scholarly journals Ecoepidemiology of American Visceral Leishmaniasis in Tocantins State, Brazil: Factors Associated with the Occurrence and Spreading of the Vector Lutzomyia (Lutzomyia) longipalpis (Lutz & Neiva, 1912) (Diptera: Psychodidae: Phlebotominae)

Author(s):  
Margarete Martins dos Santos Afonso ◽  
Sérgio Augusto de Miranda Chaves ◽  
Monica de Avelar Figueiredo Mafra Magalhães ◽  
Renata Gracie ◽  
Carina Azevedo ◽  
...  
2019 ◽  
Vol 40 (6Supl2) ◽  
pp. 3313
Author(s):  
Valéria Régia Franco Sousa ◽  
Álvaro Felipe de Lima Ruy Dias ◽  
Juliana Yuki Rodrigues ◽  
Mariana de Medeiros Torres ◽  
Janaína Marcela Assunção Rosa Moreira ◽  
...  

Visceral Leishmaniasis (VL) is a parasitic zoonosis expanding in Brazil. Several municipalities in the state of Mato Grosso including those on the river Cuiabá have reported the incidence of both human and canine cases and the identification of sandfly vector, Lutzomyia longipalpis and Lu. cruzi. Dogs are considered the main reservoir of Leishmania chagasi in the urban areas, hence, we devised a cross-sectional study aimed at assessing the prevalence of the infection in the dogs of riverside communities on Cuiabá River watershed by parasitological (parasitic isolation in culture), serological, and molecular methods. Of the 248 surveyed dogs, 24 were positive in enzyme linked immunosorbent assay (ELISA) or immunofluorescence antibody test (IFAT), with a prevalence of 9.7%. The riverside communities located in the town of Santo Antonio do Leverger displayed a higher prevalence of the disease than the cities of Cuiabá and Várzea Grande; however, the difference was not statistically significant (p > 0.05). Dogs born in the communities had a 3.24-fold higher risk of acquiring the infection. Promastigote were isolated in the axenic culture from the bone marrow samples and intact skin. Further, DNA of Leishmania sp. was detected in the bone marrow samples, lymph nodes, leukocyte cover, and skin of only one examined dog. These samples were sequenced and they showed 99% homology to L. infantum. To conclude, we observed a higher prevalence of infection in Riverside communities of Santo Antonio do Leverger and the confirmation of autochthony in these areas justifies the surveillance actions to minimise the risk of transmission within the riverine community itself, besides its dissemination to other areas by tourism.


Parasitology ◽  
2021 ◽  
pp. 1-9
Author(s):  
Cleya da Silva Santana Cruz ◽  
David Soeiro Barbosa ◽  
Vinícius Cunha Oliveira ◽  
Diogo Tavares Cardoso ◽  
Nathália Sernizon Guimarães ◽  
...  

Abstract Visceral leishmaniasis (VL) is endemic in 70 countries and has been reported in 12 countries of Latin America, with over 90% of the cases reported in Brazil, where epidemics have occurred since 1980. The objective of this review is to describe the factors associated with the occurrence of VL epidemics in humans in urban areas. A systematic review was conducted according to the PRISMA-P guidelines. The databases PubMed (by Medline), Cochrane Library, Embase, Amed, LILACS and grey literature [Google Scholar and handsearch of the database of the Information System for Notifiable Diseases (SINAN) of Brazil's Unified Health System] were used. The protocol was registered under PROSPERO (CRD42019128998). Climatic, environmental factors and indicators of urban social structure were described as influencing the outbreaks in the North and Northeast regions. Gender and age characteristics were related to a greater chance of developing VL in the Central-West, Northeast and Southeast regions. Vector indicators showed a positive correlation with the incidence of VL in studies in the Northeast region. In the Southeast and Northeast regions, studies revealed the presence of dogs with positive correlation with VL. Knowledge gaps remain regarding the contribution to the increase in the risk factors described in ecological approaches, as no analysis was performed at the individual level, and it is still necessary to discuss the influence of other associated elements in epidemic episodes in the spread of VL.


