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Revista Pan-Amazônica de Saúde

versão impressa ISSN 2176-6223versão On-line ISSN 2176-6223

Rev Pan-Amaz Saude v.7 n.esp Ananindeua dez. 2016

http://dx.doi.org/10.5123/s2176-62232016000500015 

ORIGINAL ARTICLE

Diversity and ecology of sand flies (Psychodidae: Phlebotominae): foci of cutaneous leishmaniasis in Amazon Region, Brazil

Diversidade e ecologia de flebotomíneos (Psychodidae: Phlebotominae): focos de leishmaniose cutânea na Amazônia, Brasil

Diversidad y ecología de flebótomos (Psychodidae: Phlebotominae): foco de leishmaniasis cutánea en la Amazonía, Brasil

Raquel Gonçalves1  , Daniela Cristina Soares1  2  , Ricardo José de Paula Souza e Guimarães1  , Walter Souza Santos1  , Gilberto Cesar Rodrigues de Sousa1  , Anadeiva Portela Chagas1  , Lourdes Maria Garcez1  3 

1 Instituto Evandro Chagas/SVS/MS, Seção de Parasitologia, Ananindeua, Pará, Brasil

2 Secretaria de Estado de Saúde Pública, Belém, Pará, Brasil

3 Universidade do Estado do Pará, Belém, Pará, Brasil

ABSTRACT

The aim of this study was to describe the phlebotomine sand fly fauna and its respective ecological indexes in risk zones of cutaneous leishmaniasis (CL). The study was carried out in the Municipality of Santarém, Pará State, Brazil. From the total of 102 records of CL patients in 2010 and 2011, infected with different Leishmania species, 31 were selected. Kernel density analysis was performed. CDC light traps were placed (6 p.m.-6 a.m., three nights, height of 1.5 m) in the identified risk zones (indoors, chicken sheds and surrounding forest) in two occasions: rainy and dry seasons of 2012. Shannon traps were installed in the forest during 3 h (7 p.m.-9 p.m., one night). Shannon (H'), Pielou (J') and Dominance (D) indexes were calculated and two spatial clusters (SC) of CL, SC1 (urban-rural) and SC2 (rural farm), were identified. Phlebotomines were sampled in SC1 (243) and SC2 (174). In the whole sample (417) there were 24 species of 10 genera, but only 12 species were found in both risk zones. Ecological indexes varied widely (H' = 0.5-1.72; J = 0.44-0.78; D = 0.46-0.91). The highest D values in the forest (≥ 0.75) were associated to Psychodopygus complexus during both seasons in SC1 and Psychodopygus davisi during the rainy season in SC2. Other CL vectors were identified in smaller frequence. A great diversity of phlebotomine species was described in each risk zone. The CL vectors sampled were well-matched with the Leishmania species infecting the patients. The epidemiological importance of dominant species may vary with climatic seasons and risk zones in Santarém.

Keyworks: Ecology; Phlebotomines; Leishmania; Tegumentary Leishmaniasis; Risk Zones

RESUMO

O objetivo deste estudo foi descrever a fauna de flebotomíneos e seus respectivos índices ecológicos em zonas de risco de leishmaniose cutânea (LC). O estudo foi realizado no Município de Santarém, Estado do Pará, Brasil. Do total de 102 registros de pacientes com LC em 2010 e 2011, infectados com diferentes espécies de Leishmania, 31 foram selecionados. O estimador de densidade de Kernel foi utilizado. Armadilhas luminosas do tipo CDC (18:00-6:00 h, três noites, altura de 1,5 m) foram instaladas nas zonas de risco identificadas (dentro das casas, nos galinheiros e floresta ao entorno) em duas ocasiões: estações chuvosa e seca, em 2012. As armadilhas Shannon foram instaladas na floresta durante 3 h (19:00-21:00 h, uma noite). Os índices de Shannon (H'), Pielou (J') e de Dominância (D) foram calculados e dois circuitos espaciais (CE) de LC, CE1 (urbano-rural) e CE2 (rural), foram identificados. Flebotomíneos foram amostrados em CE1 (243) e CE2 (174). No total da amostra (417) havia 24 espécies de 10 gêneros, mas apenas 12 espécies foram encontradas em ambas as zonas de risco. Os índices ecológicos variaram consideravelmente (H' = 0,5-1,72; J = 0,44-0,78; D = 0,46-0,91). Os maiores valores de D na floresta (≥ 0,75) foram associados a Psychodopygus complexus durante as duas estações em CE1 e Psychodopygus davisi durante o período chuvoso em CE2. Outros vetores de LC foram identificados em menor frequência. Uma grande diversidade de espécies de flebotomíneos foi descrita em cada zona de risco. Os vetores de LC amostrados combinam com as espécies de Leishmania que infectaram os pacientes. A importância epidemiológica das espécies dominantes pode variar de acordo com as estações climáticas e zonas de risco em Santarém.

