Epidemiology of dermal leishmaniasis in the Rio Doce Valley, State of Minas Gerais, Brazil

Comparative genomics of Leishmania isolates from Brazil confirms the presence of Leishmania major in the Americas

Leishmania (Leishmania) major is an important agent of cutaneous leishmaniasis, having as a vector sandflies belonging to the genus Phlebotomus. Although this species has been described as restricted to the Old World, parasites similar to L. major have been isolated from South American patients who have never travelled abroad. These parasites were named "L. major-like", and several studies have been carried out to characterise them biochemically, molecularly, and biologically. However, the phylogenetic origin of these isolates is still unknown. In the present study we characterised three L. major-like isolates, named BH49, BH121 and BH129, using comparative genomics approaches. We evaluated the presence of gene and segmental duplications/deletions and the presence of aneuploidies that could explain the differences in infectivity observed in the BH49 and BH121 isolates. All isolates presented a pattern of mosaic aneuploidy and gene copy number variation, which are common in the genus Leishmania. Virulence factors such as phosphatases and peptidases were found to have increased gene copy numbers in the infective isolate, which could explain the difference in infectivity previously observed between BH121 and BH49. Phylogenetic analyses revealed that BH49, BH121 and BH129 L. major-like grouped with L. major isolates, and suggest they were imported from the Old World in at least two independent events. We suggest that new epidemiological inquiries should also evaluate L. major infections in South America, to assess the epidemiological importance of this species in the New World.

A follow-up study (2007-2018) on American Tegumentary Leishmaniasis in the municipality of Caratinga, Minas Gerais State, Brazil: Spatial analyses and sand fly collection

Background

The municipality of Caratinga is an important endemic area for American Tegumentary Leishmaniasis (ATL) and no epidemiological studies were performed during the past two decades. Here, we analyzed the epidemiological situation and the geographical distribution of ATL cases in the municipality of Caratinga from 2007 to 2018 using geographic information systems (GIS). Also, we evaluated the impact of several demographic parameters in ATL distribution and the sand flies incriminated in its transmission.

Methods

All demographic information (gender, age, educational level, clinical form, diagnostic criteria and case evolution) used in this study was retrieved from the public health archives and confirmed in the State Health Services databases. All cases were analyzed using GIS software based on ATL distribution. Also, non-systematic sand fly collections and molecular detection of Leishmania were performed in the hotspots.

Results and conclusions

During the period, ATL cases continued and increased especially in the past years (2016–2018). Hotspots included urban Caratinga areas and the districts of Patrocínio de Caratinga and Sapucaia. The species Nyssomyia whitmani, Nyssomyia intermedia, Migonemyia migonei and Evandromyia cortelezzii complex were captured. However, ITS1-PCR did not detect Leishmania DNA in those insects. Based on our analyses, urbanization of ATL in Caratinga has occurred in the past years. Due to the increase in the number of cases and vectors presence, it is recommended that health authorities focus on control measures in the most affected areas (Patrocínio of Caratinga and Sapucaia districts and urban Caratinga).

Leishmaniasis is an important health problem in Latin American countries and worldwide. In some places, notification is limited and underreported hindering correct assessment of existing data. In Brazil, ATL is mainly caused by Leishmania (Viannia) braziliensis. It is transmitted by sand fly vectors Nyssomyia whitmani and Nyssomyia intermedia. ATL comprises different clinical manifestations including cutaneous leishmaniasis, muco-cutaneous leishmaniasis and atypical leishmaniasis. The objective is to present the spatial distribution of cases of ATL notified by the Public Health System of Caratinga between the period of 2007 and 2018. This city is one of the most important endemic areas in the State of Minas Gerais and compose the panel of knowledge on epidemiological aspects of cutaneous leishmaniasis caused by L. braziliensis. This information will be important for developing strategies for ATL control in the affected areas. There is strong evidence that supports ATL urbanization in the city of Caratinga and increase of cases in two rural districts (Sapucaia and Patrocínio de Caratinga).

Biodiversity of Hematophagous Diptera (Culicidae and Psychodidae) in a Small Hydroelectric Power Station and Surrounding Area in the State of Minas Gerais, Brazil

Hydroelectric power stations may affect the population dynamics of mosquitoes and sand flies, a group with impact on public health due to the possibility to transmit pathogens to humans. This work characterized and compared the fauna of mosquitoes and sand flies in a hydroelectric power station and peridomicile areas in the State of Minas Gerais, Brazil. Insect collections were performed in August 2015 at dry season and February 2016 in rainy season. Ten HP light traps were set at each of two sites for three consecutive days in each of two seasons (dry and rainy). Furthermore, collections with Shannon traps were made in each sampling area (hydropower plant and peridomicile area) from 4:00 p.m. being shut down at 8:00 p.m. for two consecutive days in each of two seasons (dry and rainy). In total, 1,222 insects from 13 genera and 27 species were collected. The most plentiful species were respectively Culex declarator (Dyar and Knab, 1906) and Pintomyia pessoai (Coutinho & Barretto, 1940). A high number of insects (78.5%) were collected during the rainy period (P < 0.05). About equitability, statistical significance was observed in the peridomicile area (dry season J = 0.75 and rainy season J = 0.82). The highest values of species diversity were observed in the hydropower plant (H = 2.68) and peridomicile area (H = 2.38) both in the rainy season with statistical significance comparing with dry season. Our results demonstrate that the occurrence of vector species in this region increases the potential risk of transmission of pathogens, especially arbovirus and Leishmania Ross, 1903.

Attraction of Lutzomyia longipalpis to synthetic sex-aggregation pheromone: Effect of release rate and proximity of adjacent pheromone sources

In South America, the Protist parasite that causes visceral leishmaniasis, a potentially fatal human disease, is transmitted by blood-feeding female Lutzomyia longipalpis sand flies. A synthetic copy of the male produced sex-aggregation pheromone offers new opportunities for vector control applications. We have previously shown that the pheromone placed in plastic sachets (lures) can attract both females and males to insecticide treated sites for up to 3 months. To use the pheromone lure in a control program we need to understand how the application of lures in the field can be optimised. In this study we investigated the effect of increasing the number of lures and their proximity to each other on their ability to attract Lu. longipalpis. Also for the first time we applied a Bayesian log-linear model rather than a classic simple (deterministic) log-linear model to fully exploit the field-collected data. We found that sand fly response to pheromone is significantly related to the quantity of pheromone and is not influenced by the proximity of other pheromone sources. Thus sand flies are attracted to the pheromone source at a non-linear rate determined by the amount of pheromone being released. This rate is independent of the proximity of other pheromone releasing traps and indicates the role of the pheromone in aggregation formation. These results have important implications for optimisation of the pheromone as a vector control tool and indicate that multiple lures placed in relatively close proximity to each other (5 m apart) are unlikely to interfere with one another.

