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Hepatitis E virus (HEV) infection is a common cause of acute viral hepatitis in tropical regions. In Brazil, HEV G3 is the only genotype detected to date. Reports on HEV prevalence are heterogeneous. We aimed to compare the prevalence of anti-HEV among three populations living in the Brazilian Amazon basin. Two cross-sectional studies were conducted in urban, rural, and Yanomami indigenous areas. Plasma samples from 428 indigenous and 383 non-indigenous subjects were tested for anti-HEV IgG using enzyme-linked immunosorbent assays. The overall prevalence of anti-HEV was 6.8% (95%CI: 5.25-8.72), with 2.8% (12/428) found in the Yanomami areas, 3% (3/101) in an urban area, and 14.2% (40/282) in a rural area. Multivariate logistic analysis indicated that patients aged 31-45 years or ≥46 years are more likely to present anti-HEV positivity, with a respective aOR of 2.76 (95%CI: 1.09-7.5) and 4.27 (95%CI: 1.58-12.35). Furthermore, residence in a rural area (aOR: 7.67; 95%CI: 2.50-33.67) represents a relevant risk factor for HEV infection. Additional studies detecting HEV RNA in fecal samples from both humans and potential animal reservoirs are necessary to comprehensively identify risk factors associated with HEV exposure.

The Araguari River, one of the most important waterways in the Brazilian state of Amapá, is ecologically relevant and essential for the conservation of Amazonian fish biodiversity. Our previous studies demonstrated contamination of water and fish by metals. In particular, water samples showed genotoxic damage in Danio rerio. Here, we extended our studies of potential genotoxic damage to native fish from sampling sites located in the Araguari River lower section. To accomplish this, we collected samples of fish with different feeding behaviors, but in the same sampling sites, and evaluated the same genotoxicity biomarkers in erythrocytes. All eleven species of fish collected in the Araguari River lower section showed profiles and frequencies of genotoxic damage similar to those previously observed in tests with D. rerio, confirming that genotoxic pollutants present in these waters are also causing damage to native fish species., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Knowledge of the embryonic development of species such as quail is important for our understanding of its production and reproduction. Quail provides a practical solution to the animal protein shortage problem in developing countries and is an excellent alternative to chicken (Shanaway, 1994). This study evaluated quail embryonic viability by comparing the main morphological changes that occur over the development in a homemade incubator with previous data; the incubator was built using easily accessible and low-cost materials, which allows small producers and communities to develop quail farms as an activity to increase income or even produce a source of animal protein for the community in the Brazilian Amazon region. The homemade incubator measured 40 cm × 42 cm × 32 cm and was constructed with wooden boards, a digital thermostat, and an incandescent lamp. A total of 24 fertile eggs were incubated at a temperature of 37.5 °C and 60% relative humidity; age "0" was set at the start of incubation. Two eggs were opened on each day of development, starting from day 5 to day 16 of incubation. After gently opening the eggs, the embryos were removed, separated from the placenta and amniotic fluid, washed with running water, and weighed on a digital scale (SHIMADZU AUY 220 brand and UNI BLOC model). Crown-rump length and other measurements were performed with a digital caliper and the morphological structures were observed using a stereomicroscope (NOVA brand and NOVA ZTX-E model). All eggs opened contained live embryos, indicating that the homemade incubator temperature, relative humidity, and manual turning were adequate to maintain the quail's viability. The morphometric data of the embryos at different developmental time points were similar to those described in the literature. Embryos weighed 0.0069 g at day 5 and 4.7863 g at day 16, and the crown-rump length (CRL) means were 0.368 cm and 3.657 cm, respectively. Weight and CRL increased by 0.434 g and 2.593 cm per day of incubation, respectively. In conclusion, after 16 days of incubation in a homemade incubator, the embryos presented all phases of the development cycle, with appropriate development of weight and height based on the days of incubation without anomaly or external interference. These findings demonstrate that the homemade incubator does not alter the embryonic development of quail embryos in the Brazilian Amazon region., Competing Interests: Conflict of interests: ACM, GCS, RTO, TSF, AALB and ASLS – No conflict of interest.

