Sandflies (Diptera, Psychodidae) from an endemic leishmaniasis area in the cerrado region of the State of Maranh?o, Brazil]

This article presents a list of ten sandfly species from the genus Lutzomyia Fran?a, 1924 found in the counties of Aldeias Altas, Capinzal do Norte, Caxias, Codó, Coelho Neto, Timbiras, Timon and Tuntum in northeastern Maranh?o, Brazil. Presence of sandflies was associated with cases of visceral and cutaneous leishmaniasis. Some 377 specimens were captured indoors with CDC light traps and 1491 specimens in the peridomicile. The species were: Lutzomyia cortelezii, Lutzomyia evandroi, Lutzomyia goiana, Lutzomyia intermedia, Lutzomyia lenti, Lutzomyia longipalpis, Lutzomyia longipennis, Lutzomyia squamiventris, Lutzomyia termitophila and Lutzomyia whitmani. The most abundant species was L. longipalpis (67. 4% and 70.2%) followed by L. whitmani (31.0% and 24.7%). L. longipalpis was captured both indoors and outdoors in all the months studied.     

Sand flies in Timóteo, Minas Gerais, Brazil

Sporadic cases of tegumentary leishmaniasis have occurred in Timóteo, Minas Gerais State, basically among the rural population. In order to study the region's sand fly population, New Jersey light traps were set in seven different neighborhoods. Specimens were gathered from June through October 1994, December 1994, and January through March 1995, with a total of 3,240 hours per trap. A total of 4,396 sand flies were captured, distributed among two genera and twenty species: Brumptomyia cunhai, Brumptomyia nitzulescui, Lutzomyia (Nyssomyia) whitmani, Lutzomyia (Nyssomyia) intermedia, Lutzomyia quinquefer, Lutzomyia lenti, Lutzomyia (Pintomyia) fischeri, Lutzomyia migonei, Lutzomyia sallesi, Lutzomyia termitophila, Lutzomyia aragaoi, Lutzomyia borgmeieri, Lutzomyia (Psathyromyia) lutziana, Lutzomyia (Sciopemyia) sordellii, Lutzomyia (Pintomyia) pessoai, Lutzomyia (Trichopygomyia) longispina, Lutzomyia misionensis, Lutzomyia (Psychodopygus) davisi, Lutzomyia lanei, Lutzomyia (Pressatia) sp. The species L. (N.) whitmani was the most frequent, with 52.12% of the total, followed by L. (N.) intermedia with 34.10%, and both may be involved in transmission of tegumentary leishmaniasis in the region.     

Natural infection of Lutzomyia longipalpis by Leishmania sp. in Teresina, Piauí State, Brazil

In Brazil, control of the vector Lutzomyia longipalpis is one of the main strategies used to limit the expansion of American visceral leishmaniasis. However, studies on the ecology of this sand fly are rare, especially regarding its natural infection with species of Leishmania. A study of the natural infection of Lu. longipalpis by Leishmania sp. was carried out in the Bela Vista neighborhood in the city of Teresina, Piauí State, Brazil, an important area of American visceral leishmaniasis transmission. From February 2004 to January 2005, sand flies were captured with CDC light traps. Approximately 10 female sand flies in each capture were dissected and examined for the presence of evolutionary forms of Leishmania sp. Two sand fly species were identified: 1,832 were Lu. longipalpis and six Lu. whitmani. Twenty female sand flies (1.1%), all Lu. longipalpis, were infected with procyclic and nectomonad forms of Leishmania sp., found mostly in the hindgut. Higher proportions of infected sand flies were found four months after the rainy season, suggesting that environmental factors may predict not only vector abundance (as already known) but also their level of infection.     

