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1.
Mem Inst Oswaldo Cruz ; 117: e210193, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35544857

RESUMO

Trypanosoma cruzi, the agent of Chagas disease (ChD), exhibits remarkable biological and genetic diversity, along with eco-epidemiological complexity. In order to facilitate communication among researchers aiming at the characterisation of biological and epidemiological aspects of T. cruzi, parasite isolates and strains were partitioned into seven discrete typing units (DTUs), TcI-TcVI and TcBat, identifiable by reproducible genotyping protocols. Here we present the potential origin of the genetic diversity of T. cruzi and summarise knowledge about eco-epidemiological associations of DTUs with mammalian reservoirs and vectors. Circumstantial evidence of a connection between T. cruzi genotype and ChD manifestations is also discussed emphasising the role of the host's immune response in clinical ChD progression. We describe genomic aspects of DTUs focusing on polymorphisms in multigene families encoding surface antigens that play essential functions for parasite survival both in the insect vector and the mammalian host. Such antigens most probably contributed to the parasite success in establishing infections in different hosts and exploring several niches. Gaps in the current knowledge and challenges for future research are pointed out.


Assuntos
Doença de Chagas , Trypanosoma cruzi , Animais , Variação Genética/genética , Genótipo , Insetos Vetores/parasitologia , Mamíferos , Polimorfismo Genético
2.
Artigo em Inglês | MEDLINE | ID: mdl-35544910

RESUMO

Leishmaniasis is a serious public health concern in the Northeastern region of Brazil, where the sand fly fauna is well studied, although few species have been identified as competent vectors. The detection of Leishmania spp. parasites in wild-caught sand flies could help sanitary authorities draw strategies to avoid the transmission of the parasites and, therefore, the incidence of leishmaniases. We detected Leishmania DNA in wild-caught sand flies and correlated that data with aspects of sand fly ecology in the Caxias municipality, Maranhao State, Brazil. The sand flies were sampled in the peridomicile (open areas in the vicinity of human residences) and intradomicile (inside the residences) from July/2019 to March/2020. Leishmania DNA was detected in females, targeting a fragment of the Internal Transcribed Spacer (ITS1) from ribosomal DNA. Among the fourteen species of sand flies identified, five (Lutzomyia longipalpis, Nyssomyia whitmani, Evandromyia evandroi, Micropygomyia trinidadensis, and Micropygomyia quinquefer) harbored DNA of Leishmania (Leishmania) amazonensis. The most abundant species in rural (Ny. whitmani: 35.2% and Ev. evandroi: 32.4%) and urban areas (Lu. longipalpis: 89.8%) are the permissive vectors of L. (L.) amazonensis, especially Ny. whitmani, a known vector of causative agents of cutaneous leishmaniasis. Although Lu. longipalpis is the vector of L. (L.) infantum, which was not detected in this study, its permissiveness for the transmission of L. (L.) amazonensis has been reported. We suspect that visceral leishmaniasis and cutaneous leishmaniasis are caused by L. (L.) amazonensis, and the transmission may be occurring through Lu. longipalpis, at least in the urban area.


Assuntos
Leishmania , Leishmaniose Cutânea , Psychodidae , Animais , Brasil/epidemiologia , DNA , Feminino , Insetos Vetores/parasitologia , Leishmania/genética , Leishmaniose Cutânea/epidemiologia , Psychodidae/genética
3.
Biol Open ; 11(4)2022 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-35373253

RESUMO

Trypanosoma theileri, a non-pathogenic parasite of bovines, has a predicted surface protein architecture that likely aids survival in its mammalian host. Their surface proteins are encoded by genes which account for ∼10% of their genome. A non-pathogenic parasite of sheep, Trypanosoma melophagium, is transmitted by the sheep ked and is closely related to T. theileri. To explore host and vector specificity between these species, we sequenced the T. melophagium genome and transcriptome and an annotated draft genome was assembled. T. melophagium was compared to 43 kinetoplastid genomes, including T. theileri. T. melophagium and T. theileri have an AT biased genome, the greatest bias of publicly available trypanosomatids. This trend may result from selection acting to decrease the genomic nucleotide cost. The T. melophagium genome is 6.3Mb smaller than T. theileri and large families of proteins, characteristic of the predicted surface of T. theileri, were found to be absent or greatly reduced in T. melophagium. Instead, T. melophagium has modestly expanded protein families associated with the avoidance of complement-mediated lysis. We propose that the contrasting genomic features of these species is linked to their mode of transmission from their insect vector to their mammalian host. This article has an associated First Person interview with the first author of the paper.