Lutzomyia longipalpis sand flies are the insect vectors of the Protist parasite Leishmania infantum which causes visceral leishmaniasis (VL) in Brazil. Control of VL has focussed on vector and infected reservoir control, but despite the sustained efforts of the Brazilian Health authorities the disease burden doubled between 1990 to 2016. New approaches to VL control are urgently needed. We previously demonstrated that Lu. longipalpis synthetic sex-aggregation pheromone placed alongside insecticide sprayed surfaces can attract and kill female sand flies. However, before the synthetic pheromone can be effectively exploited in any VL control program it is essential to understand how it might be deployed. In this study we investigated the effect of different amounts of pheromone and the spatial relationship between different pheromone sources on Lu. longipalpis catches. We developed a robust Bayesian analysis to fully exploit the field data which showed that optimal use of the pheromone could be achieved by placing individual or small numbers of pheromone releasing devices (lures) within the peridomestic environment and these can be positioned relatively closely without competing with each other. The results also revealed the significance of the pheromone in maintaining aggregations of Lu. longipalpis and suggested that Lu. longipalpis may be more evenly distributed in the peridomestic environment than previously recognised.

Lower galactosylation levels of the Lipophosphoglycan from Leishmania (Leishmania) major-like strains affect interaction with Phlebotomus papatasi and Lutzomyia longipalpis

BACKGROUND

Leishmania major is an Old World species causing cutaneous leishmaniasis and is transmitted by Phlebotomus papatasi and Phlebotomus duboscqi. In Brazil, two isolates from patients who never left the country were characterised as L. major-like (BH49 and BH121). Using molecular techniques, these isolates were indistinguishable from the L. major reference strain (FV1).

OBJECTIVES

We evaluated the lipophosphoglycans (LPGs) of the strains and their behaviour in Old and New World sand fly vectors.

METHODS

LPGs were purified, and repeat units were qualitatively evaluated by immunoblotting. Experimental in vivo infection with L. major-like strains was performed in Lutzomyia longipalpis (New World, permissive vector) and Ph. papatasi (Old World, restrictive or specific vector).

FINDINGS

The LPGs of both strains were devoid of arabinosylated side chains, whereas the LPG of strain BH49 was more galactosylated than that of strain BH121. All strains with different levels of galactosylation in their LPGs were able to infect both vectors, exhibiting colonisation of the stomodeal valve and metacyclogenesis. The BH121 strain (less galactosylated) exhibited lower infection intensity compared to BH49 and FV1 in both vectors.

MAIN CONCLUSIONS

Intraspecific variation in the LPG of L. major-like strains occur, and the different galactosylation levels affected interactions with the invertebrate host.

Risk profile for Leishmania infection in dogs coming from an area of visceral leishmaniasis reemergence

Until the 1980s, visceral leishmaniasis was concentrated in poor rural areas of Brazil. The Vale do Rio Doce, located in the Southeastern Brazilian state of Minas Gerais, was an endemic area with high numbers of human and canine cases. Prophylactic measures adopted since the 1960s reduced the number of cases and the region became a 'controlled endemic' area. In the early 1990s, however, the program was interrupted, and the human disease reemerged in 2008. This cross-sectional study evaluated the prevalence and the risk profile of infection of dogs with Leishmania spp in this reemergence area of visceral leishmaniasis. Among a population of approximately 280,000 people, a total of 3835 dog owners were interviewed about socioeconomic conditions, housing, peridomicile features, and their dogs' characteristics and behavior. Blood samples were collected from 5822 dogs of an estimated canine population of 20,000 and anti-Leishmaniasis antibodies were identified using Dual-Path Platform and ELISA. We observed that 1282 of the 5822 dogs were seropositive for the protozoan indicating a seroprevalence of 22%. The risk factors associated with Leishmania infection in dogs were: non-paved backyard (OR 1.4; 95%CI 1.2-1.7); the presence of dry leaves and decaying fruit in the backyard (OR 1.3; 95%CI 1.1-1.5); medium-sized (OR 1.3; 95% 1.1-1.5) or big-sized dogs (OR 1.8; 95%CI 1.5-2.3); short-haired dogs (OR 1.8; 95%CI 1.5-2.1); dogs that slept in the backyard (OR 2.6; 95%CI 1.8-3.6) or in the balcony (OR 1.6; 95%CI 1.1-2.3); and history of canine visceral leishmaniasis in the household (OR 1.3; 95%CI 1.1-1.5). Our results suggest a strong reemergence of canine visceral leishmaniasis after the discontinuation of the control programs. Also, the observed risk factors reinforce the role of health education and environmental management measures to the effective control of the disease.

Leishmania (Viannia) braziliensis infection in wild small mammals in ecotourism area of Brazil

Leishmaniases are parasitic diseases transmitted to mammalian hosts by sand fly vectors (Diptera: Psychodidae). Despite the increasing occurrence of visceral and cutaneous leishmaniasis cases in urban centers, their transmission still occur primarily in wild environments and may be associated with professional activities and recreation, such as ecotourism. The Reserva Particular do Patrimônio Natural Santuário do Caraça (RPPNSC) is one of the largest ecotourism attractions in the State of Minas Gerais, Brazil, and comprises an area of environmental preservation with 11,233 hectares presenting a transitional vegetation between Cerrado and Atlantic Forest. The present study describes the abundance of small mammals in RPPNSC, the isolation and identification of Leishmania in five wild animals. Small mammals were bimonthly trapped along 6 trails within the RPPNSC with 10 Tomahawk traps each. Two trails were located in peridomiciliary areas near tourist lodging facilities, and four trails were located at sites visited by tourists in forest areas. The most prevalent species were Akodon cursor, Cerradomys subflavus and Oligoryzomys nigripes. Six isolates of Leishmania were obtained from these animals and identified as Leishmania braziliensis through HSP70-PCR RFLP method. Leishmania spp. DNA was detected by kDNA-PCR method and isolated by biphasic culture. Studies point to some of the captured species as potential wild reservoirs of Leishmania, suggesting they may be involved in the transmission cycle in these wild environments.

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.

Molecular Detection of Leishmania DNA in Wild-Caught Phlebotomine Sand Flies (Diptera: Psychodidae) From a Cave in the State of Minas Gerais, Brazil

Leishmania spp. are distributed throughout the world, and different species are associated with varying degrees of disease severity. In Brazil, Leishmania transmission involves several species of phlebotomine sand flies that are closely associated with different parasites and reservoirs, and thereby giving rise to different transmission cycles. Infection occurs during the bloodmeals of sand flies obtained from a variety of wild and domestic animals, and sometimes from humans. The present study focused on detection of Leishmania DNA in phlebotomine sand flies from a cave in the state of Minas Gerais. Detection of Leishmania in female sand flies was performed with ITS1 PCR-RFLP (internal transcribed spacer 1) using HaeIII enzyme and genetic sequencing for SSUrRNA target. The survey of Leishmania DNA was carried out on 232 pools and the parasite DNA was detected in four: one pool of Lutzomyia cavernicola (Costa Lima, 1932), infected with Le. infantum (ITS1 PCR-RFLP), two pools of Evandromyia sallesi (Galvão & Coutinho, 1939), both infected with Leishmania braziliensis complex (SSUrRNA genetic sequencing analysis), and one pool of Sciopemyia sordellii (Shannon & Del Ponte, 1927), infected with subgenus Leishmania (SSUrRNA genetic sequencing analysis). The present study identified the species for Leishmania DNA detected in four pools of sand flies, all of which were captured inside the cave. These results represent the first molecular detection of Lu cavernicola with Le infantum DNA, Sc sordellii with subgenus Leishmania DNA, and Ev sallesi with Leishmania braziliensis complex DNA. The infection rate in females captured for this study was 0.17%.

