The United Nations and the World Health Organization (WHO) set March 24 every year as World Tuberculosis Day to commemorate the 1882 German microbiologist Robert Koch published his discovery of the tuberculosis pathogen to a group of doctors in Berlin, Germany.
Let’s get some facts first.
Key facts from WHO
A total of 1.6 million people died from TB in 2021 (including 187 000 people with HIV). Worldwide, TB is the 13th leading cause of death and the second leading infectious killer after COVID-19 (above HIV/AIDS).
In 2021, an estimated 10.6 million people fell ill with tuberculosis(TB) worldwide. Six million men, 3.4 million women and 1.2 million children. TB is present in all countries and age groups. But TB is curable and preventable.
In 2021, 1.2 million children fell ill with TB globally. Child and adolescent TB is often overlooked by health providers and can be difficult to diagnose and treat.
In 2021, the 30 high TB burden countries accounted for 87% of new TB cases
Multidrug-resistant TB (MDR-TB) remains a public health crisis and a health security threat. Only about one in three people with drug resistant TB accessed treatment in 2020.
Globally, TB incidence is falling at about 2% per year and between 2015 and 2020 the cumulative reduction was 11%. This was over half way to the End TB Strategy milestone of 20% reduction between 2015 and 2020.
An estimated 66 million lives were saved through TB diagnosis and treatment between 2000 and 2020.
Globally, close to one in two TB-affected households face costs higher than 20% of their household income, according to latest national TB patient cost survey data. The world did not reach the milestone of 0% TB patients and their households facing catastrophic costs as a result of TB disease by 2020.
By 2022, US$ 13 billion is needed annually for TB prevention, diagnosis, treatment and care to achieve the global target agreed at the UN high level-meeting on TB in 2018.
Funding in low- and middle-income countries (LMICs) that account for 98% of reported TB cases falls far short of what is needed. Spending in 2020 amounted to US$ 5.3 billion less than half (41%) of the global target.
There was an 8.7% decline in spending between 2019 and 2020 (from US$ 5.8 billion to US$ 5.3 billion), with TB funding in 2020 back to the level of 2016.
Ending the TB epidemic by 2030 is among the health targets of the United Nations Sustainable Development Goals (SDGs).
What is Tuberculosis?
Tuberculosis (TB) is a disease caused by Mycobacterium tuberculosis infection. Tuberculosis usually causes an infection of the lungs, but it can also infect other parts of the body [1]. It was called "phthisis" in ancient times,which is a very old and important disease and a major public health problem that still threatens human health. Before the emergence of the Covid-19 pandemic, TB was the leading cause of death from an infectious disease accounting for approximately 1.5 million deaths per annum[2].
Where does Tuberculosis occur?
Tuberculosis can occur anywhere in the body, but most often affects the lungs (it is called pulmonary tuberculosis). Extrapulmonary TB (ie, TB that occurs in organs other than the lungs) may co-exist with pulmonary TB [4].
The Clinical signs and symptoms?
Most infected people are asymptomatic, called latent TB infection. Without proper treatment at this time, 10% of patients with latent infection will progress to active tuberculosis, with a fatality rate of 50% [1]. General include fever, chills, night sweats, loss of appetite, weight loss, and fatigue [3]. Significant clubbing of the nails may also be present in patients with tuberculosis [4].
How does Tuberculosis spread?
Tuberculosis is spread by coughing, sneezing, laughing, talking loudly and releasing droplets containing mycobacterium tuberculosis into the air. Patients with certain types of TB, especially those who are sputum positive (the bacteria found in their sputum), are highly contagious. Tuberculosis is not contagious through inanimate things, you must inhale droplets directly or indirectly to get sick. Droplet transmission is the most important route of tuberculosis transmission, through the digestive tract and other routes such as skin transmission is now rare.