Assuntos
Dípteros , Trypanosoma , Animais , Bovinos , Dípteros/parasitologia , Genômica , Humanos , Insetos Vetores/parasitologia , Mamíferos , Filogenia , Ovinos , Trypanosoma/genética
4.
Parasitology ; 149(2): 155-160, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35234603

RESUMO

Trypanosoma rangeli is a protozoan that infects triatomines and mammals in Latin America, sharing hosts with Trypanosoma cruzi, the etiological agent of Chagas disease. Trypanosoma rangeli does not cause disease to humans but is strongly pathogenic to its invertebrate hosts, increasing mortality rates and affecting bug development and reproductive success. We have previously shown that this parasite is also capable of inducing a general increase in the locomotory activity of its vector Rhodnius prolixus in the absence of host cues. In this work, we have evaluated whether infection impacts the insect­vertebrate host interaction. For this, T. rangeli-infected and uninfected R. prolixus nymphs were released in glass arenas offering single shelters. After a 3-day acclimatization, a caged mouse was introduced in each arena and shelter use and predation rates were evaluated. Trypanosoma rangeli infection affected all parameters analysed. A larger number of infected bugs was found outside shelters, both in the absence and presence of a host. Infected bugs also endured greater predation rates, probably because of an increased number of individuals that attempted to feed. Interestingly, mice that predated on infected bugs did not develop T. rangeli infection, suggesting that the oral route is not effective for these parasites, at least in our system. Finally, a smaller number of infected bugs succeeded in feeding in this context. We suggest that, although T. rangeli is not transmitted orally, an increase in the proportion of foraging individuals would promote greater parasite transmission rates through an increased frequency of very effective infected-bug bites.


Assuntos
Rhodnius , Trypanosoma cruzi , Trypanosoma rangeli , Trypanosoma , Animais , Insetos Vetores/parasitologia , Mamíferos , Camundongos , Comportamento Predatório , Rhodnius/parasitologia
5.
J Infect Public Health ; 15(4): 406-411, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35339013

RESUMO

BACKGROUND: Phlebotomine sand flies are known as vectors of various pathogens such as Leishmania sp parasite and Toscana virus (TOSV). Leishmaniasis is endemic in Morocco, and TOSV is increasingly reported. Our objective is to analyze the specific composition of the natural population of sand flies in endemic and non endemic area of leishmaniasis in Morocco, thus evaluated their infection by Toscana virus. METHODS: Sand flies were collected by CDC miniature light traps from seven different localities with an altitude range from 399 m to 1496 m. Synanthropic index was calculated for each sand fly species. The collected female sand flies were grouped in 73 pools, with a maximum of 50 specimens per pool, and submitted to real time PCR for TOSV detection. RESULTS: 8 sand fly species were identified morphologically: 5 of the Phlebotomus genus and 3 of the Sergentomyia genus. Phlebotomus sergenti was the most abundant species comprising of 43,12% of identified sand flies, followed by P. papatasi (18,89%) and P. longicuspis (13,43%). Estimated synanthropic indices for these species were between + 1.1 and + 12.6 suggesting a high preference to anthropogenic environments. A total of 3558 sand fly females were grouped in 73 pools (up to 50 sand flies per pool) for TOSV detection. TOSV was detected in one pool (out of 6 tested) from Lalla Laaziza locality (Chichaoua Province) where P. sergenti was the most abundant sand fly species. CONCLUSION: We reported the TOSV for the first time in a central Morocco, where cutaneous leishmaniasis by L. tropica is endemic. This result has epidemiological importance for both researchers and health authorities to monitor circulation of TOSV and implement a surveillance plan of sand fly-borne phleboviruses in Morocco.


Assuntos
Leishmaniose Cutânea , Phlebotomus , Psychodidae , Vírus da Febre do Flebótomo Napolitano , Animais , Feminino , Humanos , Insetos Vetores/parasitologia , Leishmaniose Cutânea/epidemiologia , Leishmaniose Cutânea/parasitologia , Phlebotomus/parasitologia
6.
Microbiome ; 10(1): 45, 2022 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-35272716

RESUMO

BACKGROUND: The causative agent of Chagas disease, Trypanosoma cruzi, and its nonpathogenic relative, Trypanosoma rangeli, are transmitted by haematophagous triatomines and undergo a crucial ontogenetic phase in the insect's intestine. In the process, the parasites interfere with the host immune system as well as the microbiome present in the digestive tract potentially establishing an environment advantageous for development. However, the coherent interactions between host, pathogen and microbiota have not yet been elucidated in detail. We applied a metagenome shotgun sequencing approach to study the alterations in the microbiota of Rhodnius prolixus, a major vector of Chagas disease, after exposure to T. cruzi and T. rangeli focusing also on the functional capacities present in the intestinal microbiome of the insect. RESULTS: The intestinal microbiota of R. prolixus was dominated by the bacterial orders Enterobacterales, Corynebacteriales, Lactobacillales, Clostridiales and Chlamydiales, whereas the latter conceivably originated from the blood used for pathogen exposure. The anterior and posterior midgut samples of the exposed insects showed a reduced overall number of organisms compared to the control group. However, we also found enriched bacterial groups after exposure to T. cruzi as well as T rangeli. While the relative abundance of Enterobacterales and Corynebacteriales decreased considerably, the Lactobacillales, mainly composed of the genus Enterococcus, developed as the most abundant taxonomic group. This applies in particular to vectors challenged with T. rangeli and at early timepoints after exposure to vectors challenged with T. cruzi. Furthermore, we were able to reconstruct four metagenome-assembled genomes from the intestinal samples and elucidate their unique metabolic functionalities within the triatomine microbiome, including the genome of a recently described insect symbiont, Candidatus Symbiopectobacterium, and the secondary metabolites producing bacteria Kocuria spp. CONCLUSIONS: Our results facilitate a deeper understanding of the processes that take place in the intestinal tract of triatomine vectors during colonisation by trypanosomal parasites and highlight the influential aspects of pathogen-microbiota interactions. In particular, the mostly unexplored metabolic capacities of the insect vector's microbiome are clearer, underlining its role in the transmission of Chagas disease. Video Abstract.


