Entomological and parasitological study on phlebotomine sandflies in central and northern Albania

An entomological survey was carried out in two districts of central (Kruje) and northern (Lezhe) Albania. Six collecting sites, showing a variety of diurnal resting sites, were monitored for adult sandflies from June through October 2002. Flies were collected with CDC miniature light traps, sticky traps and mechanical or hand aspirators in peridomestic sites, in bedrooms and inside cow barns, chicken coops and pigpens. All collecting sites monitored were found positive for sandflies. A total of 849 specimens were caught (29.2% males) belonging to five Phlebotomus species. Phlebotomus neglectus (75.6%) was the most abundant species followed by P. perfiliewi (14.4%), P. papatasi (4.6%), P. tobbi (3.6%) and P. similis (1.8%). The first adult of P. neglectus appeared on June 11 and the last one was collected on October 16. The highest density for this species was observed at the end of July. A total of 111 blood-fed females were caught from the two areas studied. P. neglectus was the only species found blood fed in Lezhe and the same species was prevalent (56.1%) in Kruje followed by P. perfiliewi (30.3%), P. tobbi (10.6%); P. papatasi was represented by only two specimens. Blood meal origin was determined in 45/66 (68.2%) of the females tested from Kruie district. P. neglectus was found fed on four hosts, showing the following feeding patterns: cow (71.4%), dog (117.1%), chicken (5.7%) and human (5.7%); P. perfiliewi was found fed on cow (80.0%) and chicken (20.0%), P. tobbi on cow (50.0%), chicken (25.0%) and dog (25.0%). One specimen of P. papatasi was found fed on cow. When such prevalences were analysed by the available biomass for each host present at the collecting site, P. neglectus resulted to be an opportunistic feeder rather than exhibiting preferences for any specific animal. PCR analysis of 39 P. neglectus from the Lezhe district gave negative results for the presence of Leishmania DNA.

About the presence of Phlebotomus sergenti Parrot, 1917 (Diptera: Psychodidae) in Eastern Sicily, Italy

The note reports the data of a three-year sand fly investigation (1997-99) carried out in Eastern Sicily (Italy) with the aim to study the distribution of Phlebotomus sergenti. The survey involved a densely inhabited area at the foot of Mount Etna and the area of Iblei mounts. A total of 9,095 sand flies, of which 63.4% males, were captured. Five species belonging to the genus Phlebotomus (P. perniciosus, P. perfiliewi, P. neglectus, P. sergenti and P. papatasi) and one to the genus Sergentomyia (S. minuta) were identified. Both the prevalence and distribution of the species were different within the two areas studied. In Mount Etna area, P. perniciosus (77.7%) was the prevalent species followed by S. minuta (19.8%), P. sergenti (2.0%), P. neglectus (0.3%) and P. papatasi (0.2%). While in Iblei mounts region S. minuta (84.5%) showed the highest prevalence, followed by P. perniciosus (14.4%), P. perfiliewi (0.9%) and P. neglectus (0.1%). Here, P. sergenti was a very rare species (< 0.02). P. sergenti was mostly associated to domestic habitats of peri-urban and urban zones located between two and 750 m a.s.l. The density values of P. sergenti, expressed as number of specimens/m2 of sticky trap, were between 0.3 and 5.5 with the highest value in the hilly collecting sites. The low observed abundance of P. sergenti does not allow to draw any prediction on the role that the species could play in the transmission of leishmaniasis in Sicily.

[Prevention and control of leishmaniasis vectors: current approaches]