Abundance of Lutzomyia longipalpis in urban households as risk factor of transmission of visceral leishmaniasis

Urban occurrence of human and canine visceral leishmaniasis (VL) is linked to households with characteristics conducive to the presence of sand flies. This study proposes an ad hoc classification of households according to the environmental characteristics of receptivity to phlebotominae and an entomological study to validate the proposal. Here we describe the phlebotominae population found in intra- and peridomiciliary environments and analyse the spatiotemporal distribution of the VL vector Lutzomyia longipalpis of households receptive to VL. In the region, 153 households were classified into levels of receptivity to VL followed by entomological surveys in 40 of those properties. Kruskal-Wallis verified the relationship between the households' classification and sand fly abundance and Kernel analysis evaluated L. longipalpis spatial distribution: of the 740 sand flies were captured, 91% were L. longipalpis; 82% were found peridomiciliary whilst the remaining 18% were found intradomiciliary. No statistically significant association was found between sandflies and households levels. L. longipalpis counts were concentrated in areas of high vulnerability and some specific households were responsible for the persistence of the infestation. L. longipalpis prevails over other sand fly species for urban VL transmission. The entomological study may help target the surveillance and vector control strategies to domiciles initiating and/or maintaining VL outbreaks.

Ecological Aspects of Phlebotomine Sand Flies (Diptera, Psychodidae, Phlebotominae) in Areas of American Cutaneous Leishmaniasis, in the Municipality of Paraty, Rio de Janeiro, Brazil. I-Index of Abundance by Location and Type of Capture

The description of the first and autochthonous case of diffuse cutaneous leishmaniasis in the municipality of Paraty, State of Rio de Janeiro, brought the interest of this study. Sand flies were captured over a 3-yr period. Using manual suction tubes, sand flies were collected from the inner and outer walls of homes, in the living spaces of domestic animals, and in Shannon light traps, which were set up outside homes and in the forest. CDC light traps were installed inside homes, around the exterior of the houses, and along the divide and within the forest. A total of 102,937 sand flies were collected, representing 23 species--three from the genus Brumptomyia and 20 from the genus Lutzomyia. Of these, six species, Lutzomyia intermedia, Lutzomyia fischeri, Lutzomyia migonei, Lutzomyia whitmani, and Lutzomyia pessoai have already been recorded as being naturally infected by Leishmania braziliensis, and one species, Lutzomyia ayrozai, by Leishmania naiffi. Lu. intermedia is the vector of Le. braziliensis in the study area, particularly inside the homes and on the exterior of the houses. Lu. fischeri can also act as vector of Le. braziliensis in domestic environments and particularly in the wild. The third-ranked Lu. migonei was the most abundant in kennels, suggesting its canine affinity. Lu. whitmani, ranked fourth, still has characteristics indicative of the wild, but with a significant number located on the edge of the forest, suggesting a selection process of adaptation to the anthropic environment.

Molecular detection of Leishmania in phlebotomine sand flies (Diptera: Psychodidae) from a cutaneous leishmaniasis focus atXakriabá Indigenous Reserve, Brazil

Autochthonous cases of American cutaneous leishmaniasis (ACL) have been reported since 2001 in the Xakriabá Indigenous Reserve located in the municipality of São João das Missões in northern Minas Gerais state, Brazil. In order to study the presence of Leishmania DNA in phlebotomine sand flies, six entomological collections were carried out from July 2008 through July 2009, using 40 light traps placed in peridomicile areas of 20 randomly selected houses. From October 2011 through August 2012, another six collections were carried out with 20 light traps distributed among four trails (five traps per trail) selected for a previous study of wild and synanthropic hosts of Leishmania. A total of 4,760 phlebotomine specimens were collected belonging to ten genera and twenty-three species. Single female specimens or pools with up to ten specimens of the same locality, species and date, for Leishmania detection by molecular methods. Species identification of parasites was performed with ITS1 PCR-RFLP using HaeIII enzyme and genetic sequencing for SSU rRNA target. The presence of Leishmania DNA was detected in eleven samples from peridomicile areas: Lu. longipalpis (two), Nyssomyia intermedia (four), Lu. renei (two), Lu. ischnacantha, Micropygomyia goiana and Evandromyia lenti (one pool of each specie). The presence of Leishmania DNA was detected in twelve samples from among the trails: Martinsmyia minasensis (six), Ny. intermedia (three), Mi. peresi (two) and Ev. lenti (one). The presence of Leishmania infantum DNA in Lu. longipalpis and Leishmania braziliensis DNA in Ny. intermediasupport the epidemiological importance of these species of sand flies in the cycle of visceral and cutaneous leishmaniasis, respectively. The results also found other species associated with Leishmania DNA, such as Mt. minasensis and Ev. lenti, which may participate in a wild and/or synanthropic cycle of Leishmania transmission in the studied area.

Phlebotomine sand fly fauna and leishmania infection in the vicinity of the Serra do Cipó National Park, a natural Brazilian heritage site

In the New World, the leishmaniases are primarily transmitted to humans through the bites of Leishmania-infected Lutzomyia (Diptera: Psychodidae) phlebotomine sand flies. Any or both of two basic clinical forms of these diseases are endemic to several cities in Brazil—the American cutaneous leishmaniasis (ACL) and the American visceral leishmaniasis (AVL). The present study was conducted in the urban area of a small-sized Brazilian municipality (Jaboticatubas), in which three cases of AVL and nine of ACL have been reported in the last five years. Jaboticatubas is an important tourism hub, as it includes a major part of the Serra do Cipó National Park. Currently, no local data is available on the entomological fauna or circulating Leishmania. During the one-year period of this study, we captured 3,104 phlebotomine sand flies belonging to sixteen Lutzomyia species. In addition to identifying incriminated or suspected vectors of ACL with DNA of the etiological agent of AVL and vice versa, we also detected Leishmania DNA in unexpected Lutzomyia species. The expressive presence of vectors and natural Leishmania infection indicates favorable conditions for the spreading of leishmaniases in the vicinity of the Serra do Cipó National Park.

Anthropic effects on sand fly (Diptera: Psychodidae) abundance and diversity in an Amazonian rural settlement, Brazil

Sand flies (Diptera: Psychodidae) are responsible for the transmission of protozoan parasites that cause leishmaniases. They are found predominantly in forests, but some species exploit environments that have been subject to deforestation and subsequent human colonization. Studies conducted in Brazil over the past 30 years show that some species are adapting to peri-urban and urban settings. We evaluated sand fly diversity and abundance in the rural settlement of Rio Pardo, Presidente Figueiredo Municipality, Amazonas State, Brazil. Settlement households were divided into four categories. These categories were determined by the human population density and the degree of deforestation in the immediate area. We used CDC light traps to sample the area surrounding 24 households (6 households in each category). Samples were taken on six occasions during September-November 2009 and June-August 2010. A total of 3074 sand fly specimens were collected, including 1163 females and 1911 males. These were classified into 13 genera and 52 species. The greatest abundance of sand flies and the greatest richness of species were observed in areas where human population density was highest. Our results show that changes in the human occupancy and vegetation management in rural settlements may affect the population dynamics and distribution of sand fly species, thereby affecting the local transmission of cutaneous leishmaniases.

