Dados do Trabalho

Título

Assessment of Chimeric Antigens of Trypanosoma cruzi for the Detection of Chagas Disease in Canine Populations from Salvador, Bahia

Introdução

Chagas disease (CD), caused by the protozoan Trypanosoma cruzi, remains a significant public health challenge in Latin America. In endemic regions, dogs play a pivotal role as primary hosts and frequent blood sources for triatomine vectors. The presence of T. cruzi-infected dogs in households increases the risk of human infection, making dogs valuable sentinel indicators. Despite their critical role in T. cruzi transmission, no commercial serological tests currently exist for diagnosing CD in dogs. Recently, chimeric recombinant antigens have emerged as promising diagnostic tool for canine CD.

Objetivo (s)

This study aims to evaluate the performance of four T. cruzi-chimeric recombinant antigens, namely IBMP-8.1, -8.2, -8.3, and -8.4, in detecting anti-T. cruzi antibodies in dogs from the municipality of Salvador, Bahia.

Material e Métodos

A panel of 6,000 serum samples was collected from the CenterLab Veterinary Clinical Pathology Laboratory in Salvador, Bahia, between March 2021 and April 2024. Anti-T. cruzi antibodies were detected using indirect ELISA with chimeric antigens. Latent class analysis (LCA) classified the samples as T. cruzi-positive or T. cruzi-negative, serving as the reference test. The performance of each antigen was evaluated in terms of sensitivity, specificity, and accuracy. 

Resultados e Conclusão

Among the 3,001 tested samples, LCA classified 25 samples (0.83%) as T. cruzi-positive. The median age of the infected dogs was 58 months, with 44% being female and 56% male. The IBMP-8.2 antigen had the highest sensitivity (96%), followed by IBMP-8.1 (80%), and IBMP-8.4 (68%). IBMP-8.3 demonstrated a sensitivity of 48%, with thirteen false-negative results. While the sensitivity differences among IBMP-8.1, IBMP-8.3, and IBMP-8.4 were not statistically significant, the difference compared to IBMP-8.2 was significant. Specificity was high across all antigens, ranging from 99.3% (IBMP-8.1) and 99.4% (IBMP-8.2) to 100% for IBMP-8.3 and IBMP-8.4. Despite variations in sensitivity, all antigens demonstrated high accuracy: IBMP-8.3 at 99.6%, IBMP-8.2 at 99.4%, IBMP-8.1 at 99.1%, and IBMP-8.4 at 99.7%. These preliminary findings underscore the diagnostic potential of IBMP-8.2 and IBMP-8.4. The use of chimeric antigens is crucial giving the absence of commercial diagnostic tests, the epidemiological significance of dogs in T. cruzi transmission, and the need for effective treatment to enhance the quality of life in infected dogs. 

Palavras Chave

Chagas disease; diagnosis; Serologic Tests; Chimeric recombinant proteins; Domestic Animals