Financiamento de pesquisas sobre dengue no Brasil, 2004-2020 / Funding for research on dengue in Brazil, 2004-2020

RESUMO A dengue representa um importante problema de saúde pública no Brasil devido às constantes epidemias causadas pela doença no País. Este estudo objetivou analisar o financiamento de pesquisas sobre dengue pelo Departamento de Ciência e Tecnologia do Ministério da Saúde e parceiros no período de 2004 a 2020. Analisou-se a tendência do financiamento por regressão linear generalizada do tipo Prais-Winster e sua distribuição entre as regiões e Unidades Federadas brasileiras, modalidades de contratação das pesquisas, instituições beneficiadas e temas estudados. Entre 2004 e 2020, financiaram-se 232 pesquisas (R$ 164,03 milhões), realizadas, em sua maioria, em instituições da região Sudeste (77,55%), abordando especialmente a temática controle vetorial (37,93%). A tendência de financiamento foi estacionária nos anos estudados. As chamadas estaduais foram a principal forma de modalidade de contratação das pesquisas (65,95%). Houve diferença estatisticamente significante na distribuição do valor financiado entre as modalidades de contratação, bem como no número de pesquisas financiadas e valor financiado entre as regiões brasileiras. Esses achados demonstram a importância de monitorar o financiamento de pesquisas sobre dengue no Brasil e de implementar estratégias de avaliação das pesquisas financiadas, para subsidiar e aprimorar a política de enfrentamento da doença e de seu vetor.

ABSTRACT Dengue represents an important public health problem in Brazil, due to the constant epidemics caused by the disease in the country. This study aimed to analyze the funding of research on dengue by the Department of Science and Technology of the Ministry of Health of Brazil and partners between 2004 to 2020. Was analyzed the trend of the funding by generalized linear regression using Prais-Winster and its distribution between Brazilian regions and Federated Units, research contracting modalities, benefited institutions, and studied themes. Between 2004 and 2020, 232 research studies were funded (R$ 164.03 million), carried out mostly in institutions in the Southeast Region (77.55%), addressing especially the vector control theme (37.93%). The funding trend was stationary in the years studied. The state calls were the main form of contracting modality for the research (65.95%). There was a statistically significant difference in the distribution of the loan amount between the contracting modalities, and in the number of researches funded and loan amount among Brazilian regions. These findings demonstrate the importance of monitoring the research funding on dengue in Brazil and of implementing strategies to evaluate the research funded, to support and improve the policy to combat the disease and its vector.

Evolution of research funding for neglected tropical diseases in Brazil, 2004-2020.

Neglected tropical diseases are a global public health problem. Although Brazil is largely responsible for their occurrence in Latin America, research funding on the subject does not meet the population's health needs. The present study analyzed the evolution of research funding for neglected tropical diseases by the Ministry of Health and its partners in Brazil, from 2004 to 2020. This is a retrospective study of data from investigations registered on Health Research (Pesquisa Saúde in Portuguese), a public repository for research funded by the Ministry of Health's Department of Science and Technology. The temporal trend of funding and the influence of federal government changes on funding were analyzed using Prais-Winster generalized linear regression. From 2004 to 2020, 1,158 studies were financed (purchasing power parity (PPP$) 230.9 million), with most funding aimed at biomedical research (81.6%) and topics involving dengue, leishmaniasis and tuberculosis (60.2%). Funding was stationary (annual percent change of -5.7%; 95%CI -54.0 to 45.0) and influenced by changes to the federal government. Research funding was lacking for chikungunya, Chagas disease, schistosomiasis, malaria and taeniasis/cysticercosis, diseases with a high prevalence, burden or mortality rates in Brazil. Although the Ministry of Health had several budgetary partners, it was the main funder, with 69.8% of investments. The study revealed that research funding for neglected tropical diseases has stagnated over the years and that diseases with a high prevalence, burden and mortality rate receive little funding. These findings demonstrate the need to strengthen the health research system by providing sustainable funding for research on neglected tropical diseases that is consistent with the population's health needs.

