Association Between Wolbachia Infection and Susceptibility to Deltamethrin Insecticide in Phlebotomus papatasi (Diptera: Psychodidae), the Main Vector of Zoonotic Cutaneous Leishmaniasis

Background: Phlebotomus papatasi (Diptera: Psychodidae) is the main vector of zoonotic cutaneous leishmaniasis. Wolbachia is a symbiotic alphaproteobacteria of arthropods that can be involved in susceptibility or resistance. This study aimed to investigate the relationship between Wolbachia and Deltamethrin susceptibility/resistance in Ph. papatasi. Deltamethrin filter papers (0.00002%) were used to test sand fly field collected from southern Iran. After the test, PCR amplification of the Wolbachia surface protein gene (wsp) was used to measure Wolbachia infection rate in the killed, surviving, and control groups. Result: The rates of infection by Wolbachia strain (wPap, super group A) differed between killed (susceptible) and surviving (resistant) Ph. papatasi specimens. The rate of Wolbachia infection in susceptible individuals was more than twice (2.3) (39% vs. 17%) in resistant individuals with the same genetic background. This difference was highly significant (p < 0.001), indicating a positive association between Wolbachia infection and susceptibility to Deltamethrin. In addition, the results showed that Deltamethrin can act as a PCR inhibitor during detection of Wolbachia in Ph. papatasi. Conclusion: Results of this study show that Wolbachia is associated with Deltamethrin susceptibility level in Ph. papatasi. Also, as Deltamethrin has been identified as a PCR inhibitor, great care must be taken in interpreting Wolbachia infection status in infected populations. The results of this study may provide information for a better understanding of the host-symbiont relationship, as well as application of host symbiosis in pest management.

Characterisation of an area of coexistent visceral and cutaneous leishmaniasis transmission in the State of Piauí, Brazil

BACKGROUND

In Brazil, transmission of visceral and cutaneous leishmaniasis has expanded geographically over the last decades, with both clinical forms occurring simultaneously in the same area.

OBJECTIVES

This study characterised the clinical, spatial, and temporal distribution, and performed entomological surveillance and natural infection analysis of a leishmaniasis-endemic area.

METHODS

In order to characterise the risk of leishmaniasis transmission in Altos, Piauí, we described the clinical and socio-demographic variables and the spatial and temporal distribution of cases of American visceral leishmaniasis (AVL) and American cutaneous leishmaniasis (ACL) cases and identified potential phlebotomine vectors.

FINDINGS

The urban area concentrated almost 54% of ACL and 86.8% of AVL cases. The temporal and spatial distribution of AVL and ACL cases in Altos show a reduction in the number of risk areas, but the presence of permanent disease transmission foci is observed especially in the urban area. 3,808 phlebotomine specimens were captured, with Lutzomyia longipalpis as the most frequent species (98.45%). Of the 35 females assessed for natural infection, one specimen of Lu. longipalpis tested positive for the presence of Leishmania infantum and Leishmania braziliensis DNA.

MAIN CONCLUSION

Our results indicate the presence of risk areas for ACL and AVL in the municipality of Altos and highlight the importance of entomological surveillance to further understand a possible role of Lu. longipalpis in ACL transmission.

Infection of Leishmania donovani in Phlebotomus orientalis Sand Flies at Different Microhabitats of a Kala-Azar Endemic Village in Eastern Sudan

A study was carried out to compare the infection rates of Leishmania donovani in Phlebotomus orientalis sandflies at different microhabitats of a VL endemic village in Gedarif state, Sudan. DNA extracts of 1078 P. orientalis sand fly females sampled by CDC light traps from indoor, outdoor, peri-domestic, and sylvatic sites, in three transmission seasons, March-June 2016-18, in Helat-Belo village, were subjected to independent PCR amplifications targeting Leishmania kDNA and the cpb gene followed by ITS1 region sequencing. Leishmania kDNA was detected in 1.4% of the 1078 P. orientalis females captured in the area. Two of these specimens showed a characteristic 741 bp band of L. donovani after cpb gene amplification. The DNA sequence of the ITS1 region of the parasites matched the ITS1 L. donovani genotype F. There were no signficant differences between rates of infection of L. donovani in P. orientalis captured at different sites. Blood meals found in infected flies origninated from human (5 specimens), cattle (4 specimens) and donkey (2 specimens). The finding of fresh cow and donkey blood in the infected flies suggests the possible role of these animals in the zoopotentiation and/or zooprophylaxis against VL. The study provides important information for VL transmission models and control programs in East Africa.

Leishmania (Leishmania) infantum DNA detection in Nyssomyia neivai in Vale do Ribeira, Paraná, Brazil

BACKGROUND

The incidence of visceral leishmaniasis (VL) has increased in the Southern region of Brazil in recent years, especially in the State of Paraná. New species have been suggested with potential to act as vector in VL endemic areas.

OBJECTIVES

Identify the Leishmania species in sand fly specimens collected from 2016 to 2018 in the municipality of Itaperuçu, Vale do Ribeira, Paraná, Brazil.

METHODS

Light traps were used for collections and for the analysis of sand fly were used the multiplex polymerase chain reaction (PCR) methodology and subsequent sequencing.

FINDINGS

Among the collected specimens, 88.62% were attributed to the species Nyssomyia neivai, which were grouped into 176 pools. Three positive pools were detected: two with Leishmania (Viannia) braziliensis and one with L. (Leishmania) infantum. The positivity rate for the parasite was 0.25% based on the presence of at least one infected insect in the pool.

MAIN CONCLUSIONS

The detection of L. infantum in Ny. neivai draws attention due to its abundance and anthropophily in the State of Paraná. Moreover, this finding is considered as an alert and suggests that the vector competence of Ny. neivai and the criteria for its incrimination should be carried out, given its wide distribution in southern of Brazil.

Host preference and human blood index of Phlebotomus orientalis, an exophilic sand fly vector of visceral leishmaniasis in eastern Sudan

Visceral leishmaniasis (VL, kala azar), caused by Leishmania donovani, transmitted by Phlebotomus orientalis, is a serious systemic disease that causes high morbidity and mortality rates in Sudan and other parts of East Africa and the world. Despite progress in understanding the epidemiology of the disease in East Africa, little is known about the host preference of P. orientalis in kala azar endemic villages of Sudan, which have some of the highest VL incidence rates in the world. The present study used host choice experiments and blood-meal identification approaches to determine the host preference of P. orientalis in kala azar endemic villages in Gedarif state, eastern Sudan. In the host choice experiment, tent traps were used to compare the attractiveness of cows, donkeys, sheep and goats for host-seeking P. orientalis. In the blood-meal identification study, blood-fed P. orientalis females, captured inside houses and peri-domestic habitats, were subjected to molecular typing using cytochrome b gene (cyt b) amplification and sequence analysis. Cows and donkeys were the most attractive to blood-seeking P. orientalis, followed by goats. Similarly, the blood-meal analysis of P. orientalis showed that the vector preferentially feeds on cows, followed by donkeys, humans and goats. The human blood index of P. orientalis was 19.4% (42/216), indicating a high zoophilic habit of the vector, both inside and outside the houses. Although the order of host preference varied by location, it was clear that cows are the most preferred host of P. orientalis in the area. Results are discussed in relation to the role of domestic/livestock animals in VL zoopotentiation and zooprophylaxis. Inference is made on the potential impact of insecticide treatment of cows in control of the vector and the transmission of VL in Sudan and other parts of East Africa.

