Mapping the Silent Threat: A Comprehensive Analysis of Chagas Disease Occurrence in Riverside Communities in the Western Amazon.

Chagas disease (CD) is a typical tropical illness caused by Trypanosoma cruzi. The objective of this study was to assess the prevalence of Chagas disease in communities in two states of the Brazilian Amazon. Data collection occurred in July in the Alto Juruá region of Acre and in December in the communities of Humaitá, Amazonas, in 2019. A total of 477 participants were included in the study. In the communities of Alto Juruá, triatomine collections and analyses of T. cruzi infection were also carried out. All confirmed cases were found in the state of Acre, resulting in a total prevalence of 1.67. Of these eight cases, seven underwent ECG, all of which were concluded as normal by the physician team's cardiologists. Seventeen triatomine bugs, all belonging to the Rhodnius genus, were captured. The natural infection rate by T. cruzi was 25% in the Nova Cintra community and 66.67% in the Boca do Moa community (Alto Juruá). This research found that more than 1% of the studied population exhibited positive serological results for Chagas disease in the riverine communities during the study period, representing a small portion of cases among those who have not yet been diagnosed.

Parasitism by Amblyomma rotundatum on Teiidae lizards in the eastern part of the state of Acre, Brazil.

The aim of the present study was to report on the occurrence of parasitism by Amblyomma rotundatum ticks on two species of Teiidae lizards and test the presence of rickettsiae in the collected ticks, in the western Brazilian Amazon region. Ticks were collected in July 2019, from a fragment of terra firme forest in the municipality of Senador Guiomard, Acre, Brazil. Two lizards that were infested by immature stages of ticks were caught using mist net and Tomahawk traps. Ectoparasites were collected manually, and the lizard specimens were identified and released at the same location where they had been caught. Three nymphs and 49 larvae were collected from Ameiva ameiva, while 25 nymphs and nine larvae were collected from Tupinambis cuzcoensis, which are both in the family Teiidae. The ticks were identified morphologically as belonging to the genus Amblyomma. Nymphs were identified at species level through molecular analysis, resulting in the tick species Amblyomma rotundatum. This is the first record of parasitism by the tick A. rotundatum on T. cuzcoensis lizard, and the first report of an association between A. rotundatum and the lizard species A. ameiva and T. cuzcoensis in Acre, in the western part of the Amazon region.

First official record of Aedes (Stegomyia) albopictus (Diptera: Culicidae) in the Acre State, Northern Brazil.

Aedes (Stegomyia) albopictus (Skuse, 1854) was reported in Brazil for the first time in 1986 and has shown marked expansion throughout the Brazilian territory. During a routine activity to control dengue fever conducted by the Division of Entomology of the Municipal Health Department in Rio Branco city, adults and immatures of Culicidae were collected in a peri-urban area. The identified Culicidae forms indicated that they belonged to the species Ae. albopictus. This is the first official record of the presence of Ae. albopictus in the Acre State, confirming its current presence in all Brazilian states.

Occurrence of triatomines in public spaces: An atypical case in the Southwestern Brazilian Amazon.

BACKGROUND: Triatomines infest atypical public spaces in the Western Amazon. METHODS: Frequent visitors to these spaces captured the insects in the state of Acre, Brazil (Rio Branco and Cruzeiro do Sul). RESULTS: Six insects were found in a penitentiary, a church, a school, a university, a hospital, and a health center. Five of the insects were adults (three positive for Trypanosoma cruzi) and one was a nymph. CONCLUSIONS: This is the first report of triatomine occurrence in schools or churches. These data are important for implementing surveillance strategies and alerting individuals about possible changes in Chagas disease transmission dynamics.

Initial report of Panstrongylus rufotuberculatus (Champion, 1899) Triatominae (Hemiptera: Reduviidae) in Roraima, western Amazon state, Brazil.

BACKGROUND: This study is the first report of the species Panstrongylus rufotuberculatus in Roraima, a state in northern Brazil. METHODS: We collected specimens from a residence in the municipality of Rorainópolis. RESULTS: Our findings confirmed the occurrence of this species in Roraima, increasing the number of registered species from six to seven. CONCLUSIONS: Future studies are required to further investigate and expand our knowledge of the occurrence of this species and its epidemiological importance for this state.

Ergasilus colomesus (Copepoda: Ergasilidae) parasitizing gills of Colomesus asellus(Tetraodontiformes: Tetraodontidae) in the western Brazilian Amazon.