Assuntos
Doença de Chagas , Microbiota , Parasitos , Rhodnius , Trypanosoma cruzi , Animais , Insetos Vetores/microbiologia , Insetos Vetores/parasitologia , Microbiota/genética , Rhodnius/parasitologia , Trypanosoma cruzi/genética
7.
Parasit Vectors ; 15(1): 95, 2022 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-35313955

RESUMO

BACKGROUND: Trypanosoma theileri species complex includes parasites of Bovidae (cattle, sheep, goat, etc.) and Cervidae (deer) transmitted mainly by Tabanidae (horse flies and deerflies) and keds (Hippoboscidae). While morphological discrimination of species is challenging, two big clades, TthI and TthII, each containing parasites isolated from bovids and cervids, have been identified phylogenetically. To date, the development in the vector has been studied in detail only for the ked-transmitted sheep parasite T. melophagium (TthII), while the fate of trypanosomes in tabanids was described only briefly by light microscopy. METHODS: We collected infected tabanids of various species and identified trypanosomes by molecular phylogenetic analysis. The morphology and development of trypanosomes was studied using the combination of statistical analyses as well as light and electron microscopy. RESULTS: Two trypanosome species belonging to both TthI and TthII clades of the T. theileri complex were identified. The phylogenetic position of these two trypanosomes suggests that they parasitize deer. Both species were indiscernible by morphology in the vector and showed the same development in its intestine. In contrast to the previously described development of T. melophagium, both trypanosomes of tabanids only transiently infected midgut and settled mainly in the ileum, while pylorus and rectum were neglected. Meanwhile, the flagellates developing in the tabanid ileum (pyriform epimastigotes and metacyclic trypomastigotes) showed similarities to the corresponding stages in T. melophagium by morphology, mode of attachment to the host cuticle and formation of the fibrillar matrix surrounding the mass of developing parasites. In addition, for the first time to our knowledge we documented extraintestinal stages in these trypanosomes, located in the space between the epithelium and circular muscles. CONCLUSIONS: The development of different species of flagellates of the T. theileri complex in their insect vectors shows many similarities, which can be explained not only by their common origin, but also the same transmission mode, i.e. contamination of the oral mucosa with the gut content released after squashing the insect either by tongue or teeth. The observed differences (concerning primarily the distribution of developmental stages in the intestine) are associated rather with the identity of vectors than the phylogenetic position of parasites.


Assuntos
Cervos , Dípteros , Trypanosoma , Animais , Bovinos , Cervos/parasitologia , Dípteros/parasitologia , Insetos Vetores/parasitologia , Filogenia , Ovinos
8.
Turkiye Parazitol Derg ; 46(1): 60-71, 2022 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-35232708

RESUMO

Objective: Human and canine leishmaniasis (CanL) are endemic in Turkey, and cutaneous leishmaniasis (CL) is a primary public health problem among vector-borne diseases, with 1500-2000 autochthonous cases per year. In this study, we aimed to perform a comprehensive entomological survey, including the detection of sand fly fauna, seasonal activity, and altitudinal distribution, together with the ecological features of Aydin Mountains and their surroundings that are endemic areas for CL caused by Leishmania tropica and CanL caused by L. infantum MON-1. Methods: The survey was carried out from June 2009 to July 2010. Ten localities with different altitudes were selected. Sand fly collection was done every 15 days in July and August when sand flies are most active and every 30 days between September and June (14 months, 16 samplings) using CDC light traps and sticky traps. During the collection, the temperature, humidity, and ecological and environmental features were recorded. Sand fly specimens were dissected and identified at species level using written keys. Results: A total of 6712 sand fly specimens (3268 females and 3444 males) were collected from 10 localities throughout all study periods. Species identification revealed that nine and three species belonging to Phlebotomus (P. major s.l. 30.38%, P. tobbi 22.93%, P. papatasi 5.88%, P. sergenti s.l. 4.51%, P. alexandri 4.26%, P. simici 3.50%, P. burneyi 0.63%, P. brevis 0.45%, and Transphlebotomus spp. 0.28%) and Sergentomyia (S. dentata 23.17%, S. minuta 2.43%, and S. antennata 1.58%) were found, respectively. The seasonal activities of these 12 sand fly species were determined, and P. major s.l. and P. tobbi, which were probable vectors of VL and CanL, were present in the study area. P. sergenti s.l., a probable vector of CL, was also found in the region and was active for seven months between April and October. P. sergenti s.l. was found in the 400-600 m altitude in July, while P. major and P. tobbi were found in high densities in the 200-400 m altitude in September. Conclusion: Our results showed that leishmaniasis vectors are present in different altitudes in the Aydin mountains and surroundings. The findings revealed the time intervals of parasite transmission in the area and the period of applying protective measures, such as insecticide application.