Data on sand fly fauna (Diptera, Psychodidae, Phlebotominae) in Itatiaia National Park, Rio de Janeiro State, Brazil

The sand fly fauna in Itatiaia National Park, Rio de Janeiro, Brazil, was investigated in different habitats ranging from sylvatic areas to those altered by human activity related to ecotourism, specifically identifying species that have been suggested as potential leishmaniasis vectors. Sand flies were captured from June 2002 to March 2004, using CDC light traps and Shannon traps. A total of 1,256 sand fly specimens were captured, from species belonging to genera Lutzomyia and Brumptomyia: Brumptomyia guimaraesi, B. troglodytes, Lutzomyia (Lutzomyia) amarali, L. lanei, L. migonei, L. sallesi, L. edwardsi, L. tupynambai, L. (Pintomyia) pessoai, L. (P.) bianchigalatie, L. rupicola, L. (Psathyromyia) shannoni, L. pascalei, L. (Psychodopygus) matosi, L. (P.) davisi, L. (P.) hirsuta hirsuta, L. (P.) ayrozai, L. peresi, L. monticola, and L. misionensis. Worthy of special attention were four species that are considered potential vectors for cutaneous leishmaniasis in Brazil: L. ayrozai, L. hirsuta hirsuta, L. migonei, and L. davisi, representing 19.19% of the specimens captured in this study.     

Lutzomyia longipalpis naturally infected by Leishmania (L.) chagasi in Várzea Grande, Mato Grosso State, Brazil, an area of intense transmission of visceral leishmaniasis

The American visceral leishmaniasis (AVL) is caused by parasites belonging to the genus Leishmania (Trypanosomatidae) and is transmitted to humans through the bite of certain species of infected phlebotomine sand flies. In this study, we investigated the natural infection ratio of Lutzomyia longipalpis, the main vector species of AVL in Brazil, in Várzea Grande, Mato Grosso State. Between July 2004 and June 2006, phlebotomine sand flies were captured in peridomestic areas using CDC light-traps. Four hundred and twenty (420) specimens of Lu. longipalpis were captured. 42 pools, containing 10 specimens of Lu. longipalpis each, were used for genomic DNA extraction and PCR (polymerase chain reaction) amplification. Leishmania spp. DNA was detected in three out of the 42 pools tested, resulting in a minimal infection ratio of 0.71%. Restriction fragment length polymorphism (RFLP) analysis indicated that Leishmania (L.) chagasi was the infective agent in the positive pools.     

Ecology of sandflies in Serra do Mar, Itaguaí, state of Rio de Janeiro, Brazil. I - Sandfly fauna and prevalence of the species in collections sites and method of capture

A two-year investigation was conducted in Itaguai, State of Rio de Janeiro, an area with cases of cutaneous leishmaniasis, in order to study the ecology of sandflies and their habits and role as parasitic vector for men and animals. Capturing took place at three sites: domiciliary (human bait, walls, and light traps); peridomiciliary (walls, from baits used simultaneously: humans, dogs, and chickens; and light traps); and sylvatic (human bait and light traps). A total of 10,172 sandflies were captured, belonging to 17 species of genuses Brumptomyia Fran?a & Parrot, 1921 and Lutzomyia Fran?a, 1924. L. intermedia was predominant, 100 m above sea level, as compared to L. migonei and L. fischeri. In a drier area 300 m above sea level L. migonei was prevalent, followed by L. longipalpis and L. fischeri. The species which presented the greatest endophily was L. fischeri, showing a certain degree of eclecticism regarding the biting site. L. intermedia and L. migonei proved to be more exophilic. L. intermedia was considered to be potentially the main transmitter of the disease because of its prevalence, anthropophily, and the fact it is known to be a vector of Leishmania (V.) braziliensis in other areas of the Southeastern region of Brazil. L. fischeri, because of its anthropophily, might also be involved.     

Sandflies (Diptera, psychodidae) in a secondary forest area in the Paco do Lumiar city, Maranhao, Brazil: a leishmaniasis transmission area

This paper analyzes the wealth of species, relative abundance, seasonal fluctuation, and nocturnal activity of sandflies. The field survey was conducted in a "capoeira" (secondary forest) area in the county of Pa?o do Lumiar, Maranh?o, where cutaneous and transmission of visceral leishmaniasis frequently occurs. Sandflies were captured by CDC-type light traps from 6:00 PM to 6:00 AM, once a month, from March 1997 to February 1998. A total of 489 specimens were collected (251 males and 238 females), distributed among 10 species: Lutzomyia antunesi (45.19%), Lutzomyia whitmani (29.4%), Lutzomyia longipalpis (7.56%), Lutzomyia sordelli (6.34%), Lutzomyia flaviscutellata (4.5%), Brumptomyia avellari (4.09%), Lutzomyia evandroi (1.85%), Lutzomyia umbratilis (0.61%), Lutzomyia corossoniensis (0.41%), and Lutzomyia trispinosa (0.41%). The sandflies were present year round, with higher abundance during the rainy season. They were present in all intervals studied, with the highest frequency between 12:00 PM and 1:00 AM (31%).     

