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1.
Genes (Basel) ; 14(9)2023 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-37761811

RESUMO

Genetic diversity and population structuring for the species Haemogogus leucocelaenus, a sylvatic vector of yellow fever virus, were found to vary with the degree of agricultural land use and isolation of fragments of Atlantic Forest in municipalities in the state of São Paulo where specimens were collected. Genotyping of 115 mitochondrial SNPs showed that the populations with the highest indices of genetic diversity (polymorphic loci and mean pairwise differences between the sequences) are found in areas with high levels of agricultural land use (northeast of the State). Most populations exhibited statistically significant negative values for the Tajima D and Fu FS neutrality tests, suggesting recent expansion. The results show an association between genetic diversity in this species and the degree of agricultural land use in the sampled sites, as well as signs of population expansion of this species in most areas, particularly those with the highest forest edge densities. A clear association between population structuring and the distance between the sampled fragments (isolation by distance) was observed: samples from a large fragment of Atlantic Forest extending along the coast of the state of São Paulo exhibited greater similarity with each other than with populations in the northwest of the state.


Assuntos
Culicidae , Febre Amarela , Animais , Febre Amarela/genética , Brasil , Mosquitos Vetores/genética , Florestas
2.
Acta Trop ; 245: 106983, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37419378

RESUMO

The intense process of deforestation in tropical forests poses serious challenges for the survival of biodiversity, as well as for the human species itself. This scenario is supported by the increase in the incidence of epidemics of zoonotic origin observed over the last few decades. In the specific case of sylvatic yellow fever (YF), it has already been shown that an increase in the transmission risk of the causative agent (yellow fever virus - YFV) is associated with areas with a high degree of forest fragmentation, which can facilitate the spread of the virus. In this study we tested the hypothesis that areas with more fragmented landscapes and a higher edge density (ED) but a high degree of connectivity between forest patches favor YFV spread. To this end, we used YF epizootics in non-human primates (NHPs) in the state of São Paulo to build direct networks, and used a multi-selection approach to analyze which landscape features could facilitate YFV spread. Our results showed that municipalities with the potential to spread the virus exhibited a higher amount of forest edge. Additionally, the models with greater empirical support showed a strong association between forest edge density and the risk of occurrence of epizootic diseases, as well as the need for a minimum threshold of native vegetation cover to restrict their transmission. These findings corroborate our hypothesis that more fragmented landscapes with a higher degree of connectivity favor the spread of YFV, while landscapes with fewer connections tend to act as dead zones for the circulation of the virus.


Assuntos
Febre Amarela , Vírus da Febre Amarela , Animais , Humanos , Surtos de Doenças , Brasil/epidemiologia , Primatas , Florestas
3.
Parasitol Res ; 122(2): 419-423, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36416950

RESUMO

Intestinal parasites are a constant public health problem in the Amazon region, with a high prevalence of cases related to poor sanitary conditions. We investigated the sociodemographic and seasonal factors associated with human intestinal parasite infections in an area of the Western Amazon, Brazil, from September 2017 to August 2019. Data were collected using a database available at the Diagnostic Support Centre (Centro de Apoio ao Diagnóstico, CAD) of the Municipality of Rio Branco, on positive diagnoses for intestinal parasites. Among the 53,200 samples analysed, 18.3% (n = 9712) were positive. Of these, 96.4% (n = 9363) and 3.6% (n = 349) were protozoan and helminthic infections, respectively. Males showed higher odds ratio (OR) for Enterobius vermicularis infection (OR: 2.3) and giardiasis (OR: 1.9) and lower OR for Endolimax nana (OR: 0.9) and Entamoeba coli (OR: 0.9) infections. Individuals aged ≥ 15 presented higher OR for Strongyloides stercoralis (OR: 3.4), hookworms (OR: 2.3), and almost all protozoan infections than younger individuals. In the dry season, the OR for hookworms (OR: 1.5), Iodamoeba butschlii (OR: 1.4), and Endolimax nana (OR: 1.3) infections was higher than that in the rainy season, including a high chance of polyparasitism (OR: 1.6). We concluded that there was a significant difference between the different types of intestinal parasites, particularly protozoa, with high OR in the dry season and for certain groups.


