Rapid Tests Assessed for Chronic Chagas Disease

Chagas disease (CD) is a parasitic disease that can affect seriously the health status of affected individuals. People with CD, mainly living in remote areas of Latin America, often face major barriers to the disease recognition, diagnosis and treatment. In the U.S., there are estimated to be at least 300,000 cases of chronic Chagas disease among people originally from countries of Latin America where Chagas disease is endemic.

Rapid diagnostic tests (RDTs) are easy-to-use and less technically and time demanding than classical serological techniques. Remarkably, many of them can be performed on serum or with a very little volume of whole blood, and they can be stored on the shelf for longer than a year. Their large-scale use could contribute to increased access to diagnosis, better treatment coverage, and a reduction of disease transmission.

Tropical medicine specialists working with the Sacro Cuore - Don Calabria Hospital (Verona, Italy) undertook a comprehensive search of various databases last up-dates on the July 1, 2017, without language or date limits. Non-electronic sources have been also searched. This review included clinical studies with cohort recruitment of individuals at risk of Trypanosoma cruzi exposure, without age limits; adequate reference standards for the diagnosis of CD. Geographical area, commercial brand, disease prevalence, study size, and risk of bias were explored as possible source of heterogeneity.

The team included in the analysis 12 datasets, comprising a total of 6,123 participants, from 101 to 1,913 individuals, tested in single studies and six different RDTs were evaluated. The pooled sensitivity and specificity of the RDTs resulted 96.6% (95% CI 91.3–98.7%) and 99.3% (95% CI 98.4–99.7%), respectively. Test accuracy was particularly good in endemic areas (98.07%/99.03% of sensitivity/specificity, respectively). One test, Chagas Stat-Pak (Chembio Diagnostic Systems, Medford, NY, USA) showed an overall sensitivity of 97% (95% CI 87.6–99.3) and specificity of 99.4% (95% CI 98.6–99.8).

The authors concluded that the accuracy of all RDTs studied can be considered sufficiently good to recommend their use in endemic settings, particularly in the Southern Cone of Latin America, in order to increase access to diagnosis. The Stat-Pak test can be recommended for use in screening surveys when the expected prevalence is moderately high or high, in the setting of Southern Cone or for migrants from that area in case of non-endemic countries. The study was published on May 31, 2019, in the journal PLOS Neglected Tropical Diseases.

Related Links:
Sacro Cuore - Don Calabria Hospital
Chembio Diagnostic Systems