Diagnosis
Diagnosis is based on the identification of TB bacilli by smear or culture in the excreta or secretions of patients. As for tuberculosis occurring in bone, joint and other places, it is difficult to collect bacterial-containing specimens, so the diagnosis is mainly based on symptoms, signs and imaging characteristics. The tuberculin test is only of reference value for the diagnosis of TB because the BCG vaccine, which is currently widely administered, causes the body to mount an immune response against the TB bacterium, making the tuberculin test false positive. However, for those who have not received BCG vaccine, the tuberculin test is of greater diagnostic value.
Are there any effective biomarkers to help?
The good news is, Yes! Among 9,739 articles published between 1 January 2008 and 31 December 2020, of which 77 met the inclusion criteria. A total of 81 biomarkers were identified from 77 studies. Overall, these studies exhibited extensive heterogeneity with regard to TB treatment monitoring study design and data reporting. Based on limited data available,among the biomarkers identified, C-reactive protein (CRP), interleukin-6 (IL-6), interferon gamma-induced protein 10 (IP-10), and tumor necrosis factor alpha (TNF-α) had sufficient data to analyze fold changes. CRP, IL-6, IP-10, and TNF-α have been identified as biomarkers that should be further explored in the context of TB treatment monitoring [5]. The level of CRP is closely related to the degree of inflammatory response of TB, so CRP can also be used to diagnose tuberculosis activity and determine the clinical efficacy [6,7].
Treatment
Drug therapy is the most important means of TB treatment, in order to ensure the complete cure of TB, drug use should follow the five principles of "early, appropriate amount, combination, regular, whole process". The treatment cycle for TB is long, requiring at least 6-9 months of medication for active TB. The specific drug and duration of treatment depends on the patient's age, overall health, drug resistance, and site of infection. The most common TB drugs are isoniazid, rifampicin (Lima), ethambutol, and pyrazinamide. If the first-line drug therapy is not effective or the disease is severe, drug resistant tuberculosis should be considered and surgical treatment should be performed on the basis of drug therapy if necessary.
Yes! We can end TB
World TB Day 2023 with the theme "Yes! We can end TB!" aims to inspire hope and encourage senior leadership to make a difference, increase investment, adopt new WHO recommendations faster, adopt innovative approaches, and accelerate action and multisectoral collaboration to combat the TB epidemic.
1.Tuberculosis Fact sheet N°104. WHO. October 2015 [2016-02-11].
2.J. Chakaya, et al. Global tuberculosis report 2020 – Reflections on the Global TB burden, treatment and prevention efforts Int. J. Infect. Dis., 113 (2021), pp. S7-S12, 10.1016/j.ijid.2021.02.107
3. Dolin, [edited by] Gerald L. Mandell, John E. Bennett, Raphael. Mandell, Douglas, and Bennett's principles and practice of infectious diseases 7th. Philadelphia, PA: Churchill Livingstone/Elsevier. 2010: Chapter 250. ISBN 978-0-443-06839-3.
4. Gibson, Peter G. (ed.); Abramson, Michael (ed.); Wood-Baker, Richard (ed.); Volmink, Jimmy (ed.); Hensley, Michael (ed.); Costabel, Ulrich (ed.). Evidence-Based Respiratory Medicine 1st. BMJ Books. 2005: 321 [2016-11-26]. ISBN 978-0-7279-1605-1.
5.AJ Zimmer, F Lainati, et al. Biomarkers That Correlate with Active Pulmonary Tuberculosis Treatment Response: a Systematic Review and Meta-analysis. Journal of Clinical Microbiology.Research Article .16 February 2022.
6. Gopalan Narendran, et al. Paradoxical Tuberculosis Immune Reconstitution Inflammatory Syndrome (TB-IRIS) in HIV Patients with Culture Confirmed Pulmonary Tuberculosis in India and the Potential Role of IL-6 in Prediction. Plos one, 2013
7.N Santucci, L D'Attilio,et al. A multifaceted analysis of immune-endocrine-metabolic alterations in patients with pulmonary tuberculosis, PloS one .September 10, 2021
8.G Gallucci, N Santucci, A Díaz,et al. Increasemd levels of circulating LPS during Tuberculosis prevails in patients with advanced pulmonary involvement . Plos one,September 10, 2021