Jorge Luiz Pinto Moraes

Diagnóstico molecular da taxa de infecção natural de flebotomíneos (Psychodidae, Lutzomyia) por Leishmania sp na Amazônia maranhense

The natural infection rate due to Leishmania was studied in three different sandfly species using the polymerase chain reaction technique. Leishmania specific primers were designed to examine whether sandfly pools were infected. In total 1,100 female sandflies separated into pools of 10 individuals, consisting of 50 pools of Lutzomyia whitmani, 43 of Lutzomyia triacantha and 17 of Lutzomyia choti, were analyzed. Among all the pools examined, four pools of Lutzomyia whitmani were positive, but none of the pools of the other two species were infected. Thus, a total infection rate of 0.4% was established in this study. A similar infection rate was found in previous studies, suggesting that Lutzomyia whitmani transmits Leishmania to mammals in Buriticupu, Maranhão.

Preferência alimentar sanguínea de Lutzomyia whitmani (Diptera, Psychodidae) em área de transmissão de leishmaniose cutânea americana, no Estado do Maranhão, Brasil

The aim of this study was to determine the sources of blood meals for females of Lutzomyia whitmani, a phlebotomine species incriminated as the main vector for American cutaneous leishmaniasis in Maranhão. For this, 70 Lutzomyia whitmani females were collected in the municipality of Axixá, an area with one of the greatest numbers of cases of American cutaneous leishmaniasis in humans in Maranhão. They were analyzed using the precipitin technique. Ninety percent of the specimens showed a reaction to some type of antiserum positive immune reaction, among which 73% presented single reactions, with predominance for chicken blood (22%), rodent blood (14.3%) and human blood (12.7%). Among the double reactions, the predominant combinations were chicken/human (6.3%), chicken/opossum (4.8%), ox/human (3.2%) and opossum/human (3.2%). Thus, we conclude that humans and domestic and synanthropic animals are blood meal sources for Lutzomyia whitmani and may play an important role in the transmission cycle for American cutaneous leishmaniasis, thus explaining the cases of this disease in Axixá.

The fauna of phlebotomines (Diptera, Psychodidae) in different phytogeographic regions of the state of Maranhão, Brazil

Phlebotomine specimens were captured in domiciliary and forest environments in 47 municipalities between 1982 and 2005 with the aid of CDC light traps. A total of 91 species were found, of which four belonged to genus Brumptomyia and 87 to genus Lutzomyia, distributed among the following subgenera: Evandromyia (6), Lutzomyia (5), Micropygomyia (2), Nyssomyia (9), Pintomyia (2), Pressatia (3), Psathyromyia (6), Psychodopygus (14), Sciopemyia (4), Trichophoromyia (2), Viannamyia (2); species groups: Aragaoi (2), Baityi (1), Dreisbachi (1), Migonei (12), Oswaldoi (8), Pilosa (1), Saulensis (2), Verrucarum (4) and ungrouped (1). Species diversity was greatest in areas where there was dense evergreen seasonal forest (52 species), ombrophilous forest (31) and meridional cerrados (23) and lowest in areas with mixed forest (forest with babassu palms, cerrado and caatinga). The greatest similarity index was observed for restinga and open evergreen seasonal forest (J=0.48). Dense evergreen seasonal forest had greatest similarity with ombrophilous forest (J=0.38). The phlebotomine fauna was species rich and unevenly distributed in Maranhao, reflecting the phytogeographical complexity of the state, which is a result of the great variety of ecosystems and climate zones.

Occurrence of sand flies (Diptera, Psychodidae) in leishmaniasis foci in an ecotourism area around the Lençóis Maranhenses National Park, Brazil

The distribution and relative abundance of sand fly species were studied in the municipality of Barreirinhas, Maranhão State, Brazil, around the Lençóis Maranhenses National Park, from January to June 2005, August 2004, July 2005, and September/2008. A total of 6,658 specimens were captured. The most frequent species were Lutzomyia whitmani (46.6%), L. longipalpis (29.9%), L. evandroi (17.1%), and L. lenti (4.8%), while L. termitophila, L. flaviscutellata, L. migonei, L. infraspinosa, L. sordellii, L. wellcomei, L. antunesi, and L. trinidadensis represented 1.6%. The presence of Leishmania vector species explains the high detection rate for tegumentary leishmaniasis in 2000 (308.2), 2001 (310.9), 2002 (338.2), and 2005 (313.6) and active foci of human visceral leishmaniasis in the municipality of Barreirinhas.

