• Recognizing the burden

    Global daily SARS-CoV-2 infections fluctuated between 3 million and 17 million new infections per day between April 2020, and October 2021, peaking in mid-April 2021, primarily as a result of surges in India.

    COVID-19 has already had a staggering impact on the world up to the beginning of the omicron (B.1.1.529) wave, with over 40% of the global population infected at least once by Nov 14, 2021.

    (The Lancet.8 April 2022. doi: 10.1016/S0140-6736(22)00484-6.)

  • Estimating the impact

    The global all-age rate of excess mortality due to the COVID-19 pandemic was 120·3 deaths (113·1–129·3) per 100 000 of the population, and excess mortality rate exceeded 300 deaths per 100 000 of the population in 21 countries. The number of excess deaths due to COVID-19 was largest in the regions of south Asia, north Africa and the Middle East, and eastern Europe.

    (The Lancet. 10 March 2022. doi: 10.1016/S0140-6736(21)02796-3.)

  • Prevention and control

    Early laboratory diagnosis of a SARS-CoV-2 infection can aid clinical management and outbreak control. Diagnostic testing can involve detecting the virus itself (viral RNA or antigen) or detecting the human immune response to infection (IgG/M antibodies or other biomarkers)

    (WHO, 2022)

  • SARS-CoV-2 burden of disease

    Global Burden of Disease (GBD) study assesses mortality and disability from hundreds of diseases, injuries, and risk factors around the world.

    The Global Burden of Disease is a critical resource for informed policymaking.

    IHME updates its COVID-19 models and forecasts on a monthly basis.

  • FIND interactive SARS-CoV-2 test tracker

    Identifying and closing the testing gaps is critical, and FIND is monitoring both testing and sequencing capacity for COVID-19, and tracking the impact of new variants of concern (VOC) to test performance. The FIND interactive SARS-CoV-2 test tracker shows the current and past testing situation in each country.

  • CDC Viral testing tool

    Access the CDC reccomendation and learn when to test for COVID-19 and what the different test results mean.

    Read more.

Use Cases

A new study shows that ethnic disparities in Brazil are strongly associated with precarious environments and conditions of basic sanitation and housing. Therefore, they have important implications for the COVID- 19 mortality rate. Furthermore, minority populations have a disproportionate burden of underlying comorbidities, including hypertension and diabetes, increasing the risk of hospitalisations.

Read more

Different tests for COVID-19 (WHO)

Browse diagnostics


What is a COVID-19 variant?

Viruses constantly change through mutation and sometimes these mutations result in a new variant of the virus. Some variations allow the virus to spread more easily or make it resistant to treatments or vaccines. As the virus spreads, it may change and may become harder to stop.

Regardless of the variant, a surge in cases can impact healthcare resources.
Even if a variant causes less severe disease in general, an increase in the total number of cases could cause an increase in hospitalizations, put more strain on healthcare resources, and potentially lead to more deaths. (Source: CDC)

What is IgG and IgM antibody testing for COVID-19?

Antibodies (igG and IgM) are detected in the blood of people who have been previously infected with or vaccinated against a virus that causes a disease; they show the body’s efforts (past infection) or preparedness (past infection or vaccination) to fight off a specific virus. It is important to remember that some people with antibodies to SARS-CoV-2 may become infected after vaccination (vaccine breakthrough infection) or after recovering from a past infection (reinfected). Based on what we know right now, risk of reinfection is low for at least the first 6 months following an infection with the virus that causes COVID-19 diagnosed by a laboratory test.

What is the difference between PCR and RDTs?

Rapid diagnostic tests (RDTs) detect the presence of SARS-CoV-2 viral proteins (antigens) in respiratory tract specimens, most of these are lateral flow immunoassays (LFI), which are typically completed within 30 minutes.
In contrast, Polymerase chain reaction (PCR or rtPCR) is a Nucleic acid amplification test (NAAT), which detect genome sequences based on amplification of the target viral genome.

As RDTs do not rely on genome amplification, antigen tests are less sensitive. Additionally, false positive (indicating that a person is infected when they are not) results may occur if the antibodies on the test strip also recognize antigens of viruses other than SARS-CoV-2, such other human coronaviruses.

Data on the sensitivity and specificity of currently available Ag-RDTs for SARS-CoV-2 have been derived from studies that vary in design and in the test brands being evaluated. They have shown that sensitivity compared to NAAT in samples from upper respiratory tract (nasal or nasopharyngeal swabs) appears to be highly variable, ranging from 0-94% (4-13) but specificity is consistently reported to be high (>97%).

What is the Infection-Fatality Ration?

Estimating the Infection-Fatality Ration (IFR) helps to identify in a population vulnerabilities to COVID-19. Information about how IFR varies by age, time, and location informs clinical practice and non-pharmaceutical interventions like physical distancing measures, and underpins vaccine risk stratification and can be used for screening. (The Lancet.24 February 2022. doi: 10.1016/S0140-6736(21)02867-1.)

Disclaimer: The Learn Resources section is a compilation of information on a given topic that is drawn from credible sources; however, this does not claim to be an exhaustive document on the subject. It is not intended to be prescriptive, nor does it represent the opinion of FIND or its partners.