Phlebotomine sandflies of Southern Brazil

OBJECTIVE: To identify the sandfly fauna and some aspects of their behavior in forest and anthropic environments. METHODS: Sandfly captures were undertaken in farm (23 degrees 6' S; 50 degrees 22' W), in Southern Brazil. Falc?o light traps were set in forest, domicile and domestic animal shelters and mosquitoes were collected monthly, between 17h and 7h, from March 1997 to February 1998. RESULTS: A total of 3,655 specimens representing 13 species were captured. Nyssomyia whitmani and Nyssomyia neivai were the predominant species, with a total of 2,977 specimens (81.0%). Of these two species, a total of 2,552 (85.7%) specimens were captured in intradomiciliary and peridomiciliary environments, 2,332 (91.3%) of them in a pigsty. These two species predominated between 20h-21h when 90.4% of the specimens were captured. CONCLUSIONS: Five sandfly species, N. whitmani, N. neivai, Migonemyia migonei, Pintomyia pessoai and Pintomyia fischeri, potential vectors of cutaneous leishmaniasis, were captured. The importance of the two former species is emphasized, since both presented similar behavior in regard to seasonal period, hourly frequency and predominance in the anthropic environment. Besides, N. whitmani was the most predominant species.     

Impact of environmental changes on sand fly ecology in southern Brazil

Tree felling around a chicken coop and periodic insecticide spraying at the Palmital farm in the county of Terra Boa in southern Brazil impacted the ecology of sand fly species. The most prevalent species (51.6%) before clearing the trees and insecticide spraying was Lutzomyia migonei (Fran?a, 1920), and it is now Lutzomyia (Nyssomyia) whitmani (Antunes & Coutinho, 1939) (89.8%). There was a highly significant difference between the proportions of L. whitmani reported by this paper (89.8%) and another publication before the tree felling and insecticide spraying (32,6%).     

Attraction of sand flies (Diptera: Psychodidae) to light traps in rural areas of Minas Gerais State,Brazil

The objective of this study was to detect phlebotomine sand fly vector species by using light traps, and thus determine the risk of cutaneous leishmaniasis (CL) transmission in rural areas of the Vi?osa microregion, Minas Gerais State, Brazil. Sand flies were captured with Shannon-like and Falc?o light traps hung between 1830 and 2230 h on 22 nights. Four sampling points where CL transmission occurs naturally were chosen. A total of 888 sand flies was collected. The most abundant species was Lutzomyia intermedia. Shannon-like traps caught significantly more L. intermedia, perhaps because of a greater surface area on which the insects can land or because they reflect more light. The positive phototaxis observed in L. intermedia and L. whitmani may pose a greater risk of transmission of Leishmania in houses where an external light source is situated close to a light-colored wall that reflects light and that have adjacent bushes or trees and domestic animal shelters within 50 m.     

Human and canine American cutaneous leishmaniasis in Mariluz, Paraná State, Brazil

An outbreak of American cutaneous leishmaniasis was reported in 2002 in Mariluz, northwestern Paraná State, Brazil. Of 38 humans who were investigated, four had healed lesions, ten showed lesions in the healing process, and 24 had active lesions. Of the 126 dogs, 20 (15.9%) presented suggestive lesions and 24 (19%) had positive serology. Parasites isolated from two patients and three dogs were identified as Leishmania (Viannia) braziliensis serodeme I. The captured sand flies were identified as Nyssomyia whitmani, N. neivai, and Migonemyia migonei. Considering that the region where the cases occurred is similar to other old human settlements in Paraná State, the environmental alterations and remaining forests facilitate the maintenance of the parasite's enzootic cycle and transmission to humans and domestic animals, thereby maintaining the endemicity of American cutaneous leishmaniasis.     

