Natural infection of phlebotomines (Diptera: Psychodidae) by Leishmania (Leishmania) amazonensis in an area of ecotourism in Central-Western Brazil

Revisiting the cave-dwelling sand flies (Diptera, Psychodidae, Phlebotominae) from Brazil: Diversity and potential role in the transmission of Leishmania Ross, 1903 (Kinetoplastida: Trypanosomatidae)

Brazilian caves, one of the many tourist attractions of the country, may act as a shelter for insects, such as sand flies (Diptera: Psychodidae), natural hosts of various microorganisms including parasites of the genus Leishmania Ross, 1903. In the last decades, with the increasing global need for sustainable development, ecotourism has emerged as one of the major activities in Brazil. However, the constant monitoring in environmentally protected areas is not often carried out, endangering visitors and professionals, especially due to the occurrence of zoonoses. Several sand fly species have already been recorded in Brazilian caves, drawing attention to the possibility of Leishmania transmission at this ecotope. Indeed, this current systematic review summarizes the fauna of cave-dwelling sand flies in Brazil, focusing on their biological behaviour and the occurrence of potential vectors of Leishmania parasites.

Preliminary Research on the Sustainable Determinants of Taiwanese Ecotourism with the International Standards

To analyze Taiwanese ecotourism with international standards, this research employed the social learning theory (SLT) to identify the determinants of Taiwanese community ecotourism with the international standards. This basic theory of social psychology comprehensively assays the interplays and interconnections among the three analytical perspectives (ecotourism tours, destinations, and accommodations), the four essential issues (management, social, cultural, and environment) of the Global Sustainable Tourism Council, the six assessed dimensions of ecotourism resolution from the WCC, and the twenty-nine assessed indexes of the KES ecotourism evaluations. It was then possible to comprehensively explore the sustainable determinants of Taiwanese ecotourism with the international standards through the FA of quantitative and qualitative analyses in combination with the highest research validity, reliability, representativeness, and accuracy. After analyzing the evaluated measurements, the empirical and valuable conclusions and findings are (1) these analytical perspectives, appraised attitudes, evaluated criteria, and sub-criteria positively advance Taiwanese ecotourism with the international standards (PITEEICIS); (2) the sustainable determinants of Taiwanese ecotourism with the international standards include the Support for Capacity Building of the Local Community (SCBLC), Cooperation with the Local Community (CLC), Supports for the Local Enterprises (SLE), Local Participation and Benefits Sharing Duties (LPBSD), Tourist Management (TM), and Responsible Tourist Behaviors Inducement (RTBI). Importantly, the majority of ecotourism industrialists and experts still focus on the economic benefits, such as supporting the local community and enterprises, rather than tourist behavior inducement to stimulate ecotourism participation in order to promote and advance the Taiwanese ecotourism to the international standards; (3) in order to promote Taiwanese ecotourism to the international conventions, the Taiwanese government and organizations in ecotourism should contribute toward the local welfare and create and design various training programs and courses to enhance local community's awareness and capability of ecotourism development in order to establish a complete system that stimulates the ongoing planning and decision making of local community participation and regularly monitors, records, and reflects their opinions, based on the area's history, culture, and natural attributes, to develop and sell sustainable local products by creating fair trade principles and valuable products.

Is Ecotourism an Opportunity for Large Wild Animals to Thrive?

The development of ecotourism involving wild animals in Russia is overlooked despite the fact that the country’s territory is significant not only in terms of area but also in terms of the diversity of its flora and fauna. A significant part of Russia’s territory has a low population density, especially beyond the Ural ridge. It retains its natural primeval nature, which can contribute to the development of ecotourism. Initial attempts have been made to develop this, mainly in the European part (Tatarstan, Murmansk Region, the Baltic Sea, Baikal, Altai), but the commercial use of wild animals within ecotourism programs, including the ones in Siberia and the Far East, has not been discussed. This work focuses on the basics of launching ecotourism in the industrial region of Siberia (Kuzbass, Russia) as part of the Alcesalces conservation program.

