Phlebotomine sand flies in a focus of dermal leishmaniasis in the eastern region of the Brazilian State of Santa Catarina-preliminary results ( Diptera : Psychodidae )

Due to the occurrence of cases of dermal leishmaniasis in the Municipality of Piçarras, in the East of the Brazilian State of Santa Catarina, collections of Phlebotomine sand flies by the use of CDC-like light traps were developed near the houses of the patients. Three species (Lutzomyia neivai, Lu. fischeri and Lu. ayrozai) were collected. Lu. neivai was predominant near the houses, and Lu. ayrozai was collected in a secondary forest in a nearby municipality (Navegantes). The novelty of this focus, the most southern one in the East of Brazil, underscores the need for more complete studies on the sand fly fauna. Key-words: Phlebotominae. Dermal leishmaniasis. Santa Catarina. Brazil. Epidemiology. RESUMO Devido à ocorrência de casos de leishmaniose tegumentar no Município de Piçarras, na parte leste do Estado de Santa Catarina, Brasil, foram realizadas coletas com armadilhas luminosas tipo CDC nas proximidades de casas de pacientes. Três espécies (Lutzomyia neivai, Lu. fischeri e Lu. ayrozai) estavam representadas nas coletas. Lu. neivai foi predominante e Lu. ayrozai foi coletada em mata secundária. O ineditismo deste foco, o mais meridional no leste do Brasil, indica serem necessários estudos mais detalhados da fauna de flebotomíneos na área. Palavras-chaves: Phlebotominae. Leishmaniose tegumentar. Santa Catarina. Brasil. Epidemiologia. Biológicas da Universidade Federal de Santa Catarina, Florianópolis, SC. 2. Coordenação da Fundação Nacional de Saúde/NENSC, Florianópolis, SC. 3. Fundação Nacional de Saúde, Joinvile, SC. Adress to: Dr. Carlos Brisola Marcondes. DMP/CCB/UFSC . Campus Universitário Trindade Caixa Postal 476, 88040-900 Florianópolis, SC. e-mail: cbrisola@mbox1.ufsc.br Recebido para publicação em 7/5/2004 Aceito em 8/4/2005 Dermal leishmaniasis was previously referred in the State of Santa Catarina, caused by Leishmania braziliensis and L. amazonensis (L. is utilized here as an abbreviation of Leishmania, to differentiate Lu. from Lutzomyia). This disease has been reported in the West of this State, and some human cases of dermal leishmaniasis have been observed in the Municipality of Piçarras, in the eastern coast of the state. A survey by Montenegro reaction indicated high prevalence of infection (12.1%) in humans and in dogs (17.1%) in a locality in Piçarras (Nossa Senhora da Conceição), showing active transmission of parasites. The fauna of Phlebotomine sand flies in Santa Catarina is largely unknown. Lu. neivai was referred . Twelve species were listed for the state. Although the fauna in the western foci of Santa Catarina has been studied, nothing is known about the insects of the newly detected focus in the coastal region. The only study in the eastern region of the southern states was developed in a primary forest in Morretes (Paraná), besides some studies a long time ago in the East of Rio Grande do Sul, in which Lu. neivai (as Phlebotomus intermedius) and Lu. fischeri were reported . Collections of insects were developed in the focus of dermal leishmaniasis situated at the Municipality of Piçarras, mostly near the houses where cases of dermal leishmaniasis had been reported, and in a secondary forest in the Municipality of Navegantes.

