Tuberculosis – A re-emerging disease and the observance of World TB Day

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Tuberculosis – A re-emerging disease and the observance of World TB Day

Dr. Muhammad Najeeb Durrani, Epidemiologist, District Surveillance Coordinator, District TB Coordinator (DTC), In-charge Dengue Fever Surveillance Cell, Islamabad

Although the Government of Pakistan’s National TB Control Program through its TB DOTS strategy has revolutionized the TB treatment in the country and brought down the incidence and the prevalence of disease thereby improving the treatment indicators; still the Tuberculosis being a re-emerging and fast spreading disease remains a major health problem in the country as seen in the perspective of different developing countries of the world including Pakistan. Our country is only 5th in the high burden Countries of the world and 4th in global perspective.

Unfortunately much less attention is being paid to the most highly infectious disease world wide only second after HIV AIDS. When we compare the efforts being made at the Political level; where Government shows strong commitment for the prevention and control of other diseases that create much media hike like Dengue, Bird flu, Swine Flu or the CCHF.

This year’s theme for the world TB day

Reach the three million;  A TB test, treatment and cure for all

Observance of World TB days in all the districts of the country with new each year themes of STOP TB are creating awareness in different segments of the public against the disease being participated by different stake holders especially  women and children.

As highlighted in the WHO 2013 Global TB Report, three million people are missed every year by health systems. This has been the case for six years now. The Partnership believes that no one should be left behind in the fight against TB if we want to move towards a ZERO TB deaths world.

For World TB Day 2014, partners will call for a global effort to find, treat and cure all people with TB and accelerate progress towards the bold goals we expect to see in TB strategies post-2015 and a world with Zero TB deaths, stigma and infections.

Facts about TB

Tuberculosis (TB) is second only to HIV/AIDS as the greatest killer worldwide due to a single infectious agent. In 2012, 8.6 million people fell ill with TB and 1.3 million died from TB. Over 95% of TB deaths occur in low- and middle-income countries, and it is among the top three causes of death for women aged 15 to 44. In 2012, an estimated 530 000 children became ill with TB and 74 000 HIV-negative children died of TB. TB is a leading killer of people living with HIV causing one fifth of all deaths.

Anti-tuberculosis (TB) drug resistance has now become a major public health problem that threatens progress made in TB care and control worldwide. Drug resistance arises due to improper use of antibiotics in chemotherapy of drug-susceptible TB patients. This improper use is a result of a number of actions including, administration of improper treatment regimens and failure to ensure that patients complete the whole course of treatment. Essentially, drug resistance arises in areas with weak TB control programmes. A patient who develops active disease with a drug-resistant TB strain can transmit this form of TB to other individuals. Multi-drug resistant TB (MDR-TB) is present in virtually all countries surveyed. The estimated number of people falling ill with tuberculosis each year is declining, although very slowly, which means that the world is on track to achieve the Millennium Development Goal to reverse the spread of TB by 2015. The TB death rate dropped 45% between 1990 and 2012. An estimated 22 million lives saved through use of DOTS and the Stop TB Strategy recommended by WHO.

Disease main features

Tuberculosis, or TB, is an infectious bacterial disease caused by Mycobacterium tuberculosis, which most commonly affects the lungs. It is transmitted from person to person via droplets from the throat and lungs of people with the active respiratory disease.

In healthy people, infection with Mycobacterium tuberculosis often causes no symptoms, since the person’s immune system acts to “wall off” the bacteria. The symptoms of active TB of the lung are coughing, sometimes with sputum or blood, chest pains, weakness, weight loss, fever and night sweats. Tuberculosis is treatable with a six-month course of antibiotics.

Tuberculosis (TB) is caused by bacteria (Mycobacterium tuberculosis) that most often affect the lungs. Tuberculosis is curable and preventable.

TB is spread from person to person through the air. When people with lung TB cough, sneeze or spit, they propel the TB germs into the air. A person needs to inhale only a few of these germs to become infected.

About one-third of the world’s population has latent TB, which means people have been infected by TB bacteria but are not (yet) ill with disease and cannot transmit the disease.

People infected with TB bacteria have a lifetime risk of falling ill with TB of 10%. However persons with compromised immune systems, such as people living with HIV, malnutrition or diabetes, or people who use tobacco, have a much higher risk of falling ill.

When a person develops active TB (disease), the symptoms (cough, fever, night sweats, weight loss etc.) may be mild for many months. This can lead to delays in seeking care, and results in transmission of the bacteria to others. People ill with TB can infect up to 10-15 other people through close contact over the course of a year. Without proper treatment up to two thirds of people ill with TB will die.

People at most at risk

Tuberculosis mostly affects young adults, in their most productive years. However, all age groups are at risk. Over 95% of cases and deaths are in developing countries.

People who are co-infected with HIV and TB are 21 to 34 times more likely to become sick with TB (see TB and HIV section). Risk of active TB is also greater in persons suffering from other conditions that impair the immune system.

About half a million children (0-14 years) fell ill with TB, and 74 000 HIV-negative children died from the disease in 2012. Tobacco use greatly increases the risk of TB disease and death. More than 20% of TB cases worldwide are attributable to smoking.