Phlebotomine fauna in the urban area of Timóteo, State of Minas Gerais, Brazil

This work is characterized by an entomological research and an investigation on whether seasonal behaviours can be associated to the phlebotomine fauna found in the urban area of Timóteo-MG - an endemic focus of tegumentary leishmaniasis (TL). The analysis of the seasonal behaviour of sand flies has taken into account the following climatic variables: rainfall, relative humidity and temperature. Automatic light traps were installed in households between 2009 and 2010. The sand fly species with the highest number captured was Lutzomyia whitmani (66.5%), a TL vector species, whose abundance has provided strong evidences that this species is the main vector of TL in the municipality of Timóteo, with its cycle of transmission developing in its urban area. Amongst the results observed in the analyses of seasonal behaviour, only temperature conveyed particular association between seasonal occurrence of sand flies and climate variables. The findings of this study may assist the local epidemiological surveillance agency in defining strategies and directing efforts for controlling these insects.

Mosquito and sand fly gregarines of the genus Ascogregarina and Psychodiella (Apicomplexa: Eugregarinorida, Aseptatorina)--overview of their taxonomy, life cycle, host specificity and pathogenicity

Mosquitoes and sand flies are important blood-sucking vectors of human diseases such as malaria or leishmaniasis. Nevertheless, these insects also carry their own parasites, such as gregarines; these monoxenous pathogens are found exclusively in invertebrates, and some of them have been considered useful in biological control. Mosquito and sand fly gregarines originally belonging to a single genus Ascogregarina were recently divided into two genera, Ascogregarina comprising parasites of mosquitoes, bat flies, hump-backed flies and fleas and Psychodiella parasitizing sand flies. Currently, nine mosquito Ascogregarina and five Psychodiella species are described. These gregarines go through an extraordinarily interesting life cycle; the mosquito and sand fly larvae become infected by oocysts, the development continues transtadially through the larval and pupal stages to adults and is followed by transmission to the offspring by genus specific mechanisms. In adult mosquitoes, ascogregarines develop in the Malpighian tubules, and oocysts are defecated, while in the sand flies, the gregarines are located in the body cavity, their oocysts are injected into the accessory glands of females and released during oviposition. These life history differences are strongly supported by phylogenetical study of SSU rDNA proving disparate position of Ascogregarina and Psychodiella gregarines. This work reviews the current knowledge about Ascogregarina and Psychodiella gregarines parasitizing mosquitoes and sand flies, respectively. It gives a comprehensive insight into their taxonomy, life cycle, host specificity and pathogenicity, showing a very close relationship of gregarines with their hosts, which suggests a long and strong parasite-host coevolution.

Rattus norvegicus (Rodentia: Muridae) Infected by Leishmania (Leishmania) infantum (syn. Le. chagasi) in Brazil

In the present study we surveyed the fauna of phlebotomine sand flies and small mammals in peridomestic areas from a Brazilian municipality where the American cutaneous leishmaniasis (ACL) is endemic. A total of 608 female phlebotomine sand flies were captured during nine months in 2009 and 2010. Seven different species were represented with 60% of them being Lutzomyia intermedia and Lu. whitmani, both incriminated vectors of ACL. Lu. longipalpis, a proven vector of visceral leishmaniasis (VL) was also captured at high proportion (12.8%). Genomic DNA analysis of 136 species-specific pools of female sand flies followed by molecular genotyping showed the presence of Leishmania infantum DNA in two pools of Lu. longipalpis. The same Leishmania species was found in one blood sample from Rattus norvegicus among 119 blood and tissue samples analysed. This is the first report of Le. infantum in R. norvegicus in the Americas and suggests a possible role for this rodent species in the zoonotic cycle of VL. Our study coincided with the reemergence of VL in Governador Valadares.

Sandflies (Diptera: Psychodidae) from caves of the quartzite Espinhaço Range, Minas Gerais, Brazil

This study investigated the sandfly fauna of two quartzite caves in the Espinhaço Mountain Range, located in the municipality of Diamantina, state Minas Gerais. From August 2010-July 2011, entomological sampling was performed in the caves of Salitre and Monte Cristo with two HP light traps exposed in the photic and aphotic zones of each cave. The sandfly fauna consisted of 17 species, among which Lutzomyia cipoensis was predominant (54.76%). The male/female ratio in the total captures was 1:2.5. The aphotic zone showed the highest frequency of specimens captured (65%). A greater density of sandflies occurred during the summer (January-February), coinciding with the period of higher temperatures, humidity and rainfall. The presence of Lutzomyia longipalpis, Lutzomyia whitmani and Lutzomyia pessoai, proven or suspected vectors of leishmaniasis, is of concern because the area is visited by many tourists.

Study of sand flies (Diptera: Psychodidae) in visceral and cutaneous leishmaniasis areas in the central-western state of Minas Gerais, Brazil

The transmission of Leishmania involves several species of sand flies that are closely associated with various parasites and reservoirs, with differing transmission cycles in Brazil. A study on the phlebotomine species composition has been conducted in the municipality of Divinópolis, Minas Gerais, Brazil, an endemic area for cutaneous leishmaniasis (CL), which has intense occurrence of visceral leishmaniasis (VL) cases. In order to study the sand flies populations and their seasonality, CDC light traps (HP model) were distributed in 15 houses which presented at least one case of CL or VL and in five urban parks (green areas). Collections were carried out three nights monthly from September 2010 to August 2011. A total of 1064 phlebotomine specimens were collected belonging to two genera and seventeen species: Brumptomyia brumpti, Lutzomyia bacula, Lutzomyia cortelezzii, Lutzomyia lenti, Lutzomyia sallesi, Lutzomyia longipalpis, Lutzomyia migonei, Lutzomyia intermedia, Lutzomyia neivai, Lutzomyia whitmani, Lutzomyia christenseni, Lutzomyia monticola, Lutzomyia pessoai, Lutzomyia aragaoi, Lutzomyia brasiliensis, Lutzomyia lutziana, and Lutzomyia sordellii. L. longipalpis, the main vector of Leishmania infantum in Brazil, was the most frequent species, accounting for 76.9% of the total, followed by L. lenti with 8.3%, this species is not a proven vector. Green and urban areas had different sand flies species composition, whereas the high abundance of L. longipalpis in urban areas and the presence of various vector species in both green and urban areas were also observed. Our data point out to the requirement of control measures against phlebotomine sand flies in the municipality of Divinópolis and adoption of strategies aiming entomological surveillance.