Assuntos
Leishmaniose Cutânea , Leishmaniose Visceral , Phlebotomus , Psychodidae , Animais , Cães , Feminino , Humanos , Insetos Vetores/parasitologia , Leishmaniose Cutânea/epidemiologia , Leishmaniose Visceral/epidemiologia , Masculino , Phlebotomus/parasitologia , Psychodidae/parasitologia , Estações do Ano , Turquia/epidemiologia
9.
Infect Genet Evol ; 99: 105251, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35183751

RESUMO

Trypanosoma cruzi is the causative agent of Chagas disease, a devastating parasitic disease endemic to Central and South America, Mexico, and the USA. We characterized the genetic diversity of Trypanosoma cruzi circulating in five triatomine species (Triatoma gerstaeckeri, T. lecticularia, T.indictiva, T. sanguisuga and T. recurva) collected in Texas and Southern Arizona using multilocus sequence typing (MLST) with four single-copy loci (cytochrome oxidase subunit II- NADH dehydrogensase subunit 1 region (COII-ND1), mismatch-repair class 2 (MSH2), dihydrofolate reductase-thymidylate synthase (DHFR-TS) and a nuclear gene with ID TcCLB.506529.310). All T. cruzi variants fall in two main genetic lineages: 75% of the samples corresponded to T. cruzi Discrete Typing Unit (DTU) I (TcI), and 25% to a North American specific lineage previously labelled TcIV-USA. Phylogenetic and sequence divergence analyses of our new data plus all previously published sequence data from those four loci collected in the USA, show that TcIV-USA is significantly different from any other previously defined T. cruzi DTUs. The significant level of genetic divergence between TcIV-USA and other T. cruzi DTUs should lead to an increased focus on understanding the epidemiological importance of this DTU, as well as its geographical range and pathogenicity in humans and domestic animals. Our findings further corroborate the fact that there is a high genetic diversity of the parasite in North America and emphasize the need for appropriate surveillance and vector control programs for Chagas disease in southern USA and Mexico.


Assuntos
Doença de Chagas , Trypanosoma cruzi , Animais , Insetos Vetores/parasitologia , Tipagem de Sequências Multilocus , Filogenia , Sudoeste dos Estados Unidos/epidemiologia , Texas/epidemiologia , Trypanosoma cruzi/genética
10.
Acta Trop ; 229: 106365, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35150641

RESUMO

BACKGROUND: Mepraia spinolai, a wild vector of Trypanosoma cruzi in Chile, is an abundant triatomine species that is frequently infected by the parasite that causes Chagas disease. The aim of this study was to determine if the parasitic load of T. cruzi in M. spinolai is related to its blood meal source and the infecting DTUs of T. cruzi. METHODS: The vector was captured in rural areas. In the laboratory, DNA was extracted from its abdomen and T. cruzi was quantified using qPCR. Real time PCR assays for four T. cruzi DTUs were performed. Blood meal sources were identified by real-time PCR amplification of vertebrate cytochrome b gene sequences coupled with high resolution melting (HRM). RESULTS: Trypanosoma cruzi was detected in 735 M. spinolai; in 484 we identified one blood meal source, corresponding to human, sylvatic, and domestic species. From these, in 224 we were able to discriminate the infecting DTU. When comparing the parasitic loads between the unique blood meal sources, no significant differences were found, but infections with more than one DTU showed higher parasitic loads than single infections. DTU TcI was detected in a high proportion of the samples. CONCLUSIONS: Higher parasitic loads are related to a greater number of T. cruzi DTUs infecting M. spinolai, and this triatomine seems to have a wide span of vertebrate species in its diet.


Assuntos
Doença de Chagas , Triatominae , Trypanosoma cruzi , Animais , Genótipo , Humanos , Insetos Vetores/parasitologia , Carga Parasitária , Triatominae/parasitologia , Trypanosoma cruzi/genética
11.
Acta Trop ; 228: 106338, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35114171

RESUMO

Chagas disease (ChD), caused by the hemoflagellate protozoan Trypanosoma cruzi, is an important morbidity that affects approximately six million people in the American continent. T. cruzi parasites are mainly transmitted to human by the infected feces of blood-sucking triatomine insects. The persistent disease is endemic in many regions of South America, mostly affecting residents of rural areas. The aim of this study was to evaluate epidemiological aspects of ChD in the state of Pi-auí located in northeastern Brazil. This is an analytical cross-sectional study carried out from the collection of data of the Notifiable Diseases Information System (SINAN, in Portuguese, Sistema de Informações de Agravos de Notificação) of suspected and confirmed cases of acute ChD in the state of Piauí, in the period 2010-2019. Associations between T. cruzi positivity and the study variables were determined by the chi-square test or Fisher's exact test and were raised as prevalence ratios (PR) with 95% confidence interval. According to this survey, 517 suspected cases of acute ChD were reported in Piauí, with 70 cases (13.5%) confirmed. In 88.5% of confirmed cases, confirmation occurred by laboratory diagnosis. Most of the confirmed cases occurred in municipalities located in the semiarid region, with the municipality of São João do Piauí presenting the highest number of cases. Regarding sociodemographic data, females represent 55.7% of cases, people over 50 years of age (55.7%), being three cases in people up to 18 years of age, and less than 8 years of schooling (67.1%). 77.9% of confirmed cases had vector transmission as the probable form of infection. The data available in this study conclude that vectorial transmission of ChD in the state of Piauí remains active. This fact is corroborated by the number of notified and confirmed cases of acute ChD, requiring housing improvement programs and more effective epidemiological surveillance to control the transmission of the disease in the state.


