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PubMed1991

Description and performance of an updraft trap for sandflies.

An updraft trap for sampling sandflies in the field was developed and tested in the Marigat area of Baringo District, Kenya. The main components of the trap were a 12 cm long plastic drain pipe, 9 V d.c. electric motor, aluminium fan and a perspex sandfly collection cage. Comparisons of the updraft trap with a CDC and a 1 x 1 m polythene sheet coated with castor oil (sticky trap) showed the former was more consistent than the other traps in sampling sandflies from animal burrows. A total of 1241 sandflies belonging to eleven species were collected. Sergentomyia bedfordi, Phlebotomus martini, S. antennatus and P. duboscqi were the commonest species comprising 32.5%, 27.0%, 21.1% and 11.3% of the total catch respectively. However, the relative proportion of the different species varied according to the type of trap used. The CDC trap apparently attracted the known vectors of leishmaniases in the area, P. martini and P. duboscqi. Significantly more male than female P. martini and S. antennatus were collected by the various traps. A significantly higher proportion of female S. bedfordi was captured by the updraft and sticky traps while equal numbers of male and female P. duboscqi were collected in all traps.

Animals↗
PubMed1991

The behaviour and dispersal of sandflies in Ras el Naqb, south Jordan with particular emphasis on Phlebotomus kazeruni.

The behaviour and dispersal of sandflies from an enclosed cave were investigated during the summer of 1988 in Ras el Naqb by the mark-release-recapture technique. Nine species of sandflies were reported during this study including 5 Phlebotomus and 4 Sergentomyia species. P. sergenti, P. alexandri, S. adleri/S. clydei and S. taizi were reported for the first time from Jordan. P. kazeruni was the most abundant sandfly species inside the cave. The maximum distance travelled by a single P. kazeruni was 340m. However, the majority were recaptured within 10m of the cave. It seems likely that an independent "population" of sandflies which breeds inside the cave is developing.

Animals↗
PubMed1991

Permethrin-impregnated curtains against phlebotomine sandflies (Diptera: Psychodidae): laboratory and field studies.

The efficacy of permethrin-impregnated nets against vectors of leishmaniases was evaluated in laboratory and field studies. Permethrin-impregnated curtains were tested at different dosages in experimental tunnel against Phlebotomus perniciosus and P. papatasi. The influence on feeding behaviour and the mortality rate post contact with the impregnated curtain were investigated. The vapour effect of permethrin on P. perniciosus adults confined less than 1 cm away from a treated net was also evaluated. From laboratory studies it seems that permethrin shows low or any barrier effect against sandfly species tested, and that the high insecticidal activity (mortality rate greater than 90%, 24 hours after the contact with treated net, 1 g/m2) and the reduction of biting rate observed (between 53.56% and 85.24%) are the main effects that make permethrin-impregnated nets very effective for sandfly control. In field studies carried out in cutaneous leishmaniasis foci of Italy, it was demonstrated that permethrin-impregnated curtains around windows and around CDC light traps, reduce the number of sandflies entering the stables and traps. In Burkina Faso, indoor use of wide-mesh cotton curtains impregnated with permethrin 1 g/m2 almost completely eliminate the occurrence of endophilic sandfly species. In conclusion the use of permethrin-impregnated curtains could be an alternative to residual house-spraying for the control of endophilic vectors of leishmaniases.

Animals↗
PubMed1991

Phlebotominae sandflies as the key link of Leishmania parasitic systems.

Interrelations of Leishmania with their invertebrate hosts-sandflies are sufficiently specific. Among the factors determining the specificity of Leishmania-Phlebotominae species to species relations the peritrophic membrane is one of the most important. It has various structural and functional pecularities in representatives of different Phlebotominae species, which determine the character of the Leishmania life cycle within sandflies. The spatial and temporal existence of leishmaniases foci as well as their epidemiological manifestation are conditioned by both the adaptation of sandfly species-the invertebrate hosts of the parasites to certain landscapes and their connection with certain species of vertebrate hosts as a source of bloodfeeding. Thus Phlebotominae sandflies play the part of the key link of the Leishmania parasitic systems.

