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1.
Parasit Vectors ; 17(1): 278, 2024 Jun 28.
Article in English | MEDLINE | ID: mdl-38943218

ABSTRACT

BACKGROUND: African swine fever (ASF) is a highly contagious and severe haemorrhagic disease of Suidae, with mortalities that approach 100 percent. Several studies suggested the potential implication of non-biting dipterans in the spread of ASFV in pig farms due to the identification of the ASFV DNA. However, to our knowledge, no study has evaluated the viral DNA load in non-biting dipterans collected in outbreak farms and no risk factors have been analysed. In this context, our study aimed to analyse the risk factors associated with the presence of non-biting dipterans collected from ASF outbreaks in relation to the presence and load of viral DNA. METHODS: Backyard farms (BF), type A farms (TAF), and commercial farms (CF), were targeted for sampling in 2020. In 2021, no BF were sampled. Each farm was sampled only once. The identification of the collected flies to family, genus, or species level was performed based on morphological characteristics using specific keys and descriptions. Pools were made prior to DNA extraction. All extracted DNA was tested for the presence of the ASFV using a real-time PCR protocol. For this study, we considered every sample with a CT value of 40 as positive. The statistical analysis was performed using Epi Info 7 software (CDC, USA). RESULTS: All collected non-biting flies belonged to five families: Calliphoridae, Sarcophagidae, Fanniidae, Drosophilidae, and Muscidae. Of the 361 pools, 201 were positive for the presence of ASFV DNA. The obtained CT values of the positive samples ranged from 21.54 to 39.63, with a median value of 33.59 and a mean value of 33.56. Significantly lower CT values (corresponding to higher viral DNA load) were obtained in Sarcophagidae, with a mean value of 32.56; a significantly higher number of positive pools were noticed in August, mean value = 33.12. CONCLUSIONS: Our study brings compelling evidence of the presence of the most common synanthropic flies near domestic pig farms carrying ASFV DNA, highlighting the importance of strengthening the biosecurity measures and protocols for prevention of the insect life cycle and distribution.


Subject(s)
African Swine Fever Virus , African Swine Fever , DNA, Viral , Diptera , Disease Outbreaks , Farms , Animals , African Swine Fever Virus/genetics , African Swine Fever Virus/isolation & purification , African Swine Fever Virus/classification , African Swine Fever/epidemiology , African Swine Fever/virology , African Swine Fever/transmission , Swine , Disease Outbreaks/veterinary , DNA, Viral/genetics , Romania/epidemiology , Diptera/virology , Diptera/classification , Diptera/genetics , Insect Vectors/virology , Insect Vectors/classification
2.
J Vector Borne Dis ; 61(2): 236-242, 2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38922658

ABSTRACT

BACKGROUND OBJECTIVES: Sandflies are vector insects associated with terrestrial forest ecosystems; in the Ecuadorian Andes, they participate in the transmission of human cutaneous leishmaniasis. This geographical area represents an opportunity to evaluate the role of sandflies as bioindicators of the degree of intervention of tropical humid forest ecosystems (THF) associated with changes in the ecology of the local landscape. METHODS: CDC-light traps were used for collecting adult sandflies in February 2020 in a humid tropical forest within the Chocó Biosphere Reserve. All species were identified using morphological keys. Analysis data about abundance, richness, species accumulation, diversity index, species composition communities, species sex proportion, spatial sandflies environmental, Renyi's Diversity Profile were performed to compare six spatial habitats in Mashpi locality, Ecuador. RESULTS: Sandflies were collected (n-1435); the main species are represented by Trichophoromyia reburra, Nyssomyia trapidoi, Psathyromyia aclydifera, Psychodopygus panamensis and Lutzomyia hartmanni. Only Th. reburra is associated with not intervened forest, while the other three species are associated with intervened forest within Mashpi in the Choco Biosphere Reserve. The secondary forest has major sandflies' richness, while the primary forest exhibits major abundance. INTERPRETATION CONCLUSION: Th. reburra is a sandfly restricted to the Andean Forest and is a bioindicator of the high environmental health quality of the forest, while Ny. trapidoi and Pa. aclydifera are bioindicators of environmental disturbances in the forest. Additionally, Ps. panamensis, Lu. hartmanni and Ny. trapidoi are bioindicators of human impact and the risk of leishmaniasis.


Subject(s)
Ecosystem , Forests , Insect Vectors , Psychodidae , Animals , Psychodidae/physiology , Psychodidae/classification , Insect Vectors/physiology , Insect Vectors/classification , Ecuador , Male , Female , Leishmaniasis, Cutaneous/transmission , Biodiversity , Humans
3.
Trop Biomed ; 41(1): 125-133, 2024 Mar 01.
Article in English | MEDLINE | ID: mdl-38852142

ABSTRACT

Culicoides oxystoma Kieffer is a vector of viruses, filarial nematodes and protozoa of the genus Leishmania transmitted to humans and other animals. Understanding genetic diversity, genetic structure and genetic relationships among geographically widespread populations will provide important information related to disease epidemiology. In this study, genetic diversity, genetic structure and genetic relationships between Thai C. oxystoma and those reported from other countries were inferred based on mitochondrial cytochrome oxidase I (COI) and nuclear internal transcribed spacer 1 (ITS-1) sequences. A high level of genetic diversity was found in C. oxystoma from Thailand. The maximum K2P intraspecific genetic divergence for COI gene and ITS-1 sequences were 4.29% and 6.55%, respectively. Despite high genetic diversity, no significant genetic differentiation was found within the 13 Thai populations. This could be a result of unspecialized habitat requirement of the larval habitat, abundance and continuous distribution of host blood sources, potential for long distance movement with host via trading. Mitochondrial genealogy analysis of the global population of C. oxystoma revealed three (A, B and C) genetically divergent lineages. Specimens from Thailand were included in the main lineage (A) with those from all other countries except those from Senegal that formed lineage B and those of Lineage C that was exclusively found in Bangladesh. The nuclear (ITS-1) genetic markers genealogy indicated that Thai C. oxystoma belong to the same genet.


