Respiratory Infections Including Tuberculosis

Tuberculosis is an infectious disease that is caused by a germ or bacteria called Mycobacterium tuberculosis. Most commonly TB affects the lungs; however it can affect any organ system in the body. It can affect people of any age, class or community. It is spread from one person to another when a patient affected by active TB disease coughs and sprays the bacteria into the air. These bacteria can then be inhaled into another person’s lungs. However, inhaling the TB bacteria does not automatically mean that one gets the disease. In most instances, the body’s natural defense mechanism or immune system is able to handle the infection.

This interaction between the body’s immunity and the bacteria causes some inflammation. Usually, the cells of the body’s immune system surround the bacteria and seal off the area, forming structures called granulomas. The bacteria though sealed off can remain in the body for years without causing any symptoms and this form of sealed off infection are called Latent TB infection.

In some instances, this latent infection can progress to active disease. When the body’s immune system is low or if the amount of exposure is large either in amount or exposure over a long time, the bacteria gets a chance to grow and cause active disease,

Only about 10% of those infected by the bacteria will develop active disease.

Symptoms of Tuberculosis The common symptoms of tuberculosis affecting the lungs are as follows:

TB in the Lungs

TB can cause inflammation in the lungs similar to the pneumonia caused by other bacteria. It can also cause fluid to accumulate in the lining surfaces around the lungs. This is called pleural effusion. It can also cause enlargement of lymph nodes within the chest.

The main difference between inflammation and disease caused by tuberculosis and other bacteria is that the long term effects of the TB infection can cause significant damage and loss of function.

TB risk factors

Anyone can be infected by TB by breathing in the germs. However, not everyone will develop active disease. There are certain risk factors which increase the chances of developing active disease.

All conditions which lower the body’s immunity can increase the risk of TB Long Term Steroid Therapy for Other Conditions, Also Some Medications for Autoimmune Conditions and Cancer Chemotherapy Previous Cancer, Diabetes Mellitus, Malnutrition, Low Body Weight, HIV Infection

Extremes of Age – The very young and the very old

Certain populations are more susceptible to TB- such as those in prisons, health care workers

It was earlier thought that TB is a disease of lower socio- economic strata or poor hygiene. While overcrowding is associated with a higher incidence of TB, TB can be seen in people of all strata of society.

It is prevalent in all countries; however the incidence is higher in Asian and African countries. TB is an endemic disease in India. In addition, India, China and Russia are the countries with the highest number of drug-resistant TB cases and the government and health care community have taken several measures to control it. It remains one of the biggest challenges of our times.

How Is TB diagnosed?

Your doctor will evaluate the Symptoms, History of exposure, Clinical physical examination findings and decide on the tests necessary. The tests may include a skin test, chest X-ray, Sputum tests and blood tests. Further tests like Chest CT scan may be required.

In some instances diagnostic procedures like pleural tapping (removing fluid from the lining of the lungs). We believe that as far as possible all patients must have tests done to obtain sample for Culture and Antibiotic Sensitivity testing. In some cases, Cultures can be obtained through simple tests like Sputum culture. In some cases, your doctor may advise you to undergo a bronchoscopy (endoscopic inspection of the airways with a camera) to collect samples to establish a diagnosis of TB with a lavage. If enlarged lymph nodes are seen on CT scan, mediastinal lymph node sampling may be necessary to obtain samples. Lymph node sampling can also be done using state-of-the-art technology like Endobronchial Ulltrasound guidance to obtain samples for culture from affected lymph nodes in our Interventional Pulmonology center. Pleuroscopy and pleural biopsy is another procedure which is done to obtain tissue samples for culture.

What Is the treatment for TB?

TB is treated with a long term course of antibiotics. Unlike common bacterial infections, effective TB treatment requires multiple antibiotics for a minimum duration of 6 months. In some instances, such as TB affecting the bones or brain, the duration of treatment can be over a year.

There are a few challenges to the treatment of TB:

Lifestyle changes

Patients with active TB disease are advised to stay home and avoid going to work or school for a few weeks as active TB in the lungs is contagious. This is to prevent the spread of disease to other people. Your doctor will be able to tell you are no longer infectious, when it is safe for you to resume going out and resume normal activities.

In the early part of the treatment, it is important to wear a mask, cover your mouth and nose when coughing and sneezing to protect other family members from the increased risk of infection.

Make sure that rooms are well ventilated; exhaust fans can be placed at windows to ensure that exhaled bacteria are carried out.

Taking the medications regularly without fail is the most important aspect of TB management. Set up a daily schedule, a reminder alarm; ask a family member or friend to remind you, mark days off on a calendar for medications and doctor’s appointments. Some patients may be required to take Directly Observed Therapy (DOT).

After completion of the entire prescribed regimen, the doctor will advise the patient to stop medications and plan a follow up visit to ensure good health. However, they will not need any further medicines.

What is MDR-TB?

Multi-Drug resistant TB (MDR-TB) is a form of TB infection in which the 2 most reliable antibiotics are no longer effective as the bacteria have developed resistance to them. India has the largest number of cases of MDR-TB. Though these are still only about 3.3% of all TB cases, given our large population, it is cause for concern and we are committed to ensuring that patients are given appropriate treatment to ensure that these numbers do not rise alarmingly.

Other more resistant forms of tuberculosis have also been identified which are resistant to three and sometimes more antibiotics which have traditionally been effective in eliminating TB bacteria (XDR-TB). These cases require much longer and closely monitored drug treatment regimens sometimes lasting as much as 2 years or more.

