The Invisible Burden: factors behind undetected TB cases in India (2000-2024): A Systematic Review

Abstract

Background India aims to “End TB” by 2025. Despite efforts being made to revolutionize TB care, many factors are fuelling these missing cases in India. To understand this, we conducted a systematic review to identify factors contributing to these gaps, focusing on diagnostic issues, untreated or incompletely treated patients. Methods We searched MEDLINE, Scopus, and Web of Science (from 2000 to 2024) for studies analysing factors associated or causing missing TB cases in the Indian context. Based on standard inclusion and exclusion criteria, relevant studies were selected, data related to the factors were extracted. The CASP tool assess the risk of bias in the selected studies. Results Among 253 identified articles, 25 studies were finally included which fit the criteria under missing cases. Based on the objectives of the review, we categorized all factors leading to missing cases under patient or provider related with reference to the layers of the onion model. In summary our studies reveal that provider related factors such as: i) Private practitioners inadequate notification to central registries, ii) insufficient training among health care providers causing diagnostic errors iii) inability of the staff to deal with the adverse effects of the drug, iv) Loss to follow-up during diagnosis v) limited diagnostic infrastructure, vi) non-reporting private practitioners lead to missing cases. Likewise, patient-related factors included: i) sputum volume and sample collection, ii) non-adherence to treatment, iii) low education and awareness, iv) socio-cultural taboo, v) loss to follow-up due to poor disease treatment & management awareness which further exacerbated the extent of missing cases. Based on the onion model for missing cases, we highlighted patient and system related factors relevant for missed cases for each layer, with a focus on the Indian scenario. Conclusion The review underscores that providers related barriers are further magnified by patient-related challenges. Provider related factors dwarf patient related factors in terms of number, and classification according to the onion model. Addressing these gaps through targeted training for public and private healthcare providers for TB identification, diagnosis, and management; and strengthening diagnostic infrastructure could significantly reduce missed cases and improve TB control efforts in India.