Phlebotominae Fauna (Diptera: Psychodidae) and Molecular Detection of Leishmania (Kinetoplastida: Trypanosomatidae) in Urban Caves of Belo Horizonte, Minas Gerais, Brazil

Sand flies are often collected in urban areas, which has several implications for the risk of transmission of Leishmania Ross, 1903, to humans and other mammals. Given this scenario, we describe the sand fly fauna of caves and their surroundings in Mangabeiras Municipal Park (MMP) and Paredão Serra do Curral Park (PSCP), both located in the urban area of Belo Horizonte, Minas Gerais, Brazil, an endemic focus of visceral and cutaneous leishmaniasis. Collections were conducted monthly from November 2011 to October 2012, using CDC light traps exposed for two consecutive nights in four caves and their surroundings. Nonsystematized collections using Shannon traps and active searches were also performed around the caves. The presence of Leishmania DNA in collected female sand flies was evaluated by ITS1-PCR. A total of 857 sand flies representing fourteen species were collected in MMP, of which Evandromyia edwardsi (Mangabeira, 1941) was the most abundant. Leishmania amazonensis was detected in Brumptomyia nitzulescui (Costa Lima, 1932) and Ev. edwardsi, with the latter also having Leishmania braziliensis, Leishmania infantum, and Leishmania sp. A total of 228 sand flies representing four species were collected in PSCP, of which Sciopemyia microps (Mangabeira, 1942) was the most abundant. No females from PSCP were positive for Leishmania-DNA. Studies aimed at describing sand fly faunas of cave environments and detecting Leishmania are essential to understanding the relationship between these insects and this ecotope and assessing and monitoring areas that may pose risks to the health of visitors and employees.

First Molecular Report of Leishmania (Leishmania) amazonensis and Leishmania (Viannia) guyanensis in Paraguayan Inhabitants Using High-Resolution Melt-PCR

American tegumentary leishmaniasis is an endemic anthropozoonosis undergoing expansion on the American continent. The disease is caused by several Leishmania species and it is manifested as cutaneous and mucocutaneous leishmaniasis. In this study, we evaluate the viability of high-resolution melt polymerase chain reaction (HRM-PCR) analysis to differentiate four closely related Leishmania species as a routine tool for the diagnosis of leishmaniasis. For this purpose, biopsy specimens from cutaneous and mucocutaneous lesions were taken from 132 individuals from endemic and non-endemic areas for leishmaniasis. Each sample was processed for parasitological, histopathological, and molecular analysis. Positive biopsy samples were analyzed by HRM-PCR of a 144-bp heat-shock protein (hsp70) gene fragment, and new cases were confirmed by sequencing. Of the 132 samples analyzed, 36 (27%) were positive for Leishmania spp., of which 86% were from cutaneous lesions and 14% from mucocutaneous lesions. We identified Leishmania (Viannia) braziliensis (84%), Leishmania (Leishmania) infantum (13%), and Leishmania (Leishmania) amazonensis (3%) in cutaneous lesions, and L. (V.) braziliensis (40%), L. (L.) infantum (20%), L. (L.) amazonensis (20%), and Leishmania (Viannia) guyanensis (20%) in mucocutaneous lesions. The main purpose of this research was to report for the first time in Paraguay the presence of L. (L.) amazonensis and L. (V.) guyanensis in patients with cutaneous and mucocutaneous lesions, using the HRM-PCR technique. In addition, we report the presence of additional new cases of L. (L.) infantum in cutaneous lesions.

Pharmacokinetics of neutron-irradiated meglumine antimoniate in Leishmania amazonensis-infected BALB/c mice

Background

Cutaneous leishmaniasis (CL) is a parasitic disease caused by the protozoan Leishmania spp. Pentavalent antimonial agents have been used as an effective therapy, despite their side effects and resistant cases. Their pharmacokinetics remain largely unexplored. This study aimed to investigate the pharmacokinetic profile of meglumine antimoniate in a murine model of cutaneous leishmaniasis using a radiotracer approach.

Methods

Meglumine antimoniate was neutron-irradiated inside a nuclear reactor and was administered once intraperitoneally to uninfected and L. amazonensis-infected BALB/c mice. Different organs and tissues were collected and the total antimony was measured.