Global impact of TB

TB occurs in every part of the world. In 2012, the largest number of new TB cases occurred in Asia, accounting for 60% of new cases globally. However, sub-Saharan Africa carried the greatest proportion of new cases per population with over 255 cases per 100 000 population in 2012.

In 2012, about 80% of reported TB cases occurred in 22 countries. Some countries are experiencing a major decline in cases, while cases are dropping very slowly in others. Brazil and China for example, are among the 22 countries that showed a sustained decline in TB cases over the past 20 years. In the last decade, the TB prevalence in Cambodia fell by almost 45%.

Symptoms and diagnosis

Common symptoms of active lung TB are cough with sputum and blood at times, chest pains, weakness, weight loss, fever and night sweats.

Many countries still rely on a long-used method called sputum smear microscopy to diagnose TB. Trained laboratory technicians look at sputum samples under a microscope to see if TB bacteria are present. With three such tests, diagnosis can be made within a day, but this test does not detect numerous cases of less infectious forms of TB.

Diagnosing MDR-TB (see Multidrug-resistant TB section below) and HIV-associated TB can be more complex. A new two-hour test that has proven highly effective in diagnosing TB and the presence of drug resistance is now being rolled-out in many countries.

Tuberculosis is particularly difficult to diagnose in children.


TB is a treatable and curable disease. Active, drug-sensitive TB disease is treated with a standard six-month course of four antimicrobial drugs that are provided with information, supervision and support to the patient by a health worker or trained volunteer. Without such supervision and support, treatment adherence can be difficult and the disease can spread. The vast majority of TB cases can be cured when medicines are provided and taken properly.

Since 1995, over 56 million people have been successfully treated and an estimated 22 million lives saved through use of DOTS and the Stop TB Strategy recommended by WHO and described below.

TB and HIV

At least one-third of people living with HIV worldwide in 2012 are infected with TB bacteria, although not yet ill with active TB. People living with HIV and infected with TB are 30 times more likely to develop active TB disease than people without HIV.

HIV and TB form a lethal combination, each speeding the other’s progress. Someone who is infected with HIV and TB is much more likely to become sick with active TB. In 2012 about 320 000 people died of HIV-associated TB. Approximately 20% of deaths among people with HIV are due to TB. In 2012 there were an estimated 1.1 million new cases of HIV-positive new TB cases, 75% of whom were living in Africa.

As noted below, WHO recommends a 12-component approach to integrated TB-HIV services, including actions for prevention and treatment of infection and disease, to reduce deaths.

Multidrug-resistant TB

Most serious and disastrous for of the TB is the Multi drug Resistant TB caused by the reason that standard anti-TB drugs have been used for decades, and resistance to the medicines is now growing. The startling and fearful feature is that the resistant bacteria are now being transmitted person to person. The disease strains that are resistant to a single anti-TB drug have been documented in every country surveyed.

Multidrug-resistant tuberculosis (MDR-TB) is a form of TB caused by bacteria that do not respond to, at least, isoniazid and rifampicin, the two most powerful, first-line (or standard) anti-TB drugs.

The primary cause of MDR-TB is inappropriate treatment. Inappropriate or incorrect use of anti-TB drugs, or use of poor quality medicines, can all cause drug resistance.

Disease caused by resistant bacteria fails to respond to conventional, first-line treatment. MDR-TB is treatable and curable by using second-line drugs. However second-line treatment options are limited and recommended medicines are not always available. The extensive chemotherapy required (up to two years of treatment) is more costly and can produce severe adverse drug reactions in patients.

In some cases more severe drug resistance can develop. Extensively drug-resistant TB, XDR-TB, is a form of multi-drug resistant tuberculosis that responds to even fewer available medicines, including the most effective second-line anti-TB drugs.

About 450 000 people developed MDR-TB in the world in 2012. More than half of these cases were in India, China and the Russian Federation. It is estimated that about 9.6% of MDR-TB cases had XDR-TB.

WHO response

WHO’s pursues six core functions in addressing TB.

  • Provide global leadership on matters critical to TB.
  • Develop evidence-based policies, strategies and standards for TB prevention, care and control, and monitor their implementation.
  • Provide technical support to Member States, catalyze change, and build sustainable capacity.
  • Monitor the global TB situation, and measure progress in TB care, control, and financing.
  • Shape the TB research agenda and stimulate the production, translation and dissemination of valuable knowledge.
  • Facilitate and engage in partnerships for TB action.

The WHO’s Stop TB Strategy,

The strategyis recommended for implementation by all countries and partners, aims to dramatically reduce TB by public and private actions at national and local levels such as:

  • Pursue high-quality DOTS expansion and enhancement. DOTS is a five-point package to:
    • secure political commitment, with adequate and sustained financing
    • ensure early case detection, and diagnosis through quality-assured bacteriology
    • provide standardized treatment with supervision and patient support
    • ensure effective drug supply and management and
    • monitor and evaluate performance and impact;
  • Address TB-HIV, MDR-TB, and the needs of poor and vulnerable populations;
  • Contribute to health system strengthening based on primary health care;
  • Engage all care providers;
  • Empower people with TB, and communities through partnership;
  • Enable and promote research.