Assuntos
Giardíase , Helmintíase , Enteropatias Parasitárias , Infecções por Protozoários , Masculino , Humanos , Estações do Ano , Fezes/parasitologia , Enteropatias Parasitárias/epidemiologia , Enteropatias Parasitárias/parasitologia , Helmintíase/epidemiologia , Helmintíase/parasitologia , Infecções por Protozoários/epidemiologia , Infecções por Protozoários/parasitologia , Prevalência
4.
Acta Trop ; 231: 106430, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35367409

RESUMO

Intraspecific competition between mosquito larvae can affect several adult traits, particularly size. This study tested the hypothesis that intraspecific competition during the larval stage affects wing length in Ae. aegypti and Ae. albopictus adults, in turn influencing locomotor activity. L1 larvae of both species were reared in trays under conditions of low and high competition. After adults had emerged, the locomotor activity of virgin females of Ae. aegypti and Ae. albopictus was evaluated under light-dark cycles of 12:12 h at 25 °C and 70% relative humidity. At the end of the locomotor activity experiment, the left wings of the mosquitoes were removed to be measured, and wing length was used as an indicator of adult female size. Although the results showed that the wing lengths of Ae. aegypti and Ae. albopictus females reared under low larval competition were significantly greater than those of females reared under high larval competition, this difference did not affect locomotor activity in females of either species, demonstrating that locomotor activity in small Ae. aegypti and Ae. albopictus females is not lower than in larger females. Our findings reinforce the idea that intraspecific competition alters the wing length of Ae. aegypti and Ae. albopictus females and provide new evidence about this effect on the locomotor activity of these species.


Assuntos
Aedes , Animais , Tamanho Corporal , Feminino , Larva , Locomoção
5.
Acta Trop ; 228: 106333, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35093325

RESUMO

Man-made changes to the landscape play a crucial role in altering the epidemiologic patterns of infectious diseases, mainly as a result of pathogen spillover. Sylvatic yellow fever is ideally suited to modeling of this phenomenon as the risk of transmission of the disease as well as its circulation and dispersal are associated with forest fragmentation. In this study we investigated the temporal dispersal pattern of yellow fever virus (YFV) by means of confirmed cases of epizootics in non-human primates in municipalities in the state of São Paulo where there was no recommendation for vaccination in 2017. We analyzed the resistance to dispersal associated with different classes of land use and the geographic distances between the different locations where epizootics were recorded. The model that best explained the temporal dispersal pattern of YFV in the study area indicated that this was influenced by the geographic distance between collection locations and by the permeability of the forest edges (150 m) at the interface with the following core areas: Water, Agricultural, Non-Forest Formation and Forestry. Water, Agricultural, Urban and Forest core areas and the interfaces between the latter two formed important barriers to circulation of the virus. These findings indicate that fragmentation of vegetation tends to decrease the time taken for pathogens to spread, while conservation of forest areas has the opposite effect.


Assuntos
Febre Amarela , Vírus da Febre Amarela , Animais , Brasil/epidemiologia , Florestas , Humanos , Primatas
6.
Insects ; 12(9)2021 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-34564237

RESUMO

The physicochemical parameters of water, such as pH, salinity, conductivity, and total dissolved solids, can influence mosquito larval development, survival, and abundance. Therefore, it is important to elucidate how these factors influence mosquito occurrence. We hypothesized that the occurrence and community composition of immature mosquito species are driven not only by the availability of suitable aquatic habitats, but also by the physicochemical factors of these habitats. The primary objective of this study was therefore to investigate the influence of the physicochemical parameters of water in different types of aquatic habitats on the occurrence of mosquito species in two remnants of Atlantic Forest in the city of São Paulo, Brazil. Collections of immature mosquitoes and assessment of the physicochemical characteristics of the water in the collection sites were carried out for twelve months. The variation in species composition and occurrence with the measured physicochemical parameters and the type of breeding site was assessed using constrained ordination methods. The results indicate that there was a statistically significant difference in species composition as a function of the different types of aquatic habitats, and that pH had an influence on species occurrence even when the variance explained by the type of aquatic habitat was removed from the analysis. There was a statistically significant association between mosquito species occurrence and pH and salinity, and the former had a significant influence on the mosquito species collected regardless of the type of aquatic habitat, showing that the pH of the breeding site water is an important factor in driving mosquito population dynamics and species distribution.