Phlebotomine sandflies (Diptera: Psychodidae) are the suspected or proven vectors of Leishmania spp. in at least 88 countries, including over 40 Phlebotomus species in the Old World and a further 30 belonging to the genus Lutzomyia in the New World. In recent years, both cutaneous (CL) and zoonotic visceral leishmaniasis (ZVL) have become increasingly prevalent in urban areas, including large Latin American cities. A similar trend has been recorded in all Mediterranean areas during the last decade. Based on mathematical models, insecticidal control of sandflies appears to represent a more effective way of reducing Leishmania infantum transmission than the present strategy of culling infected dogs in Latin America as well as being more acceptable to the human population. Since man is a dead-end host of most Leishmania species, treatment of existing human cases generally does not affect transmission. Interruption of the cycle by vector control may offer a cheaper, more practical solution to treatment and improved knowledge of the alternatives available could lead to preventative measures being undertaken in more leishmaniasis foci. In this note a review of current knowledge on sandfly control is presented. Different measures to control phlebotomine sandflies, including residual spraying of dwellings and animal shelters, insecticide treated nets, application of repellents/insecticides to skin or to fabrics and impregnated dog collars are discussed. Although effective in urban areas with high concentrations of sandflies, residual spraying of insecticides is no often longer tenable in most situations. In rural areas where dwellings are more dispersed and surrounded by large, untargeted "reservoir" populations of sandflies, residual spraying of houses may be both impractical for logistic reasons and ineffective. Actually, this control measure depends on the availability of a suitable public health infrastructure, including adequate supplies of insecticide, spraying equipment and trained personnel. Ideally such personnel should be trained in insecticide application, monitoring techniques and interpretation of sampling data, as well as safety techniques. To date reports of resistance refer to one insecticide (DDT) in only three species (Phlebotomus papatasi, P. argentipes and Sergentomyia shorti) in one country (India), although there are reports of increased tolerance to this compound in several countries. Fortunately the insects remain susceptible to all the major insecticidal groups. Impregnated bednets may offer the best solution in rural areas where transmission is largely intradomiciliary. This measure has the advantage that it can be employed at the individual household level and affords collateral benefits such as privacy and control of other biting insects such as mosquitoes, fleas and bedbugs. Sandfly larvae are generally difficult to find in nature so control measures that act specifically against immatures are not feasible, although the effectiveness of a few biological and chemical agents has been demonstrated in laboratory evaluations. In ZVL foci, where dogs are the unique domestic reservoir, a reduction in Leishmania transmission would be expected if we could combine an effective mass treatment of infected dogs with a protection of both healthy and infected dogs from the sandfly bites. Laboratory and field evaluations have shown that impregnated dog collars and topical application of insecticides could protect dogs from most sandfly bites by means of both anti-feeding and killing effect of the pirethorids used.

Host preferences of phlebotomine sand flies at a hypoendemic focus of canine leishmaniasis in central Italy

A survey was carried out on phlebotomine sand flies and their feeding habits at a hypoendemic focus of Leishmania infantum in Macerata province, central Italy. During two consecutive years (2000-2001), 1465 sand fly specimens (42.5% of which were males) were collected from a variety of diurnal resting sites in the municipality of Camerino. The most prevalent species was Phlebotomus perniciosus (76.6%), followed by P. papatasi (10.4%), Sergentomyia minuta (9.1%), Phlebotomus perfiliewi (3.3%) and P. mascittii (0.5%). Among the 842 females collected, 578 (68.6%) were blood-fed. Based on the results of blood meal analyses, P. perniciosus fed on man, dogs, equines, sheep and birds; P. perfiliewi on dogs, equines, sheep and birds; P. papatasi on dogs, equines and birds. Two specimens of P. mascittii fed on equines. Forage ratios (FRs) and host selectivity indices gave different results for the large domestic animals. More than 95% of the specimens collected inside a stable, dog kennel, sheep pen and chicken house were found to have fed on the animals housed in the respective shelters. In addition, at one collecting site where almost all the hosts mentioned above were present simultaneously, both P. perniciosus and P. perfiliewi were found to have fed on all five species, indicating that host choice was probably related to its availability (i.e. number and size) rather than specific attractiveness. The feeding habits of the two Leishmania vectors may have implications for the epidemiology of leishmaniasis in urban and peri-urban areas, where sand fly females deprived of other vertebrate hosts (particularly the larger species) may begin to bite humans and dogs more frequently.

Recent findings of Phlebotomus neglectus Tonnoir, 1921 in Italy and its western limit of distribution

During the sand fly season of 2001, sand flies were collected in two different regions of Italy to investigate the northern distribution of Phlebotomus neglectus. The study areas were two provinces of northern Italy, Ivrea and Verona, in Piedmont and Veneto regions respectively. Sticky traps and CDC miniature light traps were used both inside and outside domestic and peri-domestic environments. Sand flies were also collected in domestic resting sites with mouth and electric aspirators. Of 1,295 sand fly specimens collected, 855 were from the Veneto region and 440 were from the Piedmont region. Five species of the genera Phlebotomus and Sergentomyia were identified. S. minuta (66.3%) was the most abundant sand fly followed by P. perniciosus (22.2%), P. neglectus (10.3%) and P. papatasi (1.2%). Only one specimen of P. mascittii was caught in Piedmont region. P. neglectus was found in 9 out of 15 (60%) of the sites where sand flies were found with a prevalence of 1.5% to 45.8%; the highest value was recorded in Piedmont region. P. neglectus was mostly associated with peridomestic and domestic sites. The results confirm previous observations on the presence of P. neglectus in northern Italy and suggest that this species is probably widespread in the area. From a review of all previous published and unpublished records of P. neglectus, it appears that this species is present in only two areas of the country, namely in the regions of Friuli Venezia Giulia, Veneto and Piedmont in northern Italy and the regions of Calabria, Apulia and Sicily in southern Italy. The apparent absence of P. neglectus in Central Italy is discussed and the resulting settlement through two probable migration routes from the East is analysed.

