Prevalence and Distribution of Canine Cutaneous Leishmaniasis in Brazil: A Systematic Review With Meta-Analysis

Canine leishmaniasis is a public health problem in Brazil, with high prevalence and risk of transmission to humans. This systematic review with meta-analysis evaluated the prevalence and distribution of canine cutaneous leishmaniasis (CCL) in Brazil. The research protocol was registered in PROSPERO (CRD42021262437, United Kingdom). According to PRISMA, the PICOS question was constructed: What is the epidemiological profile of CCL in Brazil? Five databases (PubMed, Web of Science, EMBASE, Scopus, and LILACS) and one gray literature source (Google Scholar) were searched for original articles published up to 2022. Two independent reviewers conducted study selection based on PICOS criteria, with discrepancies resolved by a topic expert. Risk of bias was assessed using the SYRCLE tool. Meta-analysis was performed in Stata 14 using a random-effects model (95% confidence interval; p-value considered significant when <0.05). I² values >50% were considered substantial. A total of 656 studies were retrieved, with 189 duplicates removed. After title and abstract screening, 116 studies were selected. Following full-text review, 59 original articles were included in the systematic review and 53 in the meta-analysis. All Brazilian regions reported CCL cases, mainly in peridomestic and domestic dogs from rural areas. Polymerase chain reaction (PCR) targeting Leishmania kDNA (blood and lesions) and indirect immunofluorescence assay (IFA) were the most commonly used methods. Leishmania braziliensis was the most prevalent species. Most studies highlighted a potential important role of dogs in the transmission chain of L. braziliensis to humans. Based on IFA, pooled CCL prevalence was 10%; ELISA, 15%; blood PCR, 19%; skin lesion PCR, 56%; and direct parasite detection in lesions, 21% (I²>90%, p<0.001). The Northeast, Southeast, and South regions showed the highest prevalence. Most studies had low risk of bias; 26/59 were moderate and 3/59 high risk. Given the high prevalence of disease in dogs and the risk of human transmission, control and management measures for CCL should be implemented nationwide and in border areas.