Comparative transcriptional analysis between susceptible and resistant populations of Aedes (Stegomyia) aegypti (Linnaeus, 1762) after malathion exposure.

Aedes aegypti is an important vector of arboviruses, including dengue, chikungunya and Zika. The application of synthetic insecticides is a frequently used strategy to control this insect. Malathion is an organophosphate insecticide that was widely used in Brazil in the 1980s and 1990s to control the adult form of A. aegypti. In situations where resistance to currently used insecticides is detected, the use of malathion may be resumed as a control measure. Many studies have confirmed resistance to malathion, however, comparative studies of differential gene expression of the entire transcriptome of resistant and susceptible insects are scarce. Therefore, understanding the molecular basis of resistance to this insecticide in this species is extremely important. In this paper, we present the first transcriptomic description of susceptible and resistant strains of A. aegypti challenged with malathion. Guided transcriptome assembly resulted in 39,904 transcripts, where 2133 differentially expressed transcripts were detected, and three were validated by RT-qPCR. Enrichment analysis for these identified transcripts resulted in 13 significant pathways (padj < 0.05), 8 associated with down-regulated and 5 with up-regulated transcripts in treated resistant insects. It was possible to divide the transcripts according to the mechanism of action into three main groups: (i) genes involved in detoxification metabolic pathways; (ii) genes of proteins located in the membrane/extracellular region; and (iii) genes related to DNA integration/function. These results are important in advancing knowledge of genes related to resistance mechanisms in this insect, enabling the development of effective technologies and strategies for managing insecticide resistance.

Annotation of transposable elements in the transcriptome of the Neotropical brown stink bug Euschistus heros and its chromosomal distribution.

Transposable elements (TEs) are DNA sequences capable of moving within the genome. Their distribution is very dynamic among organisms, and despite advances, there are still gaps in the understanding of the diversity and evolution of TEs in many insect species. In the case of Euschistus heros, considered the main stink bug in the soybean crop in Brazil, little is known about the participation of these elements. Therefore, the objective of the current work was to identify the different groups of transposable elements present in the E. heros transcriptome, evidencing their chromosomal distribution. Through RNA-Seq and de novo assembly, 60,009 transcripts were obtained, which were annotated locally via Blastn against specific databases. Of the 367 transcripts identified as TEs, 202 belong to Class II, with emphasis on the TIR order. Among Class I elements or retrotransposons, most were characterized as LINE. Phylogenetic analyses were performed with the protein domains, evidencing differences between Tc1-mariner sequences, which may be related to possible horizontal transfer events. The transposable elements that stood out in the transcriptome were selected for fluorescent in situ hybridization. DNA transposon probes hAT, Helitron, and Tc1-mariner showed mostly scattered signals, with the presence of some blocks. Retrotransposon probes Copia, Gypsy, Jockey, and RTE showed a more pulverized hybridization pattern, with the presence of small interstitial and/or terminal blocks. Studies like this one, integrating functional genomics and molecular cytogenetic tools, are essential to expanding knowledge about transcriptionally active mobile elements, and their behavior in the chromosomes.

Transposable elements in the transcriptome of the velvetbean caterpillar Anticarsia gemmatalis Hübner, 1818 (Lepidoptera: Erebidae).

Transposable elements (TEs) are DNA sequences that possess the ability to move from one genomic location to another. These sequences contribute to a significant fraction of the genomes of most eukaryotes and can impact their architecture and regulation. In this paper, we present the first data related to the identification and characterization of TEs present in the transcriptome of Anticarsia gemmatalis. Approximately, 835 transcripts showed significant similarity to TEs and (or) characteristic domains. Retrotransposons accounted for 71.2% (595 sequences) of the identified elements, while DNA transposons were less abundant, with 240 annotations (28.8%). TEs were classified into 30 superfamilies, with SINE3/5S and Gypsy being the most abundant. Based on the sequences of TEs found in the transcriptome, we were able to locate conserved regions in the chromosomes of this species. The analysis of differential expression of TEs in susceptible and resistant strains, challenged and not challenged with Bacillus thuringiensis (Bt) from in silico analysis, indicated that exposure to Bt can regulate the transcription of mobile genetic elements in the velvetbean caterpillar. Thus, these data contribute significantly to the knowledge of the structure and composition of these elements in the genome of this species, and suggest the role of stress on their expression.

Transcriptional Analysis of Microsatellites in Velvetbean Caterpillar Anticarsia gemmatalis Hübner, 1818.

Brazil is the largest producer of soybeans in the world. The vast extent of soybean plantations across the Brazilian territory exposes this crop to attack by several insects, including the velvetbean caterpillar, Anticarsia gemmatalis. One of the alternatives used to control this insect are the toxins produced by Bacillus thuringiensis (Bt). However, in some cases, resistance to these toxins has been reported in the laboratory. Despite the ecological and economic impact of the velvetbean caterpillar, there are few studies on the genetic structure of this species, especially with regard to microsatellites. In this paper, we carried out a comparative transcriptional analysis of microsatellites in resistant (RES) and susceptible (SUS) strains of A. gemmatalis challenged and not challenged with Bt toxins. According to the number of sequences analyzed in each group, a 7.9% simple sequence repeat (SSR) rate was identified for the SUS library, and 7.4% for SUSBt. For the RES group, this value was 8.5% and