TB exists on an epic scale in India with this country accounting for a third of the world's entire TB burden. 300 million Indians are infected, and at least 14 million have active disease. At a conservative estimate, each year, 500,000 people die of the disease which works out to 1 death from TB every minute, a grim statistic that has not changed over the decades.

The great Robert Koch showed that TB was an infection caused by a bacteria called Mycobacteria Tuberculosis. Only the pulmonary forms of TB are infectious: 1 untreated case going on to infect about 10 contacts over the course of a year. Infection is spread by droplets transmitted when the patient coughs. Within a few weeks of starting effective treatment the patient ceases to be infectious to his family and close contacts. Till then great care must be taken to cover the mouth whilst coughing.

Symptoms: Fever and cough which persist for more than 2 weeks are the cardinal symptoms of TB. Coughing up of blood is another important symptom. Weight loss and night sweats may occur.

Forms of TB: Pulmonary or lung involvement is most common but pleurisy (fluid collecting outside the lung) and gland enlargement in the neck or chest are other ways TB can commonly present. TB can occur in almost every organ of the body including brain, bone and abdomen.

Diagnosis: TB is often difficult to diagnose. Sputum tested in a reliable laboratory is the most specific test but a patient may have TB yet have a negative sputum analysis. There is no blood test that can reliably diagnose TB and a positive skin test does not denote the patient has active TB as it is positive in those with latent/dormant TB. Chest Xrays and CT scans are often very useful for diagnosis as well.

Treatment: TB can be cured if a combination of anti-TB drugs are taken for 6 to 9 months. These include isoniazid, rifampicin, ethambotol, and pyrazinamide. What is crucial is that these drugs be taken regularly and under supervision. Irregular treatment is a recipe for disaster and can lead to development of MDR (resistant) TB. Good nutrition and a healthy lifestyle help recovery.

Advances: new drugs and new diagnostic tests are emerging at a fast pace. Attempts to shorten treatment are being looked at as well. Trials of new TB vaccines have begun.