Combined use of two rapid tests for the conclusive diagnosis of Chagas disease: a systematic scoping review

OBJECTIVE: The goal of this systematic scoping review is to collect and summarise scientific evidence regarding the validity of two simultaneous immunochromatographic tests for the conclusive diagnosis of Chagas disease. The research was informed by the following review questions: Will the use of two rapid tests be a valid method for the definitive diagnosis of Chagas disease when compared with conventional serological tests? In what type of population has the operation of two rapid tests been tried for the diagnosis of Chagas disease? What are the biomedical and public health advantages of the diagnostic method resulting from the combination of two rapid tests over the conventional serological method? Will it be a cost–benefit strategy for the diagnosis of Chagas with respect to conventional serological tests? DESIGN: Systematic scoping review. SETTING: A search of the published and unpublished literature in five databases was carried out, in order to identify, screen and select the studies included in this review. RESULTS: 468 studies were identified, of which 46 were screened with a full-text reading, and finally, three articles were included in the review. All studies were in endemic countries with adult and paediatric populations (n=1133) and, together, they evaluated four different rapid tests. The rapid tests showed good sensitivity (97.4%–100%) and specificity (96.1%–100%) for the diagnosis of Chagas when used in combination and compared with the reference tests. CONCLUSIONS: The simultaneous use of at least two immunochromatographic rapid tests is a valid option for the definitive diagnosis of chronic Chagas in endemic rural areas, as long as there are studies that previously evaluate their performance on the areas of implementation. Therefore, this could be an alternative to the current diagnostic standard. However, additional studies are still needed in more countries in order to provide further evidence and to investigate the cost–benefit.