Animals↗
PubMedDate not supplied

[Virological study of cases of sandfly fever in Afghanistan].

Three strains (Af-1008, Af-1038, and Af-130) of Neapolitan sandfly fever virus (NSFF) and 2 strains (Af-1028 and Af-83) of Sicilian sandfly fever virus (SSFF) were isolated from febrile patients among soldiers of the limited military contingent of Soviet troops in Afghanistan in May-August, 1986-1987. The viruses were isolated in neonate mice and identified by indirect immunofluorescence, complement-fixation tests and plaque reduction neutralization test in Vero E6 and SPEV cells. The new NSFF strains in serological tests differed slightly from the original Sabin strain and completely differed from Toskana virus. In the examinations of 104 paired sera from convalescents, 87 subjects showed a rise in antibody titres either to NSFF or to SSFF virus, and 16 patients had antibodies to both viruses but without any rises in titre. Among 60 subjects with a presumable diagnosis of sandfly fever 12 persons had an antibody No information on isolation of sandfly fever viruses in Afghanistan has been available hitherto.

Afghanistan↗
PubMed1997

Studies on sandflies in a hyperendemic area of zoonotic cutaneous leishmaniasis in Iran.

Ecological studies on sandflies were conducted in the Borkhar rural district, north of Isfahan in central Iran from March 1991 to March 1992. Sandflies were collected once every ten days from human dwellings and cattlesheds using sticky (oiled) paper traps. A total of 29004 sandflies were collected and seven species were identified. Phlebotomus papatasi predominated (83.8% in bedrooms and stables and 42.6% in rodent burrows) in the area. The average indoor resting density of P. papatasi ranged from 0.6 (October 1991) to 62.8 per 10 traps (August 1991). The average outdoor resting density of this species varied between 0.7-141.2 per 10 traps in November and July respectively in 1991. The activity of sandflies extended from end May to mid November. There were two peaks in the density curve of most species, one in June or July and the second in August or September. A significant positive correlation was observed between rainfall and relative density. Natural leptomonad infection was found in P. papatasi, P. caucasicus and P. ansarii, P. papatasi is the main vector to man, but P. caucasicus, P. mongolensis, P. ansarii and P. papatasi act as vectors among gerbils.

Animals↗
PubMed1984

Leishmaniasis in Israel: reservoir hosts, sandfly vectors and leishmanial strains in the Negev, Central Arava and along the Dead Sea.

The reservoir animals, sandfly vectors and strains of Leishmania from foci in the southern region of Israel were studied. The rodent host species are: Psammomys obesus, Meriones crassus and probably Nesokia indica. The vector species are Phlebotomus papatasi, which were caught at all collecting sites and Ph. sergenti, which were collected in the area of the Dead Sea and in the Central Arava. Strains of Leishmania major isolated from rodents, vectors and man were serologically and enzymologically identical with regard to their excreted factor (EF) serotypes, their malate dehydrogenase (MDH), glucose-phosphate isomerase (GPI) and glucose-6-phosphate dehydrogenase (G6PDH) enzyme variant types, but exhibited three variant subtypes of 6-phosphogluconate dehydrogenase (6PGDH). The distribution of the 6PGDH subtypes correlates with three different geographical locations. Scarcity of water is the main factor limiting the biotopes of the sandflies and the spread of leishmaniasis. The subjects discussed are the dependence of sandfly distribution on rodent-burrow depth in arid areas and the inter-relationship between the leishmanial subtypes, vectors and hosts.

Animals↗
PubMedDate not supplied

Isoenzyme characterization of Leishmania from man, dog and sandflies in the Maltese islands.