Integrative taxonomy and phylogenetic systematics of the Triatoma rubrovaria subcomplex (Hemiptera, Triatominae).

Triatoma rubrovaria subcomplex consists of T. carcavalloi, T. circummaculata, T. klugi, T. limai, T. oliveirai, T. pintodiasi, T. rubrovaria, T. patagonica and T. guasayana, which can be vectors of Trypanosoma cruzi, the etiologic agent of Chagas disease. In this study, morphological, morphometric, and genetic characters of T. circummaculata, T. pintodiasi, T. carcavalloi, T. klugi, and T. rubrovaria were analyzed in view of the integrative taxonomy and phylogeny of the T. rubrovaria subcomplex. Molecular studies were carried out through the sequencing and analysis of the mitochondrial genes COI and CytB, nuclear genes ITS I, ITS 2, 16S, and 28S from rDNA and rescued a monophyletic group. Furthermore, differential morphological characters were found among the five species in the pronotum, scutellum, stridulatory sulcus, male genitalia, and external female genitalia. Finally, morphometric analyses made it possible to differentiate the five species. Phylogenetic analyzes rescued the relationship of T. pintodiasi with members of the T. rubrovaria subcomplex and demonstrated that this subcomplex is a monophyletic group composed of the species T. carcavalloi, T. circummaculata, T. klugi, T. guasayana, T. limai, T. oliveirai, T. patagonica, T. pintodiasi, and T. rubrovaria. Furthermore, through integrative taxonomy, it was possible to confirm the specific status of the species T. carcavalloi, T. circummaculata, T. pintodiasi, T. klugi, and T. rubrovaria, offering new useful morphological characters for the differentiation and characterization of these potential vectors and distributed in Southern Brazil.

Do Commercial Insect Repellents Provide Protection against the Tick Amblyomma sculptum (Acari: Ixodidae)?

Amblyomma sculptum is a species of public health interest because it is associated with the transmission of the bacteria that causes Brazilian Spotted Fever (BSF). The use of repellents on humans is a prophylactic measure widely used to provide protection against a series of arthropod vectors, including mosquitoes and ticks. However, in Brazil, the effectiveness of commercial repellents against A. sculptum is little known. Therefore, it is necessary to carry out specific studies to evaluate the repellency of these commercial products, registered for use against mosquitoes, against the star tick. The main goal of the present work was to evaluate the effectiveness of six commercial repellents against A. sculptum. Unfed nymphs, aged between two and eight weeks, were tested against products based on DEET (OFF!® and Repelex®), Icaridin (Exposis® and SBP®), and IR3535 (Johnsons and Henlau). Three bioassays were conducted to evaluate tick behavior: (i) filter paper, (ii) fingertip, and (iii) field. All bases tested showed high repellent activity, differing significantly (p < 0.05) from the control. It was observed the formulation with DEET resulted in the best results in the filter paper bioassay. In the fingertip bioassay, the DEET base repelled a greater number of ticks compared to Icaridin. In the field bioassay, there was no significant difference between the Icaridin base and DEET, and both formulations differed from the control (p < 0.05). The six formulations tested showed significant percentages of repellency against ticks; however, for the fingertip and field bioassays, the products OFF!®, Repelex®, and Exposis® were tested as they showed better performance in the filter paper test. OFF!® showed the best percentage of repellency (100%), followed by Repelex® (96.8%), and Exposis® (93.1%), considering the two-hour period of the bioassay-field-test. Proving the effectiveness of repellents on the market against A. sculptum presented in this study is crucial, since this is the main ectoparasite of humans that can transmit Rickettsia rickettsii when infected. The effectiveness of commercial insect repellents against other tick species that parasitize humans can also be explored.

Brazilian Populations of Aedes aegypti Resistant to Pyriproxyfen Exhibit Lower Susceptibility to Infection with Zika Virus.

