Cutaneous leishmaniasis (CL) in the state of Rio de Janeiro is sporadic and can be characterised as a peridomestic transmission that occurs in modified natural environments. The aim of this work was to study the fauna and ecological characteristics of sandflies in an environmentally protected area (the State Park of Serra da Tiririca) within the remnants of the Atlantic Forest in the municipalities of Niterói and Maricá and their possible relationship with leishmaniasis. Captures were performed using light traps during the night once a month for one year in both sylvatic environments and areas surrounding homes near the park. A total of 1,037 sandflies were captured, belonging to nine genera and 12 species: Evandromyia tupynambai (34.1%), Migonemyia migonei (20.6%), Brumptomyia cunhai (13.8%), Micropygomyia schreiberi (9.7%), Psathyromyia lanei (6.5%), Brumptomyia nitzulescui (5.7%), Evandromyia edwardsi (5.4%), Nyssomyia intermedia (2.8%), Evandromyia cortelezzii (0.6%), Pintomyia bianchigalatiae (0.5%), Lutzomyia longipalpis (0.2%) and Sciopemyia microps (0.1%). Both Mg. migonei and Ny. intermedia may be acting as vectors of CL in this area.
Leishmaniasis encompasses a group of diverse clinical diseases caused by protozoan parasites of the Leishmania genus. This disease is a major public health problem in the New World affecting people exposed in endemic regions. The city of Governador Valadares (Minas Gerais/Brazil) is a re-emerging area for visceral leishmaniasis, with 191 human cases reported from 2008 to 2017 and a lethality rate of 14.7%. The transmission of the parasite occurs intensely in this region with up to 22% of domestic dogs with positive serology for the visceral form. Lu. longipalpis is one of the most abundant sand fly species in this area. Despite this scenario, so far there is no information regarding the circulating Leishmania species in the insect vector Lutzomyia longipalpis in this focus. We collected 616 female Lutzomyia longipalpis sand flies between January and September 2015 in the Vila Parque Ibituruna neighborhood (Governador Valadares/MG), which is located on a transitional area between the sylvatic and urban environments with residences built near a preserved area. After DNA extraction of individual sand flies, the natural Leishmania infections in Lu. longipalpis were detected by conventional PCR, using primers derived from kDNA sequences, specific for L. (Leishmania) or L. (Viannia) subgenus. The sensitivity of these PCR reactions was 0.1 pg of DNA for each Leishmania subgenus and the total infection rate of 16.2% (100 positive specimens). Species-specific PCR detected the presence of multiple Leishmania species in infected Lu. longipalpis specimens in Governador Valadares, including L. amazonensis (n = 3), L. infantum (n = 28), L. (Viannia) spp. (n = 20), coinfections with L. infantum and L. (Viannia) spp. (n = 5), and L. (Leishmania) spp (n = 44). Our results demonstrate that multiple Leishmania species circulate in Lu. longipalpis in Governador Valadares and reveal a potential increasing risk of transmission of the different circulating parasite species. This information reinforces the need for epidemiological and entomological surveillance in this endemic focus, and the development of effective control strategies against leishmaniasis.
Background: The sand fly, Lutzomyia longipalpis, is the main vector of Leishmania infantum in Brazil. A previous laboratory study showed that covering surfaces with insecticide-impregnated netting may provide an alternative method for killing sand flies. Synthetic male Lu. longipalpis sex/aggregation pheromone co-located with micro-encapsulated l-cyhalothrin demonstrated the potential of “lure-and-kill” to significantly reduce canine infection and sand fly densities. In this study we were interested to determine if insecticide impregnated netting could replace sprayed insecticide for Lu. longipalpis control.Methods: We placed synthetic pheromone in experimental and real chicken sheds treated with a 1m2 surface of either sprayed insecticide or insecticide-impregnated netting. Two experiments in experimental chicken sheds were carried out to determine the effect of the insecticide treatments on Lu. longipalpis over 1-week and 16-week periods. We counted the number of Lu. longipalpis collected overnight and dead at 24 hours. Two longitudinal intervention studies were carried in real chicken sheds and compared the numbers of Lu. longipalpis (collected and dead at 24h) before adding the intervention (either the netting or sprayed insecticide treatments) with the numbers collected 24h after the intervention. Results: In the first experiment all flies caught in the spray treated experimental chicken sheds were dead at 24 hours and in netting treated sheds 97% of females and 88% of males were dead at 24 hours (257 vs 225, Wilcoxon Signed Ranks Test P=0.043). The netting and spray treated traps were equally effective at killing both female and male Lu. longipalpis over the first 8-weeks however after 16-weeks both treatments killed a significantly lower proportion of females (64%vs 96%; P=0.000) and males 89%vs 100%; P=0.000) compared to the beginning. In the first of the longitudinal studies in real chicken sheds only the netting intervention significantly increased the proportion of females dead after 24h (60%vs81%; P=0.042). The subsequent study showed that both netting and spraying treatments had similarly significant impacts on the proportion of females dead after 24h (netting: 60%vs80%: P=0.0194 and spraying: 43%vs72%: P=0.0004).Conclusions: The netting and spray insecticide interventions (with synthetic sex/aggregation pheromone) have similar impacts on the Lu. longipalpis population.
