Combatting TB Bacteria

Combatting TB Bacteria

Tuberculosis (TB is short), one of the biggest public health problems in Nepal, has remained so due to various reasons such as the ability of the bacteria to remain latent within the body. Another reason for its persistence is the ease with which it can spread from one person to another through an aerosolized droplet from a cough or a sneeze. Yet another reason is its opportunistic qualities and hardiness coupled with the small bacterial load that is required to be infected as well as the numerous medications required to combat it in various phases of its long life cycle.

So should we be scared of it? What is this bacterium really like and what are all the classical signs and symptoms of tuberculosis? Are there other diseases that have the same clinical features? What are the investigations done to confirm whether a patient has TB or not and what are the set of medications used to combat the disease?

TB is caused by the ‘Mycobacterium tuberculosis complex’, and it spreads through droplet infections when someone infected coughs or sneezes. As little as 10 individual bacteria can produce an infection in the susceptible population. It usually affects the lungs but can also affect other organs in the body. The people at the most risk are the ones who live in overcrowded neighbourhoods and homes, where basic sanitary measures are hard to achieve and are not able to get a nutritious diet because of abject poverty. The other people that are at the most risk are people under immunosuppressive drugs or have HIV, tumors of the lymph nodes or white blood cells, diabetes mellitus, renal diseases, malnutrition and/or recent measles.

A number of steps results in the formation of the classical pathologic lesion in Primary Pulmonary TB. Years later, reactivation and re-infection results in Post Primary Pulmonary Tuberculosis but before that it can cause meningitis, swelling and pain of the lymph nodes, abdominal pain that may be involving the kidneys with the presence of blood and pus in the urine. However, in the initial stages the patient will usually show symptoms such as night sweats and fever, weight loss and loss of appetite, a sense of generalised weakness, chest pain with productive cough mixed with blood. Besides this there are an array of types of TB and the organs it can involve such as Cryptic TB, which has subtle and generalised symptoms, TB lymphadenitis in which there’s swelling and pain in the lymph nodes, Gastrointestinal TB which presents with a multitude of abdominal symptoms, Pericardial disease, Central Nervous System disease, bone and joint disease and genitourinary disease.

A number of lab investigations can be done to diagnose TB. Sputum samples are primarily taken to diagnose pulmonary TB. Other bodily fluids are taken to diagnose TB of other organs in the body such as cerebrospinal fluid, abdominal fluid and synovial fluid. These samples are put in specialised culture media and also undergo specialised stains to be viewed under a microscope. Chest X rays are usually diagnostic of Pulmonary TB in the later stages of the disease. Another famous test is the Mantoux test which involves an intra-dermal injection and examination of the site of the injection 48 hours later.

There are always possibilities of other diseases presenting with similar signs and symptoms. Doctors will usually have to rule out pneumonia, lung cancer, pulmonary infarction which is a loss of blood supply to a certain area of the lung, sarcoidosis and other atypical organism infections.

There is a list of drugs used to combat TB and are divided into first line drugs and second line drugs. The first line of drugs consists of Isoniazid, Rifampicin, Pyrazinamide, Ethambutol and Streptomycin. These drugs are prepared in a calendar pack and must be taken in front of a health care worker according to the DOTS+ guidelines set up by the Ministry of Health, National Tuberculosis Centre of Nepal. The second line drugs are Aminoglycosides, Thioamides, Fluoroquinolones, Cycloserine and Para Amino Salicylic acid which are used in case of Multi Drug Resistant TB and Extremely Drug Resistant TB. These two forms of tuberculosis are becoming more of a problem because less and less of these drugs are found to be active against the newer strains of Mycobacterium that causes the disease. This is a result of both the bacteria finding favourable conditions to mutate into a stronger form of the Mycobacterium species and more so because of patients skipping doses of their medicine and leaving the treatment altogether before completion.

The reasons as to why these patients may be defaulting are usually due to the first line drugs having a range of side effects varying from rashes, numbness and tingling sensation of the hands and feet, liver dysfunctions, kidney dysfunctions, blood disorders, nausea, vomiting, joint pain and disorders of hearing. However, there are vitamins and other non pharmacological measures that can be taken to neutralize these adverse effects. It is also very important to remember that the benefits of anti-tubercular therapy outweigh the risks of not being under treatment. An infected person who is not under treatment is a walking hazard to other people as well.

The Ministry of Health, National Tuberculosis Program has been doing a good job in raising awareness and controlling the disease to the best of its abilities although according to their own information there are 20,000 new cases and between 5,000 to 7,000 deaths annually. Being a developing nation it is a matter of pride that Nepal will soon be reaching a development goal in significantly controlling the disease. Immunologically the majority of the population is strong enough to resist infection but it is important to stay safe.

Ask people to cover their mouths when they cough and sneeze, discourage people from spitting, discourage and ultimately stop smoking, wear masks while outdoors in areas of high air pollution, eat fruits, vegetables and other nutritious food and remember to keep yourself and your surroundings clean.