Background Leprosy remains a persistent public health challenge,where human-to-human transmission of Mycobacterium leprae via respiratory droplets is well established.In the tropical Americas,growing evidence implicat...Background Leprosy remains a persistent public health challenge,where human-to-human transmission of Mycobacterium leprae via respiratory droplets is well established.In the tropical Americas,growing evidence implicates armadillos as important zoonotic reservoirs,particularly through direct contact during hunting and handling.However,such transmission has so far been considered rare and highly localised.This study provides a comprehensive spatial analysis of the role of armadillo hunting in human leprosy transmission,quantifying its contribution to disease prevalence and identifying geographic hotspots where interventions could be most effective.Methods Using Brazil’s 326,001 reported leprosy cases from 2013 to 2022,we applied a pathogeographical approach to explore transmission dynamics.We compiled data on 554 hunted armadillos across 175 municipalities and M.leprae prevalence in 376 armadillo individuals from 97 municipalities(mean prevalence=38.5%).These were used to build spatial models assessing hunting-related infection risk and integrated as a variable into a generalised linear model alongside socioeconomic,climatic,and environmental predictors to evaluate their effects on human leprosy prevalence.Results Key predictors of armadillo hunting included higher population density(P<0.001)and firearm availability(P<0.01).Infection in armadillos was negatively correlated with native habitat coverage(coefficient:−2.28;P<0.001),suggesting that environmental degradation can amplify infection risk.The armadillo-hunting infection risk variable—generated by combining armadillo hunting and infection favourability models—emerged as the second strongest predictor of human leprosy prevalence(coefficient:1.69;P<0.001),accounting for~25%of cases nationally and around 40%in deforestation hotspots.Additional positive predictors included greater precipitation seasonality(coefficient:0.82;P<0.001)and malnutrition(coefficient:0.01;P<0.001),while higher population density(coefficient:−0.64;P<0.001),natural habitat coverage(coefficient:−0.50;P<0.001)and socioeconomic status(coefficient:−0.47;P=0.013)were linked to reduced disease prevalence.Conclusions Armadillo hunting seems to play a more significant role in human leprosy transmission than previously recognised.To address this overlooked pathway,targeted interventions should focus on reducing unsafe and illegal hunting,improving communication around zoonotic risks,strengthening disease surveillance in high-risk areas,and conducting genetic studies to confirm wildlife-to-human transmission.Our findings highlight the importance of incorporating wildlife-associated transmission pathways into strategies to reduce disease prevalence and mitigate future outbreaks in tropical regions facing rapid environmental change and persistent poverty.展开更多
Understanding of resource requirements of vulnerable species is key for conservation planning.Here,we used sta-ble carbon(δ13C)and nitrogen isotopes(δ15N)of hair from giant armadillos(Priodontes maximus)to understan...Understanding of resource requirements of vulnerable species is key for conservation planning.Here,we used sta-ble carbon(δ13C)and nitrogen isotopes(δ15N)of hair from giant armadillos(Priodontes maximus)to understand individual resource use.We collected hair from 19 giant armadillos analyzing 34 samples from the Brazilian Pan-tanal and compared the resource use between sexes and age classes.We also assessed the relationship of isotopic values with individuals’body mass and the habitat type used.We observed a wide variation in resource use by giant armadillos,showing that individuals consume prey that feeds on distinct resources and occupies different habitat types,indicating that there is individual variation in foraging behavior.Most giant armadillos presented a mixed diet(C3/C4 resources,forests/open areas),but a quarter of individuals had strictly C4 diets(open areas).Males are more prone to forage on C4 resources,presenting an isotopic niche 2.6-times larger than that of females.Subadults presented diets more associated with habitats with high arboreal cover(C3 resources,forests),while adults foraged more in open areas(C4 resources).This result is mirrored by the positive relationship betweenδ13C values and body mass,suggesting that larger giant armadillos tend to feed more in open areas.We observed thatδ13C values decreased as individuals increased the use of habitats with high arboreal cover.We stress the importance of con-serving the natural mosaic in the Pantanal landscape for the species persistence,given that giant armadillos require all habitat types to fulfill their dietary,spatial,and developmental needs.展开更多