In order to overcome these challenges, it is absolutely essential for the patients to understand the need for strict adherence to the medication regimen. The danger of incomplete or ineffective treatment is the emergence of more dangerous, harder-to treat forms of multi-drug resistant TB.

However, the majority of the patients can be effectively treated if they follow the prescribed medications for the entire duration of the treatment regimen. It is important to follow up for regular monitoring of blood tests or X-rays as prescribed by your doctor.

Frequently Asked Questions

TB infection is acquired by breathing in the bacteria into our lungs. Since TB is endemic in India, TB infection is not a reflection of hygiene or social setting. A lot of famous personalities and celebrities have contracted the disease and successfully been treated with antibiotics.

In the past TB was associated with great social stigma. Even today, many people consider this a matter to be hidden. It is important to understand that there should be NO SOCIAL STIGMA to be associated with TB.

TB bacteria are spread through the air when someone with active disease coughs and expels the bacteria suspended in microscopic droplets. These bacteria are then inhaled into the lungs and can grow there. The most common form of TB disease is in the lungs or lymph nodes. However, in some instances, the bacteria can spread to other parts of the body via the blood stream and infect other organ systems as well.

Active TB disease in the lungs is highly contagious and infectious. Until the patient has taken a few weeks of therapy, or until the doctor has determined from sputum tests that it is safe to resume normal activities, patients are advised to not go to work or school.

A face mask (N95 face mask which fits snugly over the nose and mouth, however it allows patients to breathe and speak comfortably) can reduce the spread of bacteria and is advised for use at home to protect other family members. However, considering the risk to the general population, patients are not advised to resume daily public activities until a few weeks of treatment and the doctor considers them to be at no risk for spreading the disease. TB is a reportable disease and in many countries, the law allows doctors to take actions to restrict
patients’ movements to protect the general population

Patients with active TB disease in the lungs are considered infectious until the first few weeks of treatment as they expel the bacteria into the air when they cough. In other forms of TB disease, such as TB affecting the lymph nodes or intestines, or joints, there are no TB bacteria being coughed up into the air. Hence even though, this patient has TB disease, they are not considered contagious. The restrictions for being in public places do not apply in such cases.

A positive skin test implies exposure to TB bacteria at some point. It is considered a sign of latent TB infection. It is of even greater significance if the skin test was previously negative and has recently turned positive. Not all people who are exposed to TB infection will develop active disease. The chances of developing active TB disease after a recent conversion from negative to positive skin test are greatest within the first 5 years of the test becoming positive. Hence, doctors advise treatment for latent TB infection with a single antibiotic for 9 months in such cases. In some cases, when the skin test has been positive for a long time, it hard to make a prediction on chances of developing active disease. Hence, unlike in active TB disease, doctors cannot mandate patients to take treatment for latent TB infection.

The BCG vaccine is given to newborns to protect them from potentially fatal and permanently damaging forms of TB such as TB meningitis (infection of the covering of the brain) and miliary TB (widespread TB) as newborns are most susceptible. It is about 80% effective. However, the immunity afforded by the vaccine wears off over the years (approximately 10-15 years) Therefore, even with BOG vaccination, after adolescence, a person can become susceptible to and acquire TB disease after exposure.

BCG vaccination does not guarantee lifelong immunity to TB.

Only people with active TB disease who expel TB bacteria into the air can give the disease to others. People who are exposed to TB are at risk for developing TB disease. They should be evaluated by a doctor, tested for possible disease and prescribed treatment for latent TB infection if required.

The minimum duration of treatment for TB is 6 months. The duration of treatment depends on the part of the body affected. There are strict national and international guidelines issued by health care organizations which have defined the duration of treatment. In certain instances, when TB affects the brain, spine, eyes etc, the duration of treatment can be as long as 12-18 months. In some cases when there is multi-drug resistant TB bacterial infection, the duration of treatment may be longer.

TB treatment CANNOT be stopped under any circumstances until the complete regimen has been taken. Patients typically begin to feel better within a few weeks of starting medications. It is absolutely essential that patients continue to take their medications for the entire duration. This is to make sure that the infection is eradicated and that no drug resistant forms of TB develop. The consequences of incomplete treatment can be very damaging and potentially fatal. In some instances, some patients may experience side effects related to the medications and the doctors may advise them to stop the medications for a brief time. The doctors will monitor the patients and their blood tests and resume the medications or prescribe alternative antibiotics which the patient can tolerate better However, under no circumstances can TB medication be discontinued without consulting a doctor

Your doctors will provide you with information related to the specific antibiotics prescribed. The common side effects are orange- red color of the urine, occasional nausea, abdorninal complaints, and change in liver function tests. Your doctor will monitor closely for any side effects and modify the treatment as needed. However, more than 95% of patients can take the medications comfortably without difficulty

After completing TB medication regimen, patient is considered to be cured of TB. However, since the mode of infection of TB is by breathing in the bacteria in the air, it is possible that once can get a re-infection with TB. The best way to minimize the risk of re-infection is by adopting a healthy life style which will boost the body’s natural immunity. A good diet and exercise, following health habits can reduce the risk of re-infection. It is important to tell all your doctors about any past TB infection. This will allow them to be vigilant for any possible re-infection. With a coordinated comprehensive approach, all patients can overcome TB infection and lead healthy productive lives.