A cross-sectional study on canine Leishmania (L.) infantum chagasi infection in Amazonian Brazil ratifies a higher prevalence of specific IgG-antibody response than delayed-type hypersensitivity in symptomatic and asymptomatic dogs

This was a cross-sectional study which analyzed the prevalence and the clinical and immunological spectrum of canine Leishmania (L.) infantum chagasi infection in a cohort of 320 mongrel dogs living in an endemic area of American visceral leishmaniasis in the Amazonian Brazil by using, mainly, the indirect fluorescence antibody test (IFAT-IgG) and the delayed-type hypersensitivity (DTH), and the parasite research by the popliteal lymph node aspiration. The IFAT and DTH reactivity recognized three different immune response profiles: (1) IFAT((+))/DTH((-)) (107 dogs), (2) IFAT((-))/DTH((+)) (18 dogs), and (3) IFAT((+))/DTH((+)) (13 dogs), providing an overall prevalence of infection of 43% (138/320). Thus, the specific prevalence of IFAT( (+) )/DTH( (-) ) 33.4% (107/320) was higher than those of IFAT( (-) )/DTH( (+) ) 5.6% (18/320) and IFAT( (+) )/DTH( (+) ) 4.0% (13/320). Moreover, the frequency of these profiles among 138 infected dogs showed that the IFAT( (+) )/DTH( (-) ) rate of 77.5% (107/138) was also higher than those of 13.0% (18/138) of IFAT( (-) )/DTH( (+) ) and 9.5% (13/138) of IFAT( (+) )/DTH( (+) ) rates. The frequency of asymptomatic dogs (76%-105) was higher than those of symptomatic (16.6%-23) and oligosymptomatic ones (7.4%-10). A total of 16 (11.6%) L. (L.) i. chagasi isolates were obtained from infected dogs, all from the IFAT( (+) ) /DTH( (-) ) profile: 41% (9/22) from symptomatic, 33.3% (3/9) from oligosymptomatic, and 5.2% (4/76) from asymptomatic dogs. These findings strongly suggested that despite the higher frequency of asymptomatic dogs (76%-105), the majority (72.4%-76) was characterized by the IFAT( (+) ) /DTH( (-) ) profile with a doubtful immunogenetic resistance against infection.

Leishmania spp. epidemiology of canine leishmaniasis in the Yucatan Peninsula

Canine Leishmaniasis is widespread in various Mexican states, where different species of Leishmania have been isolated from dogs. In the present study, we describe the detection of L. braziliensis, L. infantum, and L. mexicana in serum of dogs from the states of Yucatan and Quintana Roo in the Yucatan Peninsula (Mexico). A total of 412 sera were analyzed by ELISA using the total extract of the parasite and the iron superoxide dismutase excreted by different trypanosomatids as antigens. We found the prevalence of L. braziliensis to be 7.52%, L. infantum to be 6.07%, and L. mexicana to be 20.63%, in the dog population studied. The results obtained with ELISA using iron superoxide dismutase as the antigen were confirmed by western blot analysis with its greater sensitivity, and the agreement between the two techniques was very high.

A new species of Evandromyia (Diptera: Psychodidae: Phlebotominae) from Minas Gerais State, Brazil

A new species of phlebotomine sand fly found in Minas Gerais state, Brazil, is described and illustrated based on male and female morphological characteristics. The new species belongs to the rupicola series within the subgenus Evandromyia Mangabeira. Both sexes are morphologically close to Evandromyia rupicola (Martins, Godoy & Silva) and Evandromyia grimaldii Andrade Filho, Pinto, Santos & Carvalho and the characteristics for their classification are here presented.

Estrutura da comunidade de Phlebotominae (Diptera, Psychodidae) em mata ciliar do município de Urbano Santos, Maranhão, Brasil

A diversidade, abundância relativa e a distribuição de Phlebotominae foram estudadas em três setores (bordas e centro) de um fragmento de mata ciliar no município de Urbano Santos, Maranhão, Brasil. Os espécimes foram capturados em junho e novembro/2003 e em janeiro e março/2004 das 18 às 6 horas. Em cada noite de coleta foram instaladas 18 armadilhas, seis em cada setor da mata, totalizando um esforço de 864 horas. Foram encontradas 17 espécies. O centro do fragmento obteve a maior riqueza de espécies (14), seguido da borda B (13) e da borda A (12). As espécies Lutzomyia infraspinosa (Mangabeira, 1941), L. flaviscutellata (Mangabeira, 1942) e L. evandroi (Costa Lima & Antunes, 1936) foram as únicas que apareceram como dominantes nos três setores da mata. Quatorze espécies ocorreram em ambas estações, sendo que L. fluviatilis (Floch & Abonnenc, 1944) foi encontrada apenas na estação chuvosa (janeiro e março) e L. migonei (França, 1920) e L. pinottii (Damasceno & Arouck, 1956) apenas na estação seca (junho e novembro). As diferenças registradas na abundância de indivíduos entre as estações não foram estatisticamente significativas. A presença frequente de L. flaviscutellata pode explicar um caso de leishmaniose cutânea difusa em uma paciente deste município.

Phlebotomine sandflies (Diptera: Psychodidae) in Governador Valadares, a transmission area for American tegumentary leishmaniasis in State of Minas Gerais, Brazil

INTRODUCTION

A study on the phlebotomine sandfly fauna was carried out in an endemic area for American tegumentary leishmaniasis in the municipality of Governador Valadares, in the State of Minas Gerais, Brazil.

METHODS

Captures were undertaken using HP light traps in four districts, on three nights per month, for one year (from January to December 2008). Correlations between climatic factors (temperature, relative air humidity and rainfall) and the numbers of sandflies collected was observed.

RESULTS

5,413 phlebotomine specimens were caught and were identified as belonging to 12 species. Of these specimens, 2,851 (52%) were females and 2,562 (48%) were males.

CONCLUSIONS

Lutzomyia intermedia predominated (29.9% of the species caught), thus suggesting that they were responsible for transmission of American tegumentary leishmaniasis, together with L. whitmani, which was also found in the area (4.3%). The presence of L. longipalpis (11.9%), the main vector for visceral leishmaniasis in Brazil, is an important finding, which makes rigorous entomological surveillance of the area necessary.

[Visceral leishmaniasis: retrospective study on factors associated with lethality]

INTRODUCTION

Visceral leishmaniasis is a public health problem, with lethality reaching 10%. The recommended drug treatment is methylglucamine antimoniate. This study aimed to evaluate drug use for cases of visceral leishmaniasis treated at the Infectology Clinic of the Campo Grande University Hospital Center, State of Mato Grosso do Sul.

METHODS

To collect data, we examined the medical records of 76 patients with a diagnosis of visceral leishmaniasis treated at this Infectology Clinic.

RESULTS

The medical files of 76 patients (56 men and 20 women; 28.9%) showed comorbidities. The first choice drug for 88.2% of the patients was N-methylglucamine antimoniate, with a fatal outcome for 18.4%. Survival analysis showed a statistically significant difference between patients with and without comorbidities (p <0.0001) and with comorbidities who used Glucantime (p < 0.0009). The fatality rate of 18.4% indicates the low efficiency of the healthcare measures used.

CONCLUSIONS

The results suggest that the prognosis becomes poor when associated with the presence of comorbidities, and that the treatment needs to be carefully administered to minimize mortality.