Distribuição das espécies do gênero Anopheles (Diptera, Culicidae) no Estado do Maranhão, Brasil

We studied the distribution and diversity of Anopheles species in 123 counties (municipalities) in the State of Maranhão, Brazil. The basic method consisted of capturing female specimens inside and around human dwellings between 6 PM and 6 AM from January 1992 to December 2001. A total of 84,467 specimens belonging to 24 species were captured, with a predominance of A. triannulatus sensu lato (20,788), A. darlingi (19,083), A. nuneztovari (16,884), A. albitarsis s.l. (14,352), A. aquasalis (8.202), and A. evansae (2,885). The other 18 species together accounted for only 2.7% of the total. The species found in the most counties were A. albitarsis s.l. (109 counties), A. triannulatus s.l. (106), A. nuneztovari (93), A. darlingi (87), and A. evansae (64). The richness and wide distribution of anopheline species in Maranhão agree with the States geographic position among Brazils macro-regions, resulting in a mixed fauna with representative elements from these regions.

Preferência alimentar sanguínea de flebotomíneos da Amazônia do Maranhão, Brasil

The objective of this study was to determine the blood feeding sources for sand flies based on the precipitin test in Buriticupu, Amazon Region, Maranhão State, Brazil, from July 2002 to June 2004. Single (87.6%) and double (8%) reactions and non-reactive samples (4.4%) were found. The presence of sand flies fed on human blood (6.7%) and blood of animals that are possible peridomiciliary Leishmania reservoirs helps explain the reporting of autochthonous tegumentary leishmaniasis cases in Buriticupu.

Sand Flies (Diptera: Psychodidae) in a Cerrado Area of the Maranhão State, Brazil

The present paper aims to increase the knowledge on the sand fly fauna in the cerrado areas of Maranhão state in urban, rural and forest environments. The research was carried out from October 2007 to September 2008, between 18:00h and 06:00h, in the municipality of Chapadinha, northeast Maranhão. For insect sampling, CDC light traps were set up in peridomicile and domicile areas of urban and rural zones as well as in Cerrado and Gallery forests. The total of 1,401 specimens belonging to 17 species were sampled, all within the genus Lutzomyia. Lutzomyia longipalpis (Lutz & Neiva) (52.5%), Lu. evandroi (Costa Lima & Antunes) (18.3%), Lu. whitmani (Antunes & Coutinho) (12.1%), Lu. lenti (Mangabeira) (4.7%) and Lu. termitophila (Martins, Falcão & Silva) (4.0%) were the most frequently collected. From an epidemiological viewpoint, five from all of the collected species are vectors of leishmaniasis: Lu. longipalpis, Lu. whitmani, Lu. flaviscutellata (Mangabeira), Lu. gomezi (Nitzulescu) and Lu. chagasi (Costa Lima). Lutzomyia chagasi was registered for the first time in Maranhão state and Lu. saulensis (Floch & Abonnenc), Lu. monstruosa (Floch & Abonnenc) and Lu. gomezi were found for the first time in the eastern part of the state, since they had been reported only in the Amazonian region of Maranhão. Regarding to the studied environments, the urban chicken house had the highest number of specimens collected (801), while the Gallery Forest was the most diverse (15 species). This study demonstrates that the northeast cerrado exhibits a mixed sand fly fauna characterized by an extremely important species vectors assortment involved in the epidemiological cycle of leishmaniasis in Maranhão state.