Palavras-chave: Ecologia; Phlebotomus; Leishmania; Leishmaniose Tegumentar; Zonas de Risco

RESUMEN

El objetivo de este estudio fue el de describir la fauna de flebótomos y sus respectivos índices ecológicos en zonas de riesgo de leishmaniasis cutánea (LC). El estudio fue realizado en el Municipio de Santarém, Estado de Pará, Brasil. Del total de 102 historiales de pacientes infectados por LC en 2010 y 2011, con diferentes especies de Leishmania, se seleccionaron 31. El estimador de densidad de Kernel y las trampas luminosas de tipo CDC (18:00-6:00, tres noches, altura de 1,5 m) fueron utilizadas en las zonas de riesgo identificadas (en los espacios interiores, galpones y bosques circundantes), en dos ocasiones: estaciones lluviosa y seca de 2012. Las trampas Shannon se instalaron en la floresta durante 2 h (19:00-21:00, una noche). Los índices de Shannon (H'), Pielou (J') y de Dominancia (D) fueron calculados y dos clústeres espaciales de LC: CE1 (urbano-rural) y CE2 (rural) fueron identificados. Las muestras de los flebótomos se recolectaron en CE1 (243) y CE2 (174). En el total de las muestras (417) había 24 especies de 10 géneros, aunque solamente 12 especies fueron encontradas en ambas zonas de riesgo. Los índices ecológicos variaron considerablemente (H' = 0,5- 1,72; J = 0,44-0,78; D = 0,46-0,91). Los mayores valores de D en la floresta (( 0,75) fueron asociados al Psychodopygus complexus, durante las dos estaciones en CE1 y Psychodopygus davisi, durante el período de lluvias en CE2. Otros vectores de LC se identificaron en pequeña cantidad. Una gran diversidad de especies de flebótomos fue descubierta en cada zona de riesgo. Las muestras de vectores de LC se igualaban a las especies de Leishmania que infectaron a los pacientes. La importancia epidemiológica de las especies dominantes puede variar de acuerdo a las estaciones climáticas y zonas de riesgo en Santarém.

Palabras clave: Ecología; Phlebotomus; Leishmania; Leishmaniasis Tegumentaria; Zonas de Riesgo

INTRODUCTION

The American tegumentary leishmaniasis is a vector-borne disease caused by Leishmania protozoals and transmitted by phlebotomine sand flies (Psychodidae: Phlebotominae). The disease represents an important problem of public health in rural and urban areas in Brazil. High incidence rates of tegumentary leishmaniasis had been computed over the last decade (2001-2010) and more than 30,000 new occurrences were reported in 20101, mostly (~95%) represented by cutaneous leishmaniasis (CL) and the smaller proportion by mucosal or mucocutaneus leishmaniasis (ML).

Different species of phlebotomine sand fly are able to transmit CL to humans. The community composition and richness of sand flies result of ecological interactions and local geographic aspects2,3, then environmental changes affect the abundance, diversity, behaviour and habits of the different species within a community4.

Some environments become highly favourable to the CL vectors development and disease transmission depending on the local influences5,6. At least three factors determine the vectorial capacity: density of the species, ability to colonize humans changed environments and the competence for feeding human blood7.

Additionally, the Leishmania species distribution and seasonality are reflections of the events affecting their vectors8. For each Leishmania pathogen there is one or more species of sand fly vectors playing a role on the protozoal transmission to humans9,10. However, the importance of each CL vector varies with the different endemic areas and climatic seasons.

The epidemiological surveillance and phlebotomines ecology understanding are essential to guide preventive measures especially in areas of high biological diversity where continuous environmental changes take place9,11.

The Municipality of Santarém (lower Amazon Region) is the main centre reporting new CL occurrences on western Pará State. Autochthonous CL reports were firstly investigated throughout 2010 and 2011, and clusters were identified with spatial analysis tools5,12,13. Then it was described the fauna and studied the ecology of phlebotomine sand fly communities in these risk zones by calculating ecological indexes.

MATERIALS AND METHODS

For this entomologic study, recommendations were followed of the Instituto Evandro Chagas (IEC) Human Research Ethics Committee (0019/2012). Additionally, it was used a database of CL records previously obtained with ethics approval of this same committee (CAAE 0030.0.072.000-09).

The Municipality of Santarém (02º26' S, 54º42' W) is a development centre on western Pará State. The temperature (25-28° C) and relative air humidity (86%) is frequently high. The rainfall is over the whole year, despite it is more frequent from December to June (rainy season) rather than in the other months (dry season). A dense ombrophilous forest forms the natural vegetation cover, but large areas with intense agricultural activities (mainly soy culture) provide a secondary vegetation cover. Several businesses have a direct impact on the local environment, such as the Curuá-Una hydroelectric dam14.

The population was 294,580 inhabitants in 2010 and the territory extension was 24,154 km² until 2013, when it was reduced to 17,898 km². The incidence rate of CL was 42 and 66 new cases for 100,000 inhabitants in 2010 and 2011 respectively15.

The database was composed of 102 entries including autochthonous (47) and allochthonous (55) occurrences of CL reported in Santarém, during 2010 and 2011.

Thirty-one records of autochthonous CL reports were selected, including patients infected with Leishmania sp. (8, 26%), Leishmania (Viannia) sp. (9, 29%), Leishmania (Viannia) braziliensis (7, 23%), Leishmania (Viannia) shawi (4, 13%), Leishmania (Viannia) lainsoni (1, 3%), Leishmania (Viannia) naiffi (1, 3%) and a putative hybrid of L. (V.) braziliensis/guyanensis (1, 3%). Etiologic agents were previously identified by means of PCR and/or sequencing16. The database had several information about the patient, including the putative CL transmission locals and households (place of the event). The excluded records had no information about places of the event (14/47) or these places were inaccessible by road (2/47).

In order to get the GPS coordinates (Global Position System, Garmin(r) Colorado 400 T and 76 CSx) in the places of the event, it was used the ArcGIS 10 (Environmental System Research Institute Inc., Redlands, California, USA) and applied the probability density function estimated by the Kernel method as follow17:

Where is the estimated value in a region; means the Kernel function; S...Si are the places of the event in a radius of influence (τ) and centre (S).

A satellite image at 250 m spatial resolution and 10 km radius highlighted the risk zones (clusters), deforestation (2002-2009) and land uses (Amazon Deforestation Monitoring Project, PRODES - TerraClass Project, INPE, 2011).