Natural infection of Lutzomyia neivai and Lutzomyia sallesi (Diptera: Psychodidae) by Leishmania infantum chagasi in Brazil

Natural infections with Leishmania were found in females of the phlebotomine sand flies Lutzomyia neivai (Pinto) (= Nyssomyia neivai) and Lutzomyia sallesi (Galvão & Coutinho) (= Evandromyia sallesi) (Diptera: Psychodidae) from Lassance, in the Brazilian state of Minas Gerais. Promastigotes were found in the pyloric region of the former species and in the abdominal midgut of the latter species. Insects found to be infected by microscopic examination were macerated in saline solution and inoculated into hamsters. Subsequent analysis by polymerase chain reaction-restriction fragment length polymorphism revealed both isolates to belong to the species Leishmania infantum chagasi Cunha & Chagas.

[Sandflies in an areas with occurrences of human cases of American cutaneous leishmaniasis in the municipality of Seropédica, State of Rio de Janeiro]

American cutaneous leishmaniasis is caused by protozoa of the genus Leishmania, which affects the skin and mucosa. It is primarily a zoonotic infection. Sandfly surveys were conducted in four areas with occurrences of human cases of American cutaneous leishmaniasis in the municipality of Seropédica. A manual method was used to catch specimens between 6:00 pm and 10:00 pm, for 12 consecutive months. From October 2004 to September 2005, we caught 2,390 individuals belonging to four species: Lutzomyia intermedia accounted for 97.1% of the total collected, followed by Lutzomyia whitmani (1.6%), Lutzomyia migonei (1.2%) and Lutzomyia oswaldoi (0.1%). The Valão das Louças had the highest density of sandflies, followed by the localities of Km 39, Km 40 and Caçador. The low diversity of species is due to significant changes in the ecotope of the region. It is suggested that American cutaneous leishmaniasis is being transmitted by Lutzomyia intermedia in the municipality of Seropédica.

Canine leishmaniosis in South America

Canine leishmaniosis is widespread in South America, where a number of Leishmania species have been isolated or molecularly characterised from dogs. Most cases of canine leishmaniosis are caused by Leishmania infantum (syn. Leishmania chagasi) and Leishmania braziliensis. The only well-established vector of Leishmania parasites to dogs in South America is Lutzomyia longipalpis, the main vector of L. infantum, but many other phlebotomine sandfly species might be involved. For quite some time, canine leishmaniosis has been regarded as a rural disease, but nowadays it is well-established in large urbanised areas. Serological investigations reveal that the prevalence of anti-Leishmania antibodies in dogs might reach more than 50%, being as high as 75% in highly endemic foci. Many aspects related to the epidemiology of canine leishmaniosis (e.g., factors increasing the risk disease development) in some South American countries other than Brazil are poorly understood and should be further studied. A better understanding of the epidemiology of canine leishmaniosis in South America would be helpful to design sustainable control and prevention strategies against Leishmania infection in both dogs and humans.

Cutaneous leishmaniasis: progress towards a vaccine

Leishmaniases are vector-borne diseases due to the protozoan parasite Leishmania . Since no prevention method is available and as current therapy is costly, often poorly tolerated and not always efficacious, the development of alternative therapies, including vaccines, constitutes the priority in the fight of Leishmania infection. This review focuses on recent advances in the development of vaccines against leishmaniasis, with emphasis on the cutaneous form. Indeed, the fact that recovery from leishmaniasis is associated with immunity against new infection provides a rational basis for the development of vaccination strategy against infection with Leishmania . Evidence from animal studies demonstrate that protection can be achieved following infection with live-attenuated Leishmania as well as through immunization with purified proteins or DNA vaccines. In addition, recent results have shown that immunization against the saliva of the insect vector could have synergistic effects with conventional vaccination. Finally, vaccination using dendritic cells was recently demonstrated as a possible tool for Leishmania vaccination.

Failure of both azithromycin and antimony to treat cutaneous leishmaniasis in Manaus, AM, Brazil

A non-randomized controlled clinical trial was carried outin order to evaluate both azithromycin and antimony efficacy in cutaneous leishmaniasis in Manaus, AM, Brazil. Forty nine patients from both genders, aged 14 to 70, with cutaneous ulcers for less than three months and a positive imprint for Leishmania spp. amastigotes were recruited into two groups. Group I (26 patients) received a daily-single oral dose of 500 mg of azithromycin for 20 days and Group II (23 patients) received a daily-single intramuscular dose of 20 mg/kg of meglumine antimony, also for 20 days. Azithromycin cured three of 24 (12.5%) patients on days 60, 90 and 120 respectively whereas therapeutic failure was considered in 21 of 24 (87.5%) cases. In group II, antimony cured eight of 19 (42.1%) cases as follows: three on day 30, one each on day 60 and day 90, and three on day 120. Therapeutic failure occurred in 11 of 19 (57.9%) individuals. The efficacy of antimony for leishmaniasis was better than azithromycin but analysis for the intention-to-treat response rate did not show statistical difference between them. Although azithromycin was better tolerated, it showed a very low efficacy to treat cutaneous leishmaniasis in Manaus.

The first records of Leishmania (Leishmania) amazonensis in dogs (Canis familiaris) diagnosed clinically as having canine visceral leishmaniasis from Araçatuba County, São Paulo State, Brazil

Two cases of Leishmania (Leishmania) amazonensis are reported in the domestic dog (Canis familiaris). These are the first records of this parasite in this species. The animals lived in the endemic visceral leishmaniasis area of Araçatuba, São Paulo State, Brazil and were initially diagnosed, on clinical grounds, as having visceral leishmaniasis. Attempted parasite isolation from inguinal lymph node aspirates was unsuccessful and the indirect immunofluorescent test for visceral leishmaniasis was negative in both cases. Parasites were seen in cytological preparations of their lymph nodes and the DNA obtained from these same tissues produced the expected fragment in a Leishmania specific rDNA based PCR assay. The products only hybridized with the L. (L.) amazonensis specific probe S8. No human cases of L. (L.) amazonensis have been reported in this region. These results suggest that L. (L.) amazonensis is being transmitted in the peridomestic habitat and that this parasite is responsible for a clinical condition that is similar to visceral leishmaniasis caused by L. (L.) i. chagasi that is present in the same area.

Abundance of Lutzomyia longipalpis (Diptera: Psychodidae: Phlebotominae) and urban transmission of visceral leishmaniasis in Campo Grande, state of Mato Grosso do Sul, Brazil

The outspread and urbanization of visceral leishmaniasis (VL) in Campo Grande, state of Mato Grosso do Sul, lead us to undertake the present study over diversity and abundance of sand flies in the urban area to compare with previous search carried out during 1999/2000, before the identification of the disease in the human population. The captures were carried out with automatic light traps, weekly, from February 2004 to February 2005 on three sites including a forested area (Zé Pereira), two peridomicilies (shelters of domestic animals and cultivation areas), and intradomicilie. In the present study 110 collections were obtained during 13 months for 1320 h of collections, resulting in 5004 specimens, 3649 males and 1355 females belonging to the 20 following species: Brumptomyia avellari, Brumptomyia sp., Bichromomyia flaviscutellata, Evandromyia lenti, E. termitophila, E. cortelezzii, E. borrouli, Lutzomyia sp., L. longipalpis, Micropygomyia quinquefer, N. antunesi, N. whitmani, Pintomyia christenseni, Pi. damascenoi, Psathyromyia aragaoi, Ps. campograndensis, Ps. hermanlenti, Ps. shannoni, Pychodopygus claustrei, and Sciopemyia sordellii. L. longipalpis was the most abundant species in the anthropic environment with 92.22% of the captures. This shows an increase of sixty times in the density of L. longipalpis compared to the last sand fly evaluation in 1999/2000. The high density of L. longipalpis in Campo Grande is the main factor of risk in transmission of the disease to human in the urban area. The capture of N. antunesi, typical specie from Amazonian region, in Mato Grosso do Sul is reported for the first time.