As a part of a general survey on leishmaniases and sandflies of the Maltese islands, 22 Leishmania stocks were isolated from human visceral (1) and cutaneous (1) cases, dogs (16) and sandflies (4). They were characterized by the analysis of 15 enzymes. The commonest Mediterranean L. infantum zymodeme, MON 1, was found to cause human and canine visceral leishmaniasis; L. infantum MON 78, which has so far been isolated only in Malta, was the agent of human cutaneous leishmaniasis. Both zymodemes were isolated from the same sandfly species, Phlebotomus perniciosus.

Animals↗
PubMed2004

Geographic variation of metric properties within the neotropical sandflies.

Traditional morphometrics remains a useful tool for differentiating sandflies species, particularly closely related taxa. Within a single species, however, size variation among geographic populations might interfere with species distinction. In the past decades, a search for a metric property less prone to individual variations led to the use of ratios, and more recently to the use of size-free variables (after tentative size extraction). While morphometrics is continuously enriched with new, more efficient techniques describing shape, the question remains for the morphologist whether an efficient removing of within-species size variation is sufficient to produce stable, specific characters. Is a single species metrically recognizable in spite of its geographical variation? To address this question the intraspecific variation in 10 neotropical sandflies was examined within and between large South American ecogeographic regions: the Amazonian region, the Sub-Andean and the Chaco regions of Bolivia, and the Atlantic Coast of Brazil. Thus, the geographic stability of metric properties, as derived from measurements between landmarks, was investigated 10 times allowing a total of 29 inter-regional and 13 intra-regional conspecific comparisons. Metric proportions remained stable among conspecific populations of a single ecogeographic region. From one region to another, however, size-independent changes were significant and their amount was correlated with altitude. This could reflect an important role of some environmental changes in shaping the insects, and should be taken into account when using morphometrics to identify sandflies.

Altitude↗
PubMedDate not supplied

Detection of Leishmania braziliensis in naturally infected individual sandflies by the polymerase chain reaction.

The natural infection of sandflies by Leishmania in wild-caught specimens was studied, using the polymerase chain reaction (PCR)-hybridization technique. The PCR was carried out using 2 oligonucleotides (primers 3J1 and 3J2) derived from a repetitive nuclear DNA sequence. The primers support the enzymatic amplification of a fragment of approximately 500 bp, present in the nuclear DNA of Leishmania braziliensis. The expected band was observed in 5 of 65 sandflies containing flagellates. After hybridization with a species-specific probe, we confirmed natural infection by L. braziliensis. The technique allowed the identification of Lutzomyia gomezi and Lu. panamensis as vectors of L. braziliensis in an endemic area of cutaneous leishmaniasis in Urama, Puerto Cabello district in Venezuela. As far as we are aware, this work constitutes the first report of natural infection of Lu. panamensis with L. braziliensis in the study area. We also demonstrate that PCR-hybridization is a suitable approach to establish the Leishmania-sandfly relationship and will be useful in epidemiological studies of leishmaniasis in endemic areas.

Animals↗
PubMed1999

Occurrence of Leishmania major in sandfly urine.

Promastigotes of Leishmania major were frequently detected in the urine droplets discharged by infected Phlebotomus papatasi and P. duboscqui females during feeding. Parasites were present in the urine of 37.5% P. papatasi and 16.1% P. duboscqi females, even in those with low intensity gut infections. Free-swimming forms (elongated nectomonads, short slender promastigotes and metacyclic forms) predominated in excreted droplets. Viability of excreted parasites was proved by cultivation on blood agar, and the presence of metacyclic forms in urine droplets was confirmed by specific fluorescence assay with 3F12 antibodies. While the release of promatigotes from the anus of the sandfly was frequent, these were rarely egested from the mouth-parts of sandfly females (1.3% for P. duboscqi and 0% for P. papatasi) fed on microcapillaries, even if the females were heavily infected. The possible role and significance of the discharge of parasites in sandfly urine are discussed.

Animals↗
PubMed1991

High prevalence rates of antibody to three sandfly fever viruses (Sicilian, Naples, and Toscana) among Cypriots.

Neutralizing antibodies to sandfly fever Naples, sandfly fever Sicilian and Toscana viruses were investigated among 479 sera collected from a normal human population in Cyprus. Antibody prevalence rates of 57%, 32% and 20% were found to Naples, Sicilian and Toscana viruses, respectively. The observed frequency of dual and triple infections was higher than would be expected with a random chance of infection. Antibody prevalence rates were similar for men and women for all three viruses tested, but one of two study sites had significantly higher antibody prevalence to Naples and Sicilian viruses than the other. Individuals with antibodies to both Naples and Toscana viruses had higher antibody levels to Naples virus than those with antibodies to Naples virus only. If the antibody prevalence rates found in this study reflect a history of clinical disease as described in the literature, sandfly fever poses a significant public health problem in Cyprus.

Adolescent↗
PubMed2002

Molecular evolution of the cacophony IVS6 region in sandflies.

A number of insects produce acoustic signals during courtship. Genes involved in the control of the courtship song are particularly interesting from an evolutionary viewpoint because interspecific variation in this signal is potentially important as a reproductive isolation mechanism and, as a consequence, in the speciation process. The cacophony gene was identified by a mutation affecting the "lovesong" in Drosophila melanogaster. Phlebotomine sandflies (Diptera: Psychodidae) also produce acoustic stimuli during courtship and therefore cacophony can be used as an interesting molecular marker in evolutionary studies in these important disease vectors. In this paper we have studied the molecular evolution of the IVS6 region of cacophony in sandflies. We compared the level of divergence in the exon sequences encoding this conserved domain in Drosophila and Phlebotomines. We also analysed the high level of variation in an intron that is present in sandflies but that was lost in Drosophila during evolution. The available cacophony sequences were also used for a phylogenetic analysis of some species of the Neotropical genus Lutzomyia.

Amino Acid Sequence↗
PubMed1999

Impact of pyrethroid-impregnated curtains on Phlebotomus papatasi sandflies indoors at Khartoum, Sudan.

Laboratory and field investigations were made in an endemic focus of cutaneous leishmaniasis in Khartoum State, Sudan, to evaluate the effects of permethrin-impregnated curtains on the human-biting activity, nocturnal activity and resting behaviour of the vector sandfly Phlebotomus papatasi (Diptera: Psychodidae) indoors. Laboratory bioassays showed that curtains impregnated with 0.5, 1.0 or 1.5 g/m2 permethrin all gave 100% mortality within 24h of exposure of P. papatasi for 3 min. Under natural field conditions, the biting activity indoors and the resting density of P. papatasi were significantly reduced (P<0.001 and P=0.036, respectively) in rooms provided with permethrin-impregnated curtains as compared to control rooms left without curtains or fitted with unimpregnated curtains. No significant difference was found between the numbers of nocturnally active P. papatasi collected in rooms provided with impregnated curtains and rooms left without curtains or provided with unimpregnated curtains (P=0.377). Evidently P. papatasi was not repelled by these doses of permethrin on curtains, but the survival rate of sandflies collected from test rooms provided with permethrin-impregnated curtains was significantly reduced (P=0.036). We conclude that use of permethrin-impregnated curtains may provide a good control method for P. papatasi and other endophilic and/or endophagic sandfly vectors of leishmaniasis.

Animals↗
PubMed2000

Sugars in the gut of the sandfly Phlebotomus orientalis from Dinder National Park, Eastern Sudan.

The sandfly Phlebotomus orientalis Parrot (Diptera: Psychodidae) is the vector of visceral leishmaniasis in eastern and Upper Nile regions of Sudan, where vector infection rates of over 7% have been reported. Sugars are known to be important for development of the parasite and for increasing the survival and oviposition rates of several species of sandflies. In the present study we have analysed the sugars present in the guts of individuals and groups of male and female P. orientalis and compared these with sugars from several potential local plant sources: Acacia seyal, Balanites aegyptiaca and Combretum kordofanum. The distribution of these trees in Sudan is closely correlated with that of P. orientalis. Only 20% of individually analysed female sandflies had significant amounts of sugars present suggesting that P. orientalis either digest their sugar meal quickly or do not require regular sugar meals. Interestingly, the sugars present in the males were significantly different to those found in the females, indicating that they had fed on different sugar sources. There was evidence that fruit sugars from Balanites aegyptiaca, Combretum kordofanum and aphid or coccid honeydew are utilized by male and female P. orientalis. There was evidence to indicate that female P. orientalis feeds directly on honeydew. There was no evidence to indicate that direct feeding on leaves is a typical source for the sugar meal. There was no melizitose and only a very small amount of turanose present in the male, suggesting that honeydew was not an important sugar source for males.

Animals↗
PubMed1998

Sandflies on the island of Corfu, Greece.

The island of Corfu is an endemic area of human leishmaniasis, mainly visceral and secondly cutaneous. In August 1996, a survey of phlebotomine sandflies was conducted throughout the whole island. Using castor-oil paper traps, a total of 2,615 sandflies were caught. The following species were identified: 450 (17.21%) Phlebotomus neglectus, 213 (8.15%) P. tobbi, 129 (4.93%) P. perfiliewi, 12 (0.46%) P. sergenti, 11 (0.42%) P. simici, 4 (0.15%) P. papatasi, 999 (38.20%) Sergentomyia minuta and 797 (30.48%) S. dentata. Among the potential vectors of Leishmania spp., P. neglectus, P. tobbi and P. perfiliewi, were the most widespread species on the island. However, a decrease of the population density of sandflies compared to previous entomological studies was observed.

Animals↗
PubMed2001

Evaluation of avermectins as sandfly control agents.

The potential of avermectins as environmentally safe agents for the control of the sandfly vectors of Leishmania spp. was investigated in the laboratory. Female Phlebotomus papatasi and P. langeroni were fed either bloodmeals containing laboratory-grade ivermectin or sugarmeals containing a commercial-product based on abamectin. Low concentrations of either avermectin killed the sandflies, with median lethal concentrations (LC(50)) of just 13 ng ivermectin or 0.5 ng abamectin/ml for P. papatasi and 44 ng ivermectin or 35 ng abamectin/ml for P. langeroni. The feeding of female sandflies of both species with generally sublethal doses (LC(30)) of ivermectin in blood led to markedly reduced survival and fecundity (i.e. number of eggs laid/ovipositing female). However, addition of ivermectin to the bloodmeal (or of abamectin to the sugarmeal) of the females had no statistically significant effect on the proportion of their eggs that hatched. The results indicate that very small amounts of avermectin in their blood- or sugar-meals could control P. papatasi and P. langeroni, by killing many flies and, in the case of ivermectin, by reducing the fecundity of the survivors.

Animals↗
PubMed1991

Monthly variation in natural infection of the sandfly Lutzomyia ayacuchensis with Leishmania mexicana in an endemic focus in the Ecuadorian Andes.

In order to collect information on the role of Lutzomyia ayacuchensis in the transmission of leishmaniasis in a newly discovered Andean endemic focus in Ecuador, a longitudinal field study was carried out over 13 months. Monthly dissections were made of a minimum of 200 anthropophilic sandflies, collected at night during the month. A total of 2600 flies was separated from a small number of Lu. osornoi, another anthropophilic species in the area, and dissected; 95 (3.65%) were naturally infected with Leishmania mexicana promastigotes. The parasites were always located in the sandfly midgut. The current study revealed a marked monthly variation both in natural infections with Leishmania and in biting activity of sandflies in the endemic area, demonstrating a high transmission rate during the period from the early rainy season to the early or mid dry season (February to July).

Animals↗