The World Health Organization declared the new emergence of tuberculosis a global health emergency in 1993, but infection rates are still on the rise. What contributes to this increase and what can individuals and governments do to stop it

March 24 has been designated World TB Day by the World Health Organization (WHO) in an effort to bring more attention to this urgent issue of public health. The day was chosen because it is the day Dr. Robert Koch presented his discovery of the bacillus that causes the disease in 1882, when the germ-theory of illness still was not widely accepted.

The discovery of antibiotics marked the beginning of a revolution in global health. WHO established plans to eradicate or eliminate some bacterial diseases, beginning with smallpox in 1967. That disease was declared officially eradicated in 1980. Tuberculosis (TB) was also one of the diseases targeted for elimination. The elimination goal was defined in 1991 as a reduction of prevalence to a level below one case per million population.

According to the Centers for Disease Control and Prevention (CDC), In the late 19th century, tuberculosis (TB) killed one out of every seven people living in the United States and Europe.Today, it remains the second largest killer in the world, with two million victims annually. With their widespread production and use beginning in the 1950s and 1960s, the remarkable effect of antibiotics on TB caused most doctors to believe that the disease would be eradicated by the end of the century. However, before the turn of the century it was clear that not only was it not decreasing, it was increasing and mutating into multi-drug resistance strains (MDR-TB). According to WHO, about eight million people became sick with TB in 1999 alone. Currently, one-third of the world’s population is infected.

The road to elimination gets longer.

In recent decades a number of complicating factors have made global control of TB a more and more elusive goal. Two of these are the abuse of antibiotics and the spread of HIVAIDS.

AIDS, as is commonly known, is a disease involving immunosuppression. The virus that causes AIDS attacks the lymphocytes, the protective police force of the body. The specific type of lymphocyte attacked is the helper T lymphocyte, which actually coordinates all the other efforts of the immune system. Without helper T cells to organize an attack on invaders like viruses and bacteria, the body is defenseless against the simplest kind of infection. Things that the body could normally fight off, such as pneumonia or influenza, suddenly become deadly infections.

Tuberculosis is one such infection. It is very common for people to become infected with TB but not experience illness. A thick waxy coating envelops the bacterium when the immune response of the body quarantines it at the site of infection. The bacterium then lies dormant in the body, locked away in macrophage cells, until something causes a suppression of the immune system (such as AIDS or even adverse conditions like stress or malnutrition). Then, the bacterium is able to overcome its wardens and fulminant illness occurs. It is only during this stage, clinical illness, that a person infected with TB becomes infectious to others.

Then, rather than being stymied by lymphocytes in various parts of the body, the rapidly reproducing TB bacteria have migrated to the lung tissue and are present in tiny droplets every time the infected person coughs, sneezes, talks or breaths. As you can see, someone who is HIV-positive and contracts TB is more likely to experience full-blown TB (and therefore become infectious) than a person who is HIV-negative and contracts TB.