Mammals can show conspicuous behavioral responses to thermal variation,including changes in movement patterns.We used an integrative approach to understand how environmental temperature can drive the movement behavior...Mammals can show conspicuous behavioral responses to thermal variation,including changes in movement patterns.We used an integrative approach to understand how environmental temperature can drive the movement behavior of a mammal with low capacity for physiological thermoregulation,the giant anteater(Myrmecophaga tridactyla).We tracked 52 giant anteaters in 7 areas throughout the Brazilian savannah.We estimated the distance moved,area used,use of forest areas,and mean environmental temperature for each monitoring day of each individual.We modeled these data with Mixed Structural Equations—considering the possible interactions between our variables and controlling for sex and body mass.Giant anteaters reduced displacement and increased forest use with decreasing environmental temperature,probably because of their low body heat production.It is possible that they reduce distance moved and area used by reducing the duration of activity.With decreasing temperature,forest habitats become warmer than open ones,besides buffer rain and chilly winds.Reducing displacement and using forests are important strategies to reduce body heat loss and the energetic costs of thermoregulation.However,decreasing movement can limit food access and,consequently,fitness.Therefore,we highlight the importance of forests as thermal shelters.With increasing frequency and intensity of extreme weather events,we showed the need to preserve forest patches to offer suitable conditions for tropical mammals’behavioral thermoregulation.In this context,policies favoring deforestation on Brazilian territory are especially worrisome.Finally,we emphasize the need of integrative approaches to understand the complex interactions between organisms and the environment.展开更多
基金supported by the Biogeography,Diversity and Conservation Lab of the University of Malaga,Project PID2021-124063OB-I00 of the Spanish Ministry of Science and Innovation and European Regional Development Fund(ERDF)and by the Leprosy Research Initiative Foundation(Grant#FP25\19)supported by a postdoctoral contract of the Plan Propio de Investigacion,Transferencia y Divulgacion Cientifica of the University of Malaga+7 种基金supported by MOPGA:Visiting Fellowship Program for early career researchers,Campus France,Francesupported by Gordon and Betty Moore Foundation through grant GBMF9258 to the Comunidad de Manejo de Fauna Silvestre en la Amazonia y en Latinoamerica(COMFAUNA)supported UK Research and Innovation’s Global Challenges Research Fund(UKRI GCRF)Trade,Development and the Environment Hub project(ES/S008160/1)supported by the joint NSF-NIH-NIFA Ecology and Evolution of Infectious Disease program(DEB#1911457)benefited from an‘Investissement d’Avenir’Grant managed by Agence Nationale de la Recherche,France(LABEX CEBA:ANR-10-LABX-25-01)supported by Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior—Brasil(CAPES)for a PNPD research fellowship.(88887.717863/2022-00)supported by a Conselho Nacional de Desenvolvimento Cientifico e Tecnologico(CNPq)postdoctoral fellowship(150261/2023-3)supported by the Sustainable Landscapes and Livelihoods Programme.
文摘Background Leprosy remains a persistent public health challenge,where human-to-human transmission of Mycobacterium leprae via respiratory droplets is well established.In the tropical Americas,growing evidence implicates armadillos as important zoonotic reservoirs,particularly through direct contact during hunting and handling.However,such transmission has so far been considered rare and highly localised.This study provides a comprehensive spatial analysis of the role of armadillo hunting in human leprosy transmission,quantifying its contribution to disease prevalence and identifying geographic hotspots where interventions could be most effective.Methods Using Brazil’s 326,001 reported leprosy cases from 2013 to 2022,we applied a pathogeographical approach to explore transmission dynamics.We compiled data on 554 hunted armadillos across 175 municipalities and M.leprae prevalence in 376 armadillo individuals from 97 municipalities(mean prevalence=38.5%).These were used to build spatial models assessing hunting-related infection risk and integrated as a variable into a generalised linear model alongside socioeconomic,climatic,and environmental predictors to evaluate their effects on human leprosy prevalence.Results Key predictors of armadillo hunting included higher population density(P<0.001)and firearm availability(P<0.01).Infection in armadillos was negatively correlated with native habitat coverage(coefficient:−2.28;P<0.001),suggesting that environmental degradation can amplify infection risk.The armadillo-hunting infection risk variable—generated by combining armadillo hunting and infection favourability models—emerged as the second strongest predictor of human leprosy prevalence(coefficient:1.69;P<0.001),accounting for~25%of cases nationally and around 40%in deforestation hotspots.Additional positive predictors included greater precipitation seasonality(coefficient:0.82;P<0.001)and malnutrition(coefficient:0.01;P<0.001),while higher population density(coefficient:−0.64;P<0.001),natural habitat coverage(coefficient:−0.50;P<0.001)and socioeconomic status(coefficient:−0.47;P=0.013)were linked to reduced disease prevalence.Conclusions Armadillo hunting seems to play a more significant role in human leprosy transmission than previously recognised.To address this overlooked pathway,targeted interventions should focus on reducing unsafe and illegal hunting,improving communication around zoonotic risks,strengthening disease surveillance in high-risk areas,and conducting genetic studies to confirm wildlife-to-human transmission.Our findings highlight the importance of incorporating wildlife-associated transmission pathways into strategies to reduce disease prevalence and mitigate future outbreaks in tropical regions facing rapid environmental change and persistent poverty.