Assessment of sand fly (Diptera, Psychodidae) control using cypermethrin in an endemic area for visceral leishmaniasis, Montes Claros, Minas Gerais State, Brazil

Montes Claros in Minas Gerais State, Brazil, was considered an intense transmission area for visceral leishmaniasis. This study evaluated sand fly fauna after insecticide application. Captures were performed in 10 districts from September 2005 to August 2006 with CDC light traps inside and outside each residence. Cypermethrin was sprayed in two cycles during November/2005 and May/2006. The 636 specimens collected, belonging to 10 species, were predominantly Lutzomyia longipalpis (79%), and most frequently males (70%). The highest percentage of specimens were captured in areas surrounding domiciles (85.8%). The main species were observed to be sensitive to treatment with the insecticide. The results showed a reduction in the number of sand flies collected after use of cypermethrin in homes and annexes, and with residual effect lasting from two to four months.     

Host feeding preferences of sandflies in rural area, Southern Brazil

OBJECTIVE: To investigate the fauna and host feeding preferences of sandflies as for domestic animals in an endemic area of American cutaneous leishmaniasis. METHODS: The sandflies collections were carried out from 8:00 pm to 12:00 am in an area 40 meters away from one of the residences in a farm in Southern Brazil, between January and April, 2004. Collection was performed using four Falc?o light traps, placed 5 m apart from each other beside a cage, each one of them containing an animal bait (swine, dog, rabbit, and chicken). RESULTS: A total of 1,697 specimens of sandflies were collected as follows: Nyssomyia whitmani, Pintomyia fischeri, Migonemyia migonei, Nyssomyia neivai, Pintomyia pessoai and Psathromyia shannoni. The prevalent species was N. whitmani. There were no feeding preferences of sandflies as for the animals studied. CONCLUSIONS: N. whitmani and P. fischeri are opportunistic species and female insects probably adjust their eating habits to host availability, suggesting eating eclecticism of these insects in anthropic environments.     

Molecular analysis of natural infection of Lutzomyia longipalpis in an endemic area for visceral leishmaniasis in Brazil

The main purpose of this study was to investigate natural infection by Leishmania chagasi in female sand flies in a visceral leishmaniasis (VL) focus on S?o Luís Island, Maranh?o State, Brazil. Molecular analysis by polymerase chain reaction (PCR) was applied to determine the rate of natural infection of Lutzomyia longipalpis by L. chagasi in areas of old and recent human settlement on S?o Luís Island. Based on a sample of 800 female specimens captured from March to August 2005, the natural infection rate was 1.25% in an area of old settlement and 0.25% in two recently settled areas. Infection of L. longipalpis was detected in both areas, regardless of the number of reported human VL cases, indicating that other factors modulating infection in the wild need to be investigated. The results confirm PCR as a specific technique and an important tool for epidemiological surveillance.     

Absence of Lutzomyia longipalpis in some endemic visceral leishmaniasis areas in Rio de Janeiro municipality

The first autochthonous case of human visceral leishmaniasis (VL) in the Municipality of Rio de Janeiro was diagnosed in 1977. Since 1980, 54 autochthonous cases have been diagnosed in various locations, and since 1993 some 17 autochthonous human cases have been reported. Eight of these occurred in the neighborhood of Barra de Guaratiba and the others were distributed in the following neighborhoods: Camorim, Col?nia, Grota Funda, Grumari, Ilha de Guaratiba, and Carapiá. From September 1996 to December 1999, phebotomine sandfly captures were performed at 18 sites on the mountainsides of the Pedra Branca Massif, in the Municipality, and a total of 18,303 specimens were collected, with a predominance of L. intermedia (87.33%), L. migonei (6.59%), L. longipalpis (3.10%), and L. firmatoi (1.90%). The species L. longipalpis predominated in Barra de Guaratiba (46.80%) and was absent from the other six locations where VL cases also occurred, suggesting the participation of other species like L. migonei and L. firmatoi, belonging to the same paraphyletic group of the vector species, in the VL transmission chain in the region.     