Subject(s)
Ceratopogonidae , Electron Transport Complex IV , Genetic Variation , Animals , Ceratopogonidae/genetics , Ceratopogonidae/classification , Thailand , Electron Transport Complex IV/genetics , Phylogeny , Genetics, Population , DNA, Ribosomal Spacer/genetics , Insect Vectors/genetics , Insect Vectors/classification , Sequence Analysis, DNA
4.
Rev Soc Bras Med Trop ; 57: e007062024, 2024.
Article in English | MEDLINE | ID: mdl-38896655

ABSTRACT

BACKGROUND: Pressatia choti is a common sand fly found in the Atlantic Forest of Brazil, which is suspected to be involved in the transmission of Leishmania braziliensis. Herein, we aimed to establish a Pr. choti laboratory colony. METHODS: Wild-caught female sand flies were blood fed on hamsters and maintained under controlled conditions (temperature: 26 °C; relative humidity: 70%). RESULTS: Of the 301 collected female sandflies, 288 were identified as Pr. choti. The life cycle duration ranged from 31 to 56 days. CONCLUSIONS: We successfully established a Pr. choti colony, whose biological parameters were similar to those of other neotropical sand flies.


Subject(s)
Insect Vectors , Leishmania braziliensis , Psychodidae , Animals , Psychodidae/classification , Psychodidae/parasitology , Female , Insect Vectors/classification , Insect Vectors/parasitology , Brazil , Cricetinae
5.
Mem Inst Oswaldo Cruz ; 119: e230226, 2024.
Article in English | MEDLINE | ID: mdl-38865577

ABSTRACT

BACKGROUND: Monitoring and analysing the infection rates of the vector of Trypanosoma cruzi, that causes Chagas disease, helps assess the risk of transmission. OBJECTIVES: A study was carried out on triatomine in the State of Paraná, Brazil, between 2012 and 2021 and a comparison was made with a previous study. This was done to assess the risk of disease transmission. METHODS: Ecological niche models based on climate and landscape variables were developed to predict habitat suitability for the vectors as a proxy for risk of occurrence. FINDINGS: A total of 1,750 specimens of triatomines were recorded, of which six species were identified. The overall infection rate was 22.7%. The areas with the highest risk transmission of T. cruzi are consistent with previous predictions in municipalities. New data shows that climate models are more accurate than landscape models. This is likely because climate suitability was higher in the previous period. MAIN CONCLUSION: Regardless of uneven sampling and potential biases, risk remains high due to the wide presence of infected vectors and high environmental suitability for vector species throughout the state and, therefore, improvements in public policies aimed at wide dissemination of knowledge about the disease are recommended to ensure the State remains free of Chagas disease.


Subject(s)
Chagas Disease , Insect Vectors , Triatominae , Trypanosoma cruzi , Chagas Disease/transmission , Animals , Insect Vectors/classification , Insect Vectors/parasitology , Brazil/epidemiology , Triatominae/classification , Triatominae/parasitology , Humans , Risk Factors , Risk Assessment , Ecosystem
6.
Acta Trop ; 256: 107270, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38795873

ABSTRACT

This study updates knowledge on historical geographic distribution of sand fly species through identifying altitudinal and bioclimatic patterns in leishmaniasis endemic areas in Mexico. We analyze and identify sand fly specimens obtained through national efforts by the Instituto de Diagnóstico y Referencia Epidemiológicos (InDRE, Mexico), collected between 1995 and 2001, 2008-2012, and 2017-2023, and add bibliographic information (427 additional records). After a principal components analysis of WorldClim variables and altitudinal ranges, variables that better explain the distribution of sand fly species were chosen (BIO6, BIO12, and BIO16, explaining 72 % of variation). A total of 1,187 specimens of 22 species were retrieved from eight states, providing 29 new municipalities and 48 new localities, being Lutzomyia cruciata, Micropygomyia chiapanensis, and Psathyromyia shannoni the most common species. We presented new historical records of distribution for sand fly species from Morelos (3), Oaxaca (7) and Tabasco (1). The 82.7 % of sand fly species analyzed were distributed in areas with altitudinal ranges below 420 m. The anthropophilic species Psathyromyia shannoni, and Lutzomyia cruciata showed the greatest variability regarding altitudinal range, and climatic preferences, while several wild species showed abiotic preferences. It is likely that the effect of urbanization and climate change generate new beneficial biotopes for the proliferation of the vector sand fly species. Complementary studies that consider seasonality, vegetation types, and change in land use could provide new information to better understand the spread of vector-borne diseases.


