Article
Early detection and persistent positivity of anti‑Leishmania antibodies using a recombinant protein‑based ELISA in naturally infected dogs in Brazil
Registro en:
JESUS, Matheus Silva de et al. Early detection and persistent positivity of anti‑Leishmania antibodies using a recombinant protein‑based ELISA in naturally infected dogs in Brazil. Parasites and Vectors, 2021.
1756-3305
10.1186/s13071-021-04895-z
Autor
Jesus, Matheus Silva de
Cruz, João Victor Andrade
Coelho, Lívia Brito
Borja, Lairton Souza
Silva, Edmilson Domingos da
Brodskyn, Claudia Ida
Solcà, Manuela da Silva
Fraga, Deborah Bittencourt Mothé
Resumen
Foundation for Research Support of the State
of Bahia (Grants JCB0010/2013, SUS0036/2013 and PET0024/2013) and the
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brasil
(CAPES)—Finance Code 001. Visceral leishmaniasis (VL) is a zoonotic disease caused by Leishmania infantum, for which dogs constitute
the main urban parasite reservoir. Control measures and the treatment of canine visceral leishmaniasis (CVL) are
essential to reduce VL cases. Early and accurate detection of L. infantum-infected dogs is crucial to the success of VL
control. To improve the serological detection of L. infantum-exposed dogs, we evaluated the early diagnosis capacity
of a recombinant protein (rLci5) in an immunosorbent assay (ELISA) to detect naturally infected dogs. Additionally, we
evaluated the persistence of the positive results obtained by rLci5 ELISA in comparison to other conventional diagnostic
test methods.
Methods: Serum samples obtained from 48 L. infantum-infected dogs involved in a cohort study were evaluated
using different diagnostic methods (qPCR, EIE-LVC, DPP-LVC and splenic culture). The results were compared to rLci5
ELISA to determine its capacity to diagnose L. infantum infection at earlier infection time points. The persistence of
positive diagnostic test results was also compared for each dog evaluated.
Results: rLci5 ELISA presented higher rates of positive results at early time points compared to the other diagnostic
tests employed in the cohort study, as early as 24 months prior to detection by other tests. rLci5 ELISA positivity was
52.1% (25/48) at baseline, while qPCR was 35.4% (17/48), DPP-LVC 27.1% (13/48), EIE-LVC 22.9% (11/48) and culture
only 4.2% (2/48). In at least one of the time points of the 24-month cohort study, rLci5 ELISA was positive in 100%
(48/48) of the dogs, versus 83% (40/48) for qPCR, 75% (36/48) for DPP-LVC, 65% (31/48) for EIE-LVC and 31% (15/48) for
culture. Investigating clinical signs in association with diagnostic test positivity, rLci5 ELISA successfully detected CVL
in 62.9% (95/151) of the clinical evaluations with a score of 0–3, 64.3% (45/70) with scores between 4 and 7, and 73.7%
(14/19) with scores > 7, providing higher rates of positivity than all other methods evaluated. Moreover, rLci5 ELISA
presented the greatest persistence with respect to test positivity: 45.8% of the dogs evaluated.
Conclusion: Four diagnostic tests were compared to rLci5 ELISA, which presented earlier infection diagnosis and
a greater persistence of positive test results performance by detecting infected dogs sooner than other testing methods, with enhanced persistence of positive
results over the course of the infection.