Elderly Individuals Have Threefold Higher Prevalence of Tuberculosis, Confirms Study

The research was a cross-sectional survey that sought to diagnose TB in adults aged 15 years and older in Tamil Nadu. The screening was conducted through digital X-ray imaging and sputum testing to detect microbiologically confirmed pulmonary tuberculosis (MCPTB). A focused sub-analysis of the elderly population (60 years and older) was done, representing a major share of the total sample. The information gathered from these individuals were compared with the findings among younger adults to determine differences in TB risk factors and prevalence.

Results

• 130,932 participants were screened for TB, of which 16,555 (12.64%) were 60 years and older. Of the elderly, 74 individuals (0.45%) had microbiologically confirmed pulmonary tuberculosis (MCPTB), while the prevalence in adults under 60 years was 170 cases (0.15%).

• The crude prevalence of MCPTB among the elderly age group was 447 per lakh (95% CI: 351-561).

• The adjusted prevalence among the elderly was 482 per lakh (95% CI: 385-578).

• The crude prevalence of MCPTB among adults was 130 per lakh (95% CI: 111-151), and the adjusted prevalence was 166 per lakh (95% CI: 137-195).

• The adjusted prevalence ratio (aPR) for MCPTB among the elderly population was 2.99 (95% CI: 2.25-3.98, P<0.0001), showing that the elderly were almost three times more likely to develop MCPTB compared to adults younger than 60 years.

A number of risk factors were identified that raised the risk of TB among the elderly:

• Male sex had an aPR of 2.54 (95% CI: 1.41-4.57).

• Undernutrition had an aPR of 3.53 (95% CI: 1.65-7.54).

• Smoking raised the aPR to 1.94 (95% CI: 1.02-3.71).

• A history of TB raised the aPR to 2.26 (95% CI: 0.92-5.51), but the results were not significant.

The number needed to screen (NNS) to detect one case of MCPTB was estimated to be:

• 224 among the elderly population (95% CI: 178-285).

• For the entire population aged 15 years and older, the NNS was 537 (95% CI: 473-611).

• Among certain subgroups of the elderly, the NNS was significantly lower in those with a history of TB (56; 95% CI: 26-152), smokers (75; 95% CI: 52-112), and a history of alcohol consumption (78; 95% CI: 55-114), showing an increased risk among these groups.

In the elderly population in Tamil Nadu, tuberculosis prevalence was significantly higher among them than in younger adults. Male sex, undernutrition, and smoking were significantly linked to higher TB prevalence in the elderly. These observations highlight the necessity of targeted screening and intervention programs for the elderly, especially in high-burden areas for TB.

Reference:

Prathiksha Giridharan1, Ariarathinam Newtonraj​2,, Kannan Thiruvengadam1, Asha Frederick3, Sriram Selvaraju1. Tuberculosis in the elderly population: Findings from a State-level TB prevalence survey (2022) from India. Indian Journal of Medical Research, published by Scientific Scholar for Director-General, Indian Council of Medical Research, 2024.