Subject(s)
Altitude , Leishmaniasis , Psychodidae , Animals , Mexico/epidemiology , Psychodidae/classification , Psychodidae/physiology , Leishmaniasis/epidemiology , Leishmaniasis/transmission , Insect Vectors/physiology , Insect Vectors/classification , Climate , Animal Distribution , Endemic Diseases , Humans , Female , Male
7.
An Acad Bras Cienc ; 96(2): e20230872, 2024.
Article in English | MEDLINE | ID: mdl-38747792

ABSTRACT

Aiming to compare and update the sand fly fauna of Portão de Pedra site, Sumidouro District, Rio de Janeiro State, Brazil, and considering the environmental changes occurred, the biology and ecology of the local sandfly species were examined five years later as a complementary study carried. Captures were made in the cave, surroundings of cave and forest of the region, from 6 p.m. to 6 a.m. Among the 2323 sandflies of eigth species of the Lutzomyia were captured: L. gasparviannai, L. edwardsi, L. tupynambai, L. hirsuta, L. whitmani, L. migonei, L. intermedia, Lutzomyia. sp and one species of the Brumptomyia Kind: B. brumpti. In 2009 and 2010 were collected 1756 samples from ten species of the former genus and two of the second. L. gasparviannai was predominant, in the three collection sites, in both periods. Five species implicated as vectors of Leishmania: L. intermedia, L. whitmani, L. migonei, L. hirsuta and L. davisi have been collected in the area. Poisson regression and ANOVA were used to perform statistical analysis of species most relevant. The record of L. intermedia and a case of American tegumentary leishmaniasis are relevant to the public health of municipality and of state of Rio de Janeiro.


Subject(s)
Insect Vectors , Psychodidae , Animals , Psychodidae/classification , Brazil , Insect Vectors/classification , Population Density , Female , Male , Seasons , Ecosystem
8.
Med Vet Entomol ; 38(2): 216-226, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38563591

ABSTRACT

Vector control remains one of the best strategies to prevent the transmission of trypanosome infections in humans and livestock and, thus, a good way to achieve the elimination of human African trypanosomiasis and animal African trypanosomiasis. A key prerequisite for the success of any vector control strategy is the accurate identification and correct mapping of tsetse species. In this work, we updated the tsetse fly species identification and distribution in many geographical areas in Cameroon. Tsetse flies were captured from six localities in Cameroon, and their species were morphologically identified. Thereafter, DNA was extracted from legs of each tsetse fly and the length polymorphism of internal transcribed spacer-1 (ITS1) region of each fly was investigated using PCR. ITS1 DNA fragments of each tsetse species were sequenced. The sequences obtained were analysed and compared to those available in GenBank. This enabled to confirm/infirm results of the morphologic identification and then, to establish the phylogenetic relationships between tsetse species. Morphologic features allowed to clearly distinguish all the tsetse species captured in the South Region of Cameroon, that is, Glossina palpalis palpalis, G. pallicera, G. caliginea and G. nigrofusca. In the northern area, G. morsitans submorsitans could also be distinguished from G. palpalis palpalis, G. tachinoides and G. fuscipes, but these three later could not be distinguished with routine morphological characters. The ITS1 length polymorphism was high among most of the studied species and allowed to identify the following similar species with a single PCR, that is, G. palpalis palpalis with 241 or 242 bp and G. tachinoides with 221 or 222 bp, G. fuscipes with 236 or 237 bp. We also updated the old distribution of tsetse species in the areas assessed, highlighting the presence of G. palpalis palpalis instead of G. fuscipes in Mbakaou, or in sympatry with G. morsitans submorsitans in Dodeo (northern Cameroon). This study confirms the presence of G. palpalis palpalis in the Adamawa Region of Cameroon. It highlights the limits of using morphological criteria to differentiate some tsetse species. Molecular tools based on the polymorphism of ITS1 of tsetse flies can differentiate tsetse species through a simple PCR before downstream analyses or vector control planning.


Subject(s)
Insect Vectors , Polymorphism, Genetic , Tsetse Flies , Animals , Cameroon , Tsetse Flies/genetics , Insect Vectors/genetics , Insect Vectors/classification , Animal Distribution , Phylogeny , DNA, Intergenic/genetics , Female , Insect Control , Male , DNA, Ribosomal Spacer/analysis , DNA, Ribosomal Spacer/genetics , Sequence Analysis, DNA
9.
Am J Trop Med Hyg ; 110(6): 1117-1126, 2024 Jun 05.
Article in English | MEDLINE | ID: mdl-38593793

ABSTRACT

Leishmaniasis is considered one of the neglected tropical diseases in the world. Although Bhutan is a member of the visceral leishmaniasis elimination consortium in South Asia, not much attention has been accorded to the disease because of its low incidence. The vector that transmits Leishmania remains poorly understood. In this backdrop, sand-fly surveys were regularly conducted at multiple sites where leishmaniasis cases have been reported in Bhutan. Collections were made using CDC light traps and cattle-baited net traps in 15 villages from February 2019 to May 2022. Six species of Phlebotomus and four species of Sergentomyia were identified from these sites that included two Phlebotomus and three Sergentomyia species discovered for the first time in Bhutan. Sand-fly density varied significantly from village to village, and it showed strong seasonality with peak numbers collected from June to October and almost zero from December to February. Overall, sand-fly density was highest in the basements of the houses and were higher outdoors than indoors. Cattle-baited net traps collected few sand flies during the surveillance period. This work constituted the first systematic sand-fly population surveillance conducted in Bhutan and will provide a baseline for future vector ecology and Leishmania epidemiological studies.