基金the National Council of Technological and Scientific Development(CNPq)for the research productivity fellowship grant(#308632/2018-4).
文摘Understanding of resource requirements of vulnerable species is key for conservation planning.Here,we used sta-ble carbon(δ13C)and nitrogen isotopes(δ15N)of hair from giant armadillos(Priodontes maximus)to understand individual resource use.We collected hair from 19 giant armadillos analyzing 34 samples from the Brazilian Pan-tanal and compared the resource use between sexes and age classes.We also assessed the relationship of isotopic values with individuals’body mass and the habitat type used.We observed a wide variation in resource use by giant armadillos,showing that individuals consume prey that feeds on distinct resources and occupies different habitat types,indicating that there is individual variation in foraging behavior.Most giant armadillos presented a mixed diet(C3/C4 resources,forests/open areas),but a quarter of individuals had strictly C4 diets(open areas).Males are more prone to forage on C4 resources,presenting an isotopic niche 2.6-times larger than that of females.Subadults presented diets more associated with habitats with high arboreal cover(C3 resources,forests),while adults foraged more in open areas(C4 resources).This result is mirrored by the positive relationship betweenδ13C values and body mass,suggesting that larger giant armadillos tend to feed more in open areas.We observed thatδ13C values decreased as individuals increased the use of habitats with high arboreal cover.We stress the importance of con-serving the natural mosaic in the Pantanal landscape for the species persistence,given that giant armadillos require all habitat types to fulfill their dietary,spatial,and developmental needs.
基金This work was supported by the Brasilian Conselho Nacional de Desenvolvimento Científico e Tecnológico-CNPQ(133623/2017-3 to AG and 308934/2017-2 to GM)National Program of post doctorate of Coordenação de Aperfeiçoamento de Pessoal de Nível Superior-CAPES(PNPD 1694744 to ZO)São Paulo Research Foundation-FAPESP(2013/18526-9 and 2013/04957-8 to AB).
文摘Mammals can show conspicuous behavioral responses to thermal variation,including changes in movement patterns.We used an integrative approach to understand how environmental temperature can drive the movement behavior of a mammal with low capacity for physiological thermoregulation,the giant anteater(Myrmecophaga tridactyla).We tracked 52 giant anteaters in 7 areas throughout the Brazilian savannah.We estimated the distance moved,area used,use of forest areas,and mean environmental temperature for each monitoring day of each individual.We modeled these data with Mixed Structural Equations—considering the possible interactions between our variables and controlling for sex and body mass.Giant anteaters reduced displacement and increased forest use with decreasing environmental temperature,probably because of their low body heat production.It is possible that they reduce distance moved and area used by reducing the duration of activity.With decreasing temperature,forest habitats become warmer than open ones,besides buffer rain and chilly winds.Reducing displacement and using forests are important strategies to reduce body heat loss and the energetic costs of thermoregulation.However,decreasing movement can limit food access and,consequently,fitness.Therefore,we highlight the importance of forests as thermal shelters.With increasing frequency and intensity of extreme weather events,we showed the need to preserve forest patches to offer suitable conditions for tropical mammals’behavioral thermoregulation.In this context,policies favoring deforestation on Brazilian territory are especially worrisome.Finally,we emphasize the need of integrative approaches to understand the complex interactions between organisms and the environment.