Zika virus (ZIKV) infection has caused devastating consequences in Brazil as infections were associated with neurological complications in neonates. Aedes aegypti is the primary vector of ZIKV, and the evolution of insecticide resistance (IR) in this species can compromise control efforts. Although relative levels of phenotypic IR in mosquitoes can change considerably over time, its influence on vector competence for arboviruses is unclear. Pyriproxyfen (PPF)-resistant populations of Ae. aegypti were collected from five municipalities located in Northeast of Brazil, which demonstrated different resistance levels; low (Serrinha, Brumado), moderate (Juazeiro do Norte, Itabuna), and high (Quixadá). Experimental per os infection using ZIKV were performed with individuals from these populations and with an insecticide susceptible strain (Rockefeller) to determine their relative vector competence for ZIKV. Although all populations were competent to transmit ZIKV, mosquitoes derived from populations with moderate to high levels of IR exhibited similar or lower susceptibility to ZIKV infection than those from populations with low IR or the susceptible strain. These observations suggest an association between IR and arbovirus infection, which may be attributable to genetic hitchhiking. The use of PPF to control Brazilian Ae. aegypti may be associated with an indirect benefit of reduced susceptibility to infection, but no changes in disseminated infection and transmission of ZIKV among PPF-resistant phenotypes.

TriatoDex, an electronic identification key to the Triatominae (Hemiptera: Reduviidae), vectors of Chagas disease: Development, description, and performance.

Correct identification of triatomine bugs is crucial for Chagas disease surveillance, yet available taxonomic keys are outdated, incomplete, or both. Here we present TriatoDex, an Android app-based pictorial, annotated, polytomous key to the Triatominae. TriatoDex was developed using Android Studio and tested by 27 Brazilian users. Each user received a box with pinned, number-labeled, adult triatomines (33 species in total) and was asked to identify each bug to the species level. We used generalized linear mixed models (with user- and species-ID random effects) and information-theoretic model evaluation/averaging to investigate TriatoDex performance. TriatoDex encompasses 79 questions and 554 images of the 150 triatomine-bug species described worldwide up to 2017. TriatoDex-based identification was correct in 78.9% of 824 tasks. TriatoDex performed better in the hands of trained taxonomists (93.3% vs. 72.7% correct identifications; model-averaged, adjusted odds ratio 5.96, 95% confidence interval [CI] 3.09-11.48). In contrast, user age, gender, primary job (including academic research/teaching or disease surveillance), workplace (including universities, a reference laboratory for triatomine-bug taxonomy, or disease-surveillance units), and basic training (from high school to biology) all had negligible effects on TriatoDex performance. Our analyses also suggest that, as TriatoDex results accrue to cover more taxa, they may help pinpoint triatomine-bug species that are consistently harder (than average) to identify. In a pilot comparison with a standard, printed key (370 tasks by seven users), TriatoDex performed similarly (84.5% correct assignments, CI 68.9-94.0%), but identification was 32.8% (CI 24.7-40.1%) faster on average-for a mean absolute saving of ~2.3 minutes per bug-identification task. TriatoDex holds much promise as a handy, flexible, and reliable tool for triatomine-bug identification; an updated iOS/Android version is under development. We expect that, with continuous refinement derived from evolving knowledge and user feedback, TriatoDex will substantially help strengthen both entomological surveillance and research on Chagas disease vectors.

Methods for detecting insecticide resistance in sand flies: A systematic review.