Use of PCR–RFLP to identify Leishmania species in naturally-infected dogs

Tissue imprints on Giemsa stained slides from dogs were used to investigate the presence of Leishmania amastigotes by either optical microscopy (OM) or Polymerase chain reaction (PCR) detection of DNA. Samples from skin, spleen, lymph node, liver and bone marrow from a Leishmaniasis endemic area dogs where Leishmania (Leishmania) chagasi and Leishmania (Viannia) braziliensis are sympatric were studied. Dogs were initially diagnosed by Indirect Immunofluorescence (IIF), as which 39 were IIF positive (> or = 1:40) and 16 negative. The IIF positive dogs were clinically grouped as symptomatic (n = 15), oligosymptomatic (n = 12) and asymptomatic (n = 12). Although PCR positivity was higher in symptomatic dogs, specially their skin samples, there was no significant difference among clinical groups or organs examined. Ten (62.5%) out of 16 IIF and OM negative animals were positive for PCR in at least one organ. Forty-eight positive PCR amplicons were further submitted to RFLP for Leishmania identification. All dogs were infected with L. (L.) chagasi except one, infected with L. (V.) braziliensis. PCR was more efficient than IIF and OM to diagnose canine visceral Leishmaniasis (CVL), regardless of the organ examined and the clinical form present. The use of PCR together with serology helps determining the extension of sub clinical infection in CVL endemic areas and provides a better estimate of the number of dogs to be targeted for control measures. In conclusion, our data reinforce the need for a specific diagnosis of canine infection in areas where diverse Leishmania species are sympatric and demonstrate that PCR-RFLP can be used to identify Leishmania species in dog tissue imprint stained slides.

Serological screening confirms the re-emergence of canine leishmaniosis in urban and rural areas in Governador Valadares, Vale do Rio Doce, Minas Gerais, Brazil

This study performed clinical, serological and parasitological assessments in dogs from Vale do Rio Doce, in Minas Gerais State, Brazil, a region considered as a 'controlled endemic' area for canine visceral leishmaniosis (CVL). Nevertheless, there are signs that CVL in dogs may be re-emerging as a programme to control the disease was interrupted in the 1990s. The majority of the animals examined presented various symptoms associated with CVL. The enzyme-linked immunosorbent assay test indicated 13.7 and 12.4% of positivity of dogs from the urban and rural areas, respectively. According to indirect immunofluorescence assay test and TRALd tests, 18.2 and 42.2% of dogs in the rural area were seropositive, respectively. Parasitism in seropositive dogs was confirmed by in vitro tissue culture. Sand flies of the genus Lutzomyia, which are able to transmit both cutaneous and visceral leishmaniosis, were found in the area. The results provide a strong evidence of the re-emergence of CVL in this region.

Aspectos epidemiológicos da leishmaniose tegumentar americana em Varzelândia, Minas Gerais, Brasil

Para caracterizar uma área endêmica de leishmaniose tegumentar americana susceptível de intervenção com candidato à vacina anti-leishmania, foi iniciado em 1999 estudo longitudinal em área rural do Município de Varzelândia, Minas Gerais, Brasil. Inicialmente, foram cadastrados 1.253 indivíduos distribuídos em 246 domicílios, dos quais, 1.170 concordaram em participar do trabalho. Desses, 593 (50,6%) eram masculinos e 662 (56,5%), menores de 21 anos. A intradermorreação de Montenegro foi realizada em 1.120 indivíduos, lida em 1.020 dos casos, e observada reatividade em 282 (27,6%) deles. Anticorpos anti-leishmania foram testados mediante imunofluorescência indireta e teste ELISA em 970 (82,9%) indivíduos, obtendo-se positividade, respectivamente, em 127 (13,1%) e 170 (17,5%) para os dois testes. Na avaliação inicial, foram observados 297 (25,4%) indivíduos com cicatrizes cutâneas semelhantes às deixadas pela doença. Desses, 282 realizaram a intradermorreação que foi positiva em168 (59,61%). A prevalência de casos de leishmaniose tegumentar no início do estudo foi de 5,8% e, depois do primeiro ano, observou-se incidência anual de 4,6% de casos. As características epidemiológicas observadas nesse local sugerem tratar-se de uma área endêmica de colonização antiga.

[Study of the sand flies in American cutaneous leishmaniasis area, in the municipality of Alto Caparaó and Caparaó, Minas Gerais State]

In the period from November of 2000 to November of 2001, a study of sand flies was realized in the municipalities of Alto Caparaó and Caparaó with the objective of determining their seasonal variation, comparing the points of study related to the occurrence of these insects and detecting their ideal environments. Monthly collections were carried out, with Falcão light traps at nine points, four traps per point, in the following environments: of animals shelter, forest (bush), coffee plantation and the external walls of houses. Lutzomyia intermedia (Lutz & Neiva, 1912) was the predominant species, and animal shelter the environment with the largest occurrence of sand flies. A significant difference in the composition of sand fly species was found in the studied points. Lutzomyia intermedia is the species suspected of transmitting Leishmania in the region.

Comparison of polymerase chain reaction with other laboratory methods for the diagnosis of American cutaneous leishmaniasis: diagnosis of cutaneous leishmaniasis by polymerase chain reaction

An evaluation of 5 laboratory methods for diagnosing American cutaneous leishmaniasis (ACL) was carried out on patients from an endemic area of Brazil. From 164 patients presenting cutaneous lesions, and suspected to have ACL, 133 (81.1%) were confirmed for the disease by Montenegro skin test (MST) and/or parasitologic examination (PE). In both groups of patients, the positivity of polymerase chain reaction (PCR) was similar to that of immunofluorescence assay and enzyme-linked immunosorbent assay, and higher than that of MST and PE (P < .05). In the group of patients suspected to have ACL, PCR presented the same positivity as PE and MST together. No correlation between positivity of the laboratory methods and clinical or epidemiologic aspects was observed. Our data confirmed the value of PCR as an alternative laboratory method for diagnosing ACL, especially for those patients with negative PE and MST.

Nocturnal activity rhythms of Lutzomyia intermedia and Lutzomyia whitmani (Diptera: Psychodidae) in a transmission area of American cutaneous leishmaniasis in Rio de Janeiro State, Brazil

The phlebotomine sand flies Lutzomyia (Nyssomyia) intermedia (Lutz & Neiva) and Lutzomyia (Nyssomyia) whitmani (Coutinho & Antunes) are important vectors of Leishmania (Vianna) braziliensis, the etiological agent of American cutaneous leishmaniasis. In some areas, both species occur in sympatry, and their relative roles as vectors in these areas are not clear. We studied the nocturnal activity and biting rhythms of both species in Posse, a locality in Rio de Janeiro State, Brazil. Our results show differences between the activity patterns of Lu. intermedia and Lu. whitmani that might be epidemiologically important. Although the activity profiles vary between seasons and microhabitats (peridomestic versus forest), the two species show marked differences in their tendencies to bite humans in the early morning (0400-0600 hours), with Lu. whitmani showing higher feeding rates than Lu. intermedia.