Introduction:The sand fly, Lutzomyia longipalpis, is the main vector of Leishmania infantum in the Americas, primarily occurring in areas of apparent anthropomorphic modifications in several regions of Brazil. Methods. Sand flies were captured using light traps. Results: Out of all captured species, Lu. longipalpis numbers had increased within the park. Conclusions: We report the occurrence of Lu. longipalpis in an area of Atlantic Forest, possibly representing the first sylvatic population of Lu. longipalpis in an area absent of peridomestic captures, but with the risk of L. infantum transmission in the areas of Niterói and Maricá.
28Background 29 Leishmaniasis encompasses a group of diverse clinical diseases caused by protozoan 30 parasites of the Leishmania genus. This disease is a major public health problem in 31 the New World affecting people exposed in endemic regions. The city of Governador 32 Valadares (Minas Gerais/Brazil) is a re-emerging area for visceral leishmaniasis, with 33 191 human cases reported from 2008 to 2017 and a lethality rate of 14.7%. The 34 transmission of the parasite occurs intensely in this region with up to 22% of domestic 35 dogs with positive serology for the visceral form. Lu. longipalpis is one of the most 36 abundant sand fly species in this area. Despite this scenario, so far there is no 37 information regarding the circulating Leishmania species in the insect vector Lutzomyia 38 longipalpis in this focus. 39 Methodology/Principal Findings 40 We collected 616 female Lutzomyia longipalpis sand flies between January and 41 September 2015 in the Vila Parque Ibituruna neighborhood (Governador 42 Valadares/MG), which is located on a transitional area between the sylvatic and urban 43 environments with residences built near a preserved area. After DNA extraction of 44 individual sand flies, the natural Leishmania infections in Lu. longipalpis were detected 45 by end-point PCR, using primers derived from kDNA sequences, specific for L. 46 (Leishmania) or L. (Viannia) subgenus. The sensitivity of these PCR reactions was 0.1 47 pg of DNA for each Leishmania subgenus and the total infection rate of 16.2% (100 48 positive specimens). Species-specific PCR detected the presence of multiple 49 Leishmania species in infected Lu. longipalpis specimens in Governador Valadares, 50 including L. amazonensis (n=3), L. infantum (n=28), L. (Viannia) spp. (n=20), 3 51 coinfections with L. infantum and L. (Viannia) spp. (n=5), and L. (Leishmania) spp 52 (n=44). 53 Conclusions 54 Our results demonstrate that multiple Leishmania species circulate in Lu. longipalpis 55 in Governador Valadares and reveal a potential increasing risk of transmission of the 56 different circulating parasite species. This information is a key factor for planning 57 surveillance and effective control strategies against leishmaniasis in this endemic 58 focus. 59 60 Author summary 61 Leishmaniasis is a neglected tropical disease transmitted to mammals by the 62 bite of sand flies infected with parasites of the Leishmania genus. This disease affects 63 millions of people in various regions of the world, including Brazil. The municipality of 64 Governador Valadares (Minas Gerais/Brazil) is a re-emergent focus of intense 65 transmission of leishmaniasis, with a high number of human cases and a high 66 prevalence of infected domestic dogs. To develop better leishmaniasis control 67 strategies for the region, we performed a surveillance study of Lu. longipalpis, the main 68 vector of visceral leishmaniasis in Brazil, and identified circulating species of 69Leishmania in this insect vector. We estimate that the natural infection rate of Lu. 70 longipalpis...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.