Tuberculosis in Brief

When we think of Tuberculosis (TB) we tend to think of an old-timey disease. Doc Holliday, the famous gunslinger, died of consumption, the old-world name for TB. As did Fantine from Victor Hugo’s “Les Misérables” and Nicole Kidman’s, Santine, in the 2001 movie, Moulin Rouge! For the videogame fans out there, you might be familiar with Arthur Morgan from Red Dead Redemption 2 who, depending on how you played the game, may have suffered a similar fate. However, this disease is still prevalent around the world today. TB is a bacterial infection caused by Mycobacterium tuberculosis estimated to infect around 10 million people and is responsible for up to 1.5 million deaths each year¹.

Originally discovered in 1882, M. tuberculosis is an airborne pathogen which primarily affects the lungs but can also affect other parts of the body². TB infection exists in 3 states: latent, subclinical, and active. A latent TB infection is asymptomatic and non-transmissible. Subclinical infections are also asymptomatic but transmissible and will produce a positive culture. Finally, active disease is a transmissible state associated with the symptoms of TB². The World Health Organization (WHO) estimates that around ¼ of the world population is infected with M. tuberculosis³. Up to 15% of those infected with TB will progress to active disease, while those who do not are at a heightened risk of infection throughout the rest of their lives⁴. Compared with some other bacterial diseases, TB is not particularly infectious. An infected individual is estimated to infect between 3-10 people per year². However, subclinical TB infections present a challenge in reducing transmission because asymptomatic individuals may unknowingly spread the disease – over 1/3 of TB infections are never formally diagnosed⁵.

The symptoms of an active TB infection include fever, fatigue, lack of appetite, weight loss, and where the infection effects the lungs, a persistent cough and haemoptysis (coughing up blood). HIV-infection is a major risk factor for TB infection and mortality. Up to 12% of all new cases and 25% of TB deaths occur in HIV-positive persons². Other risk factors for the development of TB are, malnutrition, poor indoor air quality, Type 2 diabetes, excessive alcohol consumption and smoking¹.

TB is present around the world. However, as you might expect from the risk factors, low-to-middle income and developing countries account for a disproportionate number of cases. According to WHO, half of all TB infections are found in 8 countries: Bangladesh, China, India, Indonesia, Nigeria, Pakistan, Philippines, and South Africa.

Without effective treatment, TB will kill and estimated 50% of those infected². Treatment for TB typically involves first-line antibiotics such as isoniazid, rifampicin, pyrazinamide, and ethambutol, with second-line drugs including fluoroquinolones and injectable aminoglycosides⁶. Nonetheless, drug-resistant TB accounts for an inordinately large amount of the global AMR burden which can arise from both transmitted and acquired resistance. Resistant M. tuberculosis strains are classified as monoresistant – those resistant to 1 drug; multi-drug resistant (MDR) – those resistant to 2 or more first line treatments, commonly isoniazid and rifampicin; and extensively drug resistant (XDR) – MDR strains which are also resistant to second line therapies like fluoroquinolones and aminoglycosides⁶.

Global rates of TB have been declining. An estimated 75 million lives have been saved since 2000¹. Furthermore, between 2015 and 2020, TB incidence fell by 13.5%⁷. However, the progress made over the last decade has been compromised by the COVID-19 pandemic, illustrated by a, 18% drop in diagnosis between 2019 and 2020⁷. Explanations for this decline include delayed treatment because of lack of access to public transport and healthcare facilities, disruption of laboratory services, a personal desire to avoid the stigma of disease and misdiagnosis due to the similarities in symptoms between TB and COVID-19.

The theme for World Tuberculosis Day 2024 is “Yes, we can end TB!” The WHO have set targets of an 80% decline in new cases and a 90% drop in TB-related deaths by 2030. Screening and preventative treatments are crucial to achieving these goals. Therefore, novel methods of detection which are quick, inexpensive and include drug resistance identification are needed.

Mycobacterium Tuberculosis EQA

It is important for those carrying out TB testing to ensure their instruments and methods are accurate and effective. External Quality Assessment (EQA) programmes are an essential part of this process. QCMD is an independent international EQA organisation primarily focused on molecular infectious diseases to over 2000 participants in over 100 countries.

QCMD offers 2 programmes for those testing for TB through molecular methods: Mycobacterium tuberculosis DNA and Mycobacterium Tuberculosis Drug Resistance.

Mycobacterium tuberculosis DNA EQA Programme

Mycobacterium Tuberculosis Drug Resistance EQA Programme

Mycobacterium Tuberculosis Quality Controls

Those conducting research into TB infections and new methods of detection, screening and drug resistance profiling need to be confident that the equipment they are using is up to the task. Qnostics is a leading provider of Quality Control solutions for molecular infectious disease testing. Our range comprises hundreds of characterised viral, bacterial, and fungal targets covering a wide range of diseases.

Q Controls

Our range of positive run, whole pathogen, third party controls are designed to monitor assay performance on a routine basis. As true third-party controls, assay drift is detected, monitored, and managed, helping to ensure accurate and reliable results. The use of third-party controls will also help to support ISO 15189:2012 regulatory requirements.

Mycobacterium tuberculosis (MTB) Q Control 01

Target Pathogen – Mycobacterium tuberculosis (MTB)

Matrix – Synthetic Sputum

Stability – Single use control designed to be used immediately minimising the risk of contamination

Shelf Life – Up to 2 years from date of manufacture

Regulatory Status – Research Use Only

Mycobacterium tuberculosis (MTB) Rifampicin Resistant Q Control

Compatible for use with Cepheid analysers, this whole pathogen positive control is designed to monitor the performance of molecular assays used in the detection of Rifampicin resistant Mycobacterium tuberculosis.

Target Pathogen – Mycobacterium tuberculosis (MTB)

Target Genotype – Rifampicin Resistance

Matrix – Synthetic Sputum

Stability – Single use control designed to be used immediately minimising the risk of contamination

Shelf Life – Up to 2 years from date of manufacture

Regulatory Status – Research Use Only

Mycobacterium tuberculosis (MTB) Evaluation Panel Control

QNOSTICS Evaluation Panels cover a range of genotypes and/or levels, and may be used to evaluate assay characteristics, confirm performance claims, and ultimately ensure the assay is fit for purpose. Evaluation Panels may also be used in the validation of clinical assays and the development of new diagnostic tests.

This dedicated MTB Evaluation Panel comprises 3 targets relating to Mycobacterium tuberculosis for validating a new assay or instrument to ensure that everything is working as expected. High and medium concentrations are provided alongside a negative sample.

Target Pathogens – MTB, M. bovis, Rifampicin (Rif) resistant MTB, Isoniazid (INH) resistant MTB, Negative

Matrix – Synthetic Sputum

Panel Members – 8 (Including a negative)

Stability – Single use. Once thawed, use immediately

Shelf Life – up to 2 years from date of manufacture

Regulatory Status – Research Use Only

If you are interested in any of the TB quality control products shown above, or any other products from our wide catalogue of molecular controls and EQA programmes, get in touch with us today at marketing@randox.com. To learn more, see the links below which will take you to the relevant sites and brochures.

 

QNOSTICS – www.randox.com/molecular-infectious-disease-controls/

QNOSTICS Brochure Download

QCMD – https://www.qcmd.org/

QCMD Brochure Download