Light and hens as attraction factors of Nyssomyia whitmani in a rural area, Southern Brazil

OBJECTIVE: To verify the influence of traps with electric light and hens as factors that attract sandflies and compare results between capture methods. METHODS: The study was conducted in the Palmital Farm, Southern Brazil. Sandfly collections were conducted with Falc?o traps and an electric aspirator, fortnightly, between 8 p.m. and 11 p.m. in the presence or absence of light and hens in peridomiciliary areas, from September 1998 to June 1999. RESULTS: A total of 43,767 specimens from eight species of sandflies were collected: Nyssomyia whitmani, N. neivai and Migonemyia migonei constituting 99.9% of the total collected, with predominance of N. whitmani. The number of this species collected inside the hen's shed in the presence of hens (21,045) was greater than in their absence (10,434). In the presence of hens, with distinct intensities of light, a larger number of N. whitmani samples were collected with 3W light. In the presence of hens and light (3W), the number of N. whitmani collected with the electric aspirator (5,141) was superior to that collected with the Falc?o trap (1,675). In the absence of light, with or without the presence hens, there was no difference between the numbers of N. whitmani collected with the electric aspirator or the Falc?o trap. CONCLUSIONS: Hens and electric light together attract more N. whitmani to peridomicilary areas. The number of N. whitmani collected with an electric aspirator inside a hen's shed with the presence of hens and light is greater than those collected with a Falc?o trap in the same conditions.     

Phlebotomine fauna in a rural area of the Brazilian Pantanal

The aim of the study was to identify among the phlebotomine fauna potential leishmaniasis vectors. The study was carried out in Corumbá county, State of Mato Grosso do Sul, Mid-West Brazil (18 degrees 59' S, 56 degrees 39' W). Sand fly captures were undertaken fortnightly with automatic light traps at 11 sites in forested environments and anthropic areas from April 2001 to July 2003. A total of only 41 specimens were captured. Thirty-one percent of the specimens were captured in forests and 68.3% in anthropic areas. The predominance of non-anthropophilic groups and the low density of N. whitmani, a known cutaneous leishmaniasis vector, does not seem to indicate any actual risk of the transmission of this disease in the study area.     

Sand flies naturally infected by Leishmania (L.) mexicana in the peri-urban area of Chetumal city, Quintana Roo, México

The surveillance of prevalent Leishmania sand fly vectors is an important issue for epidemiological studies in populated areas where leishmaniasis is endemic. In this study, we collected sand flies from a peri-urban area in the southeast of Mexico. Natural infection with Leishmania (L.) mexicana was studied by PCR using a Leishmania internal transcribed spacer of the ribosomal RNA gene for amplification. Infected Lutzomyia olmeca olmeca, Lu. shannoni and Lu. cruciata sand flies were collected mainly during the high transmission season (November to March), coinciding with the highest sand fly densities. Additionally, positive specimens of Lu. olmeca olmeca were also captured during July and August. The infected sand flies were from primary forest (subperennial forest) and secondary forest (18-25 years old and 10-15 years old respectively). Sand flies collected with Disney and Shannon traps were the ones found to be infected with L. (L.) mexicana. We conclude that the high-risk period in which L. (L.) mexicana is transmitted in the peri-urban area of Chetumal City is from July to March and that transmission is associated with both the subperennial forest and the secondary forest.     

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.     

马尾口岸媒介生物调查结果分析

目的了解马尾口岸媒介生物的构成情况,为媒介生物控制以及口岸传染病监测提供科学依据。方法根据马尾口岸地理分布和港口类型,抽取4个港区和1个居民点实施为期1年的调查。结果共捕鼠形动物226只,鼠密度2.75%,经鉴定隶属2目2科3属4种,臭鼩鼱为优势种群,其次是褐家鼠;带螨鼠35只,共检获革螨283只,总染螨率为15.49%,经鉴定隶属1科2属3种;带蚤鼠9只,共检获蚤25只,总染蚤率为3.98%,经鉴定隶属1科1属2种;鼠肺检测肾综合征出血热抗原135份,阳性12份,携带率为8.89%,阳性鼠主要为成年雄性褐家鼠;共捕获蝇类24047只,经鉴定隶属4科14属19种,年平均密度为100.2只/笼·日,以大头金蝇为优势蝇种;共捕获成蚊74只,平均蚊密度为2.47只/人工小时,隶属2属3种;共捕获蜚蠊1284只,年平均密度为0.546只/盒,成虫若虫比例为1:1.68,蜚蠊成虫隶属2科3属6种;蜱、蠓未捕获。结论基本了解马尾口岸媒介生物构成情况;马尾口岸居民区存在发生流行性出血热的危险。