Results

Higher antimony levels were found in infected than uninfected footpad (0.29% IA vs. 0.14% IA, p = 0.0057) and maintained the concentration. The animals accumulated and retained antimony in the liver, which cleared slowly. The kidney and intestinal uptake data support the hypothesis that antimony has two elimination pathways, first through renal excretion, followed by biliary excretion. Both processes demonstrated a biphasic elimination profile classified as fast and slow. In the blood, antimony followed a biexponential open model. Infected mice showed a lower maximum concentration (6.2% IA/mL vs. 11.8% IA/mL, p = 0.0001), a 2.5-fold smaller area under the curve, a 2.7-fold reduction in the mean residence time, and a 2.5-fold higher clearance rate when compared to the uninfected mice.

Conclusions

neutron-irradiated meglumine antimoniate concentrates in infected footpad, while the infection affects antimony pharmacokinetics.

Current status and management of canine leishmaniasis in Latin America

Latin America encompasses diverse geographical, cultural and socio-economic conditions, which are reflected in the challenges for infectious disease control in the region. One of the most significant regional infectious diseases for humans and domestic dogs is leishmaniasis, occurring as visceral leishmaniasis (VL) caused by Leishmania infantum (syn. L. chagasi) transmitted by sand flies (Lutzomyia longipalpis) and with a canine reservoir, and the more common cutaneous leishmaniasis (CL) involving multiple Leishmania spp. (particularly L. braziliensis), sand fly vectors and reservoir hosts. VL is spreading within Latin America for reasons related to mass migration of human and canine populations, with incursion into novel environments (e.g. related to deforestation) coupled with a background of poverty and poor public health infrastructure. The challenges for control of VL also include: (1) the accurate identification of infected dogs (particularly subclinically infected dogs) with the current reliance on serological rather than molecular diagnostic methods, (2) controversy surrounding the ethics and efficacy of culling of seropositive dogs, (3) the limited efficacy of currently available canine vaccines and their potential to interfere with interpretation of serological testing, (4) the expense associated with distribution of insecticidal dog collars, which may prove to be the most valuable control method, and (5) the cost and therefore accessibility of licensed medical treatment for canine leishmaniasis by the general population. Resolution of these isssues will necessitate a 'One Health' approach to co-ordination of resources between human and veterinary healthcare.

Molecular Identification of Leishmania spp. in Sand Flies (Diptera: Psychodidae: Phlebotominae) in the Lençóis Maranhenses National Park, Brazil

Sand flies are very common in the region of Lençóis Maranhenses National Park, an important tourist attraction in Brazil. However, the role of some species and their relative importance locally in Leishmania Ross 1903 transmission is unclear. The objective of this study was to identify Leishmania infection in phlebotomine sand flies collected around the Lençóis Maranhenses National Park, an important conservation area and popular international/national tourist destination with a high incidence of leishmaniasis. Sand flies were collected in peridomiciliary areas on the tourist route from September 2012 to August 2013. The captured females were subjected to molecular analyses for the detection of Leishmania DNA. Sand flies were infected with four Leishmania species: Leishmania (Viannia) braziliensis (Vianna, 1911) was found in Lutzomyia whitmani (Antunes and Coutinho, 1939) (2.1%) and Lutzomyia longipalpis (Lutz and Neiva, 1912) (1.7%); Leishmania (Leishmania) infantum (Nicole, 1908) infected Lutzomyia wellcomei (Fraiha, Shaw, and Lainson, 1971) (20%), Lutzomyia sordellii (Shannon and Del Ponte, 1927) (4.3%), Lu. longipalpis (3.7%), and Lu. whitmani (0.8%); Leishmania (Leishmania) amazonensis (Lainson & Shaw, 1972) was found in Lu. whitmani (0.58%), while Leishmania (Viannia) lainsoni infected Lutzomyia evandroi (Costa Lima and Antunes, 1936) (3.4%), Lu. longipalpis (1.06%), and Lu. whitmani (0.29%). The occurrence of these parasites requires control measures to reduce the incidence of cutaneous leishmaniasis and to contain a possible epidemic of visceral leishmaniasis, the most severe form of the disease.

