Strategic use of 4 % deltamethrin impregnated-collar in seropositive dogs reduces the incidence of seroreactivity to visceral leishmaniasis in dogs from endemic areas.

The effectiveness of a visceral leishmaniasis (VL) control strategy based on the application of 4 % deltamethrin impregnated collars (DIC) exclusively in seropositive dogs was assessed between 2018 and 2019, through a prospective study. The effectiveness of DIC-collaring was evaluated by comparing the incidence rate of anti-leishmanial antibodies among dogs from two endemic districts in Brazil. In one of the areas, the conventional control measure which is based on the non-compulsory euthanasia of LV seropositive dogs, was practiced by the official healthy service as a regular procedure, whereas strategic collaring, conceived in this study, was carried out in the other. Results of serological tests applied to serum samples collected from all domiciled dogs were evaluated in three consecutive times, spaced by around 200 days. Incidence rates of VL seroreactivity were compared between districts in the same period of time as well as within the same district, in consecutive periods. Based on the results, the risk of infection in the population under conventional control measure was up to four times higher than the risk of infection where DIC-collaring was used. The strategic use of collar proposed here emerged as a promising measure for VL control in dogs from endemic areas. Strategic collaring does not rely on the euthanasia of infected animals, an extremely controversial procedure, and instead of being used in all dogs, as collaring is normally recommended; only seropositive dogs are intervened. Strategic use of DIC has the potential to drastically reduce costs, if compared to mass collaring canine population.

Lead exposure in an urban community: investigation of risk factors and assessment of the impact of lead abatement measures.

INTRODUCTION: A battery recycling plant located in an urbanized area contaminated the environment with lead oxides. The Secretary of Environment of the State of São Paulo demanded an evaluation of lead exposure among the population in the vicinity of the plant. OBJECTIVES: To assess the lead exposure of children, to propose control measures and evaluate the impact of these measures. METHODS: Cross-sectional study of all children<13 years old in a radius of 1km from the plant responsible for the contamination. Blood lead levels (BLL) were determined for each child and questionnaires were applied to their parents. Mean BLL were compared before and after control measures were implemented. Logistic regression identified risk factors of lead exposure. RESULTS: Of the 850 investigated children, 311 presented BLL above the action limit established by the World Health Organization. Overall, the median BLL was 7.3 micro g/dL and it varied according to age of children (higher among 1-5 years old) and distance of the residence from the plant. Risk factors identified for BLL>10 micro g/dL were: to live in unpaved areas, parent working in the plant, distance from the plant, to play on the ground, pica, and to drink locally produced milk. After control measures were implemented (closing the plant, soil removal, dust vacuum-cleaning in the households, etc.), a reduction of 46% in BLL was observed considering the 241 re-evaluated children with levels >10 micro g/dL. CONCLUSIONS: This study showed that combined abatement measures were effective in reducing BLL in children living close to a contaminating source. These results informed the decision-making process regarding management of contaminated areas in Brazil.