Medical science has evolved enormously in the past few decades. Despite such progress, the world is still struggling to eradicate tuberculosis. Solving any problem requires us to understand the factors responsible for that problem. Hence, analyzing reasons behind delayed tuberculosis eradication is essential, so as to overcome them with effective policies.
Tuberculosis is a chronic disease that has been afflicting the human civilization for many centuries. Over the course of time, extensive researches have been carried out that have greatly broadened our knowledge and understanding of tuberculosis. With every passing year, we get to know something new about the disease and this has brought radical changes in the field of diagnosis and treatment of tuberculosis. But despite the great advancements made, tuberculosis still remains a major global health problem, especially in developing countries. In 2020, an estimated 10 million people fell ill with tuberculosis (TB) worldwide.  The eradication of tuberculosis continues to be a challenge for the global medical community. Identifying the reasons behind this difficulty in tuberculosis eradication will help in formulating effective plans and policies and bring us closer towards lysis of tuberculosis.
The most important step in prevention of a disease is to break its chain of transmission. Tuberculosis mainly gets transmitted through droplet infection from people infected with pulmonary tuberculosis. The likelihood of transmission is further heightened by improper ventilation, indoor air pollution and overcrowding, that is very much prevalent in developing countries owing to unplanned urbanization and poverty.
In order to lessen the spread of disease, early diagnosis is indispensible. For this, availability of adequate health facilities is an absolute necessity. Additionally, people need to be aware about tuberculosis so that they can approach health personnel at the onset of earliest symptom. But, many parts of world still lack proper health infrastructures. Moreover, in some areas, people continue to believe that tuberculosis is not curable. So, patients are often stigmatized, creating fear of diagnosis among infected individuals. Ultimately these factors culminate in delayed diagnosis of tuberculosis.
The high transmissibility and delay in detection means that an infected individual may infect several other individuals by the time they get diagnosed. People with active TB can infect 5–15 other people through close contact over the course of a year.  Hence, a vicious chain of transmission is created, making tuberculosis eradication difficult.
Furthermore, latent tubercular infection forms another spectrum that might go undiagnosed for many years. The progression from tubercular infection to disease is governed by the immune status of the patient. So, people with latent infection act as the storehouse of disease from whom new cases might emerge every year adding to the
disease burden. Latent tuberculosis infection poses a great challenge towards timely diagnosis and prevention of tuberculosis transmission.
Tuberculosis gets activated once the immunity falls. So, any condition that hampers a person’s immunity be it malnutrition, diabetes or Human Immunodeficiency Virus (HIV), is an added risk factor. People living with HIV are 18 times more likely to develop active TB disease than people without HIV.  About 15% of TB cases globally may be linked to diabetes.  So, worldwide increase in incidences of HIV and diabetes also contribute to burden of tuberculosis. Alcohol use disorder and tobacco smoking increase the risk of TB disease by a factor of 3.3 and 1.6, respectively.  Thus, smoking and alcohol use are modifiable risk factors associated with tuberculosis.
Tuberculosis is a treatable disease, but the emerging cases of drug resistance stand in the way of effective treatment. Lack of patient compliance and injudicious use of anti- tubercular drugs are mainly responsible for the increasing number of drug resistant cases. When the bacteria becomes resistant to the regularly used drugs then alternative regimens have to be used, that may not be as efficacious as the first line drugs. Patients with resistant tuberculosis have to take drugs for a longer duration, so patient compliance is again of utmost importance. However, if this trend of resistance continues to rise and spreads to other available drugs, then we may not have any effective therapy left to treat tuberculosis. Hence, prompt diagnosis and treatment of resistant cases is the need of the hour. But this constitutes another challenge as most areas don’t have appropriate screening facilities for drug resistance. Consequently, large number of drug resistant cases goes undetected. Only about one in three people with drug resistant TB accessed treatment in 2020. 
All in all, the fact that tuberculosis has not yet been eradicated despite the availability of screening facilities, chemotherapy and vaccination, can be attributed to etiological factors like high transmissibility among close contacts, latent infection, susceptibility of immune-compromised individuals and development of drug resistance. Socio-economic factors like overcrowding, malnutrition, poverty and behavioral factors like alcohol, smoking, ignorance and low patient compliance also influence disease progression and act as barrier against disease eradication. However, if we look at the history of medical science, small pox and rinderpest are two diseases that have been successfully eradicated from the world. So, tuberculosis eradication is not some utopian fantasy and with combined efforts from the global community, we can turn this into reality.