Distribuição de Lutzomyia whitmani em fitorregiões do estado do Maranhão, Brasil

The study had the aim of characterizing the geographical distribution of Lutzomyia whitmani s.l. in the state of Maranhão, Northeastern Brazil. Between 1992 and 2005, 9,600 specimens (65.1% males and 34.9% females) were caught in the rural and urban zones of 35 municipalities in regions consisting of forests, savanna and mixed vegetation with coconut plantations, sandbanks and heath. Greater abundance was observed in areas surrounding dwellings (91.6%) than inside the dwellings (8.4%). The presence of the vector in different phytoregions and in rural and urban areas favors the transmission of tegumentary leishmaniasis in these environments. This taxon may constitute a complex of species in Maranhão, which can be confirmed by molecular biology studies.O estudo teve por objetivo caracterizar a distribuicao geografica de Lutzomyia whitmani s.l. no estado do Maranhao. De 1992 a 2005, foram capturados 9.600 especimes (machos: 65,1% e femeas: 34,9%) nas zonas rurais e urbanas de 35 municipios situados em areas de floresta, cerrado e vegetacao mista com cocal, restinga e caatinga. A abundância foi maior no peridomicilio (91,6%) do que no intradomicilio (8,4%). A ocorrencia do vetor em diferentes fitorregioes e nas areas rurais e urbanas favorece a transmissao da leishmaniose tegumentar nesses ambientes. E possivel que esse taxon constitua um complexo de especies no Maranhao, o que podera ser confirmado mediante estudos de biologia molecular.

Experimental Infection of Lutzomyia (Nyssomyia) whitmani (Diptera: Psychodidae: Phlebotominae) With Leishmania (Viannia) braziliensis and Leishmania (L.) amazonensis, Etiological Agents of American Tugumentary Leishmaniasis.

Abstract Leishmania (L.) amazonensis (Lainson & Shaw, 1972) and Leishmania (Viannia) braziliensis (Vianna, 1911) are the principal causative agents of American tegumentary leishmaniasis (ATL) in Brazil. L. amazonensis also causes diffuse cutaneous leishmaniasis (DCL) vectored principally by Lutzomyia flaviscutellata and secondarily by Lutzomyia whitmani (Antunes & Coutinho, 1939). The latter is the most common phlebotomine in the state of Maranhão, and it is the focal species for potential ATL transmission. For this reason, we tested the ability of L. whitmani to become infected with Lutzomyia parasites. Phlebotomines were derived from a colony maintained in the laboratorial conditions. The first generation, uninfected females were offered a bloodmeal with mice infected with the strains of both parasites. We found that L. whitmani can become infected with both parasite species, with infection rates of 65.2% (L. braziliensis) and 47.4% (L. amazonensis). We conclude that in Maranhão, L. whitmani is likely an important vector in the transmission of ATL and may function as a vector of DCL. This possibility should be further investigated.

Distribution of Lutzomyia whitmani in phytoregions of the state of Maranhão, Northeastern Brazil

The study had the aim of characterizing the geographical distribution of Lutzomyia whitmani s.l. in the state of Maranhão, Northeastern Brazil. Between 1992 and 2005, 9,600 specimens (65.1% males and 34.9% females) were caught in the rural and urban zones of 35 municipalities in regions consisting of forests, savanna and mixed vegetation with coconut plantations, sandbanks and heath. Greater abundance was observed in areas surrounding dwellings (91.6%) than inside the dwellings (8.4%). The presence of the vector in different phytoregions and in rural and urban areas favors the transmission of tegumentary leishmaniasis in these environments. This taxon may constitute a complex of species in Maranhão, which can be confirmed by molecular biology studies.O estudo teve por objetivo caracterizar a distribuicao geografica de Lutzomyia whitmani s.l. no estado do Maranhao. De 1992 a 2005, foram capturados 9.600 especimes (machos: 65,1% e femeas: 34,9%) nas zonas rurais e urbanas de 35 municipios situados em areas de floresta, cerrado e vegetacao mista com cocal, restinga e caatinga. A abundância foi maior no peridomicilio (91,6%) do que no intradomicilio (8,4%). A ocorrencia do vetor em diferentes fitorregioes e nas areas rurais e urbanas favorece a transmissao da leishmaniose tegumentar nesses ambientes. E possivel que esse taxon constitua um complexo de especies no Maranhao, o que podera ser confirmado mediante estudos de biologia molecular.