Recently, high concentrations of metals have been found in the waters from sampling sites located in the Araguari River lower section. These metals can be bioaccumulated by fish, but also biomagnified, representing a potential risk through human consumption. Here, we aimed to (1) determine the metal concentrations in muscle samples from fish; (2) evaluate bioaccumulation of metals in muscle tissue of fish species with different feeding behaviors; and (3) investigate the risks of single metals, as well as mixture of metals, to human fish consumption. Eleven fish species were sampled (3 carnivorous, 5 omnivorous, and 3 detritivorous). In four fish species, Cd and Pb concentrations exceeded the Brazilian maximum limits (MLs) for human consumption. Individually, Pb and Cd concentrations in the muscle of these fish indicate risks to human health. When considering the mixture of metals, the consumption of all fish species represents risks. The highest risks implicate detritivorous species. For all fish species evaluated, the estimated daily intake (EDI) of Hg shows values above its reference dose (RfD). Our results suggest the need to establish an environmental monitoring program that aims to preserve environmental quality, biodiversity, and human health. It is also necessary to develop actions that aim to educate Amazonian populations on safe fish preparation and consumption., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

This study aimed to characterize a Klebsiella pneumoniae strain (KP411) recovered from the stool samples of poultry ( Gallus gallus ) in the Brazilian Amazon Region. The whole-genome sequencing of KP411 revealed the presence of an important arsenal of antimicrobial resistance genes to β-lactams ( bla CTX-M-14 , bla TEM-1B , bla KPC-2 , bla SVH-11 ), aminoglycosides [ aph(3″)- Ib, aph(6)-Id, aph(3')-Ia ], sulfonamides ( sul1, sul2 ), quinolones ( oqxAB ), fosfomycin ( fosA KP ), and macrolides [ mph(A) ]. Furthermore, our analyses revealed that the KP411 strain belongs to the ST258 clonal lineage, which is one of the main epidemic clones responsible for the dissemination of KPC-2 worldwide. Our data suggest that food-producing animals may act as reservoirs of multidrug-resistant K. pneumoniae belonging to the ST258 clone, and, consequently, contribute to their dissemination to humans and the environment.

The characterization of behavioral patterns allows a better understanding of the transmission dynamics and the design of more effective malaria vector control strategies. This study analyzed the behavioral patterns of the Anopheles species of the Coração district situated in the northeast of the Brazilian Amazon region. The behavioral patterns of the anopheline species were measured based on the 36 collection sites of this district from December 2010 to November 2011. Collections of four hours for three consecutive nights each month and four 12-h collections, comprising two in the rainy season and two in the dry season, were performed. Furthermore, to infer the anthropophily and zoophily indexes, four additional four-hour collections were performed. The samples were also evaluated for parity rate and natural infectivity for Plasmodium spp. A total of 1689 anophelines were captured, comprising of nine species and two subgenera (Nyssorhynchus - six species, and Anopheles - three species). Anopheles darlingi was the most abundant and widely distributed species in the area, followed by A. braziliensis and A.marajoara. Anopheles darlingi and A. marajoara were the only species present in the four collections of 12-h, but only A. darlingi showed activity throughout night. Anopheles darlingi was the most anthropophilic species (AI=0.40), but the zoophily index was higher (ZI=0.60), revealing an eclectic and opportunistic behavior. Of the six most frequent species, A. nuneztovari s.l. was the most zoophilic species (ZI=1.00). All captured species showed predominance towards biting in outdoor environments. Anopheles darlingi and A. braziliensis showed multimodal biting peaks, whereas A. marajoara revealed a stable pattern, with the biting peak after sunset. Using the PCR technique, no anopheline was found infected with the malaria parasite. Since A. darlingi and A. marajoara are recognized as important vectors in this region, the district of Coração may be considered as a highly potent area for transmission of malaria, therefore, the prevention and surveillance measures should be taken constantly to prevent the same. The role of A. braziliensis as malaria vector needs to be urgently investigated., (Published by Elsevier B.V.)

JC virus (JCV) is a member of the Polyomaviridae family and is associated to a severe disease known as progressive multifocal leukoencephalopathy, PML, which is gradually increasing in incidence as an opportunistic infection among AIDS patients. The present study aimed to investigate the occurrence of JCV among HIV-1 carriers including their types and molecular subtypes and the possible association with disease. Urine samples from 66 HIV-1 infected subjects were investigated for the presence of the virus by amplifying VP1 (215bp) and IG (610bp) regions using the polymerase chain reaction. JCV was detected in 32% of the samples. The results confirmed the occurrence of type B (subtype Af2); in addition, another polyomavirus, BKV, was also detected in 1.5% of samples of the HIV-1 infected subjects. Apparently, there was no significant difference between mono- (HIV-1 only) and co-infected (HIV-1/JCV) subjects regarding their TCD4(+)/TCD8(+) lymphocyte counts or HIV-1 plasma viral load. Self admitted seizures, hearing and visual loses were not significantly different between the two groups., (Copyright © 2016 Elsevier Editora Ltda. All rights reserved.)