Records about Ergasilus colomesus and its interaction with the host fish are scarce. There is only a report describing this species from specimens collected from the gills of Colomelus asellus, in the State of Amazonas, Brazil. In this sense, this is the first record of E. colomesus parasitizing C. asellus for the southwest of the Brazilian Amazon. Fish were collected in the Môa river, located in the municipality of Cruzeiro do Sul, State of Acre, Brazil, during drought and flood. The fish captured were analyzed, and the parasites found were measured, fixed, and identified. We calculated the parasite indices and evaluated whether the seasonal periods (drought and flood) influence the levels of parasite infestation in their hosts. The prevalence and infestation of E. colomesus in C. asellus were higher in the drought, indicating that the infestation of this copepod probably occurred during this period. The lower number of individuals found during the flood indicates that this is the period when E. colomesus detaches from its host to release of eggs into the environment. In this sense, this study expanded the distribution record of E. colomesus parasitizing C. asellus to southwestern Amazonia.

First report of Amblyomma latepunctatum and the second record of Ixodes luciae in the state of Acre, Brazil.

The state of Acre is in the western part of the Brazilian Amazon region and few studies involving ticks are available. The aim of the present study was to provide the first report of occurrence of Amblyomma latepunctatum and the second record of Ixodes luciae in Acre. Ticks were collected in October 2020 inside an open forested area in the municipality of Rio Branco, the state capital of Acre. Ixodid ticks were identified according to their external morphological characteristics. Three specimens were found on the vegetation by means of a visual search and were identified as Amblyomma scalpturatum (one male and one female) and Amblyomma latepunctatum (one male). Another specimen was found parasitizing a Didelphis marsupialis female that was caught using a Tomahawk trap; this was identified as Ixodes luciae (one male). This first report of A. latepunctatum in the state of Acre increases the number of species recorded here to 22. In addition, presence of I. luciae is confirmed in this state (second record), in the western Brazilian Amazon region.

Larvicidal activity of Maytenus guianensis (Celastraceae) against Aedes aegypti (Diptera: Culicidae).

INTRODUCTION: Bioprospection of plant products is used to discover new insecticides. METHODS: The larvicidal activity of ethanolic extract and triterpene (tingenone B) from the bark of Maytenus guianensis and their effect on pupation and emergence were evaluated against Aedes aegypti. RESULTS: Crude extract LC50 was 11.3 ppm and caused ejection of the larvae intestine; tingenone B LC50 was 14.8 ppm. Pupation was reduced by 20% and 10%, respectively; however, the emergence was not affected. CONCLUSIONS: The crude bark extract exhibited a higher larvicidal effect against the vector.

Occurrence of triatomines (Hemiptera, Reduviidae) and their natural infection by Trypanosoma cruzi (Chagas, 1909) in Boca do Moa community, Cruzeiro do Sul, Acre, Brazil.

INTRODUCTION: Triatomines are insect vectors of Trypanosoma cruzi, the etiological agent of Chagas disease. METHODS: Triatomines were collected from households and by dissecting palm trees in the peri-urban areas of Cruzeiro do Sul (Acre); they were identified using a specific key and via genital analyses. Trypanosomatid infection was determined through microscopy and polymerase chain reaction. RESULTS: In total, 116 triatomines of the species Eratyrus mucronatus, Rhodnius pictipes, R. stali, and R. montenegrensis were collected, of which 13.8% were positive for T. cruzi. CONCLUSIONS: Four species of triatomines presented an infection rate above 13% in the Boca do Moa community.

Myrciaria dubia Juice (camu-camu) Exhibits Analgesic and Antiedematogenic Activities in Mice.

The Myrciaria dubia (Myrtaceae) fruit is traditionally used to treat malnutrition due to its high levels of vitamin C and phenolic compounds. Because of its composition, this plant is very promising in the research of novel natural treatment for pain disorders. This study analyzed the phytochemical profile of M. dubia juice and assessed its antinociceptive and antiedematogenic potential. The phytochemical profile was determined through high-performance liquid chromatography (HPLC), the oral antinociceptive effect of M. dubia 50% juice (Md50) was evaluated by formalin, hot plate and Complete Freund's Adjuvant tests and the antiedematogenic activity by paw edema. HPLC revealed the presence of ascorbic acid, rutin, and ellagic acid as major compounds. Md50 showed an antinociceptive effect in the acute and chronic phases of the formalin test. In the hot plate test, Md50 also induced an antinociceptive effect of 0.5 up to 6 h, showing antinociceptive and antiedematogenic potential without changing the spontaneous locomotion of animals. All protocols were submitted and approved by the Ethics Committee for use of Animals of the Lutheran University of Brazil (protocol No. 2013-30P).

Isopods Cymothoidae ectoparasites of fish from the Amazon.