Sand fly bionomics, geospatial investigation and risk factors associated with cutaneous leishmaniasis in district Mardan, Pakistan

The present investigation was designed in response to the 2019 outbreak of cutaneous leishmaniasis (CL) in 34 villages of district Mardan, Pakistan. Sand flies were collected to study their bionomics, breeding sites, and seasonal prevalence from July to September 2019. In 2020, we acquired and digitized data on CL patients in the region to assess the possible spread of the disease to new foci. In the study period, a total of 1572 sand flies were collected, comprising 11 species. Phlebotomus sergenti (827, 52.61%) was the most widespread species. The soil pH in all samples was slightly alkaline (7-8.2) and potassium (K) was the richest component (59.4%). In 2020, there were 975 reported cases, which is an increase from 536 cases in 2019. Elevations of 361-588 m, agricultural land near human settlements, and quaternary alluvium formation had maximum CL cases. In univariate analysis, age between 25 and 35, nationality, family size (7-15 individuals), knowledge of leishmaniasis, site of infection, family members suffering from leishmaniasis, knowledge of sand flies, the difference between mosquitoes and sand flies, biting times of sand flies, use of mosquito spray, an Afghan refugee in the region, preachers visiting, and material of house construction have been identified risk of getting CL (p < 0.05). In stepwise multivariate analysis, nationality, vegetation, site of infection, and material of house construction were more prone to CL (p < 0.05). This study highlights the potential risk factors and sand flies associated with the outbreak of CL in Mardan. The high abundance of P. sergenti suggests their possible role as vectors for the transmission of CL in the region. The increase in reported cases in 2020 compared to 2019 suggests a possible spread of the disease to new foci. The study also revealed that certain demographic and environmental factors were significant risk factors for contracting CL in the district.

Same parasite, different outcomes: unraveling the epidemiology of Leishmania infantum infection in Brazil and Spain

Human leishmaniosis caused by Leishmania infantum is an important health problem worldwide. One of the main aspects arousing interest is the epidemiological scenario surrounding Le. infantum infection in the New World (NW) and Old World (OW). This parasite was introduced to the Americas during European colonization leading to different epidemiology outcomes, even more enigmatic in the face of global changes. Thus, this review aims to highlight the differences and similarities between Le. infantum epidemiology between Brazil (NW) and Spain (OW), as both countries are leading the total number of leishmaniosis cases in their respective continents. Grounded on a systemic view, this article also draws attention to possible common innovative strategies to rethink ways of controlling infections caused by Le. infantum.

Biomolecular Minerals and Volcanic Glass Bio-Mimics to Control Adult Sand Flies, the Vector of Human Leishmania Protozoan Parasites

Sand flies (Diptera: Psychodidae) serve as vectors for transmitting protozoan parasites, Leishmania spp., that cause the disease called leishmaniasis. The main approach to controlling sand flies is the use of chemical insecticides. The discovery of alternative methods for their control is needed because of potential health risks of chemical insecticides and development of sand fly resistance to these pesticides. The biomineral produced by diatoms (diatomaceous earth, DE; Celite) and a volcanic glass bio-mimic (Imergard) have been shown by our group to be efficacious against mosquitoes, filth flies, and ticks but never studied for the control of sand flies. In a modified World Health Organization cone test, 50% of adult Phlebotomus papatasi sand flies at 29 ± 1 °C, 55 ± 5% RH, and 12:12 LD, when exposed to Imergard and Celite, were dead in 13.08 and 7.57 h, respectively. Proof of concept was established for the use of these biominerals for sand fly and leishmaniasis disease control. Using a light source as an attractant to the minerals had no significant effect on the LT50, the time to 50% mortality. The LT50 at a higher relative humidity of 70 ± 5% increased to 20.91 and 20.56 h for Imergard and Celite, respectively, suggesting their mode of action was dehydration. Scanning electron microscopy of dead sand flies showed high coating levels of Celite only on the sides of the thorax and on the tarsi, suggesting an alternative mode of action for mechanical insecticides.

Limited Cutaneous Leishmaniasis as Ulcerated Verrucous Plaque on Leg, Tucson, Arizona, USA1

We report a 34-year-old man who had a nonhealing, verrucous plaque with central ulceration on the lower leg. This case-patient is a rare example of endemic limited cutaneous leishmaniasis in Tucson, Arizona, USA. Clinicians should be aware of this disease because its manifestations can vary for individual patients.

Sciopemyia sordellii in the Neotropical region: distribution, biology, and ecology

The species Sciopemyia sordellii (Diptera, Phlebotominae) is widely distributed throughout the American continent. This raises doubts about their identity as a single biological entity and points to the occurrence of species complex. Here, we review the geographic distribution of S. sordellii in the Neotropical region, as well as data on its biology and ecology. Records were obtained from literature and from specimens deposited in biological collections. In total, 149 records were analysed, from 12 countries in America. However, after taxonomic revision, some specimens were wrongly identified as S. sordellii, especially those from Peru, putting in doubt the occurrence of the species in that country. In Brazil, it has been recorded in all five geographic regions and collected in different biomes, besides to other ecotypes such as caves. Furthermore, its presence in an anthropized environment has also been reported. Some studies have also diagnosed Leishmania DNA in S. sordellii, indicating that parasite circulation is being maintained between the reservoir hosts. The data evaluated in our study allowed us to provide updated information on the distribution of S. sordellii in America, which may be useful in the taxonomy of this species.

Emerging parasites and vectors in a rapidly changing world: from ecology to management

Global changes have influenced our societies in several ways with both positive (e.g., technology, transportation, and food security), and negative impacts (e.g., mental health problems, spread of diseases, and pandemics). Overall, these changes have affected the distribution patterns of parasites and arthropod vectors with the introduction and spreading of alien species in new geographical areas, eventually posing new challenges in public health. In this framework, the Acta Tropica Special Issue "Emerging parasites and vectors in a rapidly changing world: from ecology to management" provides a focus on the biology, ecology and management of emerging parasites and vectors of human and veterinary importance. Herein we review and discuss novel studies dealing with interactions of parasites and vectors with animals in changing environmental settings. In our opinion, a special focus on the implementation of management strategies of parasitic diseases to face anthropogenic environmental changes still represent a priority for public health. In the final section, key research challenges in this rapidly changing scenario are outlined.

Cutaneous Leishmaniasis Emergence in Southeastern Mexico: The Case of the State of Yucatan

Environmental changes triggered by deforestation, urban expansion and climate change are present-day drivers of the emergence and reemergence of leishmaniasis. This review describes the current epidemiological scenario and the feasible influence of environmental changes on disease occurrence in the state of Yucatan, Mexico. Relevant literature was accessed through different databases, including PubMed, Scopus, Google, and Mexican official morbidity databases. Recent LCL autochthonous cases, potential vector sandflies and mammal hosts/reservoirs also have been reported in several localities of Yucatan without previous historical records of the disease. The impact of deforestation, urban expansion and projections on climate change have been documented. The current evidence of the relationships between the components of the transmission cycle, the disease occurrence, and the environmental changes on the leishmaniasis emergence in the state shows the need for strength and an update to the intervention and control strategies through a One Health perspective.

