Dataset for: Challenges in the diagnosis and surveillance of emerging canine leishmaniasis in an urban area of the Brazilian Amazon

This dataset contains the clinical-diagnostic and epidemiological data supporting the study: "Challenges in the diagnosis and surveillance of emerging canine leishmaniasis in an urban area of the Brazilian Amazon".

Project Context: This research is the primary output of the Master’s Dissertation of Ingrid de Jesus, conducted within the Graduate Program in Epidemiology and Health Surveillance at the Evandro Chagas Institute (Programa de Pós-Graduação em Epidemiologia e Vigilância em Saúde – PPGEVS) at the Instituto Evandro Chagas (IEC).

Supervision and Research Leadership: The study was led and supervised by Lourdes Maria Garcez (Project Leader and Supervisor), Researcher at the Instituto Evandro Chagas (IEC) and Professor at the Universidade do Estado do Pará (UEPA).

The project also benefited from the scientific collaboration and expertise of:

• Ana Paula Vitoria Costa-Rodrigues: PhD student – Programa de Pós-Graduação em Saúde e Produção Animal na Amazônia (PPGSPAA/UFRA).
• Luciana de Cássia Silva do Nascimento: Postdoctoral fellow – Rede de Biodiversidade e Biotecnologia da Amazônia (BIONORTE).

Abstract

Background: Canine visceral leishmaniasis is expanding into new Amazonian urban territories, posing significant challenges for clinical diagnosis and public health surveillance. This study investigates these challenges by describing the clinical-diagnostic and epidemiological aspects of the disease in dogs at a private veterinary hospital in Belém, Pará State, Eastern Amazon, Brazil.
Methods: A retrospective cross-sectional study analyzed secondary data from 53 dogs showing signs suggestive of visceral leishmaniasis (2020-2024), representing an initial subset of 210 symptomatic animals. Diagnosis was based on a multimodal approach involving rapid immunochromatographic test, confirmatory ELISA, and PCR, supplemented by skin smears and histopathology. Dogs positive in at least one method were considered infected by Leishmania infantum. Additionally, animals were classified into clinical groups (I, II, and III) based on the presence and severity of symptoms.
Results: Overall, 17% (9/53) of the dogs tested positive for Leishmania infantum. Regarding staging, 11% (1/9) were in Group I, 78% (7/9) in Group II, and 11% (1/9) in Group III. Ocular lesions were the only statistically significant clinical predictor (p = 0.0068). Positive cases were distributed across several neighborhoods (Pratinha, Pedreira, Umarizal, Batista Campos, Cidade Velha, and Guamá) and neighboring municipalities, confirming a broader regional expansion. These areas lack official records of the primary vector, Lutzomyia longipalpis.
Conclusion: Findings confirm a silent expansion of canine visceral leishmaniasis into the urban core of Belém and metropolitan area. Case distribution across all clinical stages underscores the diagnostic challenge, requiring an integrated approach involving serology, parasitology and molecular methods. The high frequency of ocular manifestations stands out as a key clinical marker for early suspicion. The occurrence of cases in areas lacking the primary vector suggests a complex transmission scenario involving alternative routes or vectors. Private veterinary hospitals could function as valuable sentinel units for public health surveillance in Amazonian urban centers.
Key words: Dogs; Eye Manifestations; Leishmania infantum; One Health; Sentinel Surveillance; Urbanization.