Most freshwater species of Cymothoidae are distributed in South America. They have mainly been recorded in the eastern and western regions of the Amazon River basin. However, in this ecosystem, the biodiversity of this group may be greater if the entire Amazon basin is considered. In this regard, the aim of the present study was to provide an updated list of isopod species of the family Cymothoidae that are found in fish in the Brazilian Amazon region and to report on new fish host occurrences and expanded geographical distributions for cymothoid isopods that parasitize fish in the southwestern Brazilian Amazon region. The parasites found in fish specimens were collected, fixed and identified later. We found eight species of Cymothoidae parasitizing different host fish species in the southwestern Amazon region. However, we found 14 species of Cymothoidae throughout the Brazilian Amazon region. Three additional species are thus reported here, which increases the number of species of Cymothoidae in this region to 17. These additional species are also new records for Brazil. Therefore, this study has contribute to expand the knowledge about the distribution and diversity of Cymothoidae in the Amazon basin.

Snakebites in Rio Branco and surrounding region, Acre, Western Brazilian Amazon.

INTRODUCTION: Snakebites are considered a neglected tropical disease in many countries in Latin America, including Brazil. As few studies have assessed snakebites in the Amazon region and especially in the state of Acre, epidemiological studies are of great importance. The present study aimed to describe the epidemiological characteristics of snakebites in the Rio Branco region, observing their characteristics in rural and urban areas and their correlation with rainfall and river outflow. METHODS: This retrospective, descriptive study analyzed epidemiological information obtained from snakebite notifications registered on the Information System for Notifiable Diseases that occurred from March, 2018 to February, 2019. The cases of snakebite were correlated with rainfall and flow. RESULTS: A total of 165 cases of snakebite were registered in the period. Most cases were caused by Bothrops and affected mainly individuals of the male sex who were between 21 and 30 years old. Most of the snakebites occurred in Rio Branco (71.52%; 29 cases per 100,000 inhabitants). Of these, 60.2% occurred in the urban area and 39.8% in the rural area and the majority occurred during the rainy season. CONCLUSIONS: Although studies have shown that a majority of cases occur in rural areas, in this study, urbanization of snakebites was observed. The Bothrops genus was responsible for the highest number of snakebites and, during the rainy season, bites occurred more frequently. Educational prevention campaigns, population advice, and first aid in case of snakebites for the population are thus suggested.

Triatominae (Hemiptera, Reduviidae) in homes: Report of their occurrence in the municipality of Cruzeiro do Sul, Acre, South Western Amazon.

INTRODUCTION: Triatomines are hematophagous insects that are important to public health since they are the vectors of American Trypanosomiasis. The objective of this study was to describe the occurrence of triatomines in homes in Cruzeiro do Sul, Acre, Brazil. METHODS: The specimens were collected by an active search inside homes and also by a passive search by the residents. RESULTS: A total of 55 triatomines were captured comprising of 5 species each of the genera Rhodnius, Eratyrus, and Panstrongylus. No colonies were detected, ruling out the possibility of domiciliation. CONCLUSIONS: Information on regional epidemiological dynamics contributes to the prevention and control of disease.

Trypanosoma cruzi vectors in a periurban area of the Western Brazilian Amazon.

The etiological agent of American trypanosomiasis is the protozoan Trypanosoma cruzi , typically transmitted by triatomines. The aim of this study was to investigate the triatomine fauna and trypanosomiasis infections in Acre State , Western Brazilian Amazon. Insect collection was performed by dissecting palm trees and installing traps. We found that T. cruzi infection rate was 24.5% and Rhodnius pictipes (57.1%) was the most abundant triatomine species. Health education as well as epidemiological and entomological surveillance are necessary to diagnose and prevent new cases of Chagas disease in the region.

First report of Rhodnius montenegrensis (Hemiptera, Reduviidae, Triatominae) in Amazonas, Brazil.

INTRODUCTION: Triatomines are hematophagous insects of epidemiological importance because they are vectors of Chagas disease. We present here the first report of Rhodnius montenegrensis in Amazonas, Brazil. METHODS: Triatomines were collected from Attalea butyracea palm trees in the municipality of Guajará. RESULTS: Two adult female R. montenegrensis specimens were identified. CONCLUSIONS: The present study confirms that the number of triatomine species within the Amazon has increased from 10 to 11, and the number of Brazilian states with R. montenegrensis has increased from two to three.

Biological Aspects of Rhodnius montenegrensis (Hemiptera, Reduviidae, Triatominae) Under Laboratory Conditions.