Characterization of the glutathione S-transferase genes in the sand flies Phlebotomus papatasi and Lutzomyia longipalpis shows expansion of the novel glutathione S-transferase xi (X) class

Leishmaniasis control often relies upon insecticidal control of phlebotomine sandfly vector populations. Such methods are vulnerable to the evolution of insecticide resistance via a range of molecular mechanisms. There is evidence that two major resistance mechanisms, target site insensitivity and metabolic resistance, have evolved in some sandfly populations and further genetic characterization of resistance would be useful to understand and combat it. To facilitate the study of the mechanisms of metabolic resistance, here we improved the annotation and characterized a major detoxification gene family, the glutathione-s-transferases (GST), in the genomes of two sand fly species: Phlebotomus papatasi and Lutzomyia longipalpis. The compositions of the GST gene family differ markedly from those of Aedes and Anopheles mosquitoes. Most strikingly, the xi (X) class of GSTs appears to have expanded in both sand fly genomes. Our results provide a basis for further studies of metabolic resistance mechanisms in these important disease vector species.

Point Prevalence Studies Are Necessary as First Steps in Studying the Epidemiology of Viruses and Other Pathogens Transmitted by Arthropods

Studies of the epidemiology of arthropod-borne viruses are based on understanding whether a given virus is found in a particular location or locations, how prevalent the virus is in that area, which vertebrate hosts serve as reservoirs of the virus, the relationship between the size of the populations of these reservoirs and the prevalence of the virus and, of course, whether the virus causes human, livestock, or wildlife diseases, as well as other characteristics. However, seasonal conditions fluctuate, annual conditions fluctuate, human impacts alter the environment, and the habitat and ecosystems naturally change. Because these parameters provide a more encompassing view of the natural history of a virus, it is important to recognize that point prevalence studies comprise only a single view of the situation and that longitudinal studies are required to obtain a more complete and useful understanding of the natural history of the virus. This paper provides details as to whether and how to conduct such studies.

Laboratory evidence that dinotefuran, pyriproxyfen and permethrin combination abrogates Leishmania infantum transmissibility by sick dogs

Dogs are reservoir hosts of leishmaniasis caused by Leishmania infantum and transmitted by phlebotomine vectors. The effect of dinotefuran, pyriproxyfen and permethrin spot-on solution (Vectra®3D, Ceva Santé Animale, Libourne, France) on Leishmania transmissibility by naturally infected dogs via reared Phlebotomus perniciosus, was assessed. Dogs affected by leishmaniasis were submitted to xenodiagnosis and 6 infecting >10% of insects were treated topically on day 0. Antifeeding, insecticidal and anti-transmissibility effects were evaluated through xenodiagnoses performed on days 1, 7 and 28, using individual pre-treatment parameters as control. Feeding and mortality rates were assessed at 24 h, whereas promastigote infection, maturation and burden were assessed up to 96 h post blood meal (potentially infectious rate). On day 1, the anti-feeding efficacy was >95% in 4 dogs, insecticidal efficacy 100% in 4 dogs, and anti-transmissibility effect 100% in 6 dogs. Efficacy rates recorded on day 7 were very similar to day 1. On day 28, anti-feeding and insecticidal efficacy values were much broader, ranging 32.6-100% and 7.7-94.4%, respectively. Potentially infectious insects were recorded from two dogs, with sharp decrease in transmissibility rate as compared with pre-treatment condition. Altogether, Vectra®3D abrogated by >98% the potential Leishmania transmissibility by the examined pool of infected dogs over 1 month.

Phlebotomine sand flies (Diptera: Psychodidae) from an emergent focus of localized cutaneous leishmaniasis in Yucatan, Southeast Mexico

Localized cutaneous leishmaniasis (LCL) is endemic in the Yucatan Peninsula, with historical and contemporary records mainly in the states of Campeche and Quintana Roo. Recently, we reported autochthonous LCL cases and 27.6% of asymptomatic infection in the municipality of Tinum, Yucatan, where no studies of Phlebotominae (Diptera: Psychodidae) sand flies have been carried out. In this work, from November, 2019 to February, 2020, we conducted a field study in three areas of Tinum to document, for the first time, the species of Phlebotominae in areas with records of human leishmaniasis transmission. In order of abundance, the species identified were Pifanomyia serrana, Psathyromyia shannoni, Psathyromyia cratifer, Lutzomyia cruciata, Bichromomyia olmeca olmeca, and Dampfomyia deleoni. Most of the sand flies were captured in a Shannon trap where 77.8% of collected specimens were females. The distribution of sand fly species showed some degree of heterogeneity among sites, and the highest species richness was registered in a site located in Xcalakoop. We also discuss the medical importance of Lu. cruciata, Ps. shannoni, and Pi. serrana as potential vectors of causal agents of LCL in this area.

Description of Evandromyia cristacapita sp. nov., a new sand fly species of the Argentinian Chaco

A new species of phlebotomine sand fly collected in the rural and peri-urban areas of wet and dry subregions of the Chaco Province, Argentina, is described. Illustrations of male and female adults are presented. Morphological characters allow the inclusion of the new species within the Evandromyia genus, Barrettomyia subgenus, Cortelezzii series (Diptera: Psychodidae). Furthermore, we present an identification key for the Cortelezzii series of the Barrettomyia subgenus with a new distinct species complex for its correct identification. The species was denominated as Evandromyia cristacapita sp. nov.

Incubation Period for Neuroinvasive Toscana Virus Infections

Toscana virus (TOSV) is an emerging pathogen in the Mediterranean area and is neuroinvasive in its most severe form. Basic knowledge on TOSV biology is limited. We conducted a systematic review on travel-related infections to estimate the TOSV incubation period. We estimated the incubation period at 12.1 days.

Development of Various Leishmania (Sauroleishmania) tarentolae Strains in Three Phlebotomus Species

Leishmania (Sauroleishmania) tarentolae is transmitted by reptile-biting sand flies of the genus Sergentomyia, but the role of Phlebotomus sand flies in circulation of this parasite is unknown. Here, we compared the development of L. (S.) tarentolae strains in three Phlebotomus species: P. papatasi, P. sergenti, and P. perniciosus. Laboratory-bred sand flies were membrane-fed on blood with parasite suspension and dissected on days 1 and 7 post blood meal. Parasites were measured on Giemsa-stained gut smears and five morphological forms were distinguished. In all parasite-vector combinations, promastigotes were found in Malpighian tubules, often in high numbers, which suggests that this tissue is a typical location for L. (S.) tarentolae development in sand flies. All three studied strains colonized the hindgut, but also migrated anteriorly to both parts of the midgut and colonized the stomodeal valve. Significant differences were demonstrated between sand fly species: highest infection rates, high parasite loads, and the most frequent anterior migration with colonization of the stomodeal valve were found in P. perniciosus, while all these parameters were lowest in P. sergenti. In conclusion, the peripylarian type of development was demonstrated for three L. (S.) tarentolae strains in three Phlebotomus sand flies. We suggest paying more attention to Phlebotomus species, particularly P. perniciosus and P. papatasi, as potential secondary vectors of Sauroleishmania.