Subject(s)
Insect Vectors , Phlebotomus , Psychodidae , Seasons , Animals , Bhutan/epidemiology , Phlebotomus/physiology , Phlebotomus/classification , Insect Vectors/physiology , Insect Vectors/classification , Psychodidae/classification , Psychodidae/physiology , Leishmaniasis/transmission , Leishmaniasis/epidemiology , Cattle , Humans , Female , Animal Distribution , Leishmaniasis, Visceral/epidemiology , Leishmaniasis, Visceral/transmission
10.
J Med Entomol ; 59(1): 240-247, 2022 01 12.
Article in English | MEDLINE | ID: mdl-34632513

ABSTRACT

Biting midges are widespread in Brazilian natural ecosystems. However, deforestation and other activities that impact the environment are reducing natural habitats where biting midges proliferate. The objective of this study was to verify whether there is variation in the composition, richness, abundance, and seasonality of biting midges between wild and rural environments, in a forest area with intense deforestation. Biting midges were captured using 6 traps installed at an average height of 1.5 m in the peridomicile, intradomicile, and deciduous seasonal forests, once a month from May 2012 to April 2013. In total, 2,182 specimens of 13 species of the genus Culicoides were captured. Species richness was similar in the intradomicile (13 species), forest (12), and peridomicile (11), but species diversity was greater in the peridomicile (H' = 0.803) compared with the intradomicile (H' = 0.717) and forest (H' = 0.687). The order of species dominance varied between the forest (Culicoides paucienfuscatus Barbosa > Culicoides leopodoi Ortiz > Culicoides foxi Ortiz > Culicoides ignacioi Forattini) and peridomicile + intradomicile habitats (C. paucienfuscatus > C. foxi > C. filariferus Hoffman > C. ignacioi). The activity of these dipterans was strongly influenced by meteorological variables, as biting midges are predominant in the rainy season (80.7% of specimens), when higher rainfall, relative humidity, and lower temperatures prevail. The abundance of biting midges was higher in the peridomicile + intradomicile (83.7% of specimens) compared with the degraded forest (16.3%), a result that reflects the loss of forest habitat due to intense and progressive deforestation.


Subject(s)
Ceratopogonidae/classification , Classification , Animals , Brazil , Ecosystem , Forests , Insect Vectors/classification , Rural Population , Seasons
11.
PLoS Negl Trop Dis ; 15(12): e0009990, 2021 12.
Article in English | MEDLINE | ID: mdl-34890393

ABSTRACT

BACKGROUND: Discovered by Nicolle and Comte in 1908 in Tunisia, Leishmania infantum is an intracellular protozoan responsible for zoonotic canine leishmaniosis (CanL) and zoonotic human visceral leishmaniasis (HVL). It is endemic in several regions of the world, including Tunisia, with dogs considered as the main domestic reservoir. The geographic expansion of canine leishmaniosis (CanL) has been linked to global environmental changes that have affected the density and the distribution of its sand fly vectors. METHODOLOGY/PRINCIPAL FINDINGS: In this study, a cross-sectional epidemiological survey on CanL was carried out in 8 localities in 8 bioclimatic areas of Tunisia. Blood samples were taken from 317 dogs after clinical examination. Collected sera were tested by indirect fluorescent antibody test (IFAT; 1:80) for the presence of anti-Leishmania infantum antibodies. The overall seroprevalence was 58.3% (185/317). Among positive dogs, only 16.7% showed clinical signs suggestive of leishmaniosis. Seroprevalence rates varied from 6.8% to 84.6% and from 28% to 66% by bioclimatic zone and age group, respectively. Serological positivity was not statistically associated with gender. The presence of Leishmania DNA in blood, using PCR, revealed 21.2% (64/302) prevalence in dogs, which varied by bioclimatic zone (7.3% to 31%) and age group (7% to 25%). The entomological survey carried out in the studied localities showed 16 species of the two genera (Phlebotomus and Sergentomyia). P. perniciosus, P. papatasi, and P. perfiliewi were the most dominant species with relative abundances of 34.7%, 25% and 20.4%, respectively. CONCLUSIONS/SIGNIFICANCE: The present report suggests a significant increase of CanL in all bioclimatic areas in Tunisia and confirms the ongoing spread of the infection of dogs to the country's arid zone. Such an expansion of infection in dog population could be attributed to ecological, agronomic, social and climatic factors that affect the presence and density of the phlebotomine vectors.