The classification of insecticide resistance in sand flies populations is based on concepts and methodologies used to characterize the susceptibility profile in mosquitoes. This can generate erroneous and subjective interpretations since they are biologically different organisms. In this context, the goal of this review is to analyze the works and/or articles that aimed at characterizing the susceptibility of sand flies and describing the methodological parameters, in order to improve future works to estimate more accurately the resistance of sand flies to insecticides. Using keywords that refer to the purpose of this review, scientific studies in English, Spanish and Portuguese published until December 2019 were analyzed. A total of 3481 articles were found in searches in four databases (Pubmed, Scopus, BVS and ScienceDirect) and 61 were selected. The panorama of sand-fly resistance revealed 47 populations of sand flies, of species Phlebotomus papatasi, Ph. argentipes e Sergentomyia shorttii, with confirmed resistance, and 28 populations of species Ph. papatasi, Ph. argentipes, Ph. sergenti e Lutzomyia longipalpis. Of the 61 selected studies, only three studies performed comparisons between field and colony phlebotomines, and all colony populations were less susceptible than field populations to at least one tested insecticide. The lethal doses and lethal times of sand flies are very varied, revealing that there is no specific protocol for assessing the susceptibility of sand flies to insecticides. For a quick and early detection of sand flies' resistance to insecticides, we suggest the use of CDC bottle tests with an SRL to estimate the local Dose and Diagnostic Time. Males and females can be used in the same proportion, but with only female sand flies in the control group. Females with engorged abdomen or pregnant should be avoided in the experiment and, if possible, use the F1 generation of field sand flies, up to 5 days old, or at least 100 sand flies to reduce the influence of age on the susceptibility of the population.

Phenotypic and genetic variation of Triatoma costalimai (Hemiptera: Reduviidae)

Abstract INTRODUCTION: We aimed to study intraspecific variation in Triatoma costalimai, a potential vector of Chagas disease present in Brazil and Bolivia. METHODS: We analyzed phenotypic (connexivum color patterns, wing morphometrics) and genetic variation (16S mtDNA) of three Brazilian T. costalimai populations. We compared 16S sequences with those of putative Bolivian T. costalimai and its sister species, T. jatai. RESULTS: Brazilian populations had different connexivum color patterns and forewing shapes. A 16S mtDNA haplotype network showed a clear separation of Brazilian T. costalimai from both T. jatai and Bolivian T. costalimai. CONCLUSIONS: We report considerable variability in T. costalimai populations.

Phenotypic and genetic variation of Triatoma costalimai (Hemiptera: Reduviidae).

INTRODUCTION: We aimed to study intraspecific variation in Triatoma costalimai, a potential vector of Chagas disease present in Brazil and Bolivia. METHODS: We analyzed phenotypic (connexivum color patterns, wing morphometrics) and genetic variation (16S mtDNA) of three Brazilian T. costalimai populations. We compared 16S sequences with those of putative Bolivian T. costalimai and its sister species, T. jatai. RESULTS: Brazilian populations had different connexivum color patterns and forewing shapes. A 16S mtDNA haplotype network showed a clear separation of Brazilian T. costalimai from both T. jatai and Bolivian T. costalimai. CONCLUSIONS: We report considerable variability in T. costalimai populations.

Assessment of the susceptibility status of Aedes aegypti (Diptera: Culicidae) populations to pyriproxyfen and malathion in a nation-wide monitoring of insecticide resistance performed in Brazil from 2017 to 2018.

BACKGROUND: Chemical mosquito control using malathion has been applied in Brazil since 1985. To obtain chemical control effectiveness, vector susceptibility insecticide monitoring is required. This study aimed to describe bioassay standardizations and determine the susceptibility profile of Ae. aegypti populations to malathion and pyriproxyfen, used on a national scale in Brazil between 2017 and 2018, and discuss the observed impacts in arbovirus control. METHODS: The diagnostic-doses (DD) of pyriproxyfen and malathion were determined as the double of adult emergence inhibition (EI) and lethal doses for 99% of the Rockefeller reference strain, respectively. To monitor natural populations, sampling was performed in 132 Brazilian cities, using egg traps. Colonies were raised in the laboratory for one or two generations (F1 or F2) and submitted to susceptibility tests, where larvae were exposed to the pyriproxyfen DD (0.03 µg/l) and adults, to the malathion DD determined in the present study (20 µg), in addition to the one established by the World Health Organization (WHO) DD (50 µg) in a bottle assay. Dose-response (DR) bioassays with pyriproxyfen were performed on populations that did not achieve 98% EI in the DD assays. RESULTS: Susceptibility alterations to pyriproxyfen were recorded in six (4.5%) Ae. aegypti populations from the states of Bahia and Ceará, with Resistance Ratios (RR95) ranging from 1.51 to 3.58. Concerning malathion, 73 (55.3%) populations distributed throughout the country were resistant when exposed to the local DD 20 µg/bottle. On the other hand, no population was resistant, and only 10 (7.6%) populations in eight states were considered as exhibiting decreased susceptibility (mortality ratios between 90 and 98%) when exposed to the WHO DD (50 µg/bottle). CONCLUSIONS: The feasibility of conducting an insecticide resistance monitoring action on a nation-wide scale was confirmed herein, employing standardized and strongly coordinated sampling methods and laboratory bioassays. Brazilian Ae. aegypti populations exhibiting decreased susceptibility to pyriproxyfen were identified. The local DD for malathion was more sensitive than the WHO DD for early decreased susceptibility detection.