7.
Acta Trop ; 223: 106103, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34416187

RESUMO

The species richness of Amazonian phlebotomines is considered to be one of the highest in the world. In the present study, we investigated the richness and diversity of phlebotomine fauna in Xapuri city, Acre state, Western Brazilian Amazonia, which is an area that is highly endemic for cutaneous leishmaniasis. Sand fly collections were performed monthly from August 2013 to July 2015 (288 h total of sampling effort) in intradomiciliary, peridomiciliary, and forested environments of two localities. Collected females were dissected, microscopically examined for flagellates in their guts, and preserved in ethanol. A total of 21,197 specimens comprising 14 genera and 57 species were collected, and the majority of these were Nyssomyia, Psychodopygus, and Trichophoromyia genera. Three new records of phlebotomine species for Acre are presented here, including Brumptomyia brumpti, Psathyromyia pradobarrientosi, and for the first time in Brazil, Th. omagua. In Xapuri, the phlebotomine fauna of different ecotopes was varied in regard to abundance, diversity, and frequency, and they included proven and permissive vectors of Leishmania spp. The fauna discovered in the forested areas (57 species) was richer and more diverse than was that (33 species) identified in the peri­ and intra-domiciles. The identification of Leishmania subgenera that were present in sand fly guts according to SSU rRNA sequences revealed ten and three species harboring Leishmania of subgenera Viannia and Leishmania (most likely Leishmania amazonensis), respectively. The presence of Leishmania (Leishmania) in sand flies are reported here for the first time in Acre. The presence of L. (Viannia) spp. in Brumptomyia sp. and Lutzomyia sherlocki. and the occurrence of mixed infections with Leishmania of both subgenera in Ps. lainsoni have been reported for the first time in Brazil. Taken together, data from previous studies and from the present study highlight the remarkable complexity of phlebotomine fauna that is possibly due to the well-preserved Xapuri forested areas sustaining vital economic activities of plant extraction and ecological tourism. Our findings also provide new insights into the ongoing adaptation of Trichophoromyia and Psychodopygus species to human habitats.


Assuntos
Leishmania , Psychodidae , Animais , Brasil/epidemiologia , Feminino , Florestas , Humanos , Leishmania/genética , Leishmania/isolamento & purificação , Leishmaniose Cutânea/epidemiologia , Psychodidae/parasitologia
8.
Acta Trop ; 221: 106009, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34126089

RESUMO

São Paulo is one of the largest cities in the world and has several characteristics that favor a diversity of urban and wild mosquitoes. Little is known about how variations in mosquito diversity and feeding preferences for different hosts in different vegetation strata can influence the risk of pathogen transmission to humans. We investigated vertical stratification of mosquitoes and its relationship with vertebrate hosts in environments with different degrees of conservation in two conservation units in the city of São Paulo. Adult mosquitoes were collected using CDC traps, aspiration and Shannon traps. After morphological identification, host blood in engorged females was analyzed by PCR with a vertebrate-specific primer set based on mitochondrial cytochrome b DNA of vertebrates commonly found in the two conservation units. Although a higher abundance of the species Anopheles cruzii and Culex nigripalpus was found in the canopy, blood not only from birds but also from humans and rodents was identified in these mosquitoes. In one of the units, Wyeomyia confusa and Limatus durhamii were found occupying mainly niches at ground level while Culex vaxus was frequently found in the canopy. Haemagogus leucocelaenus, the main vector of yellow fever, was found in low abundance at all collection points, particularly in the canopy. Species richness and composition tended to vary little between canopy and ground level in the same environment, but the abundance between canopy and ground level varied more depending on the species analyzed, the most abundant and frequent species exhibiting a predilection for the canopy. Even those mosquito species observed more frequently in the canopy did not show an association with hosts found in this stratum as most of the blood identified in these species was from humans, suggesting opportunist feeding behavior, i.e., feeding on the most readily available host in the environment. The two most common species in the study, An. cruzii and Cx. nigripalpus, may be able to act as bridge vectors for pathogens to circulate between the forest canopy and ground level.


