scholarly journals Detection of multiple circulating Leishmania species in Lutzomyia longipalpis in the city of Governador Valadares, southeastern Brazil

2018 ◽  
Author(s):  
Mariana Santos Cardoso ◽  
Gabrielle Ariadine Bento ◽  
Laila Viana de Almeida ◽  
Joseane Camilla de Castro ◽  
João Luís Reis Cunha ◽  
...  

AbstractBackgroundLeishmaniasis 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.Methodology/Principal FindingsWe 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 end-point 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).ConclusionsOur 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 is a key factor for planning surveillance and effective control strategies against leishmaniasis in this endemic focus.Author summaryLeishmaniasis is a neglected tropical disease transmitted to mammals by the bite of sand flies infected with parasites of the Leishmania genus. This disease affects millions of people in various regions of the world, including Brazil. The municipality of Governador Valadares (Minas Gerais/Brazil) is a re-emergent focus of intense transmission of leishmaniasis, with a high number of human cases and a high prevalence of infected domestic dogs. To develop better leishmaniasis control strategies for the region, we performed a surveillance study of Lu. longipalpis, the main vector of visceral leishmaniasis in Brazil, and identified circulating species of Leishmania in this insect vector. We estimate that the natural infection rate of Lu. longipalpis for these parasites was of 16.2% in the study area. We also detected the presence of multiple circulating Leishmania species (L. amazonensis, L. infantum and Viannia subgenus) in Lu. longipalpis in Governador Valadares city, including 5 sand flies coinfected with L. infantum and L. (Viannia). Thus, our results reinforce the need for a rigid and systematic control of the sand flies monitoring in this area, due to the potential risk of transmission of different species of the Leishmania parasites.

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.


2011 ◽  
Vol 27 (11) ◽  
pp. 2117-2123 ◽  
Author(s):  
Ricardo Andrade Barata ◽  
Erika Monteiro Michalsky ◽  
Ricardo Toshio Fujiwara ◽  
João Carlos França-Silva ◽  
Marília Fonseca Rocha ◽  
...  

Montes Claros in Minas Gerais State, Brazil, was considered an intense transmission area for visceral leishmaniasis. This study evaluated sand fly fauna after insecticide application. Captures were performed in 10 districts from September 2005 to August 2006 with CDC light traps inside and outside each residence. Cypermethrin was sprayed in two cycles during November/2005 and May/2006. The 636 specimens collected, belonging to 10 species, were predominantly Lutzomyia longipalpis (79%), and most frequently males (70%). The highest percentage of specimens were captured in areas surrounding domiciles (85.8%). The main species were observed to be sensitive to treatment with the insecticide. The results showed a reduction in the number of sand flies collected after use of cypermethrin in homes and annexes, and with residual effect lasting from two to four months.


2011 ◽  
Vol 20 (3) ◽  
pp. 228-234 ◽  
Author(s):  
Gustavo Leandro da Cruz Mestre ◽  
Ana Lúcia Maria Ribeiro ◽  
Rosina Djunko Miyazaki ◽  
Jorge Senatore Vargas Rodrigues ◽  
Arleana do Bom Parto Ferreira de Almeida ◽  
...  

Visceral leishmaniasis is a systemic infectious disease that can cause to a severe, potentially life-threatening chronic condition in humans. Risk factors for infection in urban areas have been associated with poor living conditions, the presence of sand fly vectors and infected pets. This study aimed to describe sand fly and canine infection in the neighborhoods of human visceral leishmaniasis occurrence in the city of Cuiabá, Mato Grosso State, central-western Brazil, reported between January 2005 and December 2006. A total of 1,909 sand flies were collected. They were predominantly males and the most frequent species were Lutzomyia cruzi (81.25%), Lutzomyia whitmani (13.88%) and Lutzomyia longipalpis (2.62%). The sand fly density was not significantly correlated with the variation of environmental factors. The prevalence of canine visceral leishmaniasis in the neighborhoods studied was 26.82% and it was found that areas with high density of vectors coincided with areas of high prevalence of dogs and those with the highest rates of human cases. The study of vectors and other potential hosts are essential for a good understanding of visceral leishmaniasis and the related public health concerns, aiming at the prevention and control of leishmaniasis in the city of Cuiabá, Mato Grosso State.


2012 ◽  
Vol 45 (5) ◽  
pp. 601-606 ◽  
Author(s):  
Júlia Cristina Maksoud Brazuna ◽  
Elaine Araujo e Silva ◽  
Júlio Maksoud Brazuna ◽  
Iara Helena Domingos ◽  
Neuma Chaves ◽  
...  