The entomological capture units considered were environments with potential sand fly blood sources (animals and humans): indoors, chicken sheds and surrounding forest. Then four capture units in each spatial cluster (SC) or risk zone were defined. Three were represented by houses and their respective chicken sheds in the peridomiciliary areas (SC1: -2,569 -54,861 Datum SAD 69, altitude of 83-107 m; SC2: -2,831 -54,294, altitude of 35-72 m). A fourth unit was a locality in the surrounding forest (SC1: -2,551 -54,860 Datum SAD 69; 141 m altitude; SC2: -2,849 -54,299 Datum SAD 69; 64 m altitude).

Six CDC light traps were placed at a height of 1.5 m in the peri- and intradomiciliary areas of three houses from 6 p.m.-6 a.m. for three nights and a Shannon trap installed in the surrounding forest from 7 p.m.-9 p.m. for a single night. This sampling regime was carried out on two occasions, once each in the rainy (March) and dry (September) seasons of 2012. The choice of the capture units followed criteria earlier established9. The captured phlebotomines were segregated by trap and environment and then identified by morphology18.

It was used the PAST v2.03 (PAlentological STatistic) for calculating the ecological indexes and comparing attributes among samples. The standard deviation and confidence interval were computed by permutation and bootstrap (α = 0.05). The following indexes were calculated:

Shannon diversity [0-10]:

Pielou's evenness [0-1]:

Dominance [0-1]:

In the equations above n is the overall number of individuals, ni is the number of individuals of a given species (i) in each environment and S is the number of species.

It was also performed the chi-square test (χ2) for comparing the frequencies of male and female phlebotomines in the rainy and dry seasons (α = 0.05).

RESULTS

The figure 1 shows two Kernel density areas or risk zones in Santarém based on the CL occurrences density in 2010 and 2011. The bigger cluster is overlapping an urban-rural area including a locality called Jatobá, where most patients were infected. The smaller one covers a rural area on southeastern Santarém, where is found Corta-Corda locality. Entomological surveys were carried out during the rainy and dry seasons in both localities.

Figure 1 - Risk zones of CL in Santarém, Pará State, Brazil 

A total of 417 phlebotomine sand flies was captured in urban-rural (58%, 243) and rural (42%, 174) areas, most females (75%, 312). The sand flies frequency did not vary in the rainy (54%, 226) and dry seasons (46%, 191). A higher female proportion was found when used the Shannon trap irrespective of the season (p < 0.0001) and when CDC light traps were used in the dry season only (p = 0.0003). In the rainy season, no significant difference in sex proportion was found in the phlebotomine sample captured with CDC light traps (p = 0.52). Ten genera in the sample were identified: Bichromomyia, Evandromyia, Lutzomyia, Micropygomyia, Nyssomyia, Psathyromyia, Psychodopygus, Sciopemyia, Trichopygomyia and Trichophoromyia (Table 1). Vectors of the same Leishmania species causing CL were found in both urban-rural and rural areas: Psychodopygus complexus, Nyssomyia anduzei, Bichromomyia flaviscutellata, Psychodopygus davisi and Nyssomyia antunesi. It was also found Lutzomyia longipalpis, a visceral leishmaniasis (VL) vector, in urban-rural area (Table 2). For calculating ecological indexes, It was used the species frequency in different environment and seasons (Table 1).

Table 1 - Phlebotomine species abundance and frequency in different environments associated to the ecological indexes in two surveys during the rainy (March) and dry (September) seasons of 2012 in urban-rural (Jatobá) and rural (Corta-Corda) areas of Santarém, Pará State, Brazil 

Peridomiciliary areas (chicken sheds); * Significantly higher between seasons (p < 0.05); Conventional signal used: - numerical data equals zero.

Table 2 - The six phlebotomine sand flies species in the sample incriminated and/or confirmed as vectors of epidemiologically important Leishmania species in Amazon Region 

The Shannon diversity ranged 0.2-1.73, increasing significantly during the dry season in the forest of the rural area and in the chicken sheds of the urban-rural area. For the other environments, no significant difference between seasons was described.

Pielou's evenness ranged 0.28-0.96, with no season variation in rural area. Nevertheless, the J' values increased significantly during the dry season in urban-rural peridomiciliary areas.

The dominance ranged 0.21-0.91 and had the highest values associated to the forest (0.56-0.91). Potential vectors of CL were dominant species in the forest of the urban-rural area, where Ps. complexus was dominant, and in the forest of the rural farm area, where the dominant species was Ps. davisi, both in the rainy season. These CL vectors alternated the dominance behaviour in different seasons with other phlebotomine species without epidemiological importance, Lutzomyia gomezi and Nyssomyia hemandezi, respectively dominant in urban-rural and rural areas during the dry season, when the CL vectors were less frequent or entirely absent. A significant season variation concerning to the D index was only observed in the rural area. No Lu. longipalpis was found in the rural area, but was present in the urban-rural peridomiciliary areas as a dominant species during the rainy season. Lu. longipalpis shared the dominance with Lutzomyia castanheirai indoors. The D value associated to Lu. longipalpis decreased significantly though the dry season, when this species was not found indoors (Table 1).

DISCUSSION

Through the last decades, Santarém undergoes continuous environmental changes due to a fast economic development specially based on its natural richness and agricultural activities27. In despite of the high incidence of human CL with several Leishmania species causing the disease, the ecology of CL vectors in this Amazonian municipality is poorly known. In this study, twenty-four species of phlebotomines were identified including several potential vectors of Leishmania pathogens to humans, all compatible with the diversity of parasites infecting 31 patients who lived and worked in the risk zones. Surveys in areas of other Brazilian biomes had reported lower richness in samples up 10 times larger than those carried out in this study. Studies carried out in areas of Cerrado and Pantanal biomes recognized only eight phlebotomine species within a sample of 3,946 phlebotomines monthly captured with CDC light traps in the course of one year. Two of the species were epidemiologically important - Nyssomyia whitmani and Lu. longipalpis - being the second highly abundant28. A survey in Bahia State, which assembles Atlantic forest, Caatinga and Cerrado, sampled 3,000 phlebotomines of 14 species, including only one CL vector, Ny. whitmani29.