Assuntos
Anopheles , Culex , Culicidae , Ecossistema , Animais , Brasil , Cidades , Comportamento Alimentar , Feminino , Mosquitos Vetores
9.
PLoS Negl Trop Dis ; 15(2): e0008736, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33591994

RESUMO

Transmission foci of autochthonous malaria caused by Plasmodium vivax-like parasites have frequently been reported in the Atlantic Forest in Southeastern and Southern Brazil. Evidence suggests that malaria is a zoonosis in these areas as human infections by simian Plasmodium species have been detected, and the main vector of malaria in the Atlantic Forest, Anopheles (Kerteszia) cruzii, can blood feed on human and simian hosts. In view of the lack of models that seek to predict the dynamics of zoonotic transmission in this part of the Atlantic Forest, the present study proposes a new deterministic mathematical model that includes a transmission compartment for non-human primates and parameters that take into account vector displacement between the upper and lower forest strata. The effects of variations in the abundance and acrodendrophily of An. cruzii on the prevalence of infected humans in the study area and the basic reproduction number (R0) for malaria were analyzed. The model parameters are based on the literature and fitting of the empirical data. Simulations performed with the model indicate that (1) an increase in the abundance of the vector in relation to the total number of blood-seeking mosquitoes leads to an asymptotic increase in both the proportion of infected individuals at steady state and R0; (2) the proportion of infected humans at steady state is higher when displacement of the vector mosquito between the forest strata increases; and (3) in most scenarios, Plasmodium transmission cannot be sustained only between mosquitoes and humans, which implies that non-human primates play an important role in maintaining the transmission cycle. The proposed model contributes to a better understanding of the dynamics of malaria transmission in the Atlantic Forest.


Assuntos
Anopheles , Malária/transmissão , Mosquitos Vetores , Animais , Brasil , Ecossistema , Florestas , Humanos , Modelos Teóricos , Plasmodium , Doenças dos Primatas/transmissão , Primatas
10.
Artigo em Inglês | MEDLINE | ID: mdl-35284897

RESUMO

Plasmodium malariae and Plasmodium vivax are protozoan parasites that can cause malaria in humans. They are genetically indistinguishable from, respectively, Plasmodium brasilianum and Plasmodium simium, i.e. parasites infecting New World non-human primates in South America. In the tropical rainforests of the Brazilian Atlantic coast, it has long been hypothesized that P. brasilianum and P. simium in platyrrhine primates originated from P. malariae and P. vivax in humans. A recent hypothesis proposed the inclusion of Plasmodium falciparum into the transmission dynamics between humans and non-human primates in the Brazilian Atlantic tropical rainforest. Herein, we assess the occurrence of human malaria in simians and sylvatic anophelines using field-collected samples in the Capivari-Monos Environmental Protection Area from 2015 to 2017. We first tested simian blood and anopheline samples. Two simian (Aloutta) blood samples (18%, n = 11) showed Plasmodium cytb DNA sequences, one for P. vivax and another for P. malariae. From a total of 9,416 anopheline females, we found 17 pools positive for Plasmodium species with a 18S qPCR assay. Only three showed P. cytb DNA sequence, one for P. vivax and the others for rodent malaria species (similar to Plasmodium chabaudi and Plasmodium berghei). Based on these results, we tested 25 rodent liver samples for the presence of Plasmodium and obtained P. falciparum cytb DNA sequence in a rodent (Oligoryzomys sp.) liver. The findings of this study indicate complex malaria transmission dynamics composed by parallel spillover-spillback of human malaria parasites, i.e. P. malariae, P. vivax, and P. falciparum, in the Brazilian Atlantic forest.

