Tuberculosis and HIV both diseases are common in many ways. Both are chronic, debilitating and cause damage to multiple parts of the body. Their close relation is further substantiated by the fact that presence of one facilitates the acquisition of another.
In 2007, about 1.7 million people died of T.B. out of which 456,000 were positive for HIV. Majority of these cases were in Sub Saharan Africa and Asia. Due to AIDS epidemic, T.B. has re emerged in the western developed countries where it had become practically non existent.
Tuberculosis is significant because it is one oppurtunstic infection occurring in immune depressed individuals which can infect many others in the community directly. Many of us may be harboring the germs of T.B. in our bodies but we do not fall sick.
This is because our body’s defense mechanism stops the germs from progressing and multiplying so as to cause disease.
There is more T.B. in HIV affected persons leading to spread of more mycobacteria ( causative germs for T.B.) in the community, making more people sick. HIV positive individuals are not only more prone to develop T.B. but more severe, multidrug resistant and disseminated forms.
Route of acquiring infection for T.B. is the same for healthy as well as immune depressed individuals, i.e. inhalation of droplets through the nose. But in contrast to healthy individuals, there is no defense to contain the infection.
Therefore after entry of germs there is much more chance of the person developing disease due to T.B. The disease develops faster and also spreads at a faster rate in HIV positive individuals. The disease is generally widespread in the lungs by the time it is diagnosed.
To begin with It may be in the form of small lesion infiltrating the lung parenchyma . The infection may drain in to the lymphatic system causing enlargement of the cervical lymph nodes.
It may spread extensively involving large part of the lung parenchyma leading to consolidation of the lung tissue. The covering of the lung may get affected due to the spread of the T.B. germs, resulting in inflammation and exudation (pleural effusion). From here the infection can pass on to the other lung or other parts of the body directly or via the lymphatics or blood stream.
In this entire course, it is no where interrupted as in a healthy person. The person suffers from chronic cough, loss of appetite with resulting weight loss, low grade fever and sweating in the night.
Extra pulmonary T.B. ( i.e. T.B. in other parts of the body apart from the lungs is more common in immune depressed persons as compared to healthy people Any part of the body can be affected.
But commonly it is the brain, intestines, bones, joints, covering of the heart which is involved. Damage caused to these parts results in a myriad of clinical features and organ failure. Untreated the patient can die.
It is easy to diagnose pulmonary tuberculosis on basis of clinical features, but T.B. of other parts is difficult to diagnose because the typical symptoms may not be present and manifestations mimic other chronic diseases.
It needs suspicion on part of treating physician to diagnose it. X-rays help in diagnosis while positive smear examination, cultures and biopsy confirm it.
Treatment once started is for 6 to 8 months a long period. Side effects of anti T.B. drugs add on to the suffering of the HIV patient.
Like some one may be suffering from parasthesias due to HIV which may be augmented by Isonex, used for T.B. Problem in treatment also arises due to interaction between ARV and anti T.B. drugs.
It is important for HIV affected individuals to protect themselves from developing T.B. or if infected avoid transmitting the infection. Good nutritious diet, abstinence from smoking and alcohol, adherence to HIV therapy, all these help to build up the immunity in the body of immune depressed persons.
Thus the risk of acquiring T.B. becomes less. Even if infected, the disease will not become very severe and respond well to treatment.
Covering the mouth while coughing is a simple but very useful measure to prevent spread of T.B. HIV positive individuals with T.B. need to follow it religiously to avoid spreading infection to others. By adopting these measures the prevalence of T.B. can be kept low in the HIV affected people and also the community as whole.
The author is a specialist in Internal Medicine
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