Assuntos
Doença de Chagas , Trypanosoma cruzi , Animais , Brasil/epidemiologia , Estudos Transversais , Feminino , Humanos , Insetos Vetores/parasitologia , Pessoa de Meia-Idade
12.
Parasit Vectors ; 15(1): 37, 2022 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-35073983

RESUMO

BACKGROUND: The distribution of parasite load across hosts may modify the transmission dynamics of infectious diseases. Chagas disease is caused by a multi-host protozoan, Trypanosoma cruzi, but the association between host parasitemia and infectiousness to the vector has not been studied in sylvatic mammalian hosts. We quantified T. cruzi parasite load in sylvatic mammals, modeled the association of the parasite load with infectiousness to the vector and compared these results with previous ones for local domestic hosts. METHODS: The bloodstream parasite load in each of 28 naturally infected sylvatic mammals from six species captured in northern Argentina was assessed by quantitative PCR, and its association with infectiousness to the triatomine Triatoma infestans was evaluated, as determined by natural or artificial xenodiagnosis. These results were compared with our previous results for 88 humans, 70 dogs and 13 cats, and the degree of parasite over-dispersion was quantified and non-linear models fitted to data on host infectiousness and bloodstream parasite load. RESULTS: The parasite loads of Didelphis albiventris (white-eared opossum) and Dasypus novemcinctus (nine-banded armadillo) were directly and significantly associated with infectiousness of the host and were up to 190-fold higher than those in domestic hosts. Parasite load was aggregated across host species, as measured by the negative binomial parameter, k, and found to be substantially higher in white-eared opossums, cats, dogs and nine-banded armadillos (range: k = 0.3-0.5) than in humans (k = 5.1). The distribution of bloodstream parasite load closely followed the "80-20 rule" in every host species examined. However, the 20% of human hosts, domestic mammals or sylvatic mammals exhibiting the highest parasite load accounted for 49, 25 and 33% of the infected triatomines, respectively. CONCLUSIONS: Our results support the use of bloodstream parasite load as a proxy of reservoir host competence and individual transmissibility. The over-dispersed distribution of T. cruzi bloodstream load implies the existence of a fraction of highly infectious hosts that could be targeted to improve vector-borne transmission control efforts toward interruption transmission. Combined strategies that decrease the parasitemia and/or host-vector contact with these hosts would disproportionally contribute to T. cruzi transmission control.


Assuntos
Doença de Chagas/transmissão , Mamíferos/parasitologia , Triatoma/parasitologia , Trypanosoma cruzi , Animais , Animais Selvagens/parasitologia , Argentina/epidemiologia , Tatus/parasitologia , Gatos , Doença de Chagas/diagnóstico , Doença de Chagas/prevenção & controle , Didelphis/parasitologia , Reservatórios de Doenças/parasitologia , Vetores de Doenças , Cães , Florestas , Genes de Protozoários , Humanos , Insetos Vetores/parasitologia , Carga Parasitária/estatística & dados numéricos , Parasitemia/parasitologia , Reação em Cadeia da Polimerase em Tempo Real , Trypanosoma cruzi/genética , Trypanosoma cruzi/isolamento & purificação , Doenças Transmitidas por Vetores/diagnóstico , Doenças Transmitidas por Vetores/prevenção & controle , Doenças Transmitidas por Vetores/transmissão , Xenodiagnóstico
13.
Parasit Vectors ; 15(1): 18, 2022 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-34998427

RESUMO

BACKGROUND: Dogs are the reservoir host of Leishmania infantum, the agent of zoonotic visceral leishmaniasis (VL), which is transmitted by the bite of phlebotomine sand flies. The sand fly Phlebotomus perniciosus is the main vector of zoonotic VL in the western Mediterranean region. Fluralaner has been shown to effectively kill this vector. The aim of this study was to evaluate the insecticidal efficacy of oral fluralaner in dogs bitten by P. perniciosus. METHODS: Two parallel-group, negative-controlled, randomized, masked laboratory trials with equivalent designs were performed in two different locations using two different pathogen-free laboratory-bred P. perniciosus strains for the challenge. In each trial, 12 purpose-bred beagles, initially ranked on natural attractiveness to sand flies, were randomly allocated to two groups (6 animals/group). Dogs in one group received fluralaner orally at the approved dose on day 0, and dogs in the control group were not treated. Each dog was subsequently exposed to an average of 70 unfed live sand fly females on days 1, 28, 56 and 84. Viability of blood-fed females was then evaluated for up to 96 h after exposure, and insecticidal efficacy was measured as the survival rate of flies fed on the fluralaner-treated dogs versus that of dogs in the control group. Significance was calculated for the proportion of live fed sand fly counts from treated versus control group dogs. RESULTS: Comparison of the survival proportions between treated and control groups showed that fluralaner insecticidal efficacy was highly significant in both trials (P < 0.001 or P < 0.01 in different assessments) through to day 56. In the first trial, efficacy reached 100% on days 1 and 28, and 99.1% on day 56; in the second trial, the insecticidal efficacy was 98.5, 100 and 85.9%, respectively on the same days. On day 84, efficacy was in the range of 53-57% (P < 0.05) in the first trial and 0% in the second trial. CONCLUSION: A single oral fluralaner administration to dogs under laboratory conditions results in strong and reproducible insecticidal efficacy against P. perniciosus for at least 8 weeks.