Susceptibility of phlebotomine sandflies (Diptera: Psychodidae) collected in the field, to alpha-cypermethrin in four municipalities endemic to leishmaniasis.

Although the chemical control against leishmaniasis began in 1953 in Brazil, little information is available on how this strategy has affected populations of phlebotomine sandflies in the field. The objective of this study was to analyze the susceptibility profile of four populations of phlebotomine sandflies to the insecticide alpha-cypermethrin. Sandflies collected in field in four Brazilian municipalities were evaluated using CDC bottles in different concentrations of alpha-cypermethrin. A total of 1,186 phlebotomine sandflies were used in the bioassays. The LD50 ranged from 1.48 to 2.57 ug/mL in the field populations. For a dose of 5 ug/mL of alpha-cypermethrin, the LT50 and LT95 ranged from 17.9 to 27.5 minutes, and LT95 from 39.7 to 61.5 minutes, respectively. All the populations studied were highly susceptible to the insecticide alpha-cypermethrin. Routine studies are needed to detect changes in sandflies susceptibility to insecticides.

Susceptibility of Aedes aegypti populations to pyriproxyfen in the Federal District of Brazil.

INTRODUCTION: In Brasilia, pyriproxyfen (PPF; 0.01 mg/L) has been used for the larval control of Aedes aegypti mosquitoes since 2016. Information on the susceptibility of Ae. aegypti to PPF, and the development of resistance in populations from the Federal District of Brazil (FD) is limited. It is essential to monitor the susceptibility of Ae. aegypti to insecticides in order to improve vector control strategies. This study aimed to evaluate the susceptibility of Ae. aegypti populations from five areas of Brasilia to PPF. METHODS: We performed dose-response tests to estimate the emergence inhibition and resistance ratio of each field population, including the Rockefeller reference population. We also analyzed egg positivity, and the density and mortality of larvae and pupae. RESULTS: Populations from Vila Planalto (RR50=1.7), Regiment Guards Cavalry (RR50=2.5), and Sub-secretary of Justice Complex (RR50=3.7) presented high susceptibility to PPF, while the RR values of populations from Lago Norte (RR50=7.7) and Varjão (RR50=5.9) were moderately high, suggesting the emergence of insipient resistance to PPF in Brasilia. At 30 ng/mL, the highest larvae mortality rate was 2.7% for the population from Lago Norte, while that of pupae was 92.1% for Varjão and Vila Planalto. CONCLUSIONS: The five populations of Ae. aegypti from the FD are susceptible to PPF and there is a need to monitor the susceptibility of Ae. aegypti in new areas of the FD.

Susceptibility of Aedes aegypti populations to pyriproxyfen in the Federal District of Brazil