Characterization of sand fly breeding sites in district Malakand, Khyber Pakhtunkhwa, Pakistan, and evaluation of risk factors for cutaneous leishmaniasis in the region

Present study was carried to determine the sand fly species composition, breeding sites ecology, seasonal abundance, and spatial distribution in district Malakand, Khyber Pakhtunkhwa, Pakistan. In addition, risk factors associated with cutaneous leishmaniasis (CL) were also evaluated. Survey of indoor and outdoor habitats was carried out using sticky traps in 31 villages of Dargai and Batkhela tehsils of Malakand. Soil from habitats of adult and immature sand flies was analysed. Questionnaire-based household survey was also performed in these villages to assess risk factors associated with CL. Soil samples from selected CL positive households were analysed for its contents. Additionally, clinicoepidemiological data from local health centres was examined for the year 2019. Total of 3,140 sand flies belonging to 18 species were collected. Phlebotomus sergenti was the most abundant species (38.16%). Its abundance had a strong positive correlation with mean monthly relative humidity and negative correlation with average temperature. Phlebotomus sergenti and Phlebotomus papatasi were abundant at an elevation ranging from 320 to 1,120 m above sea level and in agricultural lands near human settlements. Flight height preference apparatus collected maximum sand flies at 30 cm (1ft) above the ground and all species associated negatively with height. Soil analysis from habitats of adult and immature flies showed that highest mean number of adults and immatures were recorded from silt loam which carried highest concentrations of K₂ O, Mg, Ca, and Zn. Number of immature sand flies correlated moderately (r = .7, p < .05) with K₂ O soil concentrations. There was significant similarity between organic matter contents in soil samples from positive breeding sites and CL households (Wilcoxon rank-sum test, p = .1976). In multivariate analysis model for CL risk factors, age (26-35 and >35 years), knowledge of leishmaniasis, living in a middle and upper class, preachers visit to villages, and assumption that Afghan refugees are more prone to CL were significant. CL patient's archived data from health centres showed that majority of patients had lesions on face and hands. Patient's influx was highest in February and March.

Risk Assessment of the Role of the Ecotones in the Transmission of Zoonotic Cutaneous Leishmaniasis in Central Tunisia

Zoonotic cutaneous leishmaniasis (ZCL), endemic in Central and Southern Tunisia, is caused by Leishmania major (Kinetoplastida: Trypanosomatidae), which is transmitted by the sand fly Phlebotomus papatasi. In Tunisia, the fat sand rat Psammomys obesus and the desert jird Meriones shawi are the principal reservoir hosts of L. major. The presence of the P. papatasi vector of the L. major etiologic agent of ZCL was assessed in the vicinity of villages in endemic areas of Central Tunisia. The study was performed from September through October 2019, a period corresponding to the main peak of activity of P. papatasi. Sand flies were collected from rodent burrows located at the ecotone level, which is the transition zone between the natural environment and human settlement. Sand flies were identified to species level and tested for the presence of L. major by PCR. Our entomological survey showed that P. papatasi is the most abundant sand fly species associated with rodent burrows, and this abundance is even higher in ecotones primarily occupied by P. obesus in comparison to ecotones occupied by M. shawi. Infections with Leishmania major were detected only in P. papatasi, with an overall minimum infection rate (MIR) of 2.64%. No significant difference was observed between the MIRs in ecotones of P. obesus and of M. shawi. Incidence of ZCL in the studied areas ranged from 200 to 700 cases per 100,000 inhabitants, with a mean incidence of 385.41 per 100,000. Higher ZCL incidence was identified in ecotones of M. shawi compared to ecotones of P. obesus. ZCL cases are positively correlated with the MIRs. Considering the short flight range of P. papatasi, increases in its densities associated with burrows of P. obesus or M. shawi at the ecotone level expand the overlap of infected vectors with communities and subsequently increase ZCL incidence. Therefore, control measures should target P. papatasi populations at the ecotones.

Serological Evidence of Phleboviruses in Domestic Animals on the Pre-Apennine Hills (Northern Italy)

Phleboviruses are arboviruses transmitted by sand flies, mosquitoes and ticks. Some sand fly-borne phleboviruses cause illnesses in humans, such as the summer fevers caused by the Sicilian and Naples viruses or meningitis caused by the Toscana virus. Indeed, traces of several phleboviral infections have been serologically detected in domestic animals, but their potential pathogenic role in vertebrates other than humans is still unclear, as is the role of vertebrates as potential reservoirs of these viruses. In this study, we report the results of a serological survey performed on domestic animals sampled in Northern Italy, against four phleboviruses isolated from sand flies in the same area. The sera of 23 dogs, 165 sheep and 23 goats were tested with a virus neutralization assay for Toscana virus, Fermo virus, Ponticelli I virus and Ponticelli III virus. Neutralizing antibodies against one or more phleboviruses were detected in four out of 23 dogs, 31 out of 165 sheep and 12 out of 23 goats. This study shows preliminary evidence for the distribution pattern of phleboviral infections in different animal species, highlighting the potential infection of the Toscana virus in dogs and the Fermo virus in goats.

Leishmaniases in the European Union and Neighboring Countries

A questionnaire survey of animal and human health authorities in Europe revealed that leishmaniases are not notifiable in all countries with autochthonous cases. Few countries implement surveillance and control targeting both animal and human infections. Leishmaniases are considered emergent diseases in most countries, and lack of resources is a challenge for control.

Leishmania infantum in Tigers and Sand Flies from a Leishmaniasis-Endemic Area, Southern Italy

We detected Leishmania infantum infection in 45% of tigers and 5.3% of sand flies tested at a zoo in southern Italy in 2019. These infections in tigers and the abundance of Phlebotomus perniciosus sand flies represent a potential risk to other animals and humans living in or visiting the zoo.

Emerging Sand Fly-Borne Phlebovirus in China

We isolated 17 viral strains capable of causing cytopathic effects in mammalian cells and death in neonatal mice from sand flies in China. Phylogenetic analysis showed that these strains belonged to the genus Phlebovirus. These findings highlight the need to control this potentially emerging virus to help safeguard public health.

Redescription of Two Psathyromyia Species (Diptera: Psychodidae), Including Description of the Female of Psathyromyia pradobarrientosi Using Molecular and Morphological Approaches

The taxonomic identity of two species of sand flies, Psathyromyia pradobarrientosi (Le Pont, Matias, Martinez & Dujardin, 2004) and Psathyromyia runoides (Fairchild & Hertig, 1953) (Diptera, Psychodidae), was evaluated morphologically and molecularly based upon specimens collected in Brazilian states. The morphological component compared collected specimens with paratypes of Pa. runoides and Pa. pradobarrientosi and their descriptions. Phylogenetic analysis of coI sequences of Pa. pradobarrientosi showed a well-supported group distinct from Pa. runoides. Morphologically, Psathyromyia runoides and Pa. pradobarrientosi males are distinguished by characteristics of the aedeagal ducts and parameral sheath in the genitalia; females are distinguished by the number and shape of the teeth in the cibarium and by the shape of the spermathecae. Given the morphological similarity between the males and the absence of the description of the female of Pa. pradobarrientosi, it is possible that specimens previously identified as Pa. runoides in Brazil are in fact Pa. pradobarrientosi.

TRsandflies: A Web-Based Software for the Morphometric Identification of Sand Flies in Turkey

Sand flies are vector of several diseases, mostly cutaneous and visceral leishmaniasis (CL and VL). Also, 29 sand fly species have been identified in previous fauna studies carried out in 40 provinces of Turkey. Totally, 24 sand flies species belonging to Phlebotomus (Ph.) (Diptera: Psychodidae) genus have been proven or reported as possible vector species. This study aimed to develop a new software which could contribute to researchers' decision making about the identification of sand flies with obtained data from entomological surveys conducted before in Turkey. Developed software called TRsandflies included 35 textbox created with parameters obtained from caught sand flies specimens by the above-mentioned surveys. It also contained 130 photos and distribution maps related to 24 sand flies species. In addition, C# language and MYSQL database were used in the program. TRsandflies had three different forms (pages) allowing the user to compare the specimens and known species. In the species identification trials with three repetitions carried out in the program, except for the specimens belonging to the Transphlebotomus Artemiev & Neronov, 1984 subgenus, morphometric data of all previously collected sand fly species specimens were included. The process of running the morphometric measurement results of predetermined specimens in the program provided us with an accurate prediction rate of 86.66% in male specimens and 71.66% in female specimens. We concluded that the web-based software developed could play an important role in reducing the rate of possible errors that might be encountered by conventional identification methods.