Assuntos
Doenças do Cão/tratamento farmacológico , Insetos Vetores/efeitos dos fármacos , Inseticidas/farmacologia , Isoxazóis/farmacologia , Leishmaniose Visceral/prevenção & controle , Phlebotomus/efeitos dos fármacos , Administração Oral , Animais , Reservatórios de Doenças , Doenças do Cão/parasitologia , Doenças do Cão/prevenção & controle , Cães , Feminino , Insetos Vetores/parasitologia , Inseticidas/administração & dosagem , Inseticidas/uso terapêutico , Isoxazóis/administração & dosagem , Isoxazóis/uso terapêutico , Leishmania infantum/efeitos dos fármacos , Leishmaniose Visceral/parasitologia , Phlebotomus/parasitologia , Distribuição Aleatória , Organismos Livres de Patógenos Específicos
14.
PLoS Negl Trop Dis ; 16(1): e0009952, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34990451

RESUMO

BACKGROUND: Phlebotomine sand flies (Diptera: Psychodidae) are important vectors of various human and animal pathogens such as Bartonella bacilliformis, Phlebovirus, and parasitic protozoa of the genus Leishmania, causative agent of leishmaniases that account among most significant vector-borne diseases. The Maghreb countries Mauritania, Morocco, Algeria, Tunisia, and Libya occupy a vast area of North Africa and belong to most affected regions by these diseases. Locally varying climatic and ecological conditions support diverse sand fly fauna that includes many proven or suspected vectors. The aim of this review is to summarize often fragmented information and to provide an updated list of sand fly species of the Maghreb region with illustration of species-specific morphological features and maps of their reported distribution. MATERIALS AND METHODS: The literature search focused on scholar databases to review information on the sand fly species distribution and their role in the disease transmissions in Mauritania, Morocco, Algeria, Tunisia, and Libya, surveying sources from the period between 1900 and 2020. Reported distribution of each species was collated using Google Earth, and distribution maps were drawn using ArcGIS software. Morphological illustrations were compiled from various published sources. RESULTS AND CONCLUSIONS: In total, 32 species of the genera Phlebotomus (Ph.) and Sergentomyia (Se.) were reported in the Maghreb region (15 from Libya, 18 from Tunisia, 23 from Morocco, 24 from Algeria, and 9 from Mauritania). Phlebotomus mariae and Se. africana subsp. asiatica were recorded only in Morocco, Ph. mascitti, Se. hirtus, and Se. tiberiadis only in Algeria, whereas Ph. duboscqi, Se. dubia, Se. africana africana, Se. lesleyae, Se. magna, and Se. freetownensis were reported only from Mauritania. Our review has updated and summarized the geographic distribution of 26 species reported so far in Morocco, Algeria, Tunisia, and Libya, excluding Mauritania from a detailed analysis due to the unavailability of accurate distribution data. In addition, morphological differences important for species identification are summarized with particular attention to closely related species such as Ph. papatasi and Ph. bergeroti, Ph. chabaudi, and Ph. riouxi, and Se. christophersi and Se. clydei.


Assuntos
Doenças Transmissíveis/transmissão , Insetos Vetores/microbiologia , Insetos Vetores/parasitologia , Psychodidae/microbiologia , Psychodidae/parasitologia , África do Norte/epidemiologia , Animais , Doenças Transmissíveis/epidemiologia , Humanos , Insetos Vetores/virologia , Psychodidae/virologia
15.
Infect Genet Evol ; 98: 105200, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34990852

RESUMO

OBJECTIVE: To assess the emergent zoonotic disease risk posed by the voracious human-biting blackfly species Simulium oyapockense in the peripheral regions of an expanding urban centre situated deep in the Brazilian Amazon rainforest. METHODS: We performed nine human landing catches at three periurban sites surrounding the Brazilian Amazon town of São Gabriel da Cachoeira. Using the detection of non-human primate filarial parasites as an indicator of the zoonotic disease threat posed by a biting insect, we screened 3328 S. oyapockense blackflies for the presence of zoonotic filarial DNA with an ITS-1 PCR assay and Sanger sequencing. RESULTS: Between 98 and 100% of the biting insects captured during our nine collections were identified as S. oyapockense; at our three collection sites and during our three seasonally-distinct collections this species was captured at rates between 28 and 294 blackflies per hour. PCR screening of the march-collected S. oyapockense detected infectious-stage (L3) Mansonella mariae parasites (which are only known to infect non-human primates) in >0.15% of the tested head samples. CONCLUSIONS: Our results show that residents of the periurban regions of São Gabriel da Cachoeira are routinely exposed to the bites of S. oyapockense blackflies which have previously fed on non-human primates.