Dermal leishmaniasis was previously referred in the State of Santa Catarina 15 , caused by Leishmania braziliensis and L. amazonensis 6 (L. is utilized here as an abbreviation of Leishmania, to differentiate Lu. from Lutzomyia).This disease has been reported in the West of this State, and some human cases of dermal leishmaniasis have been observed in the Municipality of Piçarras, in the eastern coast of the state 18 .A survey by Montenegro reaction indicated high prevalence of infection (12.1%) in humans and in dogs (17.1%) in a locality in Piçarras (Nossa Senhora da Conceição), showing active transmission of parasites 19 .
The fauna of Phlebotomine sand flies in Santa Catarina is largely unknown.Lu. neivai was referred 12 16 .Twelve species were listed for the state 1 .Although the fauna in the western foci of Santa Catarina has been studied, nothing is known about the insects of the newly detected focus in the coastal region.The only study in the eastern region of the southern states was developed in a primary forest in Morretes (Paraná) 12 , besides some studies a long time ago in the East of Rio Grande do Sul, in which Lu. neivai (as Phlebotomus intermedius) and Lu.fischeri were reported 3 14 .
Collections of insects were developed in the focus of dermal leishmaniasis situated at the Municipality of Piçarras, mostly near the houses where cases of dermal leishmaniasis had been reported, and in a secondary forest in the Municipality of Navegantes.
Collections were taken in March and April 2000 in the locality of Nossa Senhora da Conceição (26º45'50" S 48º41'19" W, 49m a. s. l.), in the Municipality of Piçarras.This locality is suburban, and all houses are situated at a maximum of 200m from a main street, which continues in a 3km road and starts and ends on the BR-101 highway.The distance between BR-101 and the coast is about 600m.There is a little secondary vegetation, including some banana and other fruit trees; residual secondary forests are very small and far from houses.Some collections were also developed in an area of secondary vegetation (Escalvado) in the nearby municipality of Navegantes (26 o 53'56" S 48 o 39'15" W).Six collections were done using Shannon traps 17 with a lamp, and CDClike miniature light traps, with 6.6 V rechargeable batteries 13 20 were utilized, in 30 trap/nights.
Collections with Shannon trap were negative.Sandflies collected by miniature light traps were identified as belonging to one of three species (Table 1).Lu. neivai was the predominant species, and Lu.ayrozai was collected only in the secondary forest.Since this is a preliminary study, the mean quantities per collection, which were very low, are not given.
Lu. neivai, although not fulfilling all the requirements to be considered a vector of Leishmania to man 7 , has been strongly suspected as a vector of these protozoa.In the Ribeira Valley, at the São Paulo State, where both species of the Lu.intermedia complex occur 11 , Lu. intermedia s. l. has been incriminated as a vector of L. braziliensis near the domiciles 4 .Lu. neivai is also the predominant species in the houses in the North of Paraná State, and some modifications have been proposed to reduce the risk for the population 21 .In the present preliminary study, Lu. neivai is the predominant species near the houses, where the transmission of the parasites is probably occurring.The vegetation in the region was very modified, and this modification probably facilitated the adaptation of this sand fly to the areas near the houses.
Lu. ayrozai has been strongly suspected as a vector of L. naiffi in the Amazon region 8 .Its anthropophily is low in Colombia 15 , but several insects of this species were collected biting man in the Ribeira Valley 5 , and this is the only species that sometimes has bitten man in daylight in a secondary forest in the Island of Santa Catarina (CB Marcondes: unpublished observations).This may indicate some regional variation of the species.Its role in the transmission of L. braziliensis in the region may not be discarded.However, since there is no evidence of association of cases with the forest, Lu. ayrozai has probably no direct role in the infection of humans.Several species were present in collections from primary forest in Morretes, 300km to the North 11 , but that study was much more extensive, and in a more humid and preserved area, which is probably similar to the one occurring originally in Piçarras.

Lu. migonei
was not yet found on this region, but since it is a common species in Florianópolis (CB Marcondes: unpublished results) and Morretes 11 , it will certainly be obtained in future more extensive studies.However, its absence in this study may indicate that it is a rare species in Piçarras.
Transmission of Leishmania to man depends on several factors, and there are several kinds of cycle in the different areas 9 .Other studies, preferably including the extensive collection of sand flies and the analysis of its natural infection rate, must be developed in the area.
The alleged presence of Lu. intermedia in the State of Santa Catarina 1 is probably based on the non-acceptance of the differentiation between the species of the Lu.intermedia complex 2 11 or in reports published before this proposal of resurrection of Lu. neivai 3 14 16 .Since no justification has been published for this non-acceptance, it is better to consider the species in the southern Brazilian states and in other countries as Lu.neivai.No study in this region have obtained Lu. intermedia s.s., as defined previously 2 10 .
tree, near a chicken roost-extreme of road 0 ; F-females.