India has more new tuberculosis (TB) cases annually than any other country, ranking first among the 22 high-burden TB countries worldwide according to the WHO Global TB Report 2006. TB remains one of the leading infectious causes of mortality in India, resulting in 3,64,000 deaths annually. There were more than 1.8 million new TB cases in India in 2004, representing over one-fifth of all TB cases worldwide. The estimated incidence rate in 2004 was 168 per 1,00,000 people.
The proportion of TB cases co-infected with human immunodeficiency virus (HIV) was also found to be rising. The association with HIV and increasing multi drug resistant tuberculosis (MDRTB) appears to be a serious issue, especially for the developing nations. Around 10 per cent of people infected with TB actually develop the disease in their lifetimes, but this proportion is changing as HIV severely weakens the human immune system and makes people much more vulnerable. TB causes more deaths among women than all causes of maternal mortality combined, and more than 900 million women are infected with TB worldwide. Once infected with TB, women of reproductive age are more susceptible to developing TB disease than men of the same age. Women in this age group are also at greater risk of becoming infected with HIV.
Some of the signs & symptoms
● Unintended weight loss
● Fatigue
● Slight fever
● Night sweats
● Chills
● Loss of appetite
● Pain with breathing or coughing
According to Dr. Shamma Shetye, microbiologist with Metropolis Health Services, "Rapid diagnosis of TB is important for the treatment of the individual patient and to implement appropriate public health precautions. Timely diagnosis at reputed and accredited laboratories can help in determining the infectiousness and assess drug susceptibility. Since the treatment is prolonged the tests have to be done periodically to analyze the situation and path of treatment. Once TB is diagnosed, tests are conducted every 2-3 months till the patient is declared completely cured. The RNTCP (Revised National TB Control Programme) has also laid guidelines to ensure consistency in treatment".
Tests offered by Metropolis
Metropolis Health Services provides the widest test menu for TB, costs ranging between Rs 100 to Rs 4000. Metropolis maintains high standards of quality and is a NABL, CLIA & CAP accredited laboratory. The quality of equipments and standardized reagents ensure the high accuracy of the results.
Microscopy: A basic screening test with a turnaround time of a day, rapid and the first step to diagnosis of TB.
Culture: A definitive diagnosis of TB that requires identification of the mycobacterium tuberculosis form a specimen. The microbe is made to grow in artificial medium to analyze the strain. The turnaround time is between 3-6 weeks.
Automated liquid culture/rapid culture: This is also a form of culture wherein the turn around time is brought down to as low as 10-15 days. The microbes are made to grow in liquid medium which is fully automated.
Drug susceptibility: This is a drug sensitivity test, primarily to determine that whether the drugs are reacting in the proper direction or not. This is usually recommended after the treatment has begun, ideally 2-3 months from detection.
Molecular methods: Turn around time is as low as a day. It largely deals with rapid detection of the infection, directly from specimens. This is highly sensitive and specific for the diagnosis of M. TB complex.
Quanteferon TB gold test: A highly advanced and gold standard test. It is a whole blood test used as an aid for diagnosing different strains of TB including latent tuberculosis infection ( LTBI). This has been approved by FDA in 2005.
DNA probe: To figure out the strain of the mycobacterium tuberculosis, it is a step forward in identifying the culture.
Some myths & truth
Myth - TB is a life-threatening disease
Truth - TB can be cured by taking a course of medicine
Myth - You can become infected by TB by touching someone who has it or being with someone who has it for a few minutes
Truth - TB is transmitted only by prolonged close contact with coughing infectious patients
Myth - If someone has TB they are infectious
Truth - TB patients who have taken their treatment for 2 weeks and are still taking treatment are usually not infectious
Myth - Only the poor and malnourished get TB
Truth - Anyone can get TB rich or poor and become unwilling host to bacteria
Myth - Once you have TB you are doomed and cannot get treated
Truth - TB treatment is freely available, and correct treatment cures the vast majority of cases.
(The author is HoD, Microbiology, Metropolis Health Services (I) Ltd)