The ecological indexes vary slightly as the sample size increases thus they are feasible to calculate even upon small samples, as used in this study30,31. The Shannon diversity index, higher as the diversity increases and lower as the proportion of rare species increases, despite of the large interval (H' = 0-10), usually ranges 1.5-3.5, in this study it ranged 0.2-1.72. The microenvironments that presented variations in diversity between seasons were peridomiciliary locals of the urban-rural area (dry: 1.15; rainy: 1.72) and surrounding forest of the rural area (dry: 0.49; rainy: 1.2). This rural area has agricultural activities and a hydroelectric dam of Curuá-Una river. The phlebotomine diversity and evenness there ranged respectively: H' = 0.49-1.72 and J' = 0.44-0.96. Those values represent more diversity and similar evenness if compared to the environments around another hydroelectric dam in southern Brazil (H' = 0.3-1.31; J' = 0.2-1.0), Paranapanema river, Paraná State32, where Atlantic forest is the predominant bioma.

The Pielou's evenness index (J') or equivalence of species abundance is strongly influenced by the climate variations and environmental changes. When the J' value is high, there is no dominant species and the dominance index is low. In this study, the Pielou's index increased significantly between seasons (rainy: 0.53; dry: 0.78) only in peridomiciliary areas of Jatobá, where the dominance was associated to Lu. longipalpis, the vector of L. (L.) infantum, which causes VL. The correspondent D values (rainy: 0.46; dry: 0.26) indicated that half of the phlebotomine community in this microenvironment is composed, during the rainy, by Lu. longipalpis, beside more diversity in the peridomiciliary areas (H' = 1.15) than indoors (H' = 0.83). Indoors, Lu. longipalpis shared dominance with Th. castanheirai, species with no epidemiological importance until now.

The diversity is a positive attribute of natural communities. Those with more diversity are more stable and less susceptible to environmental disturbances33, but deep environmental changes arise imbalances and can lead important species to be highly abundant in a given area. The dominant species are able to turn into competent Leishmania vectors to humans. Consequently, outbreaks of CL can take place5,6. In Santarém, Jatobá is a risk zone for both CL and VL.

Dominant species were found in the forest of the urban-rural area as well. High D values were described in both seasons (rainy: 0.75; dry: 0.91), respectively associated to Ps. complexus and Ps. gomezi, being an important vector of L. (V.) braziliensis. The species Ps. complexus usually predominates until 200 m above the sea level34. The elevated abundance of this species during the rainy season seems to be common in the western Pará State35. In the forest of the rural area, D value increased significantly through the rainy season only (0.76), what was associated to Ps. davisi, a potential vector of L. (V.) braziliensis and L. (V.) naiffi (Table 2).

The CL vectors sampled were well-matched with the findings of Leishmania pathogens that infected patients. The most frequent etiologic agent among the patients was L. (V.) braziliensis, for which it was found more than one potential vector in the sample. Another important species playing the role of L. (V.) braziliensis vector in Pará State was Ps. wellcomei36, which is morphologically indistinguishable from Ps. complexus. Nevertheless, this species lived in the range of 200-700 m above the sea level34,36, so it was supposed that this small sample had only specimens of Ps. complexus, since phlebotomines were captured in altitudes less or equal 141 m. Anyway, Ps. wellcomei could be also represented in larger samples in low altitudes in despite of a lower frequency if compared to Ps. complexus.

However, Ps. complexus was entirely absent in the rural area, where Ps. davisi was the dominant species in the forest through the rainy season. Other studies have been reported the natural infection of Ps. davisi with L. (V.) naiffi21 and L. (V.) braziliensis20 in different localities of Amazon Region. On the other hand, it was also found L. (V.) naiffi which infected the patients in the study area. Although people living in rural areas are exposed to both vectors when get into the forest, Ps. davisi shall have epidemiological importance in the rural area (around the Curuá-Una river and hydroelectric dam) during the rainy season, while Ps. complexus would be the main CL vector in Jatobá (urban-rural and ecotourism area).

Despite the importance of one or more species in a phlebotomine community can be more easily detected when observed the dominance index, it is necessary to register all potential vectors of Leishmania pathogens to humans in the sample. In addition to the dominant species mentioned above, Bi. flaviscutellata, vector of L. (L.) amazonensis was also sampled.

In contrast to Ps. complexus, Bi. flaviscutellata do not bite humans frequently, preferring animals. Traps with rodents such Disney traps strongly attracted Bi. flaviscutellata25,37,38,39, but in captures using CDC and Shannon light traps this species is poorly represented. However, Bi. flaviscutellata was one of the five most abundant species captured in other survey carried out in rural areas of Santarém40. In this study, none of the patients living and working in the risk zones (SCs) had diagnosed a L. (L.) amazonensis infection. But there was no information about the subgenus neither the Leishmania species causing CL in 26% patients, who could be possibly infected by L. (L.) amazonensis.

Interestingly, although Bi. flaviscutellata is a known vector of L. (L.) amazonensis, the natural infection of this phlebotomine species with L. (V.) guyanensis, that can induce mucosal lesion similar to L. (V.) braziliensis26 had been also reported in French Guiana41. In view of this arguments, it was considered that the presence of Bi. flaviscutellata indoors in the rural area and in the chicken sheds in both urban-rural and rural areas always in the rainy season, in despite of the low frequency, raising questions about its epidemiological importance in the SCs of CL.