Triatominae are insects notorious as vectors of Trypanosoma cruzi, which is the etiologic agent of Chagas disease, and other trypanosomatids. Triatomines of the genus Rhodnius are primarily sylvatic, nevertheless the occurrence of native species that invade households suggests their possible role in the transmission of Chagas disease. Rhodnius montenegrensis was first described in 2012, but the biological aspects of this species are still unknown. This study aimed to analyze the biological aspects of R. montenegrensis under laboratory conditions. The emergence rate was 63.0%, the mean time required for the emergence was 13.9 ± 1.7 days, the biological cycle from egg to adult phase occurred in 105.2 ± 9.2 days, the number of bloodmeals required for each nymphal stage to reach the next stage varies between a minimum of two and a maximum of seven. The weight gained after a bloodmeal varied between 10.6 times on 1st-instar nymphs and 3.9 times on 5th-instar nymphs. The adult specimens had the lowest gain of weight, reaching 2.2 times on females and 1.6 times on males. The sex ratio observed was 1:1. These data are relevant to understand the life cycle of this new described species and to elaborate more effective vector control strategies.

First report of Panstrongylus lignarius (Walker, 1873) (Hemiptera: Reduviidae: Triatominae) in the State of Acre, Brazil.

INTRODUCTION: This communication reports the first occurrence of Panstrongylus lignarius in the State of Acre, Brazil. METHODS: A specimen of P. lignarius was collected from a residence in a rural area of the municipality of Rio Branco, Acre, Western Amazon. RESULTS: This new report of P. lignarius extends the distribution of this species to eight Brazilian states, and also increases the number of species of Triatominae described from the state of Acre from nine to ten. CONCLUSIONS: The occurrence of P. lignarius deserves attention, since this species has the potential for domiciliation and transmitting Trypanosoma cruzi.

Occurrence of triatomines in an urban residential complex in the municipality of Rio Branco, Acre, South-Western Amazon.

INTRODUCTION: This study describes the occurrence of triatomines, and their positivity for trypanosomatids, in a residential complex in Rio Branco, Acre, Brazil. METHODS: Triatomines were collected through direct capture in a home environment. Positivity analysis for trypanosomatids was performed by PCR assays. RESULTS: Collected insects consisted of 31 Rhodnius robustus, 4 Rhodnius montenegrensis, and 1 Panstrongylus geniculatus specimens. All were adults, with no presence of domiciliation, and with an infection rate of 30.6%. CONCLUSIONS: Future studies are recommended in other locations of Rio Branco in order to develop a georeference database of the occurrence of triatomines in urban areas.

Confirmation of the occurrence of Panstrongylus rufotuberculatus (Champion, 1899) in the state of Acre, Western Amazon.

INTRODUCTION: This study aimed to confirm the occurrence of Panstrongylus rufotuberculatus in the state of Acre, Brazil. METHODS: The four specimens of P. rufotuberculatus were obtained from the entomological collection of the Zoobotanical Park of the Federal University of Acre (UFAC). RESULTS: Confirmation of the occurrence of this species in the state of Acre increases the number of species already registered, from nine to ten. CONCLUSIONS: The necessity to develop further studies was verified, especially with the domiciliary process of P. rufotuberculatus, resulting in tracing prophylactic measures against the vector transmission of Trypanosoma cruzi.

First Report of Natural Infection with Trypanosoma cruzi in Rhodnius montenegrensis (Hemiptera, Reduviidae, Triatominae) in Western Amazon, Brazil.

Rhodnius montenegrensis was described in 2012. Since then, reports of the occurrence of this species associated with palm trees near households in Rondônia have been published. This study aimed to analyze the natural infection of R. montenegrensis with trypanosomatids in the municipality of Monte Negro, Rondônia, Brazilian western Amazon. Capture of triatomines occurred in Attalea speciosa (babassu) specimens around households. Twelve of the 72 captured triatomines were identified by morphological and morphometric characters, by molecular analysis made using the PCR, DNA sequencing, and phylogenetic analyses. The intestinal content was collected from 60 of these 72 specimens. The positivity for trypanosomatids was confirmed by examining the intestinal content followed by PCR amplification of the cathepsin L-like gene specific for Trypanosoma cruzi (PCR-DTcrCatL) and Trypanosoma rangeli (PCR-DTraCatL). Of the 60 specimens analyzed by microscopy, 22 (36.7%) were positive for trypanosomatids in the intestinal content analysis. Of these 22 specimens of R. montenegrensis, 16 (72.7%) were infected with T. cruzi, 2 (9.1%) were infected with T. rangeli, 2 (9.1%) had mixed infection with T. cruzi and T. rangeli, and 2 were negative (9.1%). These data suggest the need for attention of the health surveillance system of Chagas disease in the State of Rondônia, as this study points out to another potential vector of the disease.