Abstract INTRODUCTION: In Brasilia, pyriproxyfen (PPF; 0.01 mg/L) has been used for the larval control of Aedes aegypti mosquitoes since 2016. Information on the susceptibility of Ae. aegypti to PPF, and the development of resistance in populations from the Federal District of Brazil (FD) is limited. It is essential to monitor the susceptibility of Ae. aegypti to insecticides in order to improve vector control strategies. This study aimed to evaluate the susceptibility of Ae. aegypti populations from five areas of Brasilia to PPF. METHODS: We performed dose-response tests to estimate the emergence inhibition and resistance ratio of each field population, including the Rockefeller reference population. We also analyzed egg positivity, and the density and mortality of larvae and pupae. RESULTS: Populations from Vila Planalto (RR50=1.7), Regiment Guards Cavalry (RR50=2.5), and Sub-secretary of Justice Complex (RR50=3.7) presented high susceptibility to PPF, while the RR values of populations from Lago Norte (RR50=7.7) and Varjão (RR50=5.9) were moderately high, suggesting the emergence of insipient resistance to PPF in Brasilia. At 30 ng/mL, the highest larvae mortality rate was 2.7% for the population from Lago Norte, while that of pupae was 92.1% for Varjão and Vila Planalto. CONCLUSIONS: The five populations of Ae. aegypti from the FD are susceptible to PPF and there is a need to monitor the susceptibility of Ae. aegypti in new areas of the FD.

Morphological study of the urotergite I process in ten species of the genus Triatoma (Hemiptera, Reduviidae, Triatominae).

The insects of subfamily Triatominae exhibit many morphological features used for taxonomic identification. In some species, however, these features are very similar. The authors have proposed by first time the description of the structure referred as urotergite I process. The objective of the study was analyse the use of urotergite I process in the species of the genus Triatoma as a taxonomic feature that may contribute to the more precise and correct identification of these Trypanosoma cruzi Chagas, 1909 vectors. Scanning electron microscopy (SEM) was used to describe the structure of urotergite I process in ten Triatoma (Hemiptera, Reduviidae, Triatominae) species: Triatoma brasiliensis Neiva, 1911; Triatoma circummaculata Stål, 1859; Triatoma infestans (Klug, 1834); Triatoma maculata (Erichson, 1848); Triatoma pseudomaculata Corrêa & Espínola, 1964; Triatoma rubrovaria (Blanchard, 1843); Triatoma sordida (Stål, 1859); Triatoma tibiamaculata (Pinto, 1926); Triatoma vitticeps (Stål, 1859) and Triatoma wygodzinskyi Lent, 1951. The morphological description of the urotergite I process reflects the taxonomic value of the structure for separating and identifying species of ten specimens of the genus Triatoma. The morphological pattern of the urotergite I process on these ten species was compared, and interspecific variability was observed. We suggest the use of the urotergite I process as a complementary character to identify insects of the subfamily Triatominae. In the future, the use of the urotergite I process in dichotomic keys to identify triatomines may contribute to the improvement of the entomological surveillance of Chagas' disease.

Author Correction: Surveillance of vector-borne pathogens under imperfect detection: lessons from Chagas disease risk (mis)measurement.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

Catalog of the entomologic collections of the Faculty of Public Health of the University of Sao Paulo - (2nd series ii): Triatominae (Hemiptera, Reduviidae).

This article reports a list with 912 specimens of the subfamily Triatominae deposited in the Entomological Collection of the Faculty of Public Health of the University of Sao Paulo. The collection is composed of 1 holotype, 3 alotypes, 15 paralectotypes, 77 paratypes, distributed in 5 tribes and 12 genera: Tribus Alberprosenini: genus Alberprosenia Martinez & Carcavallo, 1977; Tribus Bolboderini: genus Microtriatoma Prosen & Martinez, 1952; Tribus Cavernicolini: genus Cavernicola Barber, 1937; Tribus Rhodnini: genus Psammolestes Bergroth, 1941; genus Rhodnius Stal, 1859; Tribus Triatomini: genus Dipetalogaster Usinger 1939; genus Eratyrus Stal 1859; genus Hermanlentia Jurberg & Galvão, 1997; genus Linshcosteus Distant, 1904; 1944; genus Panstrongylus Berg 1879; genus Paratriatoma Barber 1938; genus Triatoma Laporte 1833.

Surveillance of vector-borne pathogens under imperfect detection: lessons from Chagas disease risk (mis)measurement.