Subject(s)
Antibodies, Protozoan/blood , Dog Diseases/epidemiology , Dog Diseases/immunology , Leishmania infantum/immunology , Leishmaniasis, Visceral/epidemiology , Leishmaniasis, Visceral/veterinary , Animals , Cross-Sectional Studies , Dog Diseases/parasitology , Dog Diseases/transmission , Dogs , Female , Insect Vectors/classification , Insect Vectors/parasitology , Leishmania infantum/genetics , Leishmania infantum/pathogenicity , Leishmaniasis, Visceral/immunology , Leishmaniasis, Visceral/transmission , Male , Phlebotomus/parasitology , Prevalence , Seroepidemiologic Studies , Tunisia/epidemiology
12.
Viruses ; 13(12)2021 12 11.
Article in English | MEDLINE | ID: mdl-34960756

ABSTRACT

In total, 332 strawberry plants from 33 different locations in the Czech Republic with or without disease symptoms were screened by RT-PCR for the presence of strawberry polerovirus 1 (SPV1) and five other viruses: strawberry mottle virus, strawberry crinkle virus, strawberry mild yellow edge virus, strawberry vein banding virus, and strawberry virus 1. SPV1 was detected in 115 tested strawberry plants (35%), including 89 mixed infections. No correlation between symptoms and the detected viruses was found. To identify potential invertebrate SPV1 vectors, strawberry-associated invertebrate species were screened by RT-PCR, and the virus was found in the aphids Aphis forbesi, A. gossypii, A. ruborum, A.sanquisorbae, Aulacorthum solani, Chaetosiphon fragaefolii, Myzus ascalonicus, and several other non-aphid invertebrate species. SPV1 was also detected in aphid honeydew. Subsequent tests of C. fragaefolii and A.gossypii virus transmission ability showed that at least 4 h of acquisition time were needed to acquire the virus. However, 1 day was sufficient for inoculation using C. fragaefolii. In conclusion, being aphid-transmitted like other tested viruses SPV1 was nevertheless the most frequently detected agent. Czech SPV1 isolates belonged to at least two phylogenetic clusters. The sequence analysis also indicated that recombination events influence evolution of SPV1 genomes.


Subject(s)
Aphids/virology , Fragaria/virology , Insect Vectors/virology , Luteoviridae/genetics , Luteoviridae/isolation & purification , Plant Diseases/virology , Animals , Aphids/classification , Aphids/physiology , Czech Republic , Genetic Variation , Genome, Viral , Insect Vectors/classification , Insect Vectors/physiology , Luteoviridae/classification , Phylogeny , Recombination, Genetic
13.
PLoS Negl Trop Dis ; 15(12): e0010055, 2021 12.
Article in English | MEDLINE | ID: mdl-34919567

ABSTRACT

BACKGROUND: Visceral leishmaniasis (VL) has been declared as one of the six major tropical diseases by the World Health Organization. This disease has been successfully controlled in China, except for some areas in the western region, such as the Xinjiang Autonomous Region, where both anthroponotic VL (AVL) and desert type zoonotic VL (DT-ZVL) remain endemic with sporadic epidemics. METHODOLOGY/PRINCIPAL FINDINGS: Here, an eleven-year survey (2004-2014) of Leishmania species, encompassing both VL types isolated from patients, sand-fly vectors and Tarim hares (Lepus yarkandensis) from the Xinjiang Autonomous Region was conducted, with a special emphasis on the hares as a potential reservoir animal for DT-ZVL. Key diagnostic genes, ITS1, hsp70 and nagt (encoding N-acetylglucosamine-1-phosphate transferase) were used for phylogenetic analyses, placing all Xinjiang isolates into one clade of the L. donovani complex. Unexpectedly, AVL isolates were found to be closely related to L. infantum, while DT-ZVL isolates were closer to L. donovani. Unrooted parsimony networks of haplotypes for these isolates also revealed their relationship. CONCLUSIONS/SIGNIFICANCE: The above analyses of the DT-ZVL isolates suggested their geographic isolation and independent evolution. The sequence identity of isolates from patients, vectors and the Tarim hares in a single DT-ZVL site provides strong evidence in support of this species as an animal reservoir.


Subject(s)
Hares/parasitology , Insect Vectors/parasitology , Leishmania/classification , Leishmaniasis, Visceral/parasitology , Leishmaniasis, Visceral/veterinary , Psychodidae/parasitology , Adolescent , Adult , Animals , Child , Child, Preschool , China/epidemiology , Female , Humans , Infant , Insect Vectors/classification , Leishmania/genetics , Male , Middle Aged , Phylogeny , Psychodidae/classification , Sequence Analysis, DNA , Young Adult
14.
PLoS Negl Trop Dis ; 15(11): e0009989, 2021 11.
Article in English | MEDLINE | ID: mdl-34843478

ABSTRACT

BACKGROUND: Glossina austeni and Glossina brevipalpis (Diptera: Glossinidae) are the sole cyclical vectors of African trypanosomes in South Africa, Eswatini and southern Mozambique. These populations represent the southernmost distribution of tsetse flies on the African continent. Accurate knowledge of infested areas is a prerequisite to develop and implement efficient and cost-effective control strategies, and distribution models may reduce large-scale, extensive entomological surveys that are time consuming and expensive. The objective was to develop a MaxEnt species distribution model and habitat suitability maps for the southern tsetse belt of South Africa, Eswatini and southern Mozambique. METHODOLOGY/PRINCIPAL FINDINGS: The present study used existing entomological survey data of G. austeni and G. brevipalpis to develop a MaxEnt species distribution model and habitat suitability maps. Distribution models and a checkerboard analysis indicated an overlapping presence of the two species and the most suitable habitat for both species were protected areas and the coastal strip in KwaZulu-Natal Province, South Africa and Maputo Province, Mozambique. The predicted presence extents, to a small degree, into communal farming areas adjacent to the protected areas and coastline, especially in the Matutuíne District of Mozambique. The quality of the MaxEnt model was assessed using an independent data set and indicated good performance with high predictive power (AUC > 0.80 for both species). CONCLUSIONS/SIGNIFICANCE: The models indicated that cattle density, land surface temperature and protected areas, in relation with vegetation are the main factors contributing to the distribution of the two tsetse species in the area. Changes in the climate, agricultural practices and land-use have had a significant and rapid impact on tsetse abundance in the area. The model predicted low habitat suitability in the Gaza and Inhambane Provinces of Mozambique, i.e., the area north of the Matutuíne District. This might indicate that the southern tsetse population is isolated from the main tsetse belt in the north of Mozambique. The updated distribution models will be useful for planning tsetse and trypanosomosis interventions in the area.


