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.

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.

Autochthonous Leishmania infantum in Dogs, Zambia, 2021.

Leishmaniases are neglected tropical diseases of humans and animals. We detected Leishmania infantum in 3 mixed-breed dogs in Zambia that had no travel history outside the country. Our findings suggest presence of and probable emergence of leishmaniasis in Zambia, indicating the need for physicians and veterinarians to consider the disease during diagnosis.

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.

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.

The repellency effect of icaridin nanostructural solution applied on cotton knitting fabric against Lutzomyia longipalpis.

The use of repellents is considered an alternative against biting insects, including Lutzomyia longipalpis (Diptera: Psychodidae), the main vector of the protozoan Leishmania infantum, visceral leishmaniasis's (VL) etiologic agent in the Americas. This study aimed to evaluate the repellent efficacy of icaridin nanostructured solution applied on cotton knitting fabric against L. longipalpis. Arm-in-cage tests were performed in eight volunteers at different concentrations (5%, 10%, 25%, and 50%), using L. longipalpis (n = 30). The bioassay was performed in 1, 24, 48, 72, 96, 120, and 144 h after impregnation and one test after washing the fabrics with icaridin. The total repellency rate (%R) > 95% was used as a reference to define a minimum effective concentration (MEC). The results revealed that the insects' landing mean decreased significantly in different icaridin concentrations, compared with the control tests (p < 0.05) and the 25% and 50% concentrations compared to lower concentration (5%) (p < 0.05). The higher concentrations (25% and 50%) provided longer complete protection times (CPTs) with 120 and 144 h of protection, respectively and the %R of 100% for 72 and 96 h after impregnation, respectively. The 25% was the MEC (%R Total = 98.18%). Our results indicate, for the first time, that icaridin nanostructured solution applied on cotton knitting fabric proved to be an efficient repellent against L. longipalpis with the presence of repellent action even after washing. The concentration of 25% showed better efficiency and may become an efficient method for L. longipalpis biting control.

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.

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.

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.

Plant-feeding phlebotomine sand flies, vectors of leishmaniasis, prefer Cannabis sativa.

Blood-sucking phlebotomine sand flies (Diptera: Psychodidae) transmit leishmaniasis as well as arboviral diseases and bartonellosis. Sand fly females become infected with Leishmania parasites and transmit them while imbibing vertebrates' blood, required as a source of protein for maturation of eggs. In addition, both females and males consume plant-derived sugar meals as a source of energy. Plant meals may comprise sugary solutions such as nectar or honeydew (secreted by plant-sucking homopteran insects), as well as phloem sap that sand flies obtain by piercing leaves and stems with their needle-like mouthparts. Hence, the structure of plant communities can influence the distribution and epidemiology of leishmaniasis. We designed a next-generation sequencing (NGS)-based assay for determining the source of sand fly plant meals, based upon the chloroplast DNA gene ribulose bisphosphate carboxylase large chain (rbcL). Here, we report on the predilection of several sand fly species, vectors of leishmaniasis in different parts of the world, for feeding on Cannabis sativa We infer this preference based on the substantial percentage of sand flies that had fed on C. sativa plants despite the apparent "absence" of these plants from most of the field sites. We discuss the conceivable implications of the affinity of sand flies for C. sativa on their vectorial capacity for Leishmania and the putative exploitation of their attraction to C. sativa for the control of sand fly-borne diseases.

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.

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.

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.

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.

Seasonal dynamics of a population of Phlebotomus (Larroussius) perfiliewi Parrot, 1930 (Diptera: Psychodidae) in North-Eastern Romania.

Sand flies were collected in a location from Romania in order to estimate their abundance and seasonal variation in correlation with environmental and anthropic factors. From May to October 2017, eight premises with different animal species were sampled for sand flies in a household from Fundatura village, Vaslui County, in North-Eastern Romania. Animal-related data, shelter-related data, and climatic parameters were recorded. All (n = 150) collected sand flies were Phlebotomus perfiliewi. A mono-modal type of abundance trend has been recorded (a single peak at the beginning of August). The first day of capture was in mid-July. The total number of females during the peak season was significantly higher than the total number of males. The highest percentage of males was recorded at the beginning and at the end of the sand fly activity. Only the traps placed in the poultry enclosure built from clay and wood were positive. A strong positive correlation was recorded between the total number of collected sand flies and the minimum and the maximum temperature. The analysis of the climatic data shows that the first presence of sand flies was registered only after the average minimum temperature for the previous 7 days was above 15 °C.

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.

First detection of Leishmania donovani in sand flies from Cameroon and its epidemiological implications.

OBJECTIVES: A sound knowledge of the vector-host-parasite transmission dynamics is a prerequisite for adequate control measures of vector-borne diseases. To achieve this, an entomological investigation was conducted in the cutaneous leishmaniasis (CL) endemic focus of Mokolo District, northern Cameroon to identify the insect vector(s) of the disease. METHODS: Phlebotomine sand flies were collected in and around Mokolo using New Standard CDC Miniature Light Traps. Individual sand flies were used for morphological species identification, and the remainder of the body for DNA analysis. Sand flies were demonstrated to harbour Leishmania spp. parasites using ITS1 PCR. Mitochondrial vertebrate-specific Cytochrome b -PCR was used to identify blood meals ingested by female sand flies. PCR amplicons were sequenced for Leishmania and blood sources discrimination. RESULTS: This study revealed the presence of Leishmania donovani complex DNA (n = 1) in Phlebotomus duboscqi and of lizard-borne Leishmania tarentolae-like DNA (n = 3) in Sergentomyia spp. in 79 sand fly specimens from Mokolo district. CONCLUSIONS: The causative agent of CL could not be detected in potential vectors. Instead, we found evidence for visceral leishmaniasis (VL) parasites in Phlebotomus duboscqi as well as enzootic reptile parasites in the Mokolo area. We recommend that an epidemiological survey be carried out in the area to evaluate the prevalence and eventually describe the clinical manifestations of VL in the human population. Political instability in neighbouring countries and the resulting refugee migration are likely explanations for the emergence of VL in Mokolo.

Serological and entomological survey of canine leishmaniasis in Lampedusa island, Italy.

BACKGROUND: During last decade Lampedusa island (Italy) has been interested by a deep social change caused by the massive arrival of migrants from north Africa. The goal of this study was to evaluate current CanL burden and risk factors for Visceral Leishmaniosis (VL) on Lampedusa, actually based on very few data obtained in a previous study performed fifteen years ago. Two hundred and forty-two dogs were enrolled for the detection of Leishmania infantum infection by serology. In addition, an entomological investigation was performed to confirm the presence of Leishmania-vectors. RESULTS: Seroprevalence was of 54.13%. 223 sand flies specimens were collected. Among them, 4 species were identified: Phlebotomus perniciosus, P. papatasi, P. neglectus, Sergentomia minuta, with P. perniciosus the most abundant (67.7%; p < 0.01). CONCLUSION: The high proportion of seropositive dogs together with the presence of the most competent vector for L. infantum, P. perniciosus, demonstrate that L. infantum abundantly circulates in the island and may constitute a risk for people, particularly for hosted migrants.