of COVID-19 tests is not measured uniformly across countries: some track 'tests performed', while others count 'people tested'.
  • Most reported data includes PCR and antigen tests; antibody tests are generally excluded since they are less relevant for current infection tracking.
  • At-home self-tests may be counted if reported nationally, but many countries still rely primarily on laboratory tests for confirmation.
  • Varying reporting standards and test definitions can complicate international comparisons and the interpretation of testing statistics.
Tests conducted per new confirmed case of COVID-19
The number of tests each day divided by the number of confirmed cases each day. The series is smoothed by averaging daily figures over a rolling 7-day window.
Source
Official data collated by Our World in Data (2022); World Health Organization (2025) – with major processing by Our World in Data
Last updated
March 10, 2025
Unit
tests per confirmed case

Related research and writing

Coronavirus (COVID-19) Testing

Edouard Mathieu, Hannah Ritchie, Lucas Rodés-Guirao, Cameron Appel, Daniel Gavrilov, Charlie Giattino, Joe Hasell, Bobbie Macdonald, Saloni Dattani, Diana Beltekian, Esteban Ortiz-Ospina and Max Roser

Sources and processing

This data is based on the following sources

This data is collected by the Our World in Data team from official reports.

On 23 June 2022, we stopped adding new datapoints to our COVID-19 testing dataset. You can read more at https://github.com/owid/covid-19-data/discussions/2667.

The data produced by third parties and made available by Our World in Data is subject to the license terms from the original third-party authors. We will always indicate the original source of the data in our database, and you should always check the license of any such third-party data before use.

Retrieved on
August 9, 2024
Retrieved from
https://github.com/owid/covid-19-data/
Citation
This is the citation of the original data obtained from the source, prior to any processing or adaptation by Our World in Data. To cite data downloaded from this page, please use the suggested citation given in Reuse This Work below.
Hasell, J., Mathieu, E., Beltekian, D. et al. A cross-country database of COVID-19 testing. Sci Data 7, 345 (2020). https://doi.org/10.1038/s41597-020-00688-8
The data has been obtained from different sources depending on the country:

Daily COVID-19 cases and deaths by date reported to WHO.

From the 31 December 2019 to the 21 March 2020, WHO collected the numbers of confirmed COVID-19 cases and deaths through official communications under the International Health Regulations (IHR, 2005), complemented by monitoring the official ministries of health websites and social media accounts. Since 22 March 2020, global data is compiled through WHO region-specific dashboards, and/or aggregate count data reported to WHO headquarters.

WHO COVID-19 Dashboard is updated every Friday for the period of two weeks prior.

Counts primarily reflect laboratory-confirmed cases and deaths, based upon WHO case definitions; although some departures may exist due to local adaptations. Counts include both domestic and repatriated cases. Case detection, definitions, testing strategies, reporting practice, and lag times (e.g. time to case notification, and time to reporting of deaths) differ between countries, territories and areas. These factors, amongst others, influence the counts presented with variable under or overestimation of true case and death counts, and variable delays to reflecting these data at a global level.

All data represent date of reporting as opposed to date of symptom onset. All data are subject to continuous verification and may change based on retrospective updates to accurately reflect trends, changes in country case definitions and/or reporting practices. Significant data errors detected or reported to WHO may be corrected at more frequent intervals.

New case and death counts from the Region of the Americas Starting from the week commencing on 11 September 2023, the source of the data from the Region of the Americas was switched to the aggregated national surveillances, received through the COVID-19, Influenza, RSV and Other Respiratory Viruses program in the Americas. Data have been included retrospectively since 31 July 2023.

Rates <0.001 per 100,000 population may be rounded to 0.

Retrieved on
March 10, 2025
Retrieved from
https://covid19.who.int/
Citation
This is the citation of the original data obtained from the source, prior to any processing or adaptation by Our World in Data. To cite data downloaded from this page, please use the suggested citation given in Reuse This Work below.
WHO COVID-19 Dashboard. Geneva: World Health Organization, 2020. Available online: https://covid19.who.int/

How we process data at Our World in Data

All data and visualizations on Our World in Data rely on data sourced from one or several original data providers. Preparing this original data involves several processing steps. Depending on the data, this can include standardizing country names and world region definitions, converting units, calculating derived indicators such as per capita measures, as well as adding or adapting metadata such as the name or the description given to an indicator.

At the link below you can find a detailed description of the structure of our data pipeline, including links to all the code used to prepare data across Our World in Data.

Read about our data pipeline
Notes on our processing step for this indicator

Not all countries report testing data on a daily basis. To generate this series we assume that testing changed equally on a daily basis over any periods in which no data was reported.

Reuse this work

  • All data produced by third-party providers and made available by Our World in Data are subject to the license terms from the original providers. Our work would not be possible without the data providers we rely on, so we ask you to always cite them appropriately (see below). This is crucial to allow data providers to continue doing their work, enhancing, maintaining and updating valuable data.
  • All data, visualizations, and code produced by Our World in Data are completely open access under the Creative Commons BY license. You have the permission to use, distribute, and reproduce these in any medium, provided the source and authors are credited.

Citations

How to cite this page

To cite this page overall, including any descriptions, FAQs or explanations of the data authored by Our World in Data, please use the following citation:

“Data Page: Tests conducted per new confirmed case of COVID-19”. Our World in Data (2025). Data adapted from Official data collated by Our World in Data, World Health Organization. Retrieved from https://ourworldindata.org/grapher/tests-per-confirmed-case-daily-smoothed [online resource]
How to cite this data

In-line citationIf you have limited space (e.g. in data visualizations), you can use this abbreviated in-line citation:

Official data collated by Our World in Data (2022); World Health Organization (2025) – with major processing by Our World in Data

Full citation

Official data collated by Our World in Data (2022); World Health Organization (2025) – with major processing by Our World in Data. “Tests conducted per new confirmed case of COVID-19” [dataset]. Official data collated by Our World in Data, “COVID-19, testing”; World Health Organization, “COVID-19 Dashboard WHO COVID-19 Dashboard - Daily cases and deaths” [original data]. Retrieved March 10, 2025 from https://ourworldindata.org/grapher/tests-per-confirmed-case-daily-smoothed