Dr. Shyam P Lohani

World TB Day 2022 was celebrated on March 24 with the theme of “Invest to End TB, Saves Lives”. Being an infectious disease, tuberculosis (TB) usually affects the lungs, although it can affect any organ in the body such as the kidney, spine, and brain. It is to be noted that everyone infected with TB bacteria does not become sick. It spreads through droplets in the air. TB can be fatal if not treated but is preventable and treatable.

Tuberculosis was a major cause of death worldwide in the past. As the living conditions improved and treatments with antibiotics available, the prevalence of TB fell dramatically in industrialised countries. People with poor immune systems develop TB disease within weeks after being infected with the bacterium while other people may get sick years later especially when their immune system becomes weak due to other reason.

Burden
An estimated 25 per cent of the world population has TB infection. This figure means people have been infected by TB bacteria but are not yet fallen sick with the disease and will not infect others. Grossly, around 5-10 per cent of infected persons will develop TB disease at some time in their lifetime if remain untreated for latent TB infection. People with a weak immune system are at higher risk of developing TB in comparison to those with a normal immune system.

Globally, 1.5 million people died from TB in 2020. This figure also includes some 214 000 people with HIV. It is the 13th leading cause of death and the second top infectious killer after COVID-19 reports the World Health Organisation (2021). The large majority of new cases, around 86 per cent, were reported from the 30 high TB burden countries in 2020. Those countries included India followed by China, Indonesia, the Philippines, Pakistan, Nigeria, Bangladesh, and South Africa (WHO, 2020). In Nepal, about 69,000 people developed TB in 2018, and the TB burden is 1.6 times higher than previously estimated (National TB Control Centre, 2020). In Nepal, TB kills around 7,000 people every year.

Generally, persons at high risk for developing TB disease fall into two categories as persons who have been recently infected with TB bacteria and persons with medical conditions that weaken the immune system. People who are in close contact with a person with infectious TB disease, those who have immigrated from areas of the world with high rates of TB, children less than five years of age who have a positive TB test are at high risk of developing active TB illness.

Homeless persons, injection drug users, and persons with HIV infection are among people vulnerable to TB transmission. Persons who work or reside with people with high risk for TB in facilities or institutions such as hospitals, homeless shelters, correctional facilities, nursing homes, and residential homes for HIV are others among at risk of contracting TB infection. The group with weak immune systems is susceptible to TB diseases such as babies and young children. Other people with HIV infection, substance abuse, silicosis, diabetes mellitus, severe kidney disease, low body weight, organ transplants, head and neck cancer, those with medical treatments with corticosteroids or organ transplants can have a weak immune system and are among people who are susceptible to developing TB disease.

Early warning signs of the active disease include a persistent cough, lasting for at least three weeks, blood in the phlegm, a loss of appetite and weight loss, a general feeling of fatigue and unwell, swelling in the neck, a fever, night sweats, and chest pain.

Tuberculosis is curable with appropriate antibiotics if detected early. TB treatment has standard treatment guidelines. However, it depends on the age of the patient and overall health, whether TB is latent or active, the location of the infection, and whether the strain of TB is drug-resistant or not. Treatment for latent TB can vary and usually involves taking an antibiotic once a week for 12 weeks or every day for nine months. Treatment for active TB may involve taking several drugs for the duration of six-nine months. When a person has a drug-resistant strain of TB, the treatment will become more complex and duration may be longer.

It is imperative to promote information that it is essential to complete the full course of treatment, even if symptoms disappear. By stopping taking their medication early, some bacteria can survive and become resistant to antibiotics. In this case, the person may go on to develop drug-resistant TB and treatment becomes more complex with serious side effects. TB prevention from infecting others include a proper diagnosis and treatment in time, staying away from other people until there is no longer a risk of transmission of infection, wearing a mask, covering the mouth, and staying in ventilating rooms.

Strategies
Globally, the incidence of TB is decreasing at about two per cent per year and during a five-year period between 2015 and 2020, the cumulative reduction was 11 per cent which is just over halfway to the End TB Strategy milestone of 20 per cent reduction between 2015 and 2020 (WHO, 2020). During the last 20 years (2000-2020), an estimated 66 million lives were saved through TB diagnosis and treatment. The burden of the cost of TB treatment takes a toll on TB-affected households amounting to around 20 per cent of their household income.

At this time, we are far from the milestone of zero per cent TB patients and in terms of households facing catastrophic costs as a result of TB disease by 2020. It has been suggested priority areas such as ensuring a high level of political commitment to ending TB, expanding high-quality TB services to all levels, and engaging private sector in high-quality TB services besides increasing awareness among the general public. Active TB case detection rate is still not optimum. Therefore, increasing surveillance among people at risk is necessary. In addition, increasing investment in high-quality TB services saves millions of lives and generates huge financial gain overall.

(Dr. Lohani is the clinical director at the Nepal Drug and Poison Information Centre. lohanis@gmail.com)