scholarly journals Molecular evidence of early vertical transmission of Leishmania ( Leishmania ) infantum in a dog

2017 ◽  
Vol 47 (1) ◽  
Author(s):  
Vinícius Vasconcelos Gomes de Oliveira ◽  
Rafael Antonio Nascimento Ramos ◽  
Carlos Alberto do Nascimento Ramos ◽  
Neurisvan Ramos Guerra ◽  
Frederico Celso Lyra Maia ◽  
...  

ABSTRACT: Visceral leishmaniasis (VL) is caused by the protozoon Leishmania infantum . Transmission of this parasite to hosts occurs mainly through the bite of infected sand flies. However, alternative infection routes have been hypothesized, especially in areas where the biological vector is absent. The exact time of infection and whether in utero transmission occurs have still not been fully elucidated. This report demonstrates molecular evidence of vertical transmission of L. infantum from a pregnant dog to the embryo. Samples (e.g. vulva, vagina, cervix, uterine body, uterine horn and ovaries) from a female naturally infected by L. infantum and from her embryo were molecularly analyzed by means of qPCR and cPCR followed by DNA sequencing. The gestational age was estimated to be 23±1 day. Through qPCR, the presence of L. infantum DNA was detected in all the samples analyzed (n=7), including the embryo, conversely through cPCR, only four samples (vagina, cervix, uterine body and embryo) were positive. This study demonstrated that transmission of L. infantum from a pregnant dog to the embryo might occur in the early days of pregnancy. In conclusion, this is the first report showing L. infantum infecting a canine embryo.

2014 ◽  
Vol 8 (04) ◽  
pp. 403-407 ◽  
Author(s):  
Andreia P Turchetti ◽  
Tayse D Souza ◽  
Tatiane A Paixão ◽  
Renato L. Santos

Visceral leishmaniasis (VL) is an important zoonosis caused by Leishmania infantum, which has in the domestic dog its principal vertebrate host. VL is usually transmitted by phlebotomine sand flies, however atypical routes of transmission have been described. In this review we discuss the the role of sexual and vertical transmissions, and their role in the maintenance of VL in canine populations.


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.


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.


Author(s):  
Joilson Ferreira Batista ◽  
Francisco das Chagas Ribeiro Magalhães Neto ◽  
Kayo Sandro Pimentel do Prado Lopes ◽  
Marcello Otake Sato ◽  
Carlos Henrique Nery Costa ◽  
...  

Abstract Leishmania infantum infection in cats has been reported in several countries, including Brazil. However, the transmission of visceral leishmaniasis (VL) from cats to another host has not been proven yet. Therefore, the aim of this study was to verify the possibility of L. infantum transmission from cats to dogs. In order to verify the possibility of VL transmission from the cat to the dog, xenodiagnosis was carried out in a VL-positive cat, using 55 female Lutzomyia longipalpis. Five days later, 40 insects were dissected to verify Leishmania infection. The remaining 15 females were fed in a healthy dog. The potential infection of the dog was verified through clinical, serological, parasitological examinations, and PCR, at three, six, and twelve months post-infection. All 55 L. longipalpis females became visibly engorged. Leishmania promastigotes were detected in 27.5% of the dissected insects. Leishmania infection in the dog was confirmed upon first evaluation. DNA sequencing of the parasite isolated from the cat confirmed L. infantum infection and showed 99% similarity with the L. infantum DNA sequences from the dogs. Through this study, it was possible to confirm the L. infantum experimental transmission from a domestic cat to a domestic dog through its biological vector L. longipalpis.


Author(s):  
Silvia Cristina Osaki ◽  
Ricardo Babinski Bregonde ◽  
Vinicius Dahm ◽  
Priscila Pereira ◽  
Claudomiro Postai ◽  
...  

Abstract Dogs are the main urban reservoir of Leishmania infantum, the causative agent of visceral leishmaniasis (VL), which is transmitted by sand flies. In the state of Paraná, the first detection of a positive dog for VL was in 2014, this year Paraná lost free status for this disease (VL). The objectives of this study were to determine the prevalence of canine visceral leishmaniasis in Palotina, the occurrence of vectors that may transmit Leishmania infantum, and the number of notifications of human visceral leishmaniasis cases from period 2010 to 2020. To determine the occurrence of canine visceral leishmaniasis, blood samples from 204 dogs were analyzed using the rapid test DPP® to detect anti-L. infantum antibodies. To investigate the occurrence of potential vectors, monthly collections were made at 18 points within the urban area of the municipality. The number of human visceral leishmaniasis cases was investigated from Epidemiological Surveillance records. None of the serologically tested dogs showed positive titration. Only two specimens of Lutzomyia neivai, one of Lutzomyia sp. and four of Brumptomyia brumpti specimens were collected. No human visceral leishmaniasis cases were reported. These results suggest that there is no evidence of circulation of L. infantum in Palotina.