Assuntos
Insetos Vetores/parasitologia , Mansonella/isolamento & purificação , Mansonelose/veterinária , Simuliidae/parasitologia , Zoonoses/transmissão , Animais , Mansonelose/parasitologia , Mansonelose/transmissão , Zoonoses/parasitologia
16.
PLoS Negl Trop Dis ; 16(1): e0010047, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-35041668

RESUMO

BACKGROUND: In the 20th century, epidemics of human African trypanosomiasis (HAT) ravaged communities in a number of African countries. The latest surge in disease transmission was recorded in the late 1990s, with more than 35,000 cases reported annually in 1997 and 1998. In 2013, after more than a decade of sustained control efforts and steady progress, the World Health Assembly resolved to target the elimination of HAT as a public health problem by 2020. We report here on recent progress towards this goal. METHODOLOGY/PRINCIPAL FINDINGS: With 992 and 663 cases reported in 2019 and 2020 respectively, the first global target was amply achieved (i.e. fewer than 2,000 HAT cases/year). Areas at moderate or higher risk of HAT, where more than 1 case/10,000 people/year are reported, shrunk to 120,000 km2 for the five-year period 2016-2020. This reduction of 83% from the 2000-2004 baseline (i.e. 709,000 km2) is slightly below the target (i.e. 90% reduction). As a result, the second global target for HAT elimination as a public health problem cannot be considered fully achieved yet. The number of health facilities able to diagnose and treat HAT expanded (+9.6% compared to a 2019 survey), thus reinforcing the capacity for passive detection and improving epidemiological knowledge of the disease. Active surveillance for gambiense HAT was sustained. In particular, 2.8 million people were actively screened in 2019 and 1.6 million in 2020, the decrease in 2020 being mainly caused by COVID-19-related restrictions. Togo and Côte d'Ivoire were the first countries to be validated for achieving elimination of HAT as a public health problem at the national level; applications from three additional countries are under review by the World Health Organization (WHO). CONCLUSIONS/SIGNIFICANCE: The steady progress towards the elimination of HAT is a testament to the power of multi-stakeholder commitment and coordination. At the end of 2020, the World Health Assembly endorsed a new road map for 2021-2030 that set new bold targets for neglected tropical diseases. While rhodesiense HAT remains among the diseases targeted for elimination as a public health problem, gambiense HAT is targeted for elimination of transmission. The goal for gambiense HAT is expected to be particularly arduous, as it might be hindered by cryptic reservoirs and a number of other challenges (e.g. further integration of HAT surveillance and control into national health systems, availability of skilled health care workers, development of more effective and adapted tools, and funding for and coordination of elimination efforts).


Assuntos
Trypanosoma brucei brucei/patogenicidade , Trypanosoma brucei gambiense/patogenicidade , Trypanosoma brucei rhodesiense/patogenicidade , Tripanossomíase Africana/prevenção & controle , África ao Sul do Saara/epidemiologia , Animais , Doenças Endêmicas , Humanos , Controle de Insetos , Insetos Vetores/parasitologia , Tripanossomíase Africana/epidemiologia , Moscas Tsé-Tsé/parasitologia , Organização Mundial da Saúde
17.
PLoS One ; 17(1): e0262552, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35073364

RESUMO

Chagas disease is mainly transmitted by triatomine insect vectors that feed on vertebrate blood. The disease has complex domiciliary infestation patterns and parasite transmission dynamics, influenced by biological, ecological, and socioeconomic factors. In this context, feeding patterns have been used to understand vector movement and transmission risk. Recently, a new technique using Liquid chromatography tandem mass spectrometry (LC-MS/MS) targeting hemoglobin peptides has showed excellent results for understanding triatomines' feeding patterns. The aim of this study was to further develop the automated computational analysis pipeline for peptide sequence taxonomic identification, enhancing the ability to analyze large datasets data. We then used the enhanced pipeline to evaluate the feeding patterns of Triatoma dimidiata, along with domiciliary infestation risk variables, such as unkempt piles of firewood or construction material, cracks in bajareque and adobe walls and intradomiciliary animals. Our new python scripts were able to detect blood meal sources in 100% of the bugs analyzed and identified nine different species of blood meal sources. Human, chicken, and dog were the main blood sources found in 78.7%, 50.4% and 44.8% of the bugs, respectively. In addition, 14% of the bugs feeding on chicken and 15% of those feeding on dogs were captured in houses with no evidence of those animals being present. This suggests a high mobility among ecotopes and houses. Two of the three main blood sources, dog and chicken, were significantly (p < 0.05) affected by domiciliary infestation risk variables, including cracks in walls, construction material and birds sleeping in the intradomicile. This suggests that these variables are important for maintaining reproducing Triatoma dimidiata populations and that it is critical to mitigate these variables in all the houses of a village for effective control of these mobile vectors.


Assuntos
Análise Química do Sangue/métodos , Doença de Chagas/transmissão , Cromatografia Gasosa-Espectrometria de Massas/métodos , Hemoglobinas/análise , Insetos Vetores/parasitologia , Triatoma/parasitologia , Animais , Galinhas/parasitologia , Cães/parasitologia , Comportamento Alimentar , Guatemala , Humanos , Modelos Logísticos , Medição de Risco , Fatores de Risco
18.
PLoS Negl Trop Dis ; 16(1): e0010108, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35020729