Acta Tropica ◽  
2016 ◽  
Vol 164 ◽  
pp. 233-242 ◽  
Author(s):  
Agda Maria Oliveira ◽  
Carolina Portugal Vieira ◽  
Margareth Regina Dibo ◽  
Marluci Monteiro Guirado ◽  
Lilian Aparecida Colebrusco Rodas ◽  
...  

2009 ◽  
Vol 104 (8) ◽  
pp. 1191-1193 ◽  
Author(s):  
Érika Monteiro Michalsky ◽  
Consuelo Latorre Fortes-Dias ◽  
João Carlos França-Silva ◽  
Marilia Fonseca Rocha ◽  
Ricardo Andrade Barata ◽  
...  

2014 ◽  
Vol 23 (3) ◽  
pp. 320-327 ◽  
Author(s):  
Rafaella Albuquerque Silva ◽  
Fabricio Kassio Moura Santos ◽  
Lindemberg Caranha de Sousa ◽  
Elizabeth Ferreira Rangel ◽  
Claudia Maria Leal Bevilaqua

The main vector for visceral leishmaniasis (VL) in Brazil is Lutzomyia longipalpis. However, the absence of L. longipalpis in a region of autochthonous VL demonstrates the participation of other species in the transmission of the parasite. Studies conducted in La Banda, Argentina, and São Vicente Férrer, Pernambuco State, Brazil, have correlated the absence of L. longipalpisand the presence of L. migonei with autochthonous cases of VL. In São Vicente Férrer, Pernambuco, there was evidence for the natural infection of L. migonei with Leishmania infantum chagasi. Thus, the objective of this work was to assess the ecology of the sand flies L. longipalpis and L. migonei in Fortaleza, an endemic area for VL. Insect capture was conducted at 22 sampling points distributed across four regions of Fortaleza. In total, 32,403 sand flies were captured; of these, 18,166 (56%) were identified as L. longipalpis and 14,237 (44%) as L. migonei. There were significant density differences found between the vectors at each sampling site (indoors and outdoors) (p <0.0001). These findings confirm that L. migonei and L. longipalpis are distributed throughout Fortaleza, where they have adapted to an indoor environment, and suggest that L. migonei may share the role as a vector with L. longipalpis in the transmission of VL in Fortaleza.


2007 ◽  
Vol 49 (2) ◽  
pp. 119-122 ◽  
Author(s):  
João Cezar do Nascimento ◽  
Byanca Regina de Paiva ◽  
Rosely dos Santos Malafronte ◽  
Wedson Desidério Fernandes ◽  
Eunice Aparecida Bianchi Galati

The main purpose of this study was to investigate natural infection by Leishmania in phlebotomine females in a visceral-leishmaniasis focus in Antonio João county in Mato Grosso do Sul State, Brazil. Between June and October 2003, the digestive tracts of 81 females captured in Aldeia Campestre, Aldeia Marangatu and Povoado Campestre were dissected. The females were separated by species, location, area and date of capture into 13 groups and kept in ethanol 70%. To identify the Leishmania species using the PCR technique, amplifications of the ribosomal-DNA (rDNA) and mini-exon genes were analyzed. Of the 81 specimens, 77 (95%) were Lutzomyia longipalpis, making this the most common species; only one specimen of each of the species Brumptomyia avellari, Evandromyia cortelezzii, Evandromyia lenti and Nyssomyia whitmani was found. Trypanosomatids were identified in eight of the nine groups of Lutzomyia longipalpis (10.39%) one group from Aldeia Campestre, one from Aldeia Marangatu and six from Povoado Campestre; of the eight groups, one from Aldeia Marangatu and another, with promastigotes forms also confirmed by dissection (1.23%) from Povoado Campestre, were identified by PCR as Leishmania chagasi (2.6%). The other groups gave negative results. These findings indicate that there is a high risk of leishmaniasis transmission in this area.


2005 ◽  
Vol 131 (3-4) ◽  
pp. 213-220 ◽  
Author(s):  
João C. França-Silva ◽  
Ricardo A. Barata ◽  
Roberto T. da Costa ◽  
Érika Michalsky Monteiro ◽  
George L. L. Machado-Coelho ◽  
...  