Subject(s)
Glossinidae/physiology , Insect Control/methods , Insect Vectors/physiology , Animal Distribution , Animals , Cattle , Cattle Diseases/epidemiology , Cattle Diseases/transmission , Ecosystem , Eswatini/epidemiology , Glossinidae/classification , Insect Vectors/classification , Mozambique/epidemiology , South Africa/epidemiology
15.
PLoS One ; 16(10): e0257992, 2021.
Article in English | MEDLINE | ID: mdl-34653197

ABSTRACT

Triatomines are hematophagous insects of great epidemiological importance, since they are vectors of the protozoan Trypanosoma cruzi, the etiological agent of Chagas disease. Triatoma brasiliensis complex is a monophyletic group formed by two subspecies and six species: T. b. brasiliensis, T. b. macromelasoma, T. bahiensis, T. juazeirensis, T. lenti, T. melanica, T. petrocchiae and T. sherlocki. The specific status of several species grouped in the T. brasiliensis complex was confirmed from experimental crossing and analysis of reproductive barriers. Thus, we perform interspecific experimental crosses between T. lenti and other species and subspecies of the T. brasiliensis complex and perform morphological analysis of the gonads and cytogenetic analysis in the homeologous chromosomes of the hybrids of first generation (F1). Besides that, we rescue all the literature data associated with the study of reproductive barriers in this monophyletic complex of species and subspecies. For all crosses performed between T. b. brasiliensis, T. b. macromelasoma, T. juazeirensis and T. melanica with T. lenti, interspecific copulas occurred (showing absence of mechanical isolation), hybrids were obtained, none of the male hybrids presented the phenomenon of gonadal dysgenesis and 100% pairing between the chromosomes homeologous of the hybrids was observed. Thus, we demonstrate that there are no pre-zygotic reproductive barriers installed between T. lenti and the species and subspecies of the T. brasiliensis complex. In addition, we demonstrate that the hybrids obtained between these crosses have high genomic compatibility and the absence of gonadal dysgenesis. These results point to reproductive compatibility between T. lenti and species and subspecies of the T. brasiliensis complex (confirming its inclusion in the complex) and lead us to suggest a possible recent diversification of the taxa of this monophyletic group.


Subject(s)
Chimera/genetics , Genetic Variation , Hybridization, Genetic , Insect Vectors/genetics , Phylogeny , Triatoma/genetics , Animals , Chagas Disease/parasitology , Chagas Disease/transmission , Chromosomes, Insect/genetics , Cytogenetic Analysis , Female , Gene Flow , Gonadal Dysgenesis/genetics , Gonadal Dysgenesis/pathology , Insect Vectors/classification , Insect Vectors/parasitology , Male , Reproduction/genetics , Testis/pathology , Testis/physiopathology , Triatoma/classification , Triatoma/parasitology , Trypanosoma cruzi
16.
Parasit Vectors ; 14(1): 492, 2021 Sep 25.
Article in English | MEDLINE | ID: mdl-34563255

ABSTRACT

BACKGROUND: Triatomine bugs transmit Chagas disease across Latin America, where vector control-surveillance is increasingly decentralized. Locally run systems often deal with highly diverse native-vector faunas-plus, in some areas, domestic populations of non-native species. Flexible entomological-risk indicators that cover native and non-native vectors and can support local decision-making are therefore needed. METHODS: We present a local-scale entomological-risk score ("TriatoScore") that leverages and builds upon information on the ecology-behavior and distribution-biogeography of individual triatomine bug species. We illustrate our approach by calculating TriatoScores for the 417 municipalities of Bahia state, Brazil. For this, we (i) listed all triatomine bug species recorded statewide; (ii) derived a "species relevance score" reflecting whether each species is native/non-native and, if native, whether/how often it invades/colonizes dwellings; (iii) mapped each species' presence by municipality; (iv) for native vectors, weighted presence by the proportion of municipal territory within ecoregions occupied by each species; (v) multiplied "species relevance score" × "weighted presence" to get species-specific "weighted scores"; and (vi) summed "weighted scores" across species to get municipal TriatoScores. Using standardized TriatoScores, we then grouped municipalities into high/moderate/low entomological-risk strata. RESULTS: TriatoScores were higher in municipalities dominated by dry-to-semiarid ecoregions than in those dominated by savanna-grassland or, especially, moist-forest ecoregions. Bahia's native triatomines can maintain high to moderate risk of vector-borne Chagas disease in 318 (76.3%) municipalities. Historical elimination of Triatoma infestans from 125 municipalities reduced TriatoScores by ~ 27% (range, 20-44%); eight municipalities reported T. infestans since Bahia was certified free of Trypanosoma cruzi transmission by this non-native species. Entomological-risk strata based on TriatoScores agreed well with Bahia's official disease-risk strata, but TriatoScores suggest that the official classification likely underestimates risk in 42 municipalities. Of 152 municipalities failing to report triatomines in 2006-2019, two and 71 had TriatoScores corresponding to, respectively, high and moderate entomological risk. CONCLUSIONS: TriatoScore can help control-surveillance managers to flexibly assess and stratify the entomological risk of Chagas disease at operationally relevant scales. Integrating eco-epidemiological, demographic, socioeconomic, or operational data (on, e.g., local-scale dwelling-infestation or vector-infection frequencies, land-use change and urbanization, housing conditions, poverty, or the functioning of control-surveillance systems) is also straightforward. TriatoScore may thus become a useful addition to the triatomine bug control-surveillance toolbox.