RESUMO

BACKGROUND: In onchocerciasis endemic areas in Africa, heterogenous biting rates by blackfly vectors on humans are assumed to partially explain age- and sex-dependent infection patterns with Onchocerca volvulus. To underpin these assumptions and further improve predictions made by onchocerciasis transmission models, demographic patterns in antibody responses to salivary antigens of Simulium damnosum s.l. are evaluated as a measure of blackfly exposure. METHODOLOGY/PRINCIPAL FINDINGS: Recently developed IgG and IgM anti-saliva immunoassays for S. damnosum s.l. were applied to blood samples collected from residents in four onchocerciasis endemic villages in Ghana. Demographic patterns in antibody levels according to village, sex and age were explored by fitting generalized linear models. Antibody levels varied between villages but showed consistent patterns with age and sex. Both IgG and IgM responses declined with increasing age. IgG responses were generally lower in males than in females and exhibited a steeper decline in adult males than in adult females. No sex-specific difference was observed in IgM responses. CONCLUSIONS/SIGNIFICANCE: The decline in age-specific antibody patterns suggested development of immunotolerance or desensitization to blackfly saliva antigen in response to persistent exposure. The variation between sexes, and between adults and youngsters may reflect differences in behaviour influencing cumulative exposure. These measures of antibody acquisition and decay could be incorporated into onchocerciasis transmission models towards informing onchocerciasis control, elimination, and surveillance.


Assuntos
Anticorpos/sangue , Mordeduras e Picadas de Insetos/epidemiologia , Saliva/imunologia , Simuliidae/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Criança , Pré-Escolar , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Insetos Vetores/imunologia , Insetos Vetores/parasitologia , Masculino , Pessoa de Meia-Idade , Onchocerca volvulus/crescimento & desenvolvimento , Oncocercose/epidemiologia , Oncocercose/transmissão , Simuliidae/parasitologia , Adulto Jovem
19.
J Med Entomol ; 59(2): 681-692, 2022 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-35022773

RESUMO

Trypanosomatids (Kinetoplastida:Trypanosomatidae) protozoa are a diverse group of obligate parasites. The genera Trypanosoma and Leishmania are the most studied because of their medical importance. This work aims to evaluate the effects of anthropization processes on the composition of the phlebotomine sand fly fauna and the natural infection by Trypanosomatids, with emphasis on Leishmania. At all 3,186 sand flies were collected, distributed in 13 genera and 52 species, being Ny. umbratilis the most abundant species. There was no difference in the diversity between canopy and soil environments. The species abundance and richness were higher in the forest environment while species diversity and evenness were highest in the forest edge. The ITS1 region was used by PCR-RFLP to identify the fragment profiles of Leishmania species, followed by genetic sequencing. Here were analyzed 100 pools of female sand flies, being six positive for DNA parasite. PCR-RFLP fragment patterns similar to Endotrypanum sp. were observed in Nyssomyia anduzei, Psychodopygus amazonensis and Lutzomyia gomezi, and those fragments similar to Leishmania (Leishmania) amazonensis were observed in Bichromomyia flaviscutellata. ITS1 sequencing confirmed the presence of Leishmania sp. in Bi. flaviscutellata, and Leishmania (Viannia) naiffi in Ny. anduzei, Psychodopygus amazonensis, and Lu. gomezi. This is the first record of Lu. gomezi and Ps. amazonensis infection by L. naiffi in the State of Amazonas. These results show the trypanosomatid infection in sandflies from different landscapes in a rural settlement, and the finding of species infected with L.(V.) naiffi suggest that they can develop a role in the transmission cycle of leishmaniasis.


Assuntos
Leishmania , Leishmaniose Cutânea , Psychodidae , Animais , Brasil , Feminino , Insetos Vetores/parasitologia , Leishmania/genética , Psychodidae/parasitologia
20.
J Med Entomol ; 59(1): 99-107, 2022 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-34608490

RESUMO

In recent years, concerns about Chagas disease in the United States have increased. Triatomine bug (Hemiptera: Reduviidae) populations are the vectors of the parasite Trypanosoma cruzi Chagas (Trypanosomatida: Trypanosomatidae), which causes Chagas disease, although the route of transmission is considered inefficient in United States. However, more studies on triatomine feeding and defecation behavior are needed. In this study, six related biological parameters from two populations of Triatoma protracta protracta (Uhler) and T. p. woodi (Uhler) from Mexican locations near the U.S. border were evaluated. The four population life cycles were less than 6 mo (161-171 d), with 9-10 blood meals needed to molt. Mortality rates were similar (31-38%) among the four populations. Triatoma p. woodi from Hidalgo, Coahuila was the most aggressive one. Feeding times were over 10 min, increasing with instar in all populations. Defecation behaviors varied among populations. High percentages of male and female fourth- and fifth-instar nymphs of T. p. protracta from Imuris and both populations of T. p. woodi defecated immediately after or <1 min of feeding. Lower percentages were observed for T. p. protracta from Jacumé. Because most parameters were similar among the four populations, independent of their subspecies and their geographic origin, we considered that T. p. protracta and T. p. woodi are efficient vectors of T. cruzi. In contrast, defecation patterns were noticeably different among some of the four triatomine populations studied. Our results highlight the importance of studying the biological parameters of local triatomine populations. They also contribute to increasing the knowledge of North American triatomine behavior and defecation patterns.


Assuntos
Insetos Vetores/parasitologia , Traços de História de Vida , Triatoma/parasitologia , Animais , Doença de Chagas/transmissão , Feminino , Insetos Vetores/crescimento & desenvolvimento , Masculino , México , Ninfa/crescimento & desenvolvimento , Ninfa/parasitologia , Triatoma/crescimento & desenvolvimento
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