Leishmania mexicana in a central Texas cat: clinical presentation, molecular identification, sandfly vector collection and novel management

Case summary

This case report documents the clinical appearance, diagnosis and novel treatment of a central Texas cat with cutaneous leishmaniosis. The cat presented with a linear erosion on the right pinnal margin, an ulcerated exophytic nodule on the right hock and a swelling in the right nostril. Cytological and histopathological findings were consistent with leishmaniosis. PCR confirmed the presence of Leishmania mexicana, a species endemic to Texas. An epidemiological investigation was conducted by trapping sandflies from the cat’s environment. Sandflies collected were identified as Lutzomyia species, known vectors of Leishmania species. Given the lack of validated medical therapies for L mexicana in cats, treatments typically prescribed for canine leishmaniosis were administered. Allopurinol achieved clinical success but was discontinued due to suspected drug-related neutropenia. Topical imiquimod also improved lesional skin but was not sustainable due to application difficulty. Oral administration of artemisinin resulted in significant clinical improvement of cutaneous lesions without reported adverse events. Nearly 8 months after the initiation of artemisinin therapy, the cat remained systemically healthy with stable lesions.

Relevance and novel information

This case report demonstrates endemic feline leishmaniosis in central Texas and provides the clinician with alternative therapeutic options for medical management.

Oviposition-Site Selection of Phlebotomus papatasi (Diptera: Psychodidae) Sand Flies: Attraction to Bacterial Isolates From an Attractive Rearing Medium

Phlebotomine sand flies are worldwide vectors of Leishmania parasites as well as other bacterial and viral pathogens. Due to the variable impact of traditional vector control practices, a more ecologically based approach is needed. The goal of this study was to isolate bacteria from the most attractive substrate to gravid Phlebotomus papatasi Scopoli sand flies and determine the role of bacterial volatiles in the oviposition attractancy of P. papatasi using behavioral assays. We hypothesized that gravid sand flies are attracted to bacterially derived semiochemical cues associated with breeding sites. Bacteria were isolated from a larvae-conditioned rearing medium, previously shown to be highly attractive to sand flies. The isolated bacteria were identified by amplifying and sequencing 16S rDNA gene fragments, and 12 distinct bacterial species were selected for two-choice olfactometer bioassays. The mix of 12 bacterial isolates elicited strong attraction at the lower concentration of 107 cells per ml and significant repellence at a high concentration of 109 cells per ml. Three individual isolates (SSI-2, SSI-9, and SSI-11) were particularly attractive at low doses. In general, we observed dose-related effects, with some bacterial isolates stimulating negative and some positive dose-response curves in sand fly attraction. Our study confirms the important role of saprophytic bacteria, gut bacteria, or both, in guiding the oviposition-site selection behavior of sand flies. Identifying the specific attractive semiochemical cues that they produce could lead to development of an attractive lure for surveillance and control of sand flies.

Detection of Changuinola virus (Reoviridae: Orbivirus) in field-caught sand flies in southern Thailand

BACKGROUND

Phlebotomine sand flies are vectors for several pathogenic bacteria, parasites and viruses that have significant impacts on public health. Sand fly-associated viruses that cause diseases in humans and animals have recently received more attention. This study aimed to detect pathogenic viruses belonging to the Orbivirus genus, Phlebovirus genus, Flavivirus genus and family Rhabdoviridae in several field-caught sand fly species in southern Thailand.

METHODS

Sand flies were collected in southern Thailand using CDC light traps. Each sample was processed individually for virus screening using RT-PCR and sequencing.

RESULTS

Seven out of 60 sand fly samples (two samples of Idiophlebotomus spp., three of Phlebotomus papatasi and two of Sergentomyia khawi) were positive for the Orbivirus genus, which is closely related to Changuinola virus (CGLV). Phlebovirus genus, Flavivirus genus and family Rhabdoviridae were negative in all samples.

CONCLUSIONS

CGLV causes Changuinola virus disease or Changuinola fever, a febrile illness in Central and South America. The virus has never been reported in Thailand. This study is the first report of the detection of CGLV in sand flies from Thailand. An extensive study of sand flies from other regions of the country and the associations between sand flies, viruses and vertebrate hosts in Thailand should be undertaken.

Sand Flies Control: A Review of the Knowledge of Health Professionals and the Local Community, Province of El Hajeb, Morocco

Sand flies are insect vectors of several diseases including leishmaniases. These vector-borne diseases represent a public health problem in several countries around the world, including Morocco. The objective of this study was to assess simultaneously the knowledge of health professionals and inhabitants on sand flies; a cross-sectional survey was conducted between April and June 2019 among 424 people, 34% of whom were health professionals and 66% of whom were inhabitants of the province of El Hajeb in central Morocco; 46.3% of doctors, 50.7% of nurses, 66.7% of midwives and 69.4% of inhabitants showed a low knowledge of sand flies. Most participants believed that sand flies breed in stagnant and polluted waters. Negative attitudes were found among 72.2% of the inhabitants. Factors associated with a high level of knowledge included continuing education among health professionals and information on vector-borne diseases among residents. The conceptual and cognitive gaps in the knowledge of sand flies reflect the lack of information and training on sand flies. The results of the sand fly knowledge review can be integrated into the national leishmaniases control program and the integrated vector management strategy to raise public awareness on the health risks of sand flies.

Beauveria bassiana (Hypocreales: Cordycipitaceae) Reduces the Survival Time of Lutzomyia longipalpis (Diptera: Psychodidae), the Main Vector of the Visceral Leishmaniasis Agent in the Americas

Visceral leishmaniasis caused by Leishmania infantum (Kinetoplastida: Trypanosomatidae) is a major neglected tropical disease and Brazil is the responsible for most cases reported in the Americas. In this region, L. infantum is primarily transmitted by Lutzomyia longipalpis and Migonemyia migonei (França) (Diptera: Psychodidae) is considered a permissive vector. We evaluated the susceptibility of Lu. longipalpis and Mg. migonei to Beauveria bassiana and to Eucalyptus globulus (Myrtales: Myrtaceae) essential oil. A spore suspension of B. bassiana was prepared and sand flies divided into five groups: test 1 (107 spores/ml of B. bassiana with E. globulus essential oil at 4 mg/ml), test 2 (107 spores/ml of B. bassiana), test 3 (E. globulus essential oil at 4 mg/ml), positive control (cypermethrin 0.1%), and negative control (sterile distilled water). Scanning electron microscopy (SEM) was performed on specimens from each group. A 50% reduction was recorded in the survival time of Lu. longipalpis in test 1 and 2, where hyphal adhesion and cuticle damage were observed by SEM. No significant differences in the survival time of Mg. migonei were found, probable due to the high mortality rate observed in the negative control group, which may be a result of the greater sensitivity of this species to laboratory conditions. The results obtained herein suggest that B. bassiana may be a potential biological control agent against Lu. longipalpis, the main vector of L. infantum in the Americas.

Efficacy of factory-treated and dip-it-yourself long lasting insecticide-treated bednets against cutaneous leishmaniasis vectors in the sub-Andean region of Colombia: results after two years of use

BACKGROUND

Long lasting insecticide-treated nets (LLINs) may be effective for vector control of cutaneous leishmaniasis (CL). Their efficacy, however, has not been sufficiently evaluated.

OBJECTIVE

To evaluate the large-scale efficacy of LLINs on Lutzomyia longiflocosa entomological parameters up to two years post-intervention in the sub-Andean region of Colombia.

