Dados do Trabalho

Título

Refining active case finding: a cost saving algorithm using automated chest X-ray analysis and sputum pooling

Introdução

Previous studies have demonstrated that screening using chest X-rays (CXR) with automated interpretation or sputum pooling can achieve high sensitivity in active case finding for tuberculosis (TB). These methodologies independently offer promising results in TB screening, yet the potential synergies from their integration—to simultaneously enhance sensitivity, reduce costs, and streamline the detection process—remain to be fully explored and understood.

Objetivo (s)

There is a need to optimize active case finding algorithms for TB in high-burden populations, to contain cost whilst preserving sensitivity. We evaluated algorithms combining automated CXR interpretations and sputum pooling in a prospective TB screening study in Brazilian prisons.

Material e Métodos

We performed a prospective, TB active case finding study in two prisons in Brazil between February 2023 to March 2024. We performed CXR with automated interpretation by LunitTB and collected two sputum samples from each participant. The first sample underwent pooling testing with GeneXpert Ultra (Xpert), followed by individual Xpert testing of positive pools. The second sample was tested individually by Xpert and culture if the first sample was negative. LunitTB scores were categorized as “low” (≤50) or “high” (>50). 

Resultados e Conclusão

Of 2547 participants, 98 individuals (3.8%) had at least one positive Xpert or culture result. Compared with this composite reference, the sensitivity of first sputum sample testing by pooling was 55% (95% confidence interval [CI] 45 - 65). Performing additional testing using individual Xpert in the second sample increased sensitivity to 91% (95%CI 84 - 95). Performing individual Xpert tests on the second sputum sample among those with high LunitTB scores allowed us to detect 85% (95%CI 77 - 91) of TB cases while reducing the number of Xpert cartridges needed by 64%. Performing a second individual Xpert testing among those with high LunitTB scores substantially improved the sensitivity of our sputum pooling strategy while reducing the number of cartridges used. Screening algorithms combining automated CXR interpretation with sputum pooling may reduce the costs and the time needed to do screening and offer an alternative for rapid and scalability approach for active case finding in highly transmitted settings. 

Palavras Chave

Tuberculosis; prison; active case finding