Species Diversity and Flagellate Infections in the Sand Fly Fauna near Porto Grande, State of Amapá, Brazil (Diptera: Psychodidae. Kinetoplastida: Trypanosomatidae)

Abstract

Key words: Phlebotominae -diversity -distribution -Leishmania -salivary glands -Amapá -BrazilThe phlebotomine sand fly fauna of the Brazilian State of Amapá has been poorly studied in comparison with neighbouring areas of the State of Pará and French Guyana (Brazil et al. 2000). Most of the sand fly distribution maps in Young and Duncan (1994) are blank for this part of Brazil, even though cutaneous leishmaniasis has long been recognized as an important public health problem in the former Federal Territory (Lainson & Shaw 1973). In this field report the faunistics of sand fly samples collected mainly along the Perimetral Norte highway (BR-210) are analyzed. The eastern end of this uncompleted highway runs west from the town of Porto Grande through lowland rainforest in the lower Amapari basin. According to Backus et al. (1991) this part of the highway lies in area 59 (Araguari) which they describe as the nucleus of the Oyapock centre of endemism.Although invasion of the vectors' salivary glands by promastigotes is not currently thought to be a necessary stage in the transmission of Leishmania by bite, the phenomenon has been reported in both naturally infected (Arias & Freitas 1978, Naiff et al. 1991) and experimentally infected sand flies (Killick-Kendrick et al. 1996). There have hitherto been so few of such observations that some workers may be reluctant to accept that invasion of the salivary glands is a normal part of the life cycle of Leishmania. The presence of large numbers of infected Lutzomyia umbratilis concentrated on the bases of trees in forest north of the Amazon River provides an opportunity to reexamine this question. In the present report we show that the prevalence of natural infection of Lutzomyia salivary glands by promastigotes, presumably of Leishmania, may be much higher than was previously suspected. MATERIALS AND METHODSStudy areas -Most of the material was collected in primary terra-firme lowland rainforest at km 7, km 17 and km 57 (from the town of Porto Grande) along the BR-210 highway. The site at km 7 is 1 km north of the highway at Recanto Ecológico Sonho Meu, where collections were made along a tourist trail rising into the forest. At km 17 traps were set in the forest on high ground near the edge of the highway. The site at km 57 is Assentamento Munguba, near 00 o 43'N 051 o 53'W; about 5 km south of the BR-210. This is a community of 28 households participating in a government sponsored (Incra) settlement programme. The vegetation was still relatively undisturbed apart from the access road itself and a clearing corresponding to the main villa. Leishmania isolates IM-4677, IM-4678 and IM-4679 cultured from skin lesions from three of the settlers are compatible with Le. guyanensis by morphology and behaviour in hamsters.The final site (BR-156: km 16) is 16 km southeast of Porto Grande on the highway to Macapá, about 300 m from the edge of the road. Light traps were set in a mature stand of Caribbean pine (Pinus caribeae var. hondurensis) part of an extensive monocultural plantati...

Ecology of the Leishmania Species in the Guianan Ecoregion Complex

“…umbratilis was the most common species found on tree trunks, 182,183 as well as in Amapá on bases of trees. 65 Lutzomyia umbratilis is found at all levels of vertical stratification from 1 to 20 meters above ground level. 62 It is present at ground level year round with important seasonal and interannual fluctuations.…”

“…Leptomonad promastigotes are found in the anterior midgut and multiply there before spreading to the buccal structures. 64,65 They are the precursors of the mammal-infective metacyclic promastigotes. Leptomonad forms also produce promastigote secretory gel, a substance that plays a key role in transmission by forming a physical obstruction in the gut, forcing the sand fly to regurgitate metacyclic promastigotes during blood feeding.…”

“…anduzei in French Guiana 144 and in Suriname. 175 It has been isolated from this vector in the Brazilian states of Amazonas, Amapá, Pará, and Rondônia 31,65,141,149,[176][177][178][179][180] and in French Guiana. 46,60,181,182 In a primary rain forest of French Guiana, Lu.…”

Primeiro registro de Evandromyia (Aldamyia) sericea (Floch & Abonnenc) (Diptera, Psychodidae, Phlebotominae) para a região Sudeste do Brasil

“…Aguiar & Medeiros (2003) verificaram que esse flebotomíneo apresenta hábitos silvestres, sendo encontrado somente em ambientes florestais. A espécie ainda não foi associada à transmissão de Leishmania, não havendo registro de infecção natural por formas flageladas (Freitas et al 2002).…”

“…sericea para a região. Soma-se a isso o fato de que em diversos estudos a quantidade de exemplares dessa espécie é muito baixa quando comparada à de outros flebotomíneos silvestres, mesmo na região Amazônica, onde é coletada com freqüência (Freitas et al 2002). Isso também justifica o registro tardio da espécie na região Sudeste.…”