METHODS

A matched-triplet cluster-randomised study of 21 rural settlements, matched by pre-intervention L. longiflocosa indoor density was used to compare three interventions: dip it yourself (DIY) lambda-cyhalothrin LLIN, deltamethrin LLIN, and untreated nets (control). Sand fly indoor density, feeding success, and parity were recorded using CDC light trap collections at 1, 6, 12, and 24 months post-intervention.

FINDINGS

Both LLINs reduced significantly (74-76%) the indoor density and the proportion of fully engorged sand flies up to two years post-intervention without differences between them. Residual lethal effects of both LLINs and the use of all nets remained high throughout the two-year evaluation period.

CONCLUSIONS

Both LLINs demonstrated high efficacy against L. longiflocosa indoors. Therefore, the deployment of these LLINs could have a significant impact on the reduction of CL transmission in the sub-Andean region. The DIY lambda-cyhalothrin kit may be used to convert untreated nets to LLINs increasing coverage.

An expert opinion assessment of blood-feeding arthropods based on their capacity to transmit African swine fever virus in Metropolitan France

To deal with the limited literature data on the vectorial capacity of blood-feeding arthropods (BFAs) and their role in the transmission of African swine fever virus (ASFV) in Metropolitan France, a dedicated working group of the French Agency for Food, Environmental and Occupational Health & Safety performed an expert knowledge elicitation. In total, 15 different BFAs were selected as potential vectors by the ad hoc working group involved. Ten criteria were considered to define the vectorial capacity: vectorial competence, current abundance, expected temporal abundance, spatial distribution, longevity, biting rate, active dispersal capacity, trophic preferences for Suidae, probability of contact with domestic pigs and probability of contact with wild boar. Fourteen experts participated to the elicitation. For each BFA, experts proposed a score (between 0 and 3) for each of the above criteria with an index of uncertainty (between 1 and 4). Overall, all experts gave a weight for all criteria (by distributing 100 marbles). A global weighted sum of score per BFA was calculated permitting to rank the different BFAs in decreasing order. Finally, a regression tree analysis was used to group those BFAs with comparable likelihood to play a role in ASF transmission. Out of the ten considered criteria, the experts indicated vectorial competence, abundance and biting rate as the most important criteria. In the context of Metropolitan France, the stable fly (Stomoxys calcitrans) was ranked as the most probable BFA to be a vector of ASFV, followed by lice (Haematopinus suis), mosquitoes (Aedes, Culex and Anopheles), Culicoides and Tabanidea. Since scientific knowledge on their vectorial competence for ASF is scarce and associated uncertainty on expert elicitation moderate to high, more studies are however requested to investigate the potential vector role of these BFAs could have in ASFV spread, starting with Stomoxys calcitrans.

Putative Role of Arthropod Vectors in African Swine Fever Virus Transmission in Relation to Their Bio-Ecological Properties

African swine fever (ASF) is one of the most important diseases in Suidae due to its significant health and socioeconomic consequences and represents a major threat to the European pig industry, especially in the absence of any available treatment or vaccine. In fact, with its high mortality rate and the subsequent trade restrictions imposed on affected countries, ASF can dramatically disrupt the pig industry in afflicted countries. In September 2018, ASF was unexpectedly identified in wild boars from southern Belgium in the province of Luxembourg, not far from the Franco-Belgian border. The French authorities rapidly commissioned an expert opinion on the risk of ASF introduction and dissemination into metropolitan France. In Europe, the main transmission routes of the virus comprise direct contact between infected and susceptible animals and indirect transmission through contaminated material or feed. However, the seasonality of the disease in some pig farms in Baltic countries, including outbreaks in farms with high biosecurity levels, have led to questions on the possible involvement of arthropods in the transmission of the virus. This review explores the current body of knowledge on the most common arthropod families present in metropolitan France. We examine their potential role in spreading ASF-by active biological or mechanical transmission or by passive transport or ingestion-in relation to their bio-ecological properties. It also highlights the existence of significant gaps in our knowledge on vector ecology in domestic and wild boar environments and in vector competence for ASFV transmission. Filling these gaps is essential to further understanding ASF transmission in order to thus implement appropriate management measures.

Non-Leishmania Parasite in Fatal Visceral Leishmaniasis-Like Disease, Brazil

Through whole-genome sequencing analysis, we identified non-Leishmania parasites isolated from a man with a fatal visceral leishmaniasis–like illness in Brazil. The parasites infected mice and reproduced the patient’s clinical manifestations. Molecular epidemiologic studies are needed to ascertain whether a new infectious disease is emerging that can be confused with leishmaniasis.

Genetic Structure of Phlebotomus orientalis (Diptera: Psychodidae) in Leishmaniasis Endemic Foci of Sudan

BACKGROUND AND OBJECTIVE

Visceral leishmaniasis (VL) remains a major concern in many parts of Sudan. The disease is transmitted by Phlebotomus orientalis. The objective of this study was to determine genetic structure of Phlebotomus orientalis population from 5 geographical regions in Sudan.

MATERIALS AND METHODS

A total of 194 individual sand flies were collected from 5 geographic regions in Sudan. The field collected sand flies were analyzed by Random Amplified Polymorphic DNA (RAPD) using 30 primers.

RESULTS

Eight hundred and 65 bands from 4 RAPD primers were analyzed for genetic variation. A higher level of intrapopulational variability was detected in populations of P. orientalis from eastern Sudan compared to those populations from central and northern Sudan. Diagnostic bands were detected in populations of P. orientalis central Sudan. Hieratical clustering analysis showed clear clustering into 2 main populations with 1 population subdivided into 4 subpopulations. However, these populations did not show any correlation with their geographical origins. Furthermore, the low genetic differentiation among subpopulations was supported by fixation index (FST) estimated by analysis of molecular variance (AMOVA).

CONCLUSION

It is concluded that the populations of P. orientalis from the selected areas in Sudan have a low genetic differentiation. However, assessment of genetic structure of P. orientalis populations is important for understanding the patterns of transmission of VL in different endemic areas.

Sand Fly-Associated Phlebovirus with Evidence of Neutralizing Antibodies in Humans, Kenya

We describe a novel virus, designated Ntepes virus (NPV), isolated from sand flies in Kenya. NPV has the characteristic phlebovirus trisegmented genome architecture and is related to, but distinct from, Gabek Forest phlebovirus. Diverse cell cultures derived from wildlife, livestock, and humans were susceptible to NPV, with pronounced permissiveness in swine and rodent cells. NPV infection of newborn mice caused rapid and fatal illness. Permissiveness for NPV replication in sand fly cells, but not mosquito cells, suggests a vector-specific adaptation. Specific neutralizing antibodies were found in 13.9% (26/187) of human serum samples taken at the site of isolation of NPV as well as a disparate site in northeastern Kenya, suggesting a wide distribution. We identify a novel human-infecting arbovirus and highlight the importance of rural areas in tropical Africa for arbovirus surveillance as well as extending arbovirus surveillance to include hematophagous arthropods other than mosquitoes.