12.
Rev. Soc. Bras. Med. Trop ; 54: e00282020, 2021. tab, graf
Artigo em Inglês | SES-SP, Coleciona SUS (Brasil), LILACS | ID: biblio-1143882

RESUMO

Abstract INTRODUCTION: We aimed to study intraspecific variation in Triatoma costalimai, a potential vector of Chagas disease present in Brazil and Bolivia. METHODS: We analyzed phenotypic (connexivum color patterns, wing morphometrics) and genetic variation (16S mtDNA) of three Brazilian T. costalimai populations. We compared 16S sequences with those of putative Bolivian T. costalimai and its sister species, T. jatai. RESULTS: Brazilian populations had different connexivum color patterns and forewing shapes. A 16S mtDNA haplotype network showed a clear separation of Brazilian T. costalimai from both T. jatai and Bolivian T. costalimai. CONCLUSIONS: We report considerable variability in T. costalimai populations.


Assuntos
Animais , Triatoma/genética , Doença de Chagas , Variação Genética/genética , Bolívia , Brasil , Insetos Vetores/genética
13.
Rev Soc Bras Med Trop ; 54: e00282020, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33338103

RESUMO

INTRODUCTION: We aimed to study intraspecific variation in Triatoma costalimai, a potential vector of Chagas disease present in Brazil and Bolivia. METHODS: We analyzed phenotypic (connexivum color patterns, wing morphometrics) and genetic variation (16S mtDNA) of three Brazilian T. costalimai populations. We compared 16S sequences with those of putative Bolivian T. costalimai and its sister species, T. jatai. RESULTS: Brazilian populations had different connexivum color patterns and forewing shapes. A 16S mtDNA haplotype network showed a clear separation of Brazilian T. costalimai from both T. jatai and Bolivian T. costalimai. CONCLUSIONS: We report considerable variability in T. costalimai populations.


Assuntos
Doença de Chagas , Triatoma , Animais , Bolívia , Brasil , Variação Genética/genética , Insetos Vetores/genética , Triatoma/genética
14.
PLoS One ; 15(10): e0227239, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33064724

RESUMO

Species of the genus Flavivirus are widespread in Brazil and are a major public health concern. The country's largest city, São Paulo, is in a highly urbanized area with a few forest fragments which are commonly used for recreation. These can be considered to present a potential risk of flavivirus transmission to humans as they are home simultaneously to vertebrate hosts and mosquitoes that are potential flavivirus vectors. The aim of this study was to conduct flavivirus surveillance in field-collected mosquitoes in the Capivari-Monos Environmental Protection Area (EPA) and identify the flavivirus species by sequence analysis in flavivirus IFA-positive pools. Monthly mosquito collections were carried out from March 2016 to April 2017 with CO2-baited CDC light traps. Specimens were identified morphologically and grouped in pools of up to 10 individuals according to their taxonomic category. A total of 260 pools of non-engorged females were inoculated into C6/36 cell culture, and the cell suspensions were analyzed by indirect immunofluorescence assay (IFA) after the incubation period. IFA-positive pools were tested by qRT-PCR with genus-specific primers targeting the flavivirus NS5 gene to confirm IFA-positive results and sequenced to identify the species. Anopheles cruzii (19.5%) and Wyeomyia confusa (15.3%) were the most frequent vector species collected. IFA was positive for flaviviruses in 2.3% (6/260) of the sample pools. This was confirmed by qRT-PCR in five pools (83.3%). All five flavivirus-positive pools were successfully sequenced and the species identified. DENV serotype 2 (DENV-2) was detected in Culex spp. and Culex vaxus pools, while ZIKV was identified in An. cruzii, Limatus durhamii and Wy. confusa pools. To the best of our knowledge, detection of flavivirus species of medical importance has never previously been reported in these species of wild-caught mosquitoes. The finding of DENV-2 and ZIKV circulating in wild mosquitoes suggests the existence of an enzootic cycle in the area. In-depth studies of DENV-2 and ZIKV, including investigation of mosquito infection, vector competence and infection in sylvatic hosts, are needed to shed light on the transmission dynamics of these important viruses and the potential risk of future outbreaks of DENV-2 and ZIKV infections in the region.