[Distribution of dog ticks (Rhipicephalus sanguineus Latreille, 1806) in Italy: a public health problem]

The dog tick, Rhipicephalus sanguineus Latreille, 1806 (Acari: Ixodidae), is a public health problem since it is widely distributed in Italy and because of its role in the transmission of many pathogens to man and dog which is its preferred host. This review deals with the main aspects of the biology and ecology of Rh. sanguineus habitat, developmental time, distribution and seasonality, behaviour and vector competence. Moreover, the preminent role of Rh, sanguineus in the transmission of boutonneuse fever is discussed.

[Survey of Phlebotomus neglectus Tonnoir, 1921 (=P. major s.l.) in a leishmaniasis focus in northern Italy (province of Verona)]

An entomological survey was carried out on leishmaniasis vectors (Diptera: Psychodidae) in North Italy (Verona province). A total of 382 sandfly specimens was caught by sticky traps in 6 collecting stations. The species identified were: Phlebotomus perniciosus (62.3%), P. neglectus (= major s.l.) (5.2%), P. papatasi (2.1%), P. mascittii (0.3%) and Sergentomyia minuta (30.1%). After the description of the olotype of P. neglectus by Tonnoir (1921) in Trieste (Opicina), this is the first time that the species is recorded in a region of North Italy being previously collected only in the regions of Southern such as Apulia, Calabria, Sicily. The role of the sandfly species in the transmission of leishmaniasis in the focus is also discussed.

Genetic and phenotypic characterization of Borrelia burgdorferi strains isolated from Ixodes ricinus ticks in the Province of Bolzano, Italy

Lyme disease is caused by three borrelial species, B. burgdorferi sensu stricto, B. garinii and Borrelia group VS461. In a restricted biotope of the Bolzano province, in the Caldaro community, five clones of two borrelial variants were isolated from Ixodes ricinus ticks. A preliminary serological study showed that the two variants cross-reacted with B. burgdorferi B31 and B. garinii N34 strains, respectively. The isolates were genomically related with strains B31 and N34, respectively, sharing a similar plasmid and restriction fragment length polymorphism profile with these strains. The phenotypic pattern of the Caldaro isolates-namely their protein and antigenic profile-showed infra-subspecific variation compared to related strains B31 and N34 respectively. The observed phenotypic variability between strains isolated from the same biotope and in the same tick host strongly indicated the variability of gene-encoded characters is a constant characteristic of borrelial strains, even when from the same ecological niche.

[Sandflies in Italy: observations on their distribution and methods for control]

The paper analyzes published and unpublished data of sandfly collections carried out in Italy by one of the authors (M.M.) over a period of 18 years (1975-1993). These data are discussed in relation to the collection methods and the habitats. The leishmaniasis foci surveyed are localized in 11 regions of Central and Southern Italy and in the two main islands, Sicily and Sardinia. Five collection methods were used: i) sticky traps, ii) light traps, iii) window exit traps, iv) emergence traps, and v) hand catches. Captures were performed in domestic and sylvatic habitats in rural, urban and periurban areas. A total of 81,915 sandflies has been collected. Specimens were identified as belonging to 6 species: Phlebotomus perniciosus (46.1%), P. perfiliewi (43.8%), P. major (0.2%), P. mascittii (0.1%), P. papatasi (0.3%), and Sergentomyia minuta (9.5%). P. perniciosus, P. perfiliewi and S. minuta have been reported in almost all the regions samples, P. major only in 3 regions of South Italy (Apulia, Calabria and Sicily), P. mascitti in 4 regions of Central Italy (Tuscany, Latium, Abruzzo, Molise) and in Campania, P. papatasi in 6 regions without any definite geographical distribution. From the analysis of sticky trap captures P. perniciosus seems to be the prevalent species in the domestic habitat (65.6%) even if present in the sylvatic one (21.8%). The report of P. perniciosus in both situations might indicate the ability of the species to colonize a large range of habitats. P. perfiliewi resulted as the predominant species (88.1%) in the domestic area from collections with CDC light traps. S. minuta was the most abundant species in the sylvatic conditions (76.6%) while P. papatasi showed a clear endophilic behaviour reaching high percentages only in bedrooms and stables. Moreover, taxonomic characters of spermathecae utilized in species identification are reported.

