TB is of two types- Pulmonary and Extra pulmonary.
TB of the lungs is called Pulmonary TB and accounts for 80% of all TB cases.
TB affecting any other part/organ of the body like brain, lymph nodes, bones, joints, kidneys, larynx, intestines, eyes etc. is called Extra-pulmonary TB.
Only microbiologically confirmed pulmonary TB patients are infectious. Patients can suffer from both pulmonary and extra-pulmonary TB simultaneously.
Although TB is an infectious disease, all forms of TB are not infectious.
When a pulmonary microbiologically confirmed TB patient coughs or sneezes, TB bacteria spread into the air as droplets. People nearby may breathe in these bacteria and become infected.
An infectious case of TB, if untreated, can infect 10-15 people in one year.
Extra-pulmonary TB is not infectious.
TB does not spread through handshakes, using public toilets, sharing food and utensils, blood transfusion and casual contact.
TB is not a hereditary disease
In most people who breathe in TB bacteria the body's immune system is able to fight the TB bacteria and stop them from multiplying. This is called TB infection. People who are infected with TB do not feel sick, do not have any symptoms and cannot spread TB.
If an infected person's immune system cannot stop the bacteria from multiplying, the bacteria eventually cause symptoms of active TB which is called TB disease. Only 10% of all people with TB infection may suffer from the TB disease.
People with conditions like HIV, Diabetes Mellitus, Malnutrition and those on treatment with immunosuppressant drugs (anti-cancer, corticosteroids etc) are at a greater risk of developing TB disease once infected.
Close prolonged contact with a sputum positive pulmonary TB patient.
Overcrowding
Smoking
HIV infection
Malnutrition
Diabetes Mellitus
Patients on immunosuppressive drugs (anti- cancer, Corticosteroids etc.)
Certain lung diseases like Silicosis
TB can occur at any age but is commonly seen in persons between 15-45 years of age which is the economically productive age group.
Disease occurs in both the genders. However, males are affected more as compared to females.
Symptoms of TB are specific to the site affected although there are some symptoms common to all types of TB
Symptoms of Pulmonary TB are:
Persistent cough for 2 weeks or more
Chest pain
Shortness of breath
Blood in sputum
Symptoms of Extra Pulmonary TB depend on the site/organ involved.
Brain TB- Meningitis
Lymphnode TB-Enlarged Lymphnodes
Bone TB- Destruction of bones and Joints
Abdominal TB –Intestinal Obstruction
Common symptoms:
Weight loss
Fatigue
Evening rise of temperature (Fever)
Night sweats
Tuberculosis is diagnosed by demonstrating TB bacteria in clinical specimen taken from the patient. While other investigations may strongly suggest tuberculosis as the diagnosis, they cannot confirm it.
Pulmonary TB is primarily diagnosed through Sputum smear microscopy. In this test patient’s sputum is examined under a microscope for the presence of TB bacteria.
In Extra pulmonary TB it is usually difficult to demonstrate TB bacteria, hence the diagnosis is made on the basis of clinical suspicion and special tests depending on the organ affected. e.g TB of the lymphnodes is diagnosed by a special test called FNAC (Fine Needle Aspiration Cytology)
In addition, CBNNAT machines are being used, which is a molecular test for diagnosing TB. In addition to the disease, it also mentions about the drug resistance to one of the potent anti TB drug Rifampicin.
Abnormalities on chest X ray may be suggestive but are never diagnostic of TB unlike smear examination in which TB bacteria are seen.
Several diseases can mimic TB on X ray such as Pneumonia, Silicosis, Bronchiectasis etc.
X rays do not help in differentiating between active and healed TB lesions. X rays therefore play only a supportive role in the diagnosis of pulmonary TB, mainly in cases where sputum smear result is negative
TB is completely curable if the prescribed drugs are taken regularly for the full duration.
TB is treated through a combination of following drugs:
Isoniazid (INH)
Rifampicin
Pyrazinamide
Ethambutol
Streptomycin
Combination of drugs is administered to kill all the bacteria and prevent them from becoming resistant to one or more drugs. The treatment is given for 6-9 months.
Very few people develop side-effects to anti TB drugs.
Most of these side-effects are minor and include vomiting, nausea, loss of appetite, joint pain, orange/red urine and skin rash. These can be easily managed with simple medicines and without stopping the anti TB drugs.