Assuntos
Vírus da Dengue/isolamento & purificação , Mosquitos Vetores/virologia , Proteínas não Estruturais Virais/genética , Zika virus/isolamento & purificação , Animais , Anopheles/virologia , Brasil/epidemiologia , Culex/virologia , Vírus da Dengue/genética , Feminino , Vigilância da População , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Meio Selvagem , Zika virus/genética
15.
Acta Trop ; 212: 105669, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32805213

RESUMO

Cantareira State Park (CSP) is located in the Metropolitan Region of São Paulo, one of the most densely populated areas on the planet. Recently, a yellow-fever epidemic practically annihilated the howler monkey population in this park, and human infections were reported in the vicinity. As simian and human plasmodia also circulate in CSP, the present study sought to provide an update on the mosquito fauna in this park, including an analysis of the diversity in areas with different degrees of conservation and a comparison of the yields achieved with different collection techniques. From October 2015 to April 2017, adult mosquitoes were collected with CDC traps, hand-held battery-powered aspirators and Shannon traps, and larvae and pupae were collected with larval dippers and suction samplers in natural and artificial breeding sites. In total, 11,038 specimens distributed in 103 taxa represented by 16 genera were collected. Both the observed species richness and diversity were greater in the environments with the highest degree of preservation. The 'wild' (most preserved) area in CSP had the greatest species richness, followed by the transition area and human-impacted area. The estimated richness indicated that the three environments may have a greater number of species than observed in this study, and Sorensen's index showed that the average degree of similarity varies little between areas. In the inventory of local species, the Shannon trap was the most efficient collection technique for adult mosquitoes, and the suction sampler the most efficient for immatures. The results highlight the increase in the number of different taxa collected as different mosquito capture techniques were included, confirming the importance of using several strategies to sample the local mosquito fauna satisfactorily when exploring a greater number of ecotopes. CSP is a refuge and shelter for native and introduced mosquito species where new biocenoses including pathogens, vertebrate hosts and vectors can form, allowing zoonotic outbreaks in the local human population to occur.


Assuntos
Culicidae/classificação , Mosquitos Vetores/classificação , Animais , Brasil/epidemiologia , Humanos , Parques Recreativos , Febre Amarela/transmissão
16.
Acta Trop ; 204: 105385, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32027836

RESUMO

The landscape's structure can play a relevant role in epidemic patterns of arboviruses, influencing factors such as abundance, movement, and dispersal ability in arthropod vectors and vertebrate hosts, besides promoting alterations in the rate of potential infectious contacts between these organisms. In the Americas, yellow fever (YF) exhibits only the sylvatic cycle, in which the virus circulates in sylvatic areas among non-human primates, being transmitted by mosquitoes of the Haemagogus and Sabethes genera. In this study, we investigate some aspects of the landscape in relation to diversity and abundance of culicid species associated with YF transmission. Studies were performed in the Cantareira State Park, a remnant of the Atlantic Forest located in Greater Metropolitan São Paulo, Brazil, where the YF virus circulated recently with dozens of deaths in howler monkeys (Alouatta guariba), in addition to reported human cases. Mosquito collections were carried out monthly from February 2015 to April 2017. Mosquitoes were collected from three sites using battery-powered aspirator (12-volt battery), CDC, and Shannon traps for adults, and suction samplers and entomological spoons in breeding sites to collect immature forms. 703 mosquitoes belonging to 12 species of the Aedini and Sabethini tribes were collected. Aedes scapularis and Psorophora ferox exhibited higher abundance, while Haemagogus leucocelaenus, the main vector of YF in São Paulo state, showed lower abundance in all sampled areas. The site with longer edge between forest area and anthropic area presented more richness and abundance of YF vector species, while the site with larger forest cover area and shorter edges between forest and anthropic areas exhibited an inverse pattern. Statistically significant differences were observed between the composition of potential YF vector species among the investigated sites. Although Hg. leucocelaenus occurred in all sampled sites, the different patterns of distribution and abundance of other mosquitoes such as Aedes scapularis and Psorophora ferox suggest that these species may be involved in the transmission of sylvatic YF in the study area.


