Old age hits tuberculosis

A study, conducted by NGO REACH and a group of TB experts , has found that 38% of older patients are less likely to respond to treatment as effectively as others.

The study, which reviewed records from April to June 2011 from 12 districts in Tamil Nadu, found that of the 10,477 patients registered, older people accounted for 14%. Of this 14%, close to half were new patients. The incidence of TB among older patients was calculated to be 259 per 1,00,000 population as compared 142 per 100,000 in other TB patients.

"While senior citizens may not account for a majority, what came as a shock is the poor outcome in this sub-category . This is disturbing, considering the change in the demographic pattern with the increase in average life expectancy. They could present problems as they become an important source of infection," said Dr Ramya Ananthakrishnan of REACH, who led the study.

Among older TB patients, those over 70 take longer to respond to medication. Patients who return for treatment, and men are also harder to cure. The study, which was published in a peer-reviewed journal, also found that the mortality rate among the elderly was higher than the 6% reported for all TB patients in the state.

Unfavourable outcomes result from people not keeping to treatment, intolerance to therapy and other complications such as diabetes, hypertension and cardiovascular diseases. "Non-communicable diseases lower their immunity, which not only makes them susceptible to the infection but also makes them respond poorly to treatment," said Dr Soumya Swaminathan of National Institute for Research in Tuberculosis , who was part of the team.

Social problems too complicate the issue. "They are dependent on family members to ferry them for treatment and are dependent on them psychologically as well," she said.

The study also found that the ration of men to women among TB-affected elderly stood at 4:1, but had no explanation about the reason. "It's probably because men have more exposure than women. Besides, tobacco use also makes men more susceptible," said Dr Ramya.

Another hurdle is misdiagnosis . "Tuberculosis is often a silent killer among the elderly. The infection is often asymptomatic as the immune system is weak and does not respond to the bacteria. They report to the doctor for conditions like loss of weight, loss of appetite and extreme fatigue which are mistaken for being age-related problems. So they often die unscreened and untreated," said geriatrist Dr V S Natarajan.

The study has called for special attention to this group. "Over the next five years, the Revised National Tuberculosis Control Programme aims to achieve universal access to TB services with a treatment success rate of at least 90%. To achieve this, it is important to examine specific clinical and demographic subgroups who might be at high risk of poor treatment outcomes and provide special attention to them, if needed," said Dr Ramya.

Source: The Times of India