Vector-borne pathogens threaten human health worldwide. Despite their critical role in disease prevention, routine surveillance systems often rely on low-complexity pathogen detection tests of uncertain accuracy. In Chagas disease surveillance, optical microscopy (OM) is routinely used for detecting Trypanosoma cruzi in its vectors. Here, we use replicate T. cruzi detection data and hierarchical site-occupancy models to assess the reliability of OM-based T. cruzi surveillance while explicitly accounting for false-negative and false-positive results. We investigated 841 triatomines with OM slides (1194 fresh, 1192 Giemsa-stained) plus conventional (cPCR, 841 assays) and quantitative PCR (qPCR, 1682 assays). Detections were considered unambiguous only when parasitologists unmistakably identified T. cruzi in Giemsa-stained slides. qPCR was >99% sensitive and specific, whereas cPCR was ~100% specific but only ~55% sensitive. In routine surveillance, examination of a single OM slide per vector missed ~50-75% of infections and wrongly scored as infected ~7% of the bugs. qPCR-based and model-based infection frequency estimates were nearly three times higher, on average, than OM-based indices. We conclude that the risk of vector-borne Chagas disease may be substantially higher than routine surveillance data suggest. The hierarchical modelling approach we illustrate can help enhance vector-borne disease surveillance systems when pathogen detection is imperfect.

Synanthropic triatomines as potential vectors of Trypanosoma cruzi in Central Brazil

Abstract INTRODUCTION: Chagas disease surveillance requires current knowledge on synanthropic triatomines. We analyzed the occurrence and Trypanosoma cruzi infection rates of triatomine bugs in central Brazil, during 2012-2014. METHODS: Triatomines were collected inside or around houses, and T. cruzi infection was determined by optical microscopy and conventional/quantitative polymerase chain reaction. RESULTS: Of the 2706 triatomines collected, Triatoma sordida was the most frequent species in Goiás State, whereas Panstrongylus megistus predominated in the Federal District. Parasites identified were T. cruzi, T. rangeli, and Blastocrithidia sp. CONCLUSIONS: P. megistus and T. sordida sustained the risk of T. cruzi transmission to humans in central Brazil.

The role of gallery forests in maintaining Phlebotominae populations: potential Leishmania spp. vectors in the Brazilian savanna

BACKGROUND Knowledge on synanthropic phlebotomines and their natural infection by Leishmania is necessary for the identification of potential areas for leishmaniasis occurrence. OBJECTIVE To analyse the occurrence of Phlebotominae in gallery forests and household units (HUs) in the city of Palmas and to determine the rate of natural infection by trypanosomatids. METHODS Gallery forests and adjacent household areas were sampled on July (dry season) and November (rainy season) in 2014. The total sampling effort was 960 HP light traps and eight Shannon traps. Trypanosomatids were detected in Phlebotominae females through the amplification of the SSU rDNA region, and the positive samples were used in ITS1-PCR. Trypanosomatid species were identified using sequencing. FINDINGS A total of 1,527 sand flies representing 30 species were captured in which 949 (28 spp.) and 578 (22 spp.) were registered in July and November, respectively. In July, more specimens were captured in the gallery forests than in the HUs, and Nyssomyia whitmani was particularly frequent. In November, most of the specimens were found in the HUs, and again, Ny. whitmani was the predominant species. Lutzomyia longipalpis was commonly found in domestic areas, while Bichromomyia flaviscutellata was most frequent in gallery forests. Molecular analysis of 154 pools of females (752 specimens) identified Leishmania amazonensis, L. infantum, and Crithidia fasciculata in Ny. whitmani, as well as L. amazonensis in Lu. longipalpis, Trypanosoma sp. and L. amazonensis in Pintomyia christenseni, and L. amazonensis in both Psathyromyia hermanlenti and Evandromyia walkeri. MAIN CONCLUSIONS These results show the importance of gallery forests in maintaining Phlebotominae populations in the dry month, as well as their frequent occurrence in household units in the rainy month. This is the first study to identify Leishmania, Trypanosoma, and Crithidia species in Phlebotominae collected in Palmas, Tocantins, Brazil.