Identification of phlebotomine sand flies (Diptera: Psychodidae) from leishmaniasis endemic areas in southeastern Mexico using DNA barcoding

Leishmaniasis, a vector-borne disease transmitted to humans through the bite of phlebotomine sand flies, is of public health significance in southeastern Mexico. Active and continuous monitoring of vectors is an important aspect of disease control for the prediction of potential outbreaks. Thus, the correct identification of vectors is paramount in this regard. In this study, we employed DNA barcoding as a tool for identifying phlebotomine sand flies collected in localized cutaneous leishmaniasis endemic areas of Quintana Roo, Mexico. Specimens were collected using CDC light and Shannon traps as part of the Mexican Ministry of Health surveillance program. DNA extraction was carried out using a nondestructive protocol, and morphological identification based on taxonomic keys was conducted on slide-mounted specimens. Molecular taxonomic resolution using the 658-bp fragment of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene was 100% congruent with the morphological identification. Seven species were identified: Lutzomyia cruciata (Coquillett 1907), Lutzomyia longipalpis (Lutz & Neiva 1912), Psathyromyia shannoni (Dyar 1929), Dampfomyia deleoni (Fairchild & Hertig 1947), Dampfomyia beltrani/steatopyga (Vargas & Díaz-Nájera 1951), Bichromomyia olmeca olmeca (Vargas & Díaz-Nájera, 1959), and Brumptomyia mesai (Sherlock 1962). Mean intraspecific divergence ranged from 0.12% to 1.22%, while interspecific distances ranged from 11.59% to 19.29%. Neighbor-joining (NJ) analysis using the Kimura 2-parameter model also showed specimens of the same species to be clustered together. The study provides the first cox1 sequences for three species of sand flies and indicates the utility of DNA barcoding for phlebotomine sand flies species identification in southeastern Mexico.

Detection of Leishmania and Trypanosoma DNA in Field-Caught Sand Flies from Endemic and Non-Endemic Areas of Leishmaniasis in Southern Thailand

Phlebotomine sand flies are tiny, hairy, blood-sucking nematoceran insects that feed on a wide range of hosts. They are known as a principal vector of parasites, responsible for human and animal leishmaniasis worldwide. In Thailand, human autochthonous leishmaniasis and trypanosomiasis have been reported. However, information on the vectors for Leishmania and Trypanosoma in the country is still limited. Therefore, this study aims to detect Leishmania and Trypanosoma DNA in field-caught sand flies from endemic areas (Songkhla and Phatthalung Provinces) and non-endemic area (Chumphon Province) of leishmaniasis. A total of 439 sand flies (220 females and 219 males) were collected. Head and genitalia dissection of female sandflies were done for morphology identification, and the remaining parts of those sand flies were then used for the detection of Leishmania and Trypanosoma parasites. The DNA was extracted from individual female sand flies. Polymerase chain reaction (PCR) anneal, specific to the ITS1 and SSU rRNA gene regions, was used to detect Leishmania and Trypanosoma DNA, respectively. The positive PCR products were cloned and sequenced. The results showed that the female sand fly species in this study consisted of Sergentomyia khawi (35.9%); Se. anodontis (23.6%); Phlebotomus betisi (18.6%); Ph. kiangsuensis (9.5%); Ph. asperulus (6.4%); Se. barraudi (2.3%); 0.9% of each Se. indica, Ph. stantoni, and Ph. major major; and 0.5% of each Se. sylvatica and Ph. mascomai. The PCR and sequence analysis were able to detect Leishmania and Trypanosoma DNA in sand fly samples, which were identified as L. martiniquensis, 1/220 (0.45%) in Se. khawi, 3/220 (1.36%) of T. noyesi in Se. anodontis, and Ph. asperulus. Fourteen (6.36%) of the unidentified trypanosome species in Se. khawi, Se. indica, Se. anodontis, Ph. asperulus, and Ph. betisi were found in all of the areas of this study. Interestingly, we found a 1/220 (0.45%) co-infection sample of L. martiniquensis and Trypanosoma in Se. khawi from Songkhla Province. These data indicate that several species of sand flies might be potential vectors of Leishmania and Trypanosoma parasites in southern Thailand. However, more extensive study for potential vectors using a larger number of sand flies should be conducted to prove whether these sand flies can be natural vectors of leishmaniasis and trypanosomiasis in both humans and animals. In addition, our study could be useful for the future study of infection prevention, including effective vector control for leishmaniasis and trypanosomiasis in Thailand.

Residual Efficacy of Insecticides Sprayed on Different Types of Surfaces Against Leishmaniasis and Filariasis Vectors in Egypt

Determination of the residual activity of insecticides is an essential component in the selection of an appropriate insecticide for indoor residual spraying operations. This report presents the results of a laboratory study to evaluate the residual bio-efficacy of four insecticides sprayed on the most common house-wall surfaces that occur in Egypt (wood, mud, and cement) against Phlebotomus papatasi (Scopoli, 1786) (Diptera: Psychodidae) and Culex pipiens Linnaeus, 1758 (Diptera: Culicidae). In total, 28,050 P. papatasi females and 31,275 Cx. pipiens females were subjected to the WHO cone bioassay. Effective and extended control (≥80% mortality) was produced by lambda-cyhalothrin on indoor wood and cement surfaces. Lambda-cyhalothrin effectively controlled (>80% mortality) P. papatasi and Cx. pipiens for 10 and 12 wk postspray on wood surfaces, respectively. Deltamethrin effectively controlled Cx. pipiens for 8 wk on indoor wood, mud, and cement surfaces. Indoor and outdoor-kept surfaces treated with permethrin and malathion provided negligible efficacy against P. papatasi and Cx. pipiens. Phlebotomus papatasi was better able to survive bioassay exposure than Cx. pipiens against all insecticides investigated. The role surfaces might play in inhibiting IRS-based vector control endeavors in rural areas in developing countries was highlighted in this study. The current insecticide labeling system that includes both sand flies with mosquitoes under the same dosage category should be revised periodically.

Identification of Leishmania Species in Naturally Infected Sand Flies from Refugee Camps, Greece

High infection rates of Leishmania donovani and L. tropica were detected in Phlebotomus spp. sand flies collected from refugee camps in Greece, indicating increased risk of infection among local populations. Detection and treatment of leishmaniasis, community education, and vector control are essential measures to prevent pathogen transmission and protect public health.

Comparative Evolution of Sand Fly Salivary Protein Families and Implications for Biomarkers of Vector Exposure and Salivary Vaccine Candidates

Sand fly salivary proteins that produce a specific antibody response in humans and animal reservoirs have been shown to be promising biomarkers of sand fly exposure. Furthermore, immunity to sand fly salivary proteins were shown to protect rodents and non-human primates against Leishmania infection. We are missing critical information regarding the divergence amongst sand fly salivary proteins from different sand fly vectors, a knowledge that will support the search of broad or specific salivary biomarkers of vector exposure and those for vaccines components against leishmaniasis. Here, we compare the molecular evolution of the salivary protein families in New World and Old World sand flies from 14 different sand fly vectors. We found that the protein families unique to OW sand flies are more conserved than those unique to NW sand flies regarding both sequence polymorphisms and copy number variation. In addition, the protein families unique to OW sand flies do not display as many conserved cysteine residues as the one unique to the NW group (28.5% in OW vs. 62.5% in NW). Moreover, the expression of specific protein families is restricted to the salivary glands of unique sand fly taxon. For instance, the ParSP15 family is unique to the Larroussius subgenus whereas phospholipase A2 is only expressed in member of Larroussius and Adlerius subgenera. The SP2.5-like family is only expressed in members of the Phlebotomus and Paraphlebotomus subgenera. The sequences shared between OW and NW sand flies have diverged at similar rates (38.7 and 45.3% amino acid divergence, respectively), yet differences in gene copy number were evident across protein families and sand fly species. Overall, this comparative analysis sheds light on the different modes of sand fly salivary protein family divergence. Also, it informs which protein families are unique and conserved within taxon for the choice of taxon-specific biomarkers of vector exposure, as well as those families more conserved across taxa to be used as pan-specific vaccines for leishmaniasis.