The main vector of L. (V.) guyanensis in Amazon Region is Nyssomyia umbratilis, which was not found in the sample. But Ny. anduzei, a secondary vector of this parasite in Amazonas State, Brazil24 had been found. One of the records of CL cases reported a patient infected with a putative hybrid of L. (V.) braziliensis/L. (V.) guyanensis. Recently, it was reported a putative hybrid involving these two Leishmania species in Santarém16,42. Hybrids are an important aspect of the Viannia subgenus whose presence would indicate the possible generation of epidemiologically important genotypes, since they have been described in focus of mucocutaneous leishmaniasis43. The Leishmania ability of infecting different phlebotomine species could modulate genetic changes in the parasite, so the vector role in the epidemiology and pathogenesis of Leishmania infections needs to be more studied44.

Ny. antunesi (Table 2), the putative vector of L. (V.) lindenbergi in Belém23, Pará State was also found in the sample. Ny. antunesi was the most abundant species captured in the dry season, both indoors and in the peridomiciliary areas. Although the high abundance described for this species, there is no evidence of L. (V.) lindenbergi circulating in the same area. The PCRs (Hsp70-234 and ITS1) using samples of patients living in the SCs of CL were unable to discriminate L. (V.) lindenbergi and L. (V.) guyanensis16,45.

In general, the current study showed a positive relation between potential CL vectors and the etiologic agents infecting the patients. However, further studies on molecular entomology searching natural infection by Leishmania species in phlebotomines are necessary especially in such areas with high biological diversity.

In despite of the high incidence of CL in Santarém, both VL and CL are public health problems there. High abundance and dominance of Lu. longipalpis were detected in the peridomiciliary areas of Jatobá during the rainy season only. This vector was absent in the rural area in both seasons. The high abundance of Lu. longipalpis in Santarém outskirts is already known46. This event seems to be consequence of the space occupation in Jatobá, where prevails the ecotourism, the flow of people is intense, houses are nestled deep in the secondary forest and there are no available water and sewerage service favours Lu. longipalpis development47. This species shows opportunistic feeding behavior and ability to colonize several environments, especially those continuously impacted by anthropogenic changes48. The domestic animals and respective shelters provide to Lu. longipalpis several sources of feeding, resting and oviposition46,49,50. These variables act as conditioning factors of the VL vector presence near the houses or even indoors, favouring their contact with humans51.

CONCLUSION

It was observed high diversity of phlebotomine species in both SCs and significant dominance variations depending on the species behaviour and adaptation following the environmental changes. Additionally, the entomological findings of CL vectors supported Leishmania species diversity in patients living in the SCs of CL in the Municipality of Santarém, representing the importance of spatial analysis methods for guiding entomological surveys.

Ps. complexus and Ps. davisi are probably the main CL vectors in urban-rural and rural areas, respectively, but the epidemiological importance of each species in both communities could vary in the different climatic seasons. Other potential CL vectors in the sample (Ny. antunesi, Bi. flaviscutellata and Ny. anduzei) would play a secondary role on dermotropic Leishmania transmission, but their epidemiological importance needs to be further investigated as well. The urban-rural area in Santarém is also a risk zone for VL transmission. It is necessary to investigate natural infection by Leishmania in sand fly species and understand better their seasonality and risk factors for Leishmania pathogen transmission.

ACKNOWLEDGEMENTS

To the Brazilian institutions for providing technical and structural facilities to carry out this study: Instituto Evandro Chagas, Universidade do Estado do Pará, Secretaria de Estado de Saúde Pública do Pará and Secretaria Municipal de Saúde de Santarém.

REFERENCES

1 Karagiannis-Voules D-A, Scholte RGC, Guimarães LH, Utzinger J, Vounatsou P. Bayesian geostatistical modeling of leishmaniasis incidence in Brazil. PLoS Negl Trop Dis. 2013 May;7(5):e2213. Doi: 10.1371/journal.pntd.0002213 [Link] [ Links ]

2 Feliciangeli MD. Ecology of sandflies (Diptera: Psychodidae) in a restricted focus of cutaneous leishmaniasis in Northern Venezuela: III. Seasonal fluctuation. Mem Inst Oswaldo Cruz. 1987 Apr-Jun;82(2):167-6. Doi: 10.1590/S0074-02761987000200003 [Link] [ Links ]

3 Rangel EF, Lainson R. Proven and putative vectors of American cutaneous leishmaniasis in Brazil: aspects of their biology and vectorial competence. Mem Inst Oswaldo Cruz. 2009 Nov;104(7):937-54. Doi: 10.1590/S0074-02762009000700001 [Link] [ Links ]

4 Arias JR, Freitas RA. On the vectors of cutaneous leishmaniasis in the Central Amazon of Brasil. 3. Phlebotomine sand fly stratification in a terra firme forest. Acta Amaz. 1982;12(3):599-608. [Link] [ Links ]

5 Kawa H, Sabroza PC, Oliveira RM, Barcellos C. A produção do lugar de transmissão da leishmaniose tegumentar: o caso da Localidade Pau da Fome na cidade do Rio de Janeiro, Brasil. Cad Saude Publica. 2010 ago;26(8):1495-507. Doi: 10.1590/S0102-311X2010000800004 [Link] [ Links ]

6 Guerra JAO, Barbosa MGV, Loureiro ACSP, Coelho CP, Rosa GG, Coelho LIACR. Leishmaniose tegumentar americana em crianças: aspectos epidemiológicos de casos atendidos em Manaus, Amazonas, Brasil. Cad Saude Publica. 2007 set;23(9):2215-23. Doi: 10.1590/S0102-311X2007000900029 [Link] [ Links ]

