Fig 1.
A) Puerto Iguazú, Misiones province, Argentina, in the border region with Brazil and Paraguay, B) Puerto Iguazú city; blocks in orange show the 32 selected study sites. Map sources: for Fig 1A, https://www.simplemappr.net/; for Fig 1B, https://www.openstreetmap.org/.
Fig 2.
Summary of microscopy, serology and molecular tests applied to the 2018 cohort of 160 dogs (number of dogs to which each test was applied shown in square brackets).
Samples were selected for LNA-PCR and LNA-LAMP based on ICT results. Serology and PCR-RFLP with skin broach and LNA samples were also applied to the additional 30 dogs sampled in 2019, and those seropositive for rK28 ICT but negative with rK39 ICT were tested serologically for exposure to six other pathogens (Methods). Bc, buffy coat; CLA, crude lysate antigen; ICT immunochromatographic test.
Fig 3.
Examples of observed clinical signs of canine visceral leishmaniasis: A. localised alopecia, B. ear chancre, C. chancre in the gluteal region, D. onychogryphosis.
Table 1.
Demographic and clinical data for 2018 (160 dogs), and where available additionally for 2019 (30 dogs).
Table 2.
Estimated concordance between diagnostic tests by Cohen’s kappa coefficient (95% confidence intervals).
*p<0.01, **p<0.05 by t-test.
Fig 4.
Skin-LAMP and buffy coat LAMP under UV light show higher sensitivity of buffy coat LAMP (samples 1–8); 9, distilled water (no template); 10, positive control.
Fig 5.
Anti-rK39 and anti-CLA antibody levels in serum suggest elevation of rK39 antibody titres (p = 0.045) in polysymptomatic disease.
(A) rK39-IgG, (B) CLA-IgG, (C) rK39-IgG2 and (D) CLA-IgG2 in 133 domestic dogs and four dogs from a non-endemic area. The 133 dogs were classified by clinical signs: BD, dogs from a non-endemic area; AD, asymptomatic; OD, oligosymptomatic; PD, polysymptomatic. Black dots show dogs detected as Leishmania-positive by molecular assays.
Fig 6.
PCR-RFLP using ITS1/HaeIII reveals the presence of canine leishmaniasis compatible with Viannia infection (see Discussion) (Lane 1, broach sample) in Puerto Iguazú, as well as CVL due to L. infantum (Lane 2, lymph node aspirate); -ve, negative control; M, size markers.