High Rates of Neutralizing Antibodies to Toscana and Sandfly Fever Sicilian Viruses in Livestock, Kosovo

Toscana and sandfly fever Sicilian viruses (TOSV and SFSV, respectively), both transmitted by sand flies, are prominent human pathogens in the Old World. Of 1,086 serum samples collected from cattle and sheep during 2013 in various regions of Kosovo (Balkan Peninsula), 4.7% and 53.4% had neutralizing antibodies against TOSV and SFSV, respectively.

Autochthonous Outbreak and Expansion of Canine Visceral Leishmaniasis, Uruguay

We report an outbreak of canine visceral leishmaniasis in Uruguay. Blood specimens from 11/45 dogs tested positive for Leishmania spp. Specimens of Lutzomyia longipalpis sand flies were captured; typing revealed Leishmania infantum. Our findings document an expansion of visceral leishmaniasis to southern South America and risk for vectorborne transmission to humans.

The midgut microbiota plays an essential role in sand fly vector competence for Leishmania major

For many arthropod vectors, the diverse bacteria and fungi that inhabit the gut can negatively impact pathogen colonization. Our attempts to exploit antibiotic treatment of colonized Phlebotomus duboscqi sand flies in order to improve their vector competency for Leishmania major resulted instead in flies that were refractory to the development of transmissible infections due to the inability of the parasite to survive and to colonize the anterior midgut with infective, metacyclic stage promastigotes. The parasite survival and development defect could be overcome by feeding the flies on different symbiont bacteria but not by feeding them on bacterial supernatants or replete medium. The inhibitory effect of the dysbiosis was moderated by lowering the concentration of sucrose (<30% w/v) used in the sugar feeds to maintain the colony. Exposure of promastigotes to 30% sucrose was lethal to the parasite in vitro. Confocal imaging revealed that the killing in vivo was confined to promastigotes that had migrated to the anterior plug region, corresponding to the highest concentrations of sucrose. The data suggest that sucrose utilization by the microbiota is essential to promote the appropriate osmotic conditions required for the survival of infective stage promastigotes in vivo.

Increased Transmissibility of Leishmania donovani From the Mammalian Host to Vector Sand Flies After Multiple Exposures to Sand Fly Bites

Background

Patients with active visceral leishmaniasis are important reservoirs in the anthroponotic transmission cycle of Leishmania donovani. The role of the blood or skin as a source of infection to sand flies remains unclear, and the possible effect of multiple exposures to fly bites on transmissibility has not been addressed.

Methods

L. donovani-infected hamsters underwent xenodiagnoses with Lutzomyia longipalpis on the same or different sites on the abdomen on 2 consecutive days or by artificial feeding on the skin or blood.

Results

The transmission of L. donovani from sick hamsters to flies was surprisingly low (mean, 24% of fed flies). New flies fed on the same site acquired significantly more infections (mean, 61%; P < .0001). By artificial feeding, flies could acquire infection from blood and skin. However, only artificial feeding on blood produced infections that correlated with the natural feeding (R = 0.792; P < .0001). Infections acquired from blood increased dramatically for blood obtained after exposure to bites, as did the parasitemia level and the number of monocytes in the circulation.

Conclusions

The bites of uninfected sand flies favor the transmissibility of L. donovani by infected hosts, owing to a systemic effect that exposure to bites has on the parasitemia. Patients with active visceral leishmaniasis are important reservoirs in the anthroponotic transmission cycle of Leishmania donovani. Using the hamster model of visceral disease, we demonstrate that prior exposure to bites of uninfected sand flies potentiates their ability to transmit infection to the vector.

Nycthemeral Rhythm of Phlebotominae (Diptera: Psychodidae) in a Craggy Region, Transitioning Between the Wetland and the Plateau, Brazil

Recording the nycthemeral rhythm of sand flies allows the evaluation of the daily activity in different ecotypes, the period of greatest activity, and their degree of anthropophily. We investigated the fauna and the rhythm of sand fly activity in an ecotourism region in Mato Grosso do Sul (MS) state, Brazil. Sand flies were captured monthly, using a Shannon trap for 24 h periods between July 2012 and June 2014. We collected 1,815 sand flies, in which Lutzomyia whitmani (=Nyssomyia whitmani, sensu Galati) and Lutzomyia longipalpis were the most abundant species during the dry season, with activity from 5 p.m.-7 a.m. and 6 p.m.-5 a.m., respectively. Both species require particular attention as vectors of Leishmania (Viannia) braziliensis and Leishmania (Leishmania) infantum in several regions of Brazil, including MS. However, Lutzomyia dispar was more anthropophilic, and was most active between January and March, from 5 p.m. to 5 a.m. Lutzomyia misionensis (=Pintomyia misionensis, sensu Galati) was present throughout both years, active from 4 p.m. to 5 a.m. Other species were active from 5 p.m. to 6 a.m. Due to intense tourism in the months that coincide with a high number of vectors for leishmaniases in Piraputanga, it is essential to determine vector-monitoring strategies in the area by investigating sand fly rhythm while not neglecting other periods of the year when the insects are present.

Changes of Sand Fly Populations and Leishmania infantum Infection Rates in an Irrigated Village Located in Arid Central Tunisia

The current spread of zoonotic visceral leishmaniasis (ZVL) throughout arid areas of Central Tunisia is a major public health concern. The main objective of this study is to investigate whether the development of irrigation in arid bio-geographical areas in Central Tunisia have led to the establishment of a stable cycle involving sand flies of the subgenus Larroussius and Leishmania infantum, and subsequently to the emergence of ZVL. Sand flies were collected from the village of Saddaguia, a highly irrigated zone located within an arid bio-geographical area of Central Tunisia by using modified Centers for Diseases Control (CDC) light traps. Morphological keys were used to identify sand flies. Collected sand flies were pooled with up to 30 specimens per pool according to date and tested by nested Polymerase Chain Reaction (PCR) DNA sequencing from positive pools was used to identify Leishmania spp. A total of 4915 sand flies (2422 females and 2493 males) were collected from Saddaguia in September and in October 2014. Morphological identification confirmed sand flies of the subgenus Larroussius to be predominant. PCR analysis followed by DNA sequencing indicated that 15 pools were infected with L. infantum yielding an overall infection rate of 0.6%. The majority of the infected pools were of sand fly species belonging to subgenus Larroussius. Intense irrigation applied to the arid bio-geographical areas in Central Tunisia is at the origin of the development of an environment capable of sustaining important populations of sand flies of the subgenus Larroussius. This has led to the establishment of stable transmission cycles of L. infantum and subsequently to the emergence of ZVL.

Sampling strategies for phlebotomine sand flies (Diptera: Psychodidae) in Europe

The distribution of phlebotomine sand flies is widely reported to be changing in Europe. This can be attributed to either the discovery of sand flies in areas where they were previously overlooked (generally following an outbreak of leishmaniasis or other sand fly-related disease) or to true expansion of their range as a result of climatic or environmental changes. Routine surveillance for phlebotomines in Europe is localized, and often one of the challenges for entomologists working in non-leishmaniasis endemic countries is the lack of knowledge on how to conduct, plan and execute sampling for phlebotomines, or how to adapt on-going sampling strategies for other haematophagous diptera. This review brings together published and unpublished expert knowledge on sampling strategies for European phlebotomines of public health concern in order to provide practical advice on: how to conduct surveys; the collection and interpretation of field data; suitable techniques for the preservation of specimens obtained by different sampling methods; molecular techniques used for species identification; and the pathogens associated with sand flies and their detection methods.