7 Gomes AC, Galati EAB. Aspectos ecológicos da Leishmaniose tegumentar americana: 7-Capacidade vetorial flebotomínea em ambiente florestal primário do Sistema da Serra do Mar, região do Vale do Ribeira, Estado de São Paulo, Brasil. Rev Saude Publica. 1989 abr;23(2):136-42. Doi: 10.1590/S0034-89101989000200007 [Link] [ Links ]

8 Rangel E, Lainson R, organizadores. Flebotomíneos do Brasil. Rio de Janeiro: Fiocruz; 2003. Ecologia das leishmanioses; p. 311-36. [ Links ]

9 Ministério da Saúde (BR). Secretaria de Vigilância em Saúde. Manual de vigilância da leishmaniose tegumentar americana. 2. ed. Brasília: Ministério da Saúde; 2007. (Série A. Normas e manuais técnicos). [Link] [ Links ]

10 Lainson R, Shaw JJ. A brief history of the genus Leishmania (Protozoa: Kinetoplastida) in the Americas with particular reference to Amazonian Brazil. Cienc Cult. 1992 Mar-Jun;44(2/3):94-106. [ Links ]

11 Alvar J, Vélez ID, Bern C, Herrero M, Desjeux P, Cano J, et al. Leishmaniasis worldwide and global estimates of its incidence. PLoS One. 2012 May;7(2):e35671. Doi: 10.1371/journal.pone.0035671 [Link] [ Links ]

12 Sabroza PC, Maia ANS, Soares VB. Vigilância e monitoramento da leishmaniose tegumentar americana em unidades territoriais - Brasil, 1994-2001. Bol Eletr Epidemiol Funasa. 2002 dez;2(5):1-7. [Link] [ Links ]

13 Barcellos C, RamalhoW. Situação atual do geoprocessamento e da análise de dados espaciais em saúde no Brasil. Inform Publica. 2002;4(2): 221-30. [Link] [ Links ]

14. Instituto Brasileiro de Geografia e Estatística. Cidades@: Pará - Santarém [Internet]. Rio de Janeiro: IBGE; 2010 [citado 2011 jul 3]. Disponível em: Disponível em: http://cod.ibge.gov.br/59C . [ Links ]

15 Instituto Brasileiro de Geografia e Estatística. Cidades@: Pará - Santarém [Internet]. Rio de Janeiro: IBGE ; 2016 [citado 2016 jul 19]. Disponível em: Disponível em: http://cidades.ibge.gov.br/xtras/perfil.php?lang=&codmun=1506807 . [ Links ]

16 Soares DC. Etiologia da leishmaniose tegumentar a mesorregião do baixo Amazonas, estado do Pará, Brasil [tese]. Belém (PA): Universidade Federal do Pará, Programa de Pós-Graduação em Biologia de Agentes Infecciosos e Parasitários; 2014. [ Links ]

17 Santos SM, Barcellos C, Carvalho MS, Flôres R. Detecção de aglomerados espaciais de óbitos por causas violentas em Porto Alegre, Rio Grande do Sul, Brasil, 1996. Cad Saude Publica. 2001 set-out;17(5):1141-51. Doi: 10.1590/S0102-311X2001000500015 [Link] [ Links ]

18 Galati EAB. Classificação de Phlebotominae. In: Rangel E, Lainson R, organizadores. Flebotomíneos do Brasil. Rio de Janeiro: Fiocruz ; 2003. p. 23-51. [ Links ]

19 Cunha AM, Chagas E. Nova espécie de protozoário do gênero Leishmania patogênico para o homem. Leishmania chagasi n.sp. Nota prévia. Hospital. 1937;11(2):3-9. [ Links ]

20 Souza AAA, Silveira FT, Lainson R, Barata IR, Silva MGS, Lima JAN, et al. Fauna flebotomínica da Serra dos Carajás, Estado do Pará, Brasil, e sua possível implicação na transmissão da leishmaniose tegumentar americana. Rev Pan-Amaz Saude. 2010 mar;1(1):45-51. Doi: 10.5123/S2176-62232010000100007 [Link] [ Links ]

21 Gil LHS, Basano SA, Souza AA, Silva MGS, Barata I, Ishikawa EA, et al. Recent observations on the sand fly (Diptera: Psychodidae) fauna of the State of Rondônia, Western Amazônia, Brazil: the importance of Psychdopygus davisi as a vector of zoonotic cutaneous leishmaniasis. Mem Inst Oswaldo Cruz. 2003 Sep;98(6):751-5. Doi: 10.1590/S0074-02762003000600007 [Link] [ Links ]

22 Souza A, Ishikawa E, Braga R, Silveira F, Lainson R, Shaw J. Psychodopygus complexus, a new vector of Leishmania braziliensis to humans in Pará State, Brazil. Trans R Soc Trop Med Hyg. 1996 Mar-Apr;90(2):112-4. Doi: 10.1016/S0035-9203(96)90103-0 [Link] [ Links ]

23 Silveira FT, Ishikawa EAY, Souza AAA, Lainson R. An outbreak of cutaneous leishmaniasis among soldiers in Belém, Pará State, Brazil, caused by Leishmania (Viannia) lindenbergi n. sp.: a new leishmanial parasite of man in the Amazon region. Parasite. 2002 Mar;9(1):43-50. Doi: 10.1051/parasite/200209143 [Link] [ Links ]

24 Arias JR, Freitas RA. Sobre os vetores de leishmaniose cutânea na Amazônia central do Brasil. 2: incidência de flagelados em flebótomos selváticos. Acta Amaz. 1978;8(3):387-96. [Link] [ Links ]

