Frequently Asked Questions

Tuberculosis and Testing

Yes. Tuberculosis remains a major global health concern. It is one of the top infectious disease killers worldwide, affecting millions of people each year.

It's estimated that:

  • people are infected with Tuberculosis
  • 10.000.000 of these get sick from Tuberculosis every year
  • 1.500.000 of these die from Tuberculosis every year

The choice of testing method for tuberculosis (TB) depends on the specific circumstances, resources available, and the purpose of testing. There are several methods used for diagnosing TB, each with its own advantages and limitations. Here are some of the commonly used testing methods:

1. Mantoux Tuberculin Skin Test (TST): This test involves injecting a small amount of purified protein derivative (PPD) under the skin, usually on the forearm. After 48 to 72 hours, the healthcare provider checks the injection site for a raised bump. The size of the bump is measured, and if it's above a certain threshold, it's considered a positive reaction. However, TST can give false-positive results in people who have received the BCG vaccine for TB.

2. Interferon-Gamma Release Assays (IGRAs): These blood tests measure the release of interferon-gamma by immune cells when they come into contact with proteins specific to Mycobacterium tuberculosis. IGRAs, like the QuantiFERON-TB Gold and T-SPOT.TB tests, are less likely to give false-positive results due to BCG vaccination.

3. Chest X-ray: A chest X-ray can show signs of active pulmonary TB, such as lung abnormalities, cavities, or infiltrates. It's often used in conjunction with other tests to diagnose TB.

4. Sputum Smear Microscopy: This is a simple and widely used method to detect TB bacteria in a patient's sputum (mucus coughed up from the lungs). The sputum is stained with special dyes and examined under a microscope. While it's a quick test, it might not always provide accurate results, and additional testing is often needed.

5. Culture: Mycobacterial culture involves growing TB bacteria from a sample. This used to be via sputum and could take weeks to get the result. With our saliva-based tests results are ready in a couple of hours. Also, it is highly specific and can identify drug-resistant strains of TB. Finally, collecting a saliva sample is much easier (and comfortable to the test-person) compared to to a sputum sample.

Read more about our technology here.

6. Nucleic Acid Amplification Tests (NAATs): These molecular tests detect the genetic material (DNA or RNA) of the TB bacteria in sputum samples. NAATs, such as the GeneXpert MTB/RIF test, are rapid and can also provide information about drug resistance.

7. Chest CT Scan: This imaging technique provides detailed cross-sectional images of the chest and can help identify areas of concern, such as lung damage or abnormalities, in more detail than a regular X-ray.

The choice of testing method depends on the patient's clinical presentation, risk factors, and available resources. For active TB disease, a combination of clinical evaluation, chest imaging, and microbiological testing is often used. It's important to consult with a healthcare professional to determine the most appropriate testing approach based on individual circumstances.

Testing through saliva has several potential advantages over sputum testing, particularly in terms of convenience, ease of collection, and potential for widespread use.

However, the choice between saliva testing and sputum testing depends on the specific context, the target disease, and the accuracy of the testing method.

Here are some reasons why saliva testing might be considered better than sputum testing in certain situations:

1. Non-Invasive Collection: Collecting saliva is a non-invasive process that does not require individuals to produce sputum by coughing, which can be uncomfortable and difficult for some people.

2. Ease of Collection: Collecting saliva is generally simpler and less intimidating than collecting sputum. It's a straightforward process that can be performed by the individuals themselves with minimal assistance.

3. Reduced Contamination Risk: Collecting sputum samples might pose a higher risk of contamination due to the nature of the sample and the potential for aerosolization during collection. Saliva collection is less likely to lead to the same level of contamination.

4. Reduced Infection Risk: Collecting saliva samples reduces the risk of exposing healthcare workers to potentially infectious aerosols that might be generated during sputum collection.

5. Accessibility: Saliva collection can be done almost anywhere and does not require specialized equipment or facilities, making it suitable for point-of-care testing and home-based testing.

6. Acceptance: Many people find providing a saliva sample more acceptable and less invasive than providing a sputum sample, which can lead to higher rates of compliance with testing.

7. Pediatric, Elderly Populations and HIV Positive Patients: Saliva collection is often more feasible and less distressing for children and older adults who might have difficulty producing sputum.

8. Automation: Automated processing and analysis of saliva samples can streamline testing and reduce the need for labor-intensive sample preparation.

Antimicrobial Resistance (AMR) occurs when bacteria, viruses, fungi and parasites change over time and no longer respond to medicines making infections harder to treat and increasing the risk of disease spread, severe illness and death. 

As a result of drug resistance, antibiotics and other antimicrobial medicines become ineffective and infections become increasingly difficult or impossible to treat.

While often linked to hospital infections like MRSA, drug-resistant Tuberculosis accounts for 29% of antimicrobial infection-related deaths today.

All-in-all: a major threat to public health, safety, and the global economy.

A few facts:

  • WHO has declared that AMR is one of the top 10 global public health threats facing humanity
  • Driven by the misuse of antibiotics
  • Poor sanitation and infection control spread resistant microbes
  • AMR's economic cost is high, leading to longer hospital stays and financial burdens
  • Effective antimicrobials are crucial for modern medicine's success in treating infections, including surgery and chemotherapy


A lateral flow test, also known as a lateral flow assay, test stick, dip stick or a rapid test, is a diagnostic test used to detect the presence or absence of a target substance in a sample, often without the need for specialized equipment or laboratory analysis.

These tests are designed for quick and simple use, making them suitable for point-of-care testing and situations where rapid results are important.

The basic principle behind a lateral flow test is that it uses capillary action to move a liquid sample along a test strip or membrane. The strip contains different zones, each with specific components that enable the detection process. Here's a simplified breakdown of how a lateral flow test works:

1. Sample Application: The liquid sample, such as blood, saliva, urine, or other bodily fluids, is applied to one end of the test strip.

2. Migration: Capillary action draws the sample across the strip, moving it through various zones.

3. Reaction Zone: As the sample flows through the strip, it encounters zones containing reagents (antibodies, antigens, or other molecules) specific to the target substance being tested for.

4. Test Line: If the target substance is present in the sample, it binds with the reagents in the reaction zone. This binding forms a visible line, often referred to as the "test line" or "T-line."

5. Control Line: A control line is also present on the strip. This line should appear regardless of whether the target substance is present. It serves as a validation that the test has worked properly.

6. Result Interpretation: After a specific amount of time (usually a few minutes), the test is examined for the presence of lines. If both the test line and control line appear, it indicates a positive result (the target substance is present). If only the control line appears, it's a negative result (the target substance is absent). If no lines appear, the test might be invalid, and it might need to be repeated.

Lateral flow tests are commonly used for various purposes, including the rapid detection of infectious diseases, pregnancy testing, drug testing, and more.

They offer advantages such as speed, simplicity, and portability.


VPCIR Biosciences is a spin-out from Aarhus University, Denmark.

20 years in the making, our technology is capable of detecting living pathogens in saliva.

This technology is currently being implemented in lateral flow tests (test sticks) which means that we can test for – first Tuberculosis and later for other infectious diseases – faster, cheaper and in a non-invasive way.

See our team here...