2014 ◽  
Vol 23 (4) ◽  
pp. 456-462 ◽  
Author(s):  
Julio Cesar Pereira Spada ◽  
Diogo Tiago da Silva ◽  
Kennya Rozy Real Martins ◽  
Lílian Aparecida Colebrusco Rodas ◽  
Maria Luana Alves ◽  
...  

This study aimed to investigate the occurrence of Lutzomyia longipalpis and also the canine visceral leishmaniasis (CVL) in a rural area of Ilha Solteira, state of São Paulo. Blood samples were collected from 32 dogs from different rural properties (small farms) and were analyzed by ELISA and the indirect immunofluorescence antibody test (IFAT) in order to diagnose CVL. From these serological tests, 31.25% of the dogs were positive for CVL and these were distributed in 66.7% (8/12) of the rural properties, which were positive for L. longipalpis. CDC (Center for Disease Control and Prevention) light traps were installed in 12 properties (one per property) and insects were caught on three consecutive days per month for one year. L. longipalpis was present on 100% of the rural properties visited, at least once during the twelve-month interval, totaling 64 males and 25 females. The insects were more numerous after the peak of the rain, but the association between prevalence of peridomestic vectors and the climatic data (precipitation, relative air humidity and temperature) and the occurrences of CVL among dogs on each rural property were not statistical significant (p <0.05). However, the occurrence of CVL cases in dogs and the presence of L. longipalpis indicate that more attention is necessairy for the control of this disease in the rural area studied.


2020 ◽  
Author(s):  
Monica E. Staniek ◽  
James G.C. Hamilton

AbstractGlobally visceral leishmaniasis (VL) causes thousands of human deaths every year. In South America, the etiologic agent, Leishmania infantum, is transmitted from an infected canine reservoir to human hosts by the blood-feeding activity of the sand fly vector, predominantly, Lutzomyia longipalpis. Previous evidence from model rodent systems have suggested that the odour of infected hosts is altered by the parasite making them more attractive to the vector leading to an increased biting rate and improved transmission prospects for the pathogen. However, the effect of Le. infantum infection on the attractiveness of naturally infected dogs which are integral to human infection, has not been assessed.Hair collected from infected and uninfected dogs residing in a VL endemic city in Brazil. was entrained to collect the volatile chemical odours present in the headspace. Female and male Lu. longipalpis sand flies were offered a choice of infected or uninfected odour in a series of behavioural experiments. Control experiments established that female and male Lu. longipalpis were equally attracted to uninfected dog odour, female Lu. longipalpis were significantly more attracted to infected dog odour than uninfected dog odour in all 15 experimental replicates (average 45.7±0.87 females attracted to infected odour; 23.9±0.82 to uninfected odour; paired T-test, P=0.000). Male Lu. longipalpis did not significantly prefer either infected or uninfected odour (average 36.1±0.4 males to infected odour; 35.7±0.6 to uninfected odour; paired T-test, P=0.722). A significantly greater proportion of females chose the infected dog odour compared to the males (paired T-test, P=0.000).The results show that dogs infected with Le. infantum are significantly more attractive to blood-feeding female than male sand flies. This is strong evidence for parasite manipulation of the host odour in a natural transmission system and indicates that infected dogs may have a disproportionate significance in maintaining infection in canine and human infection.Author SummaryVisceral leishmaniasis (VL) is a disease caused by the Protist parasite Leishmania infantum. In Brazil and other South and Central American countries, the parasite is transmitted by the blood-feeding activity of infected female Lutzomyia longipalpis sand flies. The disease leads to thousands of human cases and deaths every year. Domestic dogs are the reservoir of infection for humans therefore understanding the effect of infection on dogs is important in developing an understanding of the epidemiology of the disease. Although previous studies on rodent models of Le. infantum infection have shown that infected Golden Hamsters are more attractive to Lu. longipalpis the attractiveness of naturally infected dogs to the insect vector has not been previously been investigated. In this study we showed that the odour of infected dogs is significantly more attractive to female sand flies which can transmit the pathogen than to male sand flies which do not. This clear-cut difference in attraction of female and males suggests that the females are preferentially attracted by parasite infected hosts and may lead to enhanced infection and transmission opportunities for the parasite.


Sign in / Sign up

Export Citation Format

Share Document