Perfil de isotipos de imunoglobulinas e subclasses de IgG na leishmaniose tegumentar americana

O presente trabalho avaliou o perfil de anticorpos em amostras de soro de 37 pacientes com diagnóstico clínico confirmado ou compatível com leishmaniose tegumentar americana atendidos no Hospital de Clínicas da Universidade Federal de Uberlândia, MG. Os perfis das classes de imunoglobulinas e subclasses de IgG foram analisados pelo teste ELISA indireto, utilizando-se antígeno solúvel de Leishmania (Leishmania) amazonensis. A avidez dos anticorpos foi determinada pelo tratamento com uréia a 6 M, após incubação dos soros com o antígeno. Observou-se que 97%, 94,6%, 57,5 e 21,5% das amostras testadas apresentaram anticorpos anti-Leishmania das classes IgE, IgG, IgA e IgM, respectivamente e, os perfis das subclasses de IgG demonstraram, IgG1>IgG3>IgG2>IgG4. Os anticorpos IgE anti-Leishmania de alta avidez corresponderam a 44,4%. Por outro lado, IgG e IgA anti-Leishmania foram em sua maioria (62,8 e 47,8%, respectivamente), de média avidez. A variação do perfil de isotipos, bem como a avidez das imunoglobulinas refletiu a complexidade da resposta imune humoral contra a leishmaniose tegumentar americana.

Risk factors for mucosal manifestation of American cutaneous leishmaniasis

A case-comparison study was carried out to identify risk factors for mucosal manifestations of American cutaneous leishmaniasis (ACL) in southeast Brazil, using a series of 2820 patients, diagnosed with ACL between 1966 and 1999. The significant factors independently associated with mucosal leishmaniasis were: gender, age, nutritional status and length of disease. Mucosal leishmaniasis occurred 1.7 times more frequently among males than females; twice as often in individuals older than 22 years compared with the younger group; almost four times as often in individuals with severe malnutrition compared with those who were well nourished; and almost four times more frequently in individuals reporting the disease for more than 4 months compared with those reporting a shorter duration of the disease. Among individuals older than 22 years the risk of mucosal leishmaniasis increased significantly (from 1.9 to 9.6) as the nutritional status decreased, when compared with younger and well-nourished patients. The characteristics herein described and correlated with severe forms could be used as diagnostic markers as part of clinical screening in areas endemic for ACL.

Ecoepidemiologia da leishmaniose tegumentar no Município de Buriticupu, Amazônia do Maranhão, Brasil, 1996 a 1998

Estuda-se a distribuição da Leishmaniose Tegumentar no Município de Buriticupu, Maranhão, Brasil, de acordo com os meses, estações e as ocupações, sexos e faixas etárias das pessoas, nos anos de 1996 a 1998. Os dados referentes a estes aspectos são comparados com os da fauna flebotomínica obtidos por outros autores, no mesmo período. A doença atingiu todas as faixas etárias, obedecendo à seguinte ordem: 0-5 (4,1%), 6-10 (7,1%), 11-15 (13,6%), 16-21 (20,8%), 22-30 (21,1%) e > 30 (33,3%). O predomínio foi do sexo masculino (70,1%) e, quanto à ocupação, os lavradores (52,5%), seguidos dos estudantes (17,7%) e das domésticas (16,0%). A exemplo dos flebotomíneos, a doença distribuiu-se durante todos os meses do ano, mas a maior concentração de casos foi registrada na estação seca (58,5%), enquanto os flebotomíneos apresentaram picos bimodais nos dois primeiros anos. Ocorreu em maior freqüência no período chuvoso em 1998. A doença continua apresentando características que a definiam em épocas passadas, mas houve um aumento proporcional de casos em crianças e no sexo feminino, sugestivo de transmissão no ambiente antrópico.

Phenetic studies on randomly amplified polymorphic DNA-polymerase chain reaction-variability of four geographical populations of Lutzomyia whitmani (Diptera: Psychodidae) in Brazil

Previous evaluation of the genetic variability of four biogeographical populations of Lutzomyia whitmani from known foci of cutaneous leishmaniasis in Brazil demonstrated two main spatial clusters: Corte de Pedra-BA, Ilhéus-BA and Serra de Baturité-CE in the first cluster, and Martinho Campos-MG in the second. Further analysis showed a high degree of homogeneity in Corte de Pedra population but not in the others, which presented a significant percentage of specimens displaced from their phenon of origin (discrepant individuals). In the present work we analyzed the frequencies of association coefficients in the matrixes of similarity per population of Lutzomyia whitmani from both sexes and the general phenograms obtained, in a more detailed study of those discrepant specimens. Populational stability was observed for Corte de Pedra population, whereas the three remaining populations showed varying degrees of heterogeneity and different displacements according to sex. Our results strongly suggested the existence of a genetic flow between the lineages North-South/North-East and Ilhéus/Serra do Baturité of Lutzomyia whitmani.

Genetic variability in geographical populations of Lutzomyia whitmani elucidated by RAPD-PCR

Unequivocal identification of phlebotomine sand flies is of crucial importance in epidemiological studies of leishmaniasis, because certain species may act as vectors, depending on behavior and physiology. For Lutzomyia whitmani, a major vector of American human cutaneous leishmaniasis in Brazil, an increasing number of studies have suggested the existence of a species complex. In the present work, we evaluated the genetic variability of L. whitmani populations from four Brazilian foci of that disease: Corte de Pedra, Ilhéus, Martinho Campos, and Serra de Baturité. Computational analysis of 85 characters, generated by RAPD-polymerase chain reaction, demonstrated high intrapopulational variability. Those characters led to sex discrimination in three of the populations, with the exception of Martinho Campos individuals, in which sex distinction was not complete. One and two interpopulational phenograms were obtained for females and males, respectively. A higher similarity was observed among the specimens from Ilhéus, Corte de Pedra, and Serra de Baturité, whereas the Martinho Campos population remained external to that cluster. These results, which are in partial accordance with a previous morphometric survey of L. whitmani from the same regions, provide additional evidence to support the existence of at least two spatial clusters of biogeographical populations of L. whitmani in Brazil.

PCR-RFLP to identify Leishmania (Viannia) braziliensis and L. (Leishmania) amazonensis causing American cutaneous leishmaniasis

A PCR-RFLP based method was developed to diagnose and identify the Leishmania species causing American cutaneous leishmaniasis (ACL) in a panel of clinical samples obtained from an endemic region of Brazil. The comparison of the results obtained by PCR-RFLP and PCR-hybridization in the identification of Leishmania (Viannia) braziliensis and L. (Leishmania) amazonensis were highly concordant (kappa=91.5%). The PCR-RFLP method was reliable, fast and easy to conduct on biopsies and presents potential value of utmost importance for the diagnosis and identification of Leishmania in clinical specimens, infected reservoirs and vectors.