Validation of a direct agglutination test prototype kit for the diagnosis of visceral leishmaniasis
Edward Oliveira1, Soraya Wilke Saliba, Juliana Wilke Saliba
1Clinical Research Laboratory, Centro de Pesquisas René Rachou-FIOCRUZ, Av. Augusto de Lima, 1715, 30190-002, Belo Horizonte, Minas Gerais State, Brazil.
Background:
A freeze-dried antigen was developed with Leishmania (L.) infantum and used for the production of a prototype direct agglutination test kit for the laboratory diagnosis of visceral leishmaniasis (VL), called DAT-LPC. On this study the diagnosis validity of this prototype was performed.
Methods:
To evaluate the sensitivity and specificity 103 samples from Brazilian patients with VL and 110 samples from patients with other parasitic infections, and healthy subjects were assayed with DAT-LPC and DAT-KIT (Royal Tropical Institute, Amsterdam, NL). Additionally, the results of 103 samples of VL patients based on two agglutination tests were transformed in Log10 and correlated.
Results:
The DAT-LPC showed a sensitivity of 99.0%, specificity of 98.2% and diagnosis validity of 98.6%, which were similar to those found by the DAT-KIT (p > 0.05). Moreover, there was positive correlation between the positive titers obtained by DAT-LPC and by DAT-KIT (Spearman correlation coefficient of 0.75 p = 0.0001).
Conclusions:
DAT-LPC showed thermal stability and diagnosis performance similar to those of the DAT-KIT. Our results suggest that DAT-LPC is a robust, simple, equipment-independent and efficient tool for the diagnosis of VL and should thus replace the IFAT as routine diagnostic test in the Brazilian public health system.