Subject(s)
Chagas Disease/transmission , Insect Vectors/physiology , Triatominae/physiology , Trypanosoma cruzi/physiology , Animals , Brazil/epidemiology , Chagas Disease/epidemiology , Chagas Disease/parasitology , Entomology , Environment , Housing Quality , Humans , Insect Vectors/classification , Insect Vectors/parasitology , Risk Factors , Triatominae/classification , Triatominae/parasitology
17.
Parasit Vectors ; 14(1): 448, 2021 Sep 06.
Article in English | MEDLINE | ID: mdl-34488868

ABSTRACT

BACKGROUND: An entomological study was conducted in the Canaraua Fetii Special Protection Area in the Dobrogea region, South-Eastern Romania. Four sand fly species were recorded at this location between 1968 and 1970: Phlebotomus neglectus, Ph. balcanicus, Ph. sergenti and Sergentomyia minuta. The most abundant sand fly species recorded at that time were Ph. balcanicus and Se. minuta. In the context of a countrywide study to update the sand fly species diversity, we surveyed the same area, recording also a previously unknown Ph. (Transphlebotomus) sp., for which we provide a formal description here. METHODS: Sand flies were collected between July and August in 2018 and 2019 in three sites from Canaraua Fetii, Dobrogea region, Romania. The general aspect of the landscape is of a canyon (vertical, narrow walls and deep valleys). Species identification was done using both morphological and molecular analyses. RESULTS: Out of 645 collected sand flies, 644 (99.8%) were morphologically identified as Ph. neglectus, while one female specimen (0.2%) was assigned to a previously unknown species, belonging to the subgenus Transphlebotomus. The morphological and molecular examination of this specimen showed that it is a previously unknown species which we formally describe here as Phlebotomus (Transphlebotomus) simonahalepae n. sp. Also, Ph. balcanicus, Ph. sergenti, and Se. minuta (previously recorded in this location) were not present. CONCLUSIONS: The study revealed for the first time the presence of sand flies of the subgenus Transphlebotomus in Romania. Moreover, a new species, Ph. simonahalepae n. sp., was described based on a female specimen, raising the number of species in this subgenus to six. In the investigated natural habitat, the predominant species was Ph. neglectus instead of Ph. balcanicus and Se. minuta (recorded as the predominant species in 1968-1970).


Subject(s)
Insect Vectors/classification , Insect Vectors/genetics , Phlebotomus/classification , Phlebotomus/genetics , Animals , Ecosystem , Female , Insect Vectors/anatomy & histology , Male , Phlebotomus/anatomy & histology , Romania , Species Specificity
18.
Parasit Vectors ; 14(1): 411, 2021 Aug 18.
Article in English | MEDLINE | ID: mdl-34407880

ABSTRACT

BACKGROUND: Culex (Culex) tritaeniorhynchus is an important vector of Japanese encephalitis virus (JEV) affecting feral pigs, native mammals and humans. The mosquito species is widely distributed throughout Southeast Asia, Africa and Europe, and thought to be absent in Australia. METHODS: In February and May, 2020 the Medical Entomology unit of the Northern Territory (NT) Top End Health Service collected Cx. tritaeniorhynchus female specimens (n = 19) from the Darwin and Katherine regions. Specimens were preliminarily identified morphologically as the Vishnui subgroup in subgenus Culex. Molecular identification was performed using cytochrome c oxidase subunit 1 (COI) barcoding, including sequence percentage identity using BLAST and tree-based identification using maximum likelihood analysis in the IQ-TREE software package. Once identified using COI, specimens were reanalysed for diagnostic morphological characters to inform a new taxonomic key to related species from the NT. RESULTS: Sequence percentage analysis of COI revealed that specimens from the NT shared 99.7% nucleotide identity to a haplotype of Cx. tritaeniorhynchus from Dili, Timor-Leste. The phylogenetic analysis showed that the NT specimens formed a monophyletic clade with other Cx. tritaeniorhynchus from Southeast Asia and the Middle East. We provide COI barcodes for most NT species from the Vishnui subgroup to aid future identifications, including the first genetic sequences for Culex (Culex) crinicauda and the undescribed species Culex (Culex) sp. No. 32 of Marks. Useful diagnostic morphological characters were identified and are presented in a taxonomic key to adult females to separate Cx. tritaeniorhynchus from other members of the Vishnui subgroup from the NT. CONCLUSIONS: We report the detection of Cx. tritaeniorhynchus in Australia from the Darwin and Katherine regions of the NT. The vector is likely to be already established in northern Australia, given the wide geographical spread throughout the Top End of the NT. The establishment of Cx. tritaeniorhynchus in Australia is a concern to health officials as the species is an important vector of JEV and is now the sixth species from the subgenus Culex capable of vectoring JEV in Australia. We suggest that the species must now be continuously monitored during routine mosquito surveillance programmes to determine its current geographical spread and prevent the potential transmission of exotic JEV throughout Australia.