25 Shaw JJ, Lainson R. Leishmaniasis in Brazil: II. Observations on enzootic rodent leishmaniasis in the lower amazon region - the feeding habits of the vector, Lutzomyia flaviscutellata in reference to man, rodents and other animals. Trans R Soc Trop Med Hyg. 1968 Feb;62(3):396-405. Doi: 10.1016/0035-9203(68)90091-6 [Link] [ Links ]

26 Guerra JAO, Prestes SR, Silveira H, Coelho LIARC, Gama P, Moura A, et al. Mucosal leishmaniasis caused by Leishmania (Viannia) braziliensis and Leishmania (Viannia) guyanensis in the Brazilian Amazon. PLoS Negl Trop Dis. 2011 Mar;5(3):e980. Doi: 10.1371/journal.pntd.0000980 [Link] [ Links ]

27 Almeida PS, Minzão ER, Minzão LD, Silva SR, Ferreira AD, Faccenda O, et al. Aspectos ecológicos de flebotomíneos (Diptera: Psychodidae) em área urbana do município de Ponta Porã, Estado de Mato Grosso do Sul. Rev Soc Bras Med Trop. 2010 nov-dez;43(6):723-7. Doi: 10.1590/S0037-86822010000600025 [Link] [ Links ]

28 Sathler D, Monte-Mór RL, Carvalho JAM. As redes para além dos rios: urbanização e desequilíbrios na Amazônia brasileira. Nova Econ. 2009 jan-abr;19(1):11-39. Doi: 10.1590/S0103-63512009000100002 [Link] [ Links ]

29 Carvalho SMS, Santos PRB, Lanza H, Brandão-Filho SP Diversidade de flebotomíneos no Município de Ilhéus, Bahia. Epidemiol Serv Saude. 2010 set;19(3):239-44. Doi: 10.5123/S1679-49742010000300006 [Link] [ Links ]

30 Morris EK, Caruso T, Buscot F, Fischer M, Hancock C, Maier TS, et al. Choosing and using diversity indices: insights for ecological applications from the German Biodiversity Exploratories. Ecol Evol. 2014;4(18):3514-24. Doi: 10.1002/ece3.1155 [Link] [ Links ]

31 Magurran AE. Medindo a diversidade biológica. Curitiba: UFPR; 2011. [ Links ]

32 Cruz MFR, Galati EAB, Cruz CFR. Ecological aspects of the sandfly fauna (Diptera, Psychodidae) in an American cutaneous leishmaniasis endemic area under the influence of hydroelectric plants in Paranapanema river, State of Paraná, Brazil. Rev Soc Bras Med Trop. 2012 Jul-Aug;45(4):430-6. Doi: 10.1590/S0037-86822012000400003 [Link] [ Links ]

33 Tilman D, Lehman CL, Bristow CE. Diversity-stability relationships: statistical inevitability or ecological consequence? Am Nat. 1998 Mar;151(3):277-82. [Link] [ Links ]

34 Ready PD, Lainson R, Shaw JJ. Habitat and seasonality of Psychodopygus wellcomei help incriminate it as a vector of Leishmania braziliensis in Amazônia and Northeast Brazil. Trans R Soc Trop Hyg. 1984 Feb;78(4):543-4. Doi: 10.1016/0035-9203(84)90079-8 [Link] [ Links ]

35 Garcez LM, Soares DC, Chagas AP, Souza GCR, Miranda JFC, Fraiha H, et al. Etiology of cutaneous leishmaniasis and anthropophilic vectors in Juruti, Pará State, Brazil. Cad Saude Publica. 2009 Oct;25(10):2291-5. Doi: 10.1590/S0102-311X2009001000019 [Link] [ Links ]

36 Fraiha H, Shaw JJ, Lainson R. Phlebotominae brasileiros - II. Psychodopygus wellcomei, nova espécie antropófila de flebótomo do grupo Squamiventris, do sul do Estado do Pará, Brasil (Diptera, Psychodidae). Mem Inst Oswaldo Cruz. 1971;69(3):489-500. Doi 10.1590/S0074-02761971000300007 [Link] [ Links ]

37 Ward RD, Shaw JJ, Lainson R, Fraiha H. Leishmaniasis in Brazil: VIII. Observations on the phlebotomine fauna of an area highly endemic for cutaneous leishmaniasis, in the Serra dos Carajas, Pará State. Trans R Soc Trop Med Hyg. 1973;67(2):174-83. Doi: 10.1016/0035-9203(73)90142-9 [Link] [ Links ]

38 Ready PD, Lainson R, Shaw JJ. Leishmaniasis in Brazil: XX. Prevalence of "enzootic rodent leishmaniasis" (Leishmania mexicana amazonensis), and apparent absence of "pian bois" (Le. braziliensis guyanensis), in plantations of introduced tree species and in other non-climax forests in eastern Amazônia. Trans R Soc Trop Med Hyg. 1983;77(6): 775-85. Doi: 10.1016/0035-9203(83)90288-2 [Link] [ Links ]

39 Barbosa MGV, Fé NF, Marcião AHR, Silva APT, Monteiro WM, Guerra JAO. Fauna de flebotomíneos (Diptera: Psychodidae) em um foco de leishmaniose tegumentar americana na área periurbana de Manaus, Estado do Amazonas. Rev Soc Bras Med Trop. 2008 set-out;41(5):485-91. Doi: 10.1590/S0037-86822008000500010 [Link] [ Links ]

40 Feitosa MAC, Julião GR, Costa MDP, Belém B, Pessoa FAC. Diversity of sand flies in domiciliary environment of Santarém, state of Pará, Brazil: species composition and abundance patterns in rural and urban areas. Acta Amaz. 2012;42(4): 507-14. Doi: 10.1590/S0044-59672012000400008 [Link] [ Links ]

