What is Pulmonary Tuberculosis?
Although more than 20 million suffer from the ravages of tuberculosis around the world, it has largely been removed from modern society. Improved standards of living and nutrition, plus the development of high-powered antibiotics that have a specific beneficial effect are the reasons. However cases are still occurring with disturbing regularity and it is no time fir complacency.
Pulmonary tuberculosis, commonly referred to as “TB,” is a serious disease of the lungs produced by the germ with the tongue-twister name of Mycobacterium tuberculosis, or simply “tubercle bacillus.” Throughout the world, this disease is still a major killer, but in Western lands, over the past 80 years. There has been a dramatic and massive decline in its occurrence. In Australia, its incidence has scaled down to about 60 deaths annually, although over the past couple of years there has been a slight upswing in reported cases which is causing disquiet in official and medical circles. The view has been expressed that doctors today rarely consider TB as a possible diagnosis and for this reason may be overlooking cases and failing to make the full investigations that would produce such a diagnosis.
Awareness is reducing in the general community and, as fewer cases are around, a whole new generation of people is growing up hardly knowing what the disease is all about, let alone having ever seen a case. The same applies to the newer generation of doctors.
However, although the disease has declined spectacularly in the developed Western countries, it still races on with alarming speed in the Third World. Countries such as India, China, Africa and South America register enormously high levels, and the figure of 10 million cases of infectious tuberculosis is probably a relatively accurate “guesstimate” today.
In the Western world, the death rate from pulmonary tuberculosis fell dramatically and swiftly from 125 to 43 persons per 100,000 of the population in the period between 1900 and 1950. However, over the past couple of decades, the development of specific and very potent forms of chemotherapy has also played a very significant part in reducing the frequency and severity of tuberculosis.
Pulmonary Tuberculosis Symptoms
Tuberculosis may creep on insidiously and without warning. By the time the well-known, significant symptoms appear, the disease is well advanced. Cough, with production of sputum (probably blood-stained), and breathlessness occur only with a well established disease. Generalised symptoms such as weight loss, fever and copious sweating are also indications of an advanced state of TB.
In the past in many cases (probably the majority), TB was detected during mass radiograph screenings, or if the patient happened to have a chest X-ray for some other purpose. At this stage, symptoms are usually totally absent. Sometimes situations call for a chest X-ray, such as a chest infection that is not responding to the usual forms of treatment within a reasonable period of time.
Left untreated, the lung substance is gradually destroyed as “caseating” lesions (wax like material) develop in the diseased parts. The lung structure may become destroyed, thus reducing the amount of lung tissue available for the body’s respiratory requirements. An unusual form of the disease, termed “military tuberculosis,” can occur in which there is a very fine spread of the disease throughout the lung substance. Even with radiography, these cases are sometimes missed by the experienced X-ray interpreter.
Pulmonary Tuberculosis Treatment
Indeed, the situation has now been reached that practically anyone with active TB can be cured. It is merely a matter of time, and sticking to the recommended forms of medication. No longer are the long drawn out forms of therapy of a few decades ago being used. Many persons can resume their usual activities, and live a relatively normal life. Also, their expected life span following a cure is about the same as that of the rest of the population.
In the unprotected situation, infants under the age of three years are particularly liable to infection. After this, there is relatively good protection in youngsters and adolescents. This also applies to young adults. Over the age of 40 years the male is much more likely to succumb to infection than the female. Many in the over 40 years age group were infected during their youth, and re-infections in this group are likely. Factors such as cigarette smoking may play a part in reactivation of the disease that has been dormant for many years.
Today, younger people are rarely exposed to infection. In many communities protection against TB is available in the form of the BCG vaccination, and large numbers have received this. Although the spread of the human strain of the TB germ is the most likely to infect other humans, the bovine (cow) strain may also play a part. However, in recent years with mass TB testing of dairy herds and pasteurisation of milk supplies, this source has largely been removed as a possible risk in most modern communities. During the next 20 years there was another dramatic fall, to 4.6 per 100,000 males and to the low figure of 1.6 for females.
Pumonary Tuberculosis Prevention
The first dramatic fall has been attributed to the massive improvement that occurred in the Western world in general with improved social and economic conditions. Reduced overcrowding with better housing and improved sanitation and water supplies greatly improved the general level of living standards, and collectively they have proved to be effective in reducing the incidence of pulmonary tuberculosis.
The tubercle bacillus is freely shed from infected persons in the sputum that is coughed up from the lungs. This may persist for a long time, particularly if not exposed to the sunlight, which acts as a sterilising agent. This is the most common form of spread. Therefore, in times when overcrowding was the rule, it was very easy for persons to spread it readily to those in the nearby environment. The germ is spread in the air by droplet infection. Thus, if an infected person coughs, millions of germs may be sprayed into the surrounding environment, and anyone present is at risk.
With modern housing and less crowded situations, the risk of all this has largely been reduced. Also, with a general increase in the nutritional level of the community and an increase in personal vitality; the risk of contracting the germ is much less. This is one of the major advantages of living in today’s modern world. Nevertheless, these sophisticated conditions are not present in many developing countries, and this is why the disease is still rife in so many impoverished lands even today.
Very small numbers of germs may establish infection in a person exposed to the germs. The tubercle bacillus has a predilection for the lung tissue, although tuberculosis may occur in virtually any organ of the body. In the lung, in the primary infection, it is the upper part that is usually affected first.