Subject(s)
Culex/classification , Culex/genetics , Insect Vectors/classification , Insect Vectors/genetics , Animals , Australia , Culex/virology , Electron Transport Complex IV/genetics , Encephalitis Virus, Japanese/pathogenicity , Encephalitis, Japanese/transmission , Encephalitis, Japanese/virology , Female , Insect Vectors/virology
19.
Viruses ; 13(8)2021 08 21.
Article in English | MEDLINE | ID: mdl-34452524

ABSTRACT

Sand flies transmit Leishmania infantum, which is responsible for causing leishmaniasis, as well as many phleboviruses, including the human pathogenic Toscana virus. We screened sand flies collected from a single site between 2017 and 2020 for the presence of both phleboviruses and Leishmania. The sand flies were sampled with attractive carbon dioxide traps and CDC light traps between May and October. We collected more than 50,000 sand flies; 2826 were identified at the species level as Phlebotomus perfiliewi (98%) or Phlebotomus perniciosus (2%). A total of 16,789 sand flies were tested in 355 pools, and phleboviruses were found in 61 pools (6 Toscana virus positive pools, 2 Corfou virus positive pools, 42 Fermo virus positive pools, and 7 Ponticelli virus positive pools, and 4 unidentified phlebovirus positive pools). Leishmania was found in 75 pools and both microorganisms were detected in 16 pools. We isolated nine phleboviruses from another 2960 sand flies (five Ponticelli viruses and for Fermo viruses), not tested for Leishmania; the complete genome of a Fermo virus isolate was sequenced. The simultaneous detection in space and time of the Fermo virus and L. infantum is evidence that supports the co-circulation of both microorganisms in the same location and partial overlap of their cycles. A detailed characterization of the epidemiology of these microorganisms will support measures to limit their transmission.


Subject(s)
Insect Vectors/parasitology , Insect Vectors/virology , Leishmania infantum/isolation & purification , Phlebotomus/parasitology , Phlebotomus/virology , Phlebovirus/isolation & purification , Animals , Humans , Insect Vectors/classification , Insect Vectors/genetics , Italy/epidemiology , Leishmania infantum/genetics , Leishmania infantum/physiology , Leishmaniasis, Visceral/epidemiology , Leishmaniasis, Visceral/parasitology , Leishmaniasis, Visceral/transmission , Phlebotomus/classification , Phlebotomus/genetics , Phlebotomus Fever/epidemiology , Phlebotomus Fever/transmission , Phlebotomus Fever/virology , Phlebovirus/genetics , Phlebovirus/physiology , Phylogeny
20.
Parasit Vectors ; 14(1): 371, 2021 Jul 21.
Article in English | MEDLINE | ID: mdl-34289883

ABSTRACT

BACKGROUND: Phlebotomine sand flies (Diptera: Psychodiae) in the Republic of Moldova have been understudied for decades. Our study provides a first update on their occurrence, species composition and bloodmeal sources after 50 years. METHODS: During 5 seasons (2013-2017), 58 localities from 20 regions were surveyed for presence of sand flies using CDC light traps and manual aspirators. Species identification was done by a combination of morphological and molecular approaches (DNA barcoding, MALDI-TOF MS protein profiling). In engorged females, host blood was identified by three molecular techniques (RFLP, cytb sequencing and MALDI-TOF peptide mass mapping). Population structure of most abundant species was studied by cox1 haplotyping; phylogenetic analyses of ITS2 and cox1 genetic markers were used to resolve relationships of other detected species. RESULTS: In total, 793 sand flies were collected at 30 (51.7%) localities from 12 regions of Moldova. Three species were identified by an integrative morphological and molecular approach: Phlebotomus papatasi, P. perfiliewi and Phlebotomus sp. (Adlerius), the first being the most abundant and widespread, markedly anthropophilic based on bloodmeal analyses, occurring also indoors and showing low population structure with only five haplotypes of cox1 detected. Distinct morphological and molecular characters of Phlebotomus sp. (Adlerius) specimens suggest the presence of a yet undescribed species. CONCLUSIONS: Our study revealed the presence of stable sand fly populations of three species in Moldova that represent a biting nuisance as well as a potential threat of pathogen transmission and shall be further studied.


Subject(s)
Insect Vectors/classification , Leishmaniasis/transmission , Psychodidae/classification , Animals , Female , Haplotypes , Host Specificity , Humans , Insect Vectors/genetics , Insect Vectors/parasitology , Male , Moldova/epidemiology , Phlebotomus/classification , Phlebotomus/genetics , Phlebotomus/physiology , Phylogeny , Psychodidae/genetics , Psychodidae/physiology , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
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