We report the detailed molecular characterization of two PLA₂s, Lys49 and Asp49 isolated from Bothrops leucurus venom, and examined their effects against Dengue virus (DENV). The Bl-PLA₂s, named BlK-PLA₂ and BlD-PLA₂, are composed of 121 and 122 amino acids determined by automated sequencing of the native proteins and peptides produced by digestion with trypsin. They contain fourteen cysteines with pIs of 9.05 and 8.18 for BlK- and BlD-PLA₂s, and show a high degree of sequence similarity to homologous snake venom PLA₂s, but may display different biological effects. Molecular masses of 13,689.220 (Lys49) and 13,978.386 (Asp49) were determined by mass spectrometry. DENV causes a prevalent arboviral disease in humans, and no clinically approved antiviral therapy is currently available to treat DENV infections. The maximum non-toxic concentration of the proteins to LLC-MK2 cells determined by MTT assay was 40 µg/mL for Bl-PLA₂s (pool) and 20 µg/mL for each isoform. Antiviral effects of Bl-PLA₂s were assessed by quantitative Real-Time PCR. Bl-PLA₂s were able to reduce DENV-1, DENV-2, and DENV-3 serotypes in LLC-MK2 cells infection. Our data provide further insight into the structural properties and their antiviral activity against DENV, opening up possibilities for biotechnological applications of these Bl-PLA₂s as tools of research.

Visceral leishmaniasis (VL) is a vector-borne disease that is caused by the protozoan Leishmania infantum and transmitted to humans and other mammals through the bites of infected female sandflies. VL has been prevalent in Minas Gerais, Brazil, since the 1940s. As the vector completes its reproductive cycle in the soil with organic matter, the association between the occurrence of VL and unimproved solid waste disposal sites has been investigated. Thus, in this study, we analyzed the relationship of waste disposal conditions, inadequacies in disposal, and waste collection with the rates of VL, using statistical regression models. A case-control study was conducted to elucidate the relationship between VL and waste management; sick individuals (cases) were compared to healthy individuals (control), to determine the cause, by constructing a multiple regression model to analyze data through a stepwise method. In Minas Gerais, according to the reports of the government in 2017, 60.1% of the urban population has access to an adequate final disposal system for urban solid waste, with an increase of 2.3% compared to the size of the disposal system in 2016. Thus, almost 40% of the population is forced to use poor or unimproved waste disposal sites. The results confirmed the direct relationship between VL and the unimproved disposal of solid waste in the municipalities (waste coverage collection: p = 0.004; waste found in the streets: p = 9.69 × 10–13). These rates also indicated that the proper management of wastes can help to combat VL by considerably reducing the breeding sites of sandflies, curbing adverse health effects, and improving the health of the population.

Introduction: In recent years, the global burden of tegumentary leishmaniasis (TL) has significantly increased in the Americas. Objective: To estimate the prevalence of TL in South America based on publications from the past 13 years. Methods: Three databases were searched, and articles were selected based on inclusion criteria and methodological relevance. The random effects model was used to calculate pooled prevalence, and heterogeneity was assessed with the I ² statistic. Results: Out of the 225 articles initially identified, six studies remained eligible for review and meta‐analysis. No publication bias was found. TL prevalence in South America ranged from 0.2% to 87.7%, showing significant heterogeneity ( I ² = 99.83%, p < 0.001). Colombia and Ecuador had the highest prevalence rates (> 76.6%). The pooled prevalence in the general population was 0.4% (95% CI: 0.1–1.0), and 81.8% (95% CI: 75.4–87.4) in symptomatic patients attending health units. Conclusions: TL prevalence varied widely across countries, reflecting national epidemiological disparities. High positivity rates in suspicious samples and molecular detection in samples confirmed by microscopy underscore the importance of accurate diagnosis and clinical expertise. This meta‐analysis emphasises the need for tailored health policies and accessible laboratory diagnoses to guide disease control strategies.