Assuntos
Culicidae/fisiologia , Mosquitos Vetores/fisiologia , Febre Amarela/epidemiologia , Vírus da Febre Amarela , Animais , Oceano Atlântico , Brasil/epidemiologia , Cidades , Culicidae/classificação , Culicidae/virologia , Entomologia , Florestas , Humanos , Mosquitos Vetores/classificação , Mosquitos Vetores/virologia , Febre Amarela/parasitologia
17.
Acta Trop ; 205: 105394, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32070677

RESUMO

Water's physical and chemical characteristics are important constraints in aquatic ecosystems, acting on the development, survival, and adaptation of different organisms. Immature forms of mosquitoes develop in widely diverse aquatic environments and are mainly found in permanent or temporary freshwater bodies with little or no movement. The current study aimed to investigate whether variations in larval habitats' pH, salinity, dissolved oxygen, and water temperature influence the composition of Culicidae assemblages and the presence and abundance of Aedes albopictus and Ae. aegypti. From August 2012 to July 2013, captures of immature forms and measurement of water's physical and chemical profiles were performed monthly in natural and artificial breeding sites in four urban parks in the city of São Paulo, Brazil. Changes in species composition related to the parameters' variation were assessed by multivariate analysis. Regression trees were performed to evaluate the effect of breeding sites' physical and chemical variations on the presence and abundance of Ae. albopictus and Ae. aegypti. The observations suggest ranges of conditions for the measured variables in which most species tend to be found more frequently, and pH and salinity are the variables most closely associated with variations in mosquito composition. Ae. aegypti and Ae. albopictus were present in both natural and artificial breeding sites and were observed under significantly varying conditions of pH, salinity, dissolved oxygen, and temperature. For Ae. albopictus, larval habitat type and pH were the best predictors of incidence and abundance. For Ae. aegypti, pH and salinity were the best predictors of abundance, while dissolved oxygen and larval habitat type were better predictors of presence. This information broadens our understanding of the ecology and interaction of the investigated species with abiotic factors in the aquatic environments, providing useful data for studies that seek to elucidate the underlying mechanisms of selection and colonization of breeding sites by these mosquitoes. This study also reinforces previous observations indicating that Ae. albopictus and Ae. aegypti can colonize diverse types of larval habitats with widely varying physical and chemical conditions.


Assuntos
Aedes/fisiologia , Parques Recreativos , Água/química , Animais , Brasil/epidemiologia , Cidades , Ecossistema , Larva/crescimento & desenvolvimento , Temperatura
18.
Acta Trop ; 202: 105264, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31770518

RESUMO

Microculex is a subgenus of wild mosquitoes belonging to genus Culex, closely related to preserved environments. Its immature forms are generally associated with natural breeding sites, especially bromeliads. Recent years have witnessed the presence of some Microculex species in anthropic environments, including immature forms in artificial breeding sites, which may represent an adaptive tendency. This study aimed to investigate the variation in the abundance and dispersal of Microculex species in environments with different forest cover proportions. Three sites with different proportions of plant cover (60%, 70%, and 90%) were selected in an environmental protection area in the city of São Paulo, with varying degrees of modification and human presence. Collection was performed from March 2015 to April 2017, targeting bromeliads and artificial containers. Variations in the species' richness, composition, and abundance in different environments were analyzed. Variations in mean abundance and larval density between the different forest cover gradients were analyzed with generalized linear mixed-effects models. A total of 1,028 specimens belonging to 14 species were collected. Richness and composition were similar across the environments. Culex (Mcx.) imitator and Cx. (Mcx.) pleuristriatus were the most abundant species. The results showed a relationship between forest cover reduction and an increase in larval abundance and density for Cx. (Mcx.) pleuristriatus. Cx. (Mcx.) imitator showed a decrease in larval abundance related to a reduction in forest cover. Species from Pleuristriatus Series were found both in bromeliads and in artificial breeding sites. The findings emphasize that the Microculex Group of mosquitoes is not limited to preserved environments, but that some species such as Cx. (Mcx.) pleuristriatus appear to be well-adapted to areas impacted by human activity, colonizing artificial breeding sites, which may suggest a possible domiciliation process.


