Does active case finding detect TB early in programme settings? A national-level study in India

Area of Science:

• Public Health
• Infectious Disease Epidemiology
• Tuberculosis Control

Background:

• India's national tuberculosis (TB) program employs active case finding (ACF) in high-risk groups since 2017.
• The ACF strategy involves symptom screening and confirmatory testing to identify TB cases.

Purpose of the Study:

• To compare pre-treatment delays and severity of illness at diagnosis between adults with drug-sensitive pulmonary TB detected through ACF and passive case finding (PCF).
• To assess the effectiveness of ACF in reaching vulnerable populations and facilitating early TB detection.

Main Methods:

• A cross-sectional analytical study was conducted in 28 randomly selected districts across India in 2023.
• Data were collected from 790 adults diagnosed with drug-sensitive pulmonary TB, comparing 426 ACF-detected and 364 PCF-detected individuals.
• Severe illness was defined by the presence of very severe undernutrition, respiratory insufficiency, or poor performance status.

Main Results:

• ACF-detected adults were older, resided farther from healthcare facilities, had lower formal education, lower household income, and fewer healthcare provider visits compared to PCF-detected individuals.
• Despite ACF reaching vulnerable populations, pre-treatment delays (median 46 days for both groups) and the burden of severe illness (39% vs. 34%) were similar between ACF and PCF groups.
• ACF successfully linked vulnerable individuals to care, evidenced by reduced healthcare provider visits.

Conclusions:

• Active case finding in India connects vulnerable populations to TB care but does not appear to shorten pre-treatment delays or reduce the severity of illness at diagnosis.
• The high burden of severe illness observed at diagnosis in both ACF and PCF groups highlights a persistent challenge in early TB detection.
• Further strategies are needed to improve timely diagnosis and reduce illness severity among high-risk populations targeted by TB programs.