Author(s):  
Fredy Galvis-Ovallos ◽  
Adriele Eiko Ueta ◽  
Gabriella de Oliveira Marques ◽  
Ana Maria Casagrande Sarmento ◽  
Gabriela Araujo ◽  
...  

Abstract Visceral leishmaniasis is spreading in Brazil where the main vector of its agent, Leishmania infantum Nicolle, 1908, is the Lutzomyia longipalpis (Lutz & Neiva, 1912) species complex (Diptera: Psychodidae: Phlebotominae), on which many of the activities of the visceral leishmaniasis surveillance program are based. However, there are areas where canine, and/or human cases have been occurring without the presence of this species complex as in the western part of the Greater São Paulo Metropolitan region, where Embu das Artes municipality is situated. In this area, Pintomyia fischeri (Pinto, 1926) has been implicated as potential vector of Le. infantum but so far its natural infection with this parasite has not yet been ascertained. Therefore, the present study sought to investigate the natural infection in sand flies of a CVL focus in Embu das Artes. The sand fly collections were undertaken with Shannon and CDC traps, monthly, between 1800 and 2100 hours from November 2018 to October 2019, inclusive. A total of 951 sand flies (457 males and 494 females), belonging to 10 species, were captured. Pintomyia fischeri was the predominant species (89.5%); of which 426 females were dissected and one of them (0.23%) was found to be harboring flagellates in its midgut. A sample of these flagellates was isolated in culture and characterized by a 234 base pair fragment of Leishmania heat-shock protein 70 gene (hsp70) and restriction fragment length polymorphism with Hae III restriction enzyme as Le. infantum. This finding reinforces previous evidence of Pi. fischeri as a vector of Le. infantum in foci of visceral leishmaniasis and highlights the importance of vector surveillance in areas where this species occurs.


2021 ◽  
Vol 15 (1) ◽  
pp. 1-4
Author(s):  
Carlos Roberto Cruz Ubirajara Filho ◽  
Carlos Alberto do Nascimento Ramos ◽  
Alessio Giannelli ◽  
Leucio Câmara Alves ◽  
Gílcia Aparecida de Carvalho ◽  
...  

Visceral leishmaniasis (VL) is a disease that affects dogs. The aim of this study was to describe an autochthonous case of VL and to report the presence of sand flies in a high-altitude area of Northeastern Brazil. In February 2019, a sampling was performed of a suspected animal (n=1), and the presence of sand flies was investigated using CDC light traps. The dog scored positive for Leishmania infantum, and four specimens of sand flies were captured and classified as Lutzomyia evandroi. This study detected the first autochthonous case of canine visceral leishmaniasis (CVL) in an area of high altitude were only L. evandroi has been collected.


2021 ◽  
Author(s):  
Aurélie Schwing ◽  
Didier F. Pisani ◽  
Christelle Pomares ◽  
Alissa Majoor ◽  
Sandra Lacas-Gervais ◽  
...  

Abstract Leishmania infantum is the causative agent of visceral leishmaniasis transmitted by the bite of female sand flies. According to the WHO, the estimated annual incidence of leishmaniasis is one million new cases, resulting in 30 000 deaths per year. The recommended drugs for treating leishmaniasis include Amphotericin B. But over the course of the years, several cases of relapses have been documented. These relapses cast doubt on the efficiency of actual treatments and raise the question of potential persistence sites. Indeed, Leishmania has the ability to persist in humans for long periods of time and even after successful treatment. Several potential persistence sites have already been identified and named ‘safe targets’. As adipose tissue has been proposed as a sanctuary of persistence for several pathogens, we investigated whether Leishmania infantum could be found in this tissue. We demonstrated both in cell cultures and in vivo that Leishmania infantum was able to infect adipocytes. Altogether our results suggest adipocytes as a ‘safe target’ for Leishmania infantum parasites.


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