Assuntos
Distribuição Animal , Culicidae/fisiologia , Florestas , Animais , Cidades , Culicidae/classificação , Humanos , Larva
19.
Acta Trop ; 199: 105151, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31449783

RESUMO

The interior of caves usually presents climate, light, soil, flora and fauna that distinguish it from the external environment. Among the sandfly species found in caves, several may act as vectors of Leishmania spp. and others are a nuisance to humans due to their painful bites. This study sought to identify the phlebotomine fauna in a cavern with cave paintings ("Gruta do Pitoco") which attract tourists in Alcinopólis municipality, Mato Grosso do Sul state, Brazil. The sandflies were collected from March 2014 to September 2015, with automatic light traps, installed monthly, in the entrance and interior of the cave and outside it. A total of 7645 specimens belonging to 27 species were collected. Lutzomyia dispar, Martinsmyia oliverai and those of the Lu. longipalpis complex (Lu. cruzi and Lu. longipalpis) were the predominant species. Among the three environments sampled, no great difference between species richness was observed. Comparing these environments, the interior of the cave presented the lowest diversity index due to the high frequency of Lu. dispar (46%). For the first time, specimens (only females) of the genus Deanemyia were collected in Mato Grosso do Sul state. Moreover, the study revealed the sympatric occurrence of Lu. cruzi and Lu. longipalpis, both proven vectors of L. infantum, and also Lu. dispar, a highly anthropophilic species, which often causes annoyance to those who visit the cave.


Assuntos
Insetos Vetores , Psychodidae , Animais , Brasil/epidemiologia , Cavernas , Feminino , Humanos , Leishmaniose/transmissão , Masculino , Pinturas , Phlebotomus
20.
Malar J ; 18(1): 110, 2019 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-30940142

RESUMO

BACKGROUND: The mosquito Anopheles (Kerteszia) cruzii is the main vector of human and simian malaria in the Atlantic Forest. This species is usually abundant in the forests where it occurs, preferring to live and feed on canopies, behaviour known as acrodendrophily. However, in several studies and locations this species has been observed in high density near the ground in the forest. In this study, it was hypothesized that factors associated with anthropogenic landscape changes may be responsible for the variation in abundance and acrodendrophily observed in An. cruzii. METHODS: The study was conducted in a conservation unit in the city of São Paulo, Brazil. Monthly entomological collections were performed from March 2015 to April 2017, and the resulting data were used with data from another study conducted in the same area between May 2009 and June 2010. Mosquitoes were collected from five sites using CDC and Shannon traps. Landscape composition and configuration metrics were measured, and generalized linear mixed-effect models were used to investigate the relationship between these metrics and variations in the abundance and acrodendrophily of An. cruzii. RESULTS: The model that showed the best fit for the relationship between landscape metrics and An. cruzii abundance suggests that an increase in the proportion of forest cover leads to an increase in the abundance of this mosquito, while the model that best explained variations in An. cruzii acrodendrophily suggests that an increase in total forest-edge length leads to greater activity by this species at ground level. CONCLUSION: While the data indicate that changes in landscape due to human activities lead to a reduction in An. cruzii abundance, such changes may increase the contact rate between this species and humans living on the edges of forest fragments where An. cruzii is found. Future studies should, therefore, seek to elucidate the effect of these landscape changes on the dynamics of Plasmodium transmission in the Atlantic Forest, which according to some studies includes the participation of simian hosts.


Assuntos
Anopheles/crescimento & desenvolvimento , Comportamento Animal , Florestas , Atividades Humanas , Mosquitos Vetores/crescimento & desenvolvimento , Densidade Demográfica , Animais , Brasil , Transmissão de Doença Infecciosa , Entomologia/métodos , Humanos , Malária/transmissão
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