Entomological surveys of Lutzomyia flaviscutellata and other vectors of cutaneous leishmaniasis in municipalities with records of Leishmania amazonensis within the Bragança region of Pará State, Brazil

In southeast Amazon, Lutzomyia (Nyssomyia) flaviscutellata is the incriminated vector of Leishmania (Leishmania) amazonensis, a causative agent of zoonotic cutaneous leishmaniasis (CL). The optimal methods for surveying Lu. flaviscutellata were investigated in the Bragança region, northeast Pará State, Brazil, selected for the presence of Le. amazonensis. The performances of modified Disney traps and CDC light traps were compared in four ecotopes within and around four village transects during the wet and dry seasons. The physiological age of female sand flies was estimated and natural infection by flagellates was evaluated by dissection. Disney traps were better for detecting the presence of Lu. flaviscutellata, while CDC traps performed well for detecting Lutzomyia (Nyssomyia) antunesi, suspected vector of Leishmania lindenbergi. The former was more abundant during the wet season, when female flies were naturally infected with Le. amazonensis. These findings identified the environments of local transmission. In order to improve surveys of Lu. flaviscutellata as part of integrated epidemiological surveillance of CL, our recommendations include focusing vector surveys with Disney traps on forest fragments where people work, during the seasonal peak of the vector. Further field studies are required to make model-based predictions of seasonal variations in the vectorial capacity of vector populations.

Detection of Leishmania DNA and Blood Meal Identification in Sand Flies (Diptera: Psychodidae) From Lençois Maranhenses National Park Region, Brazil

To elucidate portions of the transmission cycles of American tegumentary leishmaniasis (TL) and visceral leishmaniasis (VL) occurring in the region surrounding the Lençóis Maranhenses National Park, an important tourist center in Brazil, the present study objectives were to determine the rate of natural infection by Leishmania spp. and the blood meal in caught sand flies species in the region. Sand flies were captured over 36 mo in 62 locations of the municipality of Barreirinhas, Maranhão with notifications of disease incidence. Species identification of parasites was performed with internal transcribed spacer 1 (ITS1) PCR-RFLP using HaeIII enzyme. Blood meal identification was performed with cytochrome b (cytb) gene PCR-RFLP using HaeIII and MboI enzyme. The species Lutzomyia longipalpis (Lutz and Neiva 1912) presented a positivity rate of 3.7% for Leishmania infantum. Species not considered vectors of this parasite such as Lu. lenti (Mangabeira 1938) and Lu. whitmani (Antunes & Coutinho 1939) showed infection rates of 0.6% and 0.9%, respectively. Among the vectors of Leishmania spp. was Lu. whitmani with detection rate of 0.3% for Le. braziliensis and Lu. flaviscutellata (Mangabeira 1942) with a detection rate of 8% for Le. amazonensis. After restriction of amplification product encoding a 359bp sequence of the cytb recognized in as follows: pigs (37.9%); dogs (27.4%); chickens (20.9%); horses (9%), rodents (3.3%), and humans (1.4%). The presence of Leishmania DNA in sand flies fed with human blood and domestic animals in villages with transmission of VL and TL suggests that transmission could be occurring in the locations of the infected patients.

Leishmania infection and blood food sources of phlebotomines in an area of Brazil endemic for visceral and tegumentary leishmaniasis

