Dataset on prevalence, risk factors, and diagnostic results for canine heartworm (Dirofilaria immitis) in 481 dogs from Ilhéus, Brazil (2024)
Description
This dataset contains the raw data for the study titled "Prevalence, risk factors, and molecular characterization of Dirofilaria immitis in dogs from a previously non-endemic tourist area on the southern coast of Bahia, Brazil." The research investigated the prevalence, associated risk factors, and molecular characteristics of D. immitis in domestic dogs from Ilhéus, Bahia, a coastal region in northeastern Brazil previously considered non-endemic. Data were collected through a cross-sectional study conducted between January and December 2024. The dataset comprises information from 481 domiciled or semi-domiciled dogs residing in the study area for one year or more. Data collection involved several methods. First, a questionnaire was administered to the owners to gather information on animal demographics (breed, sex, age), management practices (e.g., time spent outdoors, vaccination status), environmental characteristics (e.g., type of residence, presence of standing water), and owner-reported clinical signs. Second, blood samples were collected from each dog. These samples were processed for the detection of adult female D. immitis antigens using the SNAP® 4Dx® Plus test and for the presence of microfilariae using the modified Knott’s test. Finally, all households were georeferenced using a GPS device. This spatial data was used to calculate the Normalized Difference Vegetation Index (NDVI) within a 300-meter buffer around each residence to quantify surrounding vegetation density. The data file includes columns for a unique animal identifier, all questionnaire variables, the binary results (Positive/Negative) for both the SNAP antigen test and the Modified Knott's test, and the calculated median NDVI value for each sampling point. This dataset supports the study's conclusions, which confirm the endemic circulation of D. immitis in Ilhéus and identify key risk factors associated with infection in the region.
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Steps to reproduce
This dataset was generated from an observational, prospective, cross-sectional study conducted in the municipality of Ilhéus, Bahia, Brazil, between January and December 2024. All procedures were approved by the Ethics Committee on the Use of Animals (CEUA) of the State University of Santa Cruz (UESC) under protocol 008/2022. Dog owners provided informed consent prior to participation. Data were collected from 481 domiciled or semi-domiciled dogs that had been living in the study area for at least one year. The data collection workflow included three main components: Questionnaire and Clinical Evaluation: A structured questionnaire was administered to owners to gather demographic data (breed, sex, age), management practices, and information on potential clinical signs of heartworm disease. A physical examination was also conducted on all animals by the research team's veterinarians. Biological Sample Collection and Analysis: Blood samples (3 mL) were collected from each dog via jugular or cephalic vein puncture into tubes containing EDTA. Samples were processed using two primary diagnostic methods: the SNAP® 4Dx® Plus test (IDEXX Laboratories) for the detection of Dirofilaria immitis antigen, and the modified Knott’s test (MK) for the detection of microfilariae. Samples positive in at least one test underwent DNA extraction using the QIAamp DNA Blood & Tissue Kit (Qiagen), followed by conventional PCR targeting the cox1 gene. Spatial and Environmental Data Collection: All participating households were georeferenced using a Garmin® 64st device. This spatial data was used to generate environmental variables. The Normalized Difference Vegetation Index (NDVI) was calculated within a 300-meter buffer of each residence using red and near-infrared bands from Sentinel-2 satellite imagery. The analysis and map creation were performed using QGIS software (version 3.34.15). All statistical analyses, including logistic regression to identify risk factors, were performed using R software (version 4.2.2).
Institutions
- Universidade Estadual de Santa CruzBA, Ilheus