Q: My 58 years old father has been diagnosed with bone tuberculosis in the fifth ring from the bottom of his spinal cord last month. The fifth ring from the bottom of the spinal cord is almost damaged. He is now taking DOTS (II level) treatment with streptomycin injections. But he is still feeling pain in his back near the fifth ring of the spinal cord from bottom. Is my father taking the right treatment?

A:Tuberculosis (TB) of the bone like other forms of tuberculosis affecting other areas of the body is caused by the bacterium Mycobacterium tuberculosis. In most cases, especially in adults TB of the bone is a complication of a previous or concurrent episode of pulmonary tuberculosis. However, in as many as 1/3rd of cases no evidence pulmonary disease may be found. Bone TB of the spine (back bone) is a type of extra-pulmonary TB (a term used to describe TB of organs other than the lungs). The disease may affect both the vertebral bones and the inter-vertebral joints, and usually occurs in the lower thoracic vertebra and the lumbar spine in about 90% of cases. It is generally manifested by certain constitutional symptoms (such as fever, weight loss), and some localised signs and symptoms (such as back pain, swelling or deformity at or near the vertebra/spine, neurologic deficits such as diminished sensation, weakness of the limbs, difficulty in urination, impotence, paralysis of limbs etc). The pain, often severe, which accompanies many cases of TB spine is due to compression of the spinal cord, or involvement of the nerve roots. However, it must be remembered that there are other diseases, which may have similar clinical presentation. These other diseases are generally considered (by experienced physicians) before reaching a diagnosis of spinal TB. Some of these other diseases which may have clinical signs and symptoms like bone TB of the spine include septic arthritis or pyogenic osteomyelitis of spine, metastasis or spread of cancer to the spine from other areas of the body, a form of blood cancer called multiple myeloma, and in certain areas of the world another bacterial infection called brucellosis, etc. Bone TB affecting the spine is diagnosed by medical history, clinical examination (of the back and general physical examination), imaging investigations of the spine (such as X-ray, CT scan or MRI scan) and certain supplementary investigations such as (high ESR or CRP on blood tests). Specific diagnosis of bone TB of the spine is achieved by histopathology and microbiological investigation of tissue or pus obtained after biopsy or needle aspiration of materials. If the bacteria (M. tuberculosis) is cultured from these samples it would be important to do a sensitivity test on the isolate since in India about 3% of primary TB cases about 15% of re-treated cases of TB have got MDR or multi-drug resistant TB. In cases of MDR TB the treatment is often more difficult, chances of failure of treatment and complications are higher. In all cases of extra-pulmonary TB including bone TB of the spine it would be important to rule out pulmonary or lung TB, and consider doing an HIV test. In the absence of pulmonary TB bone TB is not generally infectious to others except in situations where the pus may come out through the skin in the form of a sinus. In case of co-existing lung TB the usual precautions concerning pulmonary TB must be followed in order to prevent spread of infections. These include observing respiratory etiquette (covering the nose or mouth while coughing and sneezing), using a surgical mask in a infectious period, avoiding contact with other vulnerable individuals (e.g. children, immunocompromised persons), and remaining in a separate room in the infectious period (especially while in a hospital to avoid contact with other vulnerable patients/individuals). Carers of patients with active pulmonary TB may wear a face-mask (ideally an FFP3 or N95 respirator for health care workers, otherwise a surgical mask) while entering the room to reduce chances of transmission [other practical measures in resource limited community settings may include improving natural ventilation through open windows and sunlight]. In patients adhering to the recommended treatment the sputum is generally rendered non-infectious within 2 weeks in case of drug sensitive TB. The treatment duration for bone TB is usually for 9-12 months. The treatment generally consists of taking 4 drugs for the first 2 months and at least 2 drugs for the remaining duration. Compliance or adherence to treatment is very important because failure to do so may lead to drug resistant TB, and development of complications. The complications arising due to bone TB of the spine may involve development of spinal deformity, neurologic deficits (paralysis). Surgical treatment is an option to minimise or treat complications. DOTS (Directly Observed Treatment, Short-course) is a TB control strategy initiated by the WHO and implemented in India’s Revised National Tuberculosis Control Programme to effectively treat TB. This involves administering the anti-TB medications to the patient under direct observation. This significantly reduces the chance of non-compliance to medications, reduces chance of development of MDR-TB, increases cure rate to up to 80%, and reduces chances of complications. During the course of anti-TB treatment it would be important to monitor the patient for possible side effects of therapy by regular clinical check up and routine investigations such as full blood count, urea/creatinine/electrolytes/uric acid, CRP/ESR measurement, LFT (liver function test). Repeat imaging studies (X-ray/CT scan) may have to be done to monitor course of disease as per the discretion of the physician.