The aims of the study were to determine the blood feeding preferences of sandflies and to identify species of Leishmania that infected phlebotomines in Caxias, Maranhão, Brazil, an area that is highly endemic for leishmaniasis. Sandflies were captured in light traps located in the peridomiciliary environments of randomly selected houses in urban and rural settings between 1800 and 0600 hours on new moon days between March 2013 and February 2015. DNA extracts from 982 engorged female sandflies were submitted to fragment length polymorphism analysis to identify infecting species of Leishmania, and blood sources were identified for 778 of these specimens. Infection by Leishmania infantum was detected in Lutzomyia longipalpis, Lu. whitmani and Lu. termitophila; L. infantum/L. braziliensis in Lu. longipalpis, Lu. whitmani and Lu. trinidadensis; L. shawi in Lu. longipalpis; L. mexicana in Lu. longipalpis; L. braziliensis in Lu. longipalpis and Lu. whitmani; L. guyanensis in Lu. longipalpis and Lu. termitophila; L. amazonensis in Lu. longipalpis and L. lainsoni or L. naiffi in Lu. longipalpis, while Lu. longipalpis and Lu. trinidadensis were infected with unidentified Leishmania sp. Blood sources were identified in 573 individual phlebotomines and the preferred hosts were, in decreasing order, chicken, dog, rodent and human with lower preferences for pig, horse, opossum and cattle. Lu. longipalpis and Lu. whitmani performed mixed feeding on man, dog and rodent, while Lu. longipalpis was the most opportunistic species, feeding on the blood of all hosts surveyed, but preferably on dog/chicken, dog/rodent and rodent/chicken. Our findings reveal the concomitant circulation of Leishmania species that cause visceral leishmaniasis and tegumentary leishmaniasis in the study area, and explain the occurrence of autochthonous human cases of both clinical forms of leishmaniasis in Caxias, Maranhão. The results support our hypothesis that, in the municipality of Caxias, transmission of Leishmania occurs in close proximity to humans.

Leishmania in synanthropic rodents (Rattus rattus): new evidence for the urbanization of Leishmania (Leishmania) amazonensis

This study aimed to detect parasites from Leishmania genus, to determine the prevalence of anti-Leishmania spp. antibodies, to identify circulating species of the parasite, and to determine epidemiological variables associated with infection in rats caught in urban area of Londrina, Paraná, Brazil. Animal capture was carried out from May to December 2006, serological and molecular methods were performed. DNA was extracted from total blood, and nested-PCR, targeting SSu rRNA from Leishmania genus, was performed in triplicate. The positive samples were sequenced twice by Sanger method to species determination. In total, 181 rodents were captured, all were identified as Rattus rattus and none showed clinical alterations. Forty-one of the 176 (23.3%) animals were positive for Leishmania by ELISA and 6/181 (3.3%) were positive by IFAT. Nine of 127 tested animals (7.1%) were positive by PCR; seven were identified as L. (L.) amazonensis, one as L. (L.) infantum. Four rats were positive using more than one test. This was the first description of synanthropic rodents naturally infected by L. (L.) amazonensis (in the world) and by L. (L.) infantum (in South Brazil). Regarding L. (L.) amazonensis, this finding provides new evidence of the urbanization of this etiological agent.

Sandflies in an urban area of transmission of visceral leishmaniasis in midwest Brazil

The phlebotomine fauna of Campo Grande city, capital of Mato Grosso do Sul state in Brazil, an endemic area for visceral leishmaniasis, has been thoroughly investigated, but all the insect collections were undertaken with automatic light traps. The present study sought to investigate the fauna in this city using Shannon and Disney traps, having human beings and hamsters, respectively, as bait. Both types of traps were installed in forest fragment and peridomiciliary areas in the period from 2007 to 2009. The phlebotomine females were analyzed by PCR for Leishmania identification. Lutzomyia longipalpis was the only species collected in the peridomiciles and rendered a total of 574 specimens with a 5.2:1 male:female ratio. A total of eight species were attracted to the two traps (one of each type) installed in the forest fragment, including: Bichromomyia flaviscutellata, Evandromyia bourrouli, Evandromyia lenti, Lutzomyia longipalpis, Nyssomyia whitmani, Pintomyia christenseni, Psathyromyia bigeniculata, and Sciopemyia sordellii. A total of 143 specimens were collected, Bi. flaviscutellata accounting for 81% and Lu. longipalpis for 1.4% of them. In one female of Lu. longipalpis collected in a Disney trap installed in a peridomicile, Leishmania (Leishmania) infantum DNA was found, thus strengthening the hypothesis that the transmission of leishmaniasis is in fact occurring in the anthropic environment.