INTRODUCTION: This study sought to describe the profile and geographic distribution of reported cases of visceral leishmaniasis (VL) in the City of Campo Grande, State of Mato Grosso do Sul (MS), Brazil, from 2002 to 2009. METHODS: Human data were collected from the Brazilian National Information System for Notifiable Diseases. Canine cases and entomological data were obtained from the Information Service for Canine Visceral Leishmaniasis Control/Campo Grande, MS. RESULTS: A total of 951 records from 2002 to 2009 were investigated. The number of reported cases of VL in males was significantly higher (p < 0.0001) than that in females. The higher frequency observed among males was associated with age (p < 0.0001), which increased in individuals aged 40 years and older. The overall fatality rate was 7.4%. Entomological surveys conducted in 2006, 2007, and 2009 showed the insect vector Lutzomyia longipalpis to be present in all urban regions of the county. CONCLUSIONS: VL cases in humans and dogs, as well as in vectors, occurs in all urban regions of Campo Grande. Despite not observing tendencies of increase or reduction in the incidence of the disease due to aging, the major incidence in men is higher in those aged 40 years or above.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Ricardo Andrade Barata ◽  
Jennifer Cunha Peixoto ◽  
Aline Tanure ◽  
Marcela Esteves Gomes ◽  
Estefânia Conceição Apolinário ◽  
...  

This study was developed in the urban area of Governador Valadares, a reemerging focus of intense transmission of visceral leishmaniasis (VL) in Brazil, presenting 86 human cases of VL from 2008 to 2011. The disease prevailed in males (73.2%) with most patients between 0 and 9 years (44.1%) and a lethality rate of 16.2%. A canine survey was carried out on 16,529 domestic dogs in 35 districts in the area and it showed that 30.2% of them (4,992 dogs) were positive for VL by serum assays. Prevalence ratios for canine VL varied between 13.6% and 53.4%. The clinical exam of 343 seropositive dogs showed that 49.9% of them were considered symptomatic, with larger prevalence of canine VL being in short-furred animals (90%). The entomological survey was performed in eight districts, where 2,539 phlebotomines were captured, preferentially in the peridomicile (84.5%).Lutzomyia longipalpiswas the predominant species (90%) suggesting its participation in the VL transmission in the area. The correlation between canine prevalence andL. longipalpisdensity was evaluated.


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.


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 ◽  
...  

2011 ◽  
Vol 44 (5) ◽  
pp. 561-566 ◽  
Author(s):  
Patrícia Fernandes do Prado ◽  
Marília Fonseca Rocha ◽  
Joel Fontes de Sousa ◽  
Dênio Iuri Caldeira ◽  
Gustavo Fontes Paz ◽  
...  

INTRODUCTION: Visceral leishmaniasis (VL) is an expanding zoonosis in Brazil and is becoming urbanized in several Brazilian regions. This study aims to describe the epidemiological features of human and canine VL in the municipality of Montes Claros, State of Minas Gerais, by focusing on their spatial distribution. METHODS: Data concerning human cases and reactive dogs for VL from 2007 to 2009 were obtained from the Information System for Disease Notification (SINAN) and from reports of the local Centro de Controle de Zoonoses (CCZ), respectively. The addresses of human and canine cases have been georeferenced and localized in thematic maps, allowing their spatial visualization as well as the identification of areas at risk of VL transmission. RESULTS: Ninety-five cases of human VL were reported in the period. The 0-9-year-old age group (48.4%) was the most affected, within which the majority consisted of male patients (64%). Of the samples collected for the canine serological survey, 2,919 (6.3%) were reactive to VL. The spatial localization of these cases shows that the disease was scattered in the urban area of the municipality. Areas showing a higher dissemination risk were concentrated in the central, northwestern, and southern regions of the city. CONCLUSIONS: Identifying the areas most at risk in urban Montes Claros may help guide actions toward local epidemiological vigilance and control.


2019 ◽  
Vol 56 (5) ◽  
pp. 1368-1376 ◽  
Author(s):  
Josiane V Lopes ◽  
Erika M Michalsky ◽  
Nathalia C L Pereira ◽  
Adão J V de Paula ◽  
Fabiana O Lara-Silva ◽  
...  

Abstract Among neglected tropical diseases, visceral leishmaniasis (VL) shows great relevance in global terms and is a serious public health concern due to the possibility of severe and lethal forms in humans. In this study, we evaluate entomological factors such as diversity and abundance of phlebotomine sand flies (Diptera:Psychodidae) and the Leishmania species circulating in these species in possible association with VL transmission in the Brazilian town Itaúna. The entomological collections were performed during three consecutive nights, always in the third week of each month, within a period of 12 mo. A total of 1,786 sand fly specimens were collected, from which 20% were collected inside houses. The influence of three local climatic variables (temperature, rainfall, relative humidity) on the population sizes of these insects was evaluated. Temperature was the most influential factor, with a significant positive correlation with the local population size of phlebotomine sand flies collected per month. Lutzomyia longipalpis (Lutz & Neiva, 1912) was the predominant species in the study area. Leishmania DNA was detected in nine out of 133 pools of sand fly females, using nested/PCR, which resulted in a minimal natural infection rate of 2.91%. DNA from Leishmania infantum Nicolle, 1908 (Kinetoplastida: Trypanosomatida), was detected in Evandromyia cortelezzii (Bréthes, 1923), Ev. evandroi (Costa, Lima & Antunes, 1936), Ev. lenti (Mangabeira, 1938), and Ev. termitophila (Martins, Falcão & Silva, 1964), besides Lu. longipalpis. Our study indicates favorable conditions for VL spreading in Itaúna due to the presence of Lu. longipalpis and Le. infantum-infected phlebotomine sand flies.


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