41 Fouque F, Gaborit P, Issaly J, Carinci R, Gantier J-C, Ravel C, et al. Phlebotomine sand flies (Diptera: Psychodidae) associated with changing patterns in the transmission of the human cutaneous leishmaniasis in French Guiana. Mem Inst Oswaldo Cruz. 2007 Feb;102(1):35-40. Doi: 10.1590/S0074-02762007000100005 [Link] [ Links ]

42 Boité MC, Santos BN, Soares DC, Mota MSS, Garcez LM, Cupolillo E. Multilocus analysis supports the existence of inter-species recombination in an endemic area of cutaneous leishmaniasis where Leishmania species are sympatric. In: 18º Congresso Internacional de Medicina Tropical e Malária; 48º Congresso da Sociedade Brasileira de Medicina Tropical; 2012 set 23-27; Rio de Janeiro, Brasil. Rio de Janeiro: Sociedade Brasileira Medicina Tropical; 2012. [ Links ]

43 Nolder D, Roncal N, Davies CR, Llanos-Cuentas A, Miles MA. Multiple hybrid genotypes of Leishmania (Viannia) in a focus of mucocutaneous leishmaniasis. Am J Trop Med Hyg. 2007 Mar;76(3):573-8. [Link] [ Links ]

44 Carvalho EM. Parasite, vectors and reservoirs as determinants of tegumentary leishmaniasis. Rev Soc Bras Med Trop. 2012 Jul-Aug;45(4): 423-4. Doi: 10.1590/S0037-86822012000400001 [Link] [ Links ]

45 Soares DC, Martins NVN, Silva AMP, Silva FLD, Mota MSS, Quiroga MM, et al. Diversity of dermotropic Leishmania species in Santarém, Brazil. In: 18º Congresso Internacional de Medicina Tropical e Malária; 48º Congresso da Sociedade Brasileira de Medicina Tropical; 2012 set 23-27; Rio de Janeiro, Brasil. Rio de Janeiro: Sociedade Brasileira Medicina Tropical ; 2012. [ Links ]

46 Feitosa MAC, Castellón EG. Flebotomíneos (Diptera: Psychodidae) na periferia de Santarém (PA). Estratificação horizontal e fatores agravantes para transmissão domiciliar de leishmanioses. Rev Colombiana Cienc Anim. 2009;1(2): 222-39. [Link] [ Links ]

47 Almeida AS, Medronho RA, Werneck GL. Identification of risk areas for visceral leishmaniasis in Teresina, Piaui State, Brazil. Am J Trop Med Hyg. 2011 May;84(5):681-7. Doi: 10.4269/ajtmh.2011.10-0325 [Link] [ Links ]

48 Marzochi MCA, Marzochi KBF. Tegumentary and visceral leishmaniases in Brazil - emerging anthropozoonosis and possibilities for their control. Cad Saude Publica. 1994 Jul;10 Suppl 2:359-75. Doi: 10.1590/S0102-311X1994000800014 [Link] [ Links ]

49 Ryan L, Silveira FT, Lainson R, Shaw JJ. Leishmanial infections in Lutzomyia longipalpis and Lu. antunesi (Diptera: Psychodidae) on the island of Marajó, Pará State, Brazil. Trans R Soc Trop Med Hyg. 1984;78(4):547-8. Doi: 10.1016/0035-9203(84)90081-6 [Link] [ Links ]

50 Rebêlo JMM. Freqüência horária e sazonalidade de Lutzomyia longipalpis (Diptera: Psychodidae: Phlebotominae) na Ilha de São Luís, Maranhão, Brasil. Cad Saude Publica. 2001 jan-fev;17(1):221-7. Doi: 10.1590/S0102-311X2001000100023 [Link] [ Links ]

51 Quinnell RJ, Dye C. Correlates of the peridomestic abundance of Lutzomyia longipalpis (Diptera: Psychodidae) in Amazonian Brazil. Med Vet Entomol. 1994 Jul;8(3):219-24. Doi: 10.1111/j.1365-2915.1994.tb00502.x [Link] [ Links ]

National Council for Scientific and Technological Development (CNPq), Fundação Amazônia Paraense de Amparo à Pesquisa and Coordination for the Improvement of Higher Education Personnel (CAPES).

Received: June 02, 2016; Accepted: September 15, 2016

Correspondence / Correspondência: Lourdes Maria Garcez. Instituto Evandro Chagas, Seção de Parasitologia, Laboratório de Epidemiologia e Imunologia Aplicada às Leishamanioses, Rodovia BR-316 km 7, s/n. Bairro: Levilândia - CEP: 67030-000 - Ananindeua, Pará, Brazil - Phone #: +55 (91) 3214-2152. E-mail: lourdesgarcez@iec.pa.gov.br

R. Gonçalves participated in preparing the research proposal, coordinated the sample collection and entomological identification, performed ecological analysis and collaborated with the drafting of the manuscript with important intellectual contribution.

D. C. Soares, W. S. Santos and A. P. Chagas collaborated with analysis and interpretation of data with important intellectual contribution and critical revision of the manuscript.

R. Guimarães performed the Kernel analysis and collaborated with analysis and interpretation of data with important intellectual contribution and critical revision of this manuscript.

G. C. Souza performed the entomological captures and identification, collaborated with analysis and interpretation of data with important intellectual contribution and critically revised this manuscript.

L. M. Garcez participated in preparing the research proposal, methodological design, fundraising, coordination, analyses of the results, student supervision and drafting of the manuscript with important intellectual contribution and critical revision.

The authors declare that there is no competing interest concerning to political and/or financial relationships with other people or organisations that could inappropriately influence this work.

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