In some very rare cases serious side effects like deafness and jaundice may develop which may require temporary withdrawal of some of the anti TB drugs.
BCG (Bacille Calmette-Guerin) vaccine is currently the only vaccine available against TB.
Though BCG appears to reduce the risk of serious childhood forms of TB it is not effective in preventing TB in adults and children.
In the absence of an effective vaccine the only way to prevent TB is by early detection and treatment of infectious TB patients.
Patients with sputum positive pulmonary disease should cover their mouth while coughing, sneezing and talking to reduce the transmission of TB bacteria.
HIV is the strongest risk factor for tuberculosis among adults as it debilitates the immune system.
An HIV positive person is 20-40 times more likely to develop TB disease once infected with TB bacilli as compared to an HIV negative person.
TB is curable in HIV co-infected patients with the same medicines which are used to treat HIV negative TB patients.
However, HIV/TB co-infected patients require other medications like Antiretroviral therapy (ART) and Co-trimoxazole preventive therapy (CPT) to prevent other opportunistic infections.
Multidrug-resistant TB (MDR-TB) is defined as the disease caused by TB bacilli resistant to at least isoniazid and rifampicin, the two most powerful anti-TB drugs.
MDR TB, like all drug resistance TB, is a man made phenomenon caused by irregular or inadequate treatment when Patients do not take all their medicines regularly for the required period.
Health care providers prescribe inappropriate treatment regimens
The quality and supply of drugs is unreliable.
MDR TB is diagnosed through a special test called culture and drug susceptibility testing (C & DST) which can be performed by some specialized laboratories.
Conventional C & DST (also called solid C & DST) takes 3-4 months to diagnose MDR TB.
Newer rapid diagnostics for MDR TB are now available, like liquid C & DST, and molecular tests (CBNAAT & Line probe assay) which give results much earlier.
RNTCP or the Revised National Tuberculosis Control Program is the Tuberculosis Control Initiative of the Government of India.
It is based on DOTS- the global TB control strategy recommended by WHO.
The program was launched in 1997 and expanded to the entire country in 2006.
Programme has now been renamed as National TB Elimination Programme (NTEP)
Under NTEP the treatment is available free of cost at all government and identified private and NGO health facilities called as treatment centres. There are about 4 lakh such centres in the country.
Once the diagnosis of TB is confirmed the patient is treated with a standardized regimen which is based on past history of treatment for TB.
The regimen is given in 2 phases – Intensive phase (IP) and Continuation phase (CP)
‘New TB patients’ i.e. patients who have never been treated for TB in the past (both pulmonary and extra-pulmonary) are treated for 6 months with the following regimen:
Cap Rifampicin, Tab Isoniazid, Tab Pyrazinamide and Tab Ethambutol for 2 months i.e. IP followed by
Cap Rifampicin, Tab Isoniazid and Tab. Ethambutol for 4 months i.e. CP.
All drugs are given on daily basis in FDC’s (Fixed Drug Combination). Total pill burden is reduced to make it more convenient for the patients.
The only criteria for becoming a treatment provider is that he/she should be acceptable to the patient and accountable to the health system. The identified treatment providers are given adequate training on administration of drugs, identification of adverse reactions, follow up and retrieval of the patient in case of treatment interruption.
Treatment providers include
Staff of the health system (Doctors, Nurses, MPW, ANM, pharmacists etc)
NGOs
Private practitioners
Community volunteers – family member, Teachers, religious leaders, anganwadi workers, dais, ASHAs, Shop owners, cured TB patients etc.
Once a patient has been diagnosed to be suffering from TB a home visit is undertaken by the health worker for address verification and for counseling and educating the patient and family members on the disease and importance of regular treatment.
Contact details of the patient and a responsible family member/neighbor/friend/relative are recorded on the patient’s treatment card in case the patient interrupts treatment.
If a patient misses a dose the DOT provider contacts the patient by a house visit and encourages him to return for treatment. In case the DOT provider fails to retrieve the patient the supervisory staff (i.e. the Senior TB supervisor, Medical Officer etc.) are informed for taking necessary action.
In addition, ICT interventions like 99 DOTS are being used by the programme for adherence monitoring.
Under NTEP there is a provision of ‘Transferring Out’ to ensure continuity of treatment if a patient has to shift his residence to an area which is outside the TB unit in which he/she has been registered. This could be another district or even another State anywhere in the country.
The treatment is continued at the treatment centre nearest to the new residence of the patient.
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