[Temporal distribution of ticks (Acarina: Ixodidae) in "Macchia Grande" park in Manziana in the province of Rome]

Temporal distribution of tick species was studied in the woodland "Macchia Grande" of Manziana in the province of Rome, Italy. A total of 2,494 ticks was collected by means of drag sampling during one year of survey (1993). Among the species identified, Ixodes ricinus (Linnaeus, 1758) (95.9%) was the most abundant, followed by Haemaphysalis inermis (Birula, 1895) (2.2%), Rhipicephalus bursa (Canestrini e Fanzago, 1877) (1.8%), Dermacentor marginatus Sulzer, 1776) (0.1%). I. ricinus was present during the whole year, showing a diphasic trend, with peaks in January-April (95-173 specimens per drag) and in November-December (29-126); H. inermis was recovered only during the cold season (January-April and in December) with the highest density in February (7); Rh. bursa was collected from May to October showing maximum occurrence in July (10). The presence of I. ricinus and H. inermis, proven vectors of Borrelia burgdorferi (Lyme disease) and TBE virus, is discussed in relation to the possible exposure risk for park visitors and operators.

[Parasitic horse ticks in Italy. Observations on their distribution and pathogenic role]

The following 13 species of ticks, belonging to Ixodidae family, were recorded in Italy on horse (Equus caballus) since 1931: Ixodes ricinus, I. gibbosus, Haemaphysalis inermis, H. parva, H. punctata, H. sulcata, Dermacentor marginatus, Rhipicephalus sanguineus, Rh. bursa, Rh. turanicus, Hyalomma marginatum, Hy. detritum, Boophilus annulatus. The regional distribution and the role of the species in the transmission of pathogens are reported.

Induction of maturation of cumulus-oocyte complex by gonadotropin-releasing hormone analog is associated with lower progesterone secretion

Induction of ovulation by CG in women subjected to in vitro fertilization and embryo transfer results in maturation of the cumulus-oocyte complex (COC) in terms of oocyte meiotic maturation, cumulus mucification, and an increase in progesterone (P4) secretion. Recently an alternative approach, in which the ovulatory processes are induced by the administration of GnRH analog (GnRHa), has resulted in COCs yielding viable embryos. In the present study the effect of GnRHa administration on oocyte meiotic maturation and cumulus cell steroidogenesis was evaluated in 27 women undergoing ovarian stimulation with gonadotropin for the purpose of in vitro fertilization and embryo transfer. In GnRHa- or CG-treated women, 79.5 +/- 4.2% and 72.0 +/- 8.4% of the oocytes, respectively, manifested the first polar body. The percentages of atretic oocytes and of oocytes failing to resume meiosis were 5.8 +/- 2.1% and 6.0 +/- 2.4%, respectively, in GnRHa-treated women, and were 9.3 +/- 4.7% and 7.9 +/- 4.1%, respectively, in CG-treated women. P4 was secreted in high quantity in human cumulus cells (CCs) during a 7-day culture period. However, in CCs collected from GnRHa-treated women, P4 secretion was more than 50% less than in CCs of CG-treated women (P < 0.005). Addition of 20 alpha-hydroxycholesterol significantly increased P4 secretion in CCs collected from GnRHa-treated women, similar to P4 secretion in CCs collected from CG-treated women. This study evaluated for the first time the effectiveness of GnRHa administration on COC maturation. It seems that although oocyte meiotic maturation in GnRHa-treated women proceeds as in CG-stimulated women, CC steroidogenic activity is marked by cholesterol deficiency or availability.

