The top infectious killer

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Micrograph of Mycobacterium tuberculosis — CDC Public Health Image Library

Tuberculosis (TB) is one of the top 10 causes of death and the leading infectious disease threat in the world which is responsible for more deaths than HIV (human immunodeficiency virus) and malaria. According to the latest Global Tuberculosis Report published by World Health Organization (WHO), there were an estimated 1.8 million people died from TB in 2015 or an equivalent of over 4,900 TB deaths every day. Over 95% of these cases occurred in low- and middle-income countries.

The report also said that an estimated 10.4 million new TB cases were recorded, which 5.9 million (56%) were among men, 3.5 million (34%) among women and 1.0 million (10%) among children. 60% of the figure was accounted to only six countries namely: China, India, Indonesia, Nigeria, Pakistan and South Africa.

Generally, the number of TB deaths worldwide fell by 22% between 2000 and 2015. In the same period, an estimated 49 million lives were saved through TB diagnosis and treatment. However, the case fatality ratio or the global proportion people with TB who die from disease varied under 5% in a few countries to more than 20% in most countries in the African region. This implies that there are considerable inequalities in access to TB diagnostics and treatment among the countries.

As explained by WHO, TB is caused by bacteria called Mycobacterium tuberculosis that attacks the lungs. It can also spread to the other parts of the body like the brain and spine.

TB is contagious and airborne which means it can be passed from person to person through air. When someone with lung TB coughs, sneezes, or spits, tiny droplets that contain germs are release into the air. Once a person inhales and catches a few of these germs, he or she become infected.

There are two types of TB conditions, the latent TB and the active TB disease. According to WHO, 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 the disease and cannot transmit it. However, the infection is still alive in the body and can become active anytime. WHO noted that 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.

On the other hand, active TB disease is a condition which germs in the body multiply and make the person suffers from cough with sputum and blood at times, chest pains, weakness, weight loss, fever and night sweats. People with active TB can infect 10 to 15 people through close contact over the course of a year.

TB can be cured with proper treatment. The active TB disease is treated with a standard of six-month course of four antimicrobial drugs with a supervision and support by health worker or trained volunteer. As for WHO, “Without such 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.”

In 2035, reducing tuberculosis death cases by 95% and TB incidence rate by 90% are among the targets of WHO under its “End TB Strategy”. In addition, it aims to ensure that no family is burdened with catastrophic expenses due to TB. It may be an uphill battle to reach these targets, but WHO has assured that significant strides are made by setting specific targets every period. — Mark Louis F. Ferrolino