Tuberculosis is a communicable bacterial disease resulting from infection with the tubercle bacilli , mycobacterium tuberculosis (Mtb).

Tuberculosis is an ancient disease with a lineage that can be traced to the early history of mankind.

It has been called by many names, the most common one being consumption.

Mtb infection in humans is generally acquired by inhalation of droplet nuclei that contain tubercle bacilli .

These droplet nuclei are expelled into the air when someone suffering with tuberculosis coughs, sneezes, or talks.

The droplet nuclei, when inhaled, travels to the lungs. The body's immune system fights back and kills some of the bacilli, and encapsulates them. This is known as TB infection, and a person can remain infected for many years and not have any signs of illness, nor are they infectious and able to spread the bugs to others.

TB disease can occur many years after infection. This is when the tubercle bacilli start to multiply and "break out'' of the capsule they were contained in.

A person will now have signs of illness such as a cough, tiredness, loss of weight, weakness and fever. They are also infectious and able to transmit to others.

Although tuberculosis is not a highly infectious disease, certain people are more at risk than others, for instance people who have had prolonged or frequent contact with an infectious person, i.e. household members.

Others who are at risk are foreign-born persons from countries that are known to have a high prevalence of Mtb (Asia, South America, Mexico), alcoholics and injection drug users, low income populations and the homeless, persons with HIV infection and other medical conditions such as diabetes mellitus, end-stage renal disease and certain blood disorders to name a few. Testing for Mtb requires having a simple test.

There are two tests that can be administered. One is the Tine test, which is a simple prick on the forearm with a four prong needle, or the PPd test, which is an injection of tuberculin under the skin on the forearm. The results can be known within 48 to 72 hours.

A positive reaction (red bump), may indicate the presence of tuberculosis infection, but not tuberculosis disease. Follow-up tests such as a chest x-ray and sputum specimens would be required to determine TB disease.

Treatment depends on whether a person has TB infection or TB disease. If a person has been diagnosed with TB disease, they will need a multi-drug regimen for at least one year.

Presently, persons with HIV infection are advised to have the test for Mtb, as throughout the world and here in Bermuda, it has been proven that there is an association between HIV infection and Mtb.

Currently it is estimated that at least eight million new cases of Mtb occur each year in the world and that there is an estimated eight to 10 million people in the US who are infected with the tubercle bacillus .

TB disease can be cured as long as the infected person takes the medication as prescribed.

Further information can be obtained by calling the Department of Health at 236-0224 ext. 326. Rhonda C.K. Daniels Nurse epidemiologist Department of Health.

HEALTH AND SOCIAL ISSUES HTH