Effect of cell-plating density on the steroidogenic activity of human cumulus cells

Expansion of the cumulus mass results in dilution of cumulus cells in accumulated hyaluronic acid. This process is associated with an increase in progesterone secretion. The present study was carried out to evaluate the relationship between these two processes in vitro. Dilution of human cumulus cells was attempted by changing the cell-plating density of cumulus cells in culture. Concurrent with an increase in cell-plating density from 0.25 x 10(4) to 8 x 10(4), progesterone secretion increased by 10.5 times (P < 0.001), 9 times (P < 0.001), and 5.9 times (P < 0.001), and oestradiol secretion increased by 1.4 times (P < 0.001), 1.1 times (P > 0.05), and 2.6 times (P < 0.005) during days 0-3, 3-5, and 5-7 of culture, respectively. However, when steroid secretion was expressed in terms of ng per number of cells, the increase in cell-plating density from 0.25 x 10(4) to 8 x 10(4) coincided with a decrease in progesterone secretion of 3 times (P < 0.001), 3.5 times (P < 0.001), 30 times (P < 0.001), and 12.5 times (P < 0.001) during days 0-3, 3-5, and 5-7 of culture, respectively. The progesterone:oestradiol ratio increased gradually with the increase in cell-plating density. However, at the higher range of cell-plating density the progesterone:oestradiol ratio decreased with extension of the culture period. Addition of human FSH (hFSH) or hCG increased progesterone secretion when the cumulus cells were plated at 2 x 10(4), but in most cases not at 0.25 x 10(4) or 8 x 10(4) cells per dish.(ABSTRACT TRUNCATED AT 250 WORDS)

Increasing progesterone secretion in human granulosa-luteal cells induced by human follicular fluid

Increasing evidence suggests that local ovarian agents play a central role in the regulation of follicular maturation and corpus luteum formation. In previous studies, we have shown that porcine follicular fluid induces granulosa cell luteinization in sow, human and rat. In the present study, the effect was investigated of either human follicular fluid (FF) alone, human follicle-stimulating hormone (FSH) alone, or both upon progesterone secretion of human granulosa-luteal cells. Granulosa-luteal cells were cultured in the presence of either FSH (5, 50 and 250 ng/ml), lyophilized FF (50 and 250 micrograms/ml) or both. Secretion of progesterone increased from a minimum of 2.5-fold to a maximum of 23-fold in the presence of FSH alone and, significantly less (approximately 2-fold) in the presence of FF alone, compared to cells cultured in medium alone. The co-administration of FSH and FF was significantly more effective than either alone, while addition of both FSH (250 ng/ml) and FF (250 micrograms/ml) gave maximal progesterone secretion. In granulosa-luteal cells pre-cultured with both FSH and FF, subsequent exposure to human chorionic gonadotrophin (HCG) alone increased progesterone secretion 1.6-fold to 11-fold, compared to cells pre-cultured with FSH alone. The effect of FF from individual follicles was also studied. FF from follicles yielding mature cumulus-oocyte complexes was 4.2-fold more effective, than FF obtained from follicles yielding immature cumulus-oocyte complexes in enhancing the FSH stimulation of progesterone secretion.(ABSTRACT TRUNCATED AT 250 WORDS)

Secretion of two different flowing masses by lymphokine-activated killer cells

When grown on mesenchyme-fibroblastoid monolayers made of 16-day-old embryos, lymphokine-activated killer (LAK) cells in clones derived from nude mouse lymph node cells are signaled to synthesize and secrete two mucoid masses. The first is made of chondroitin sulfate, as determined by the degradation of 35S- and [3H]glucosamine-labeled macromolecules in the extracellular matrix, by hyaluronidase, and by chondroitin sulfate lyase AC. This determination correlates with the distinctive blue staining by periodic acid-Schiff/alcian blue (PAS-Ab) at pH 1.0. In the present study, two different masses were identified when methanol-fixed and dried LAK cells and their secretions were examined prior to staining. The chondroitin-sulfate-containing mass appeared as an optically bright structure. It also produced a positive fluorescence with rabbit anti-mouse perforin. The second structure, which appeared as a flowing material or as filling holes in the first, could be identified by its high optical density. However, it was not stained by PAS-Ab and was not blackened by osmium tetroxide. The biochemical nature of the second mass has yet to be determined. Both masses seemed eventually to mix, producing pools, in lacunae, or to spread into the culture space.

[Haemaphysalis (Alloceraea) inermis Birula, 1895, in a wooded area of Latium]

Haemaphysalis (Alloceraea) inermis Birula specimens have been collected in a woody land of Manziana in the province of Rome. This is the first report in Latium region and suggests the presence of autochthonous populations of the species in Central Italy since no exotic fauna has been introduced in the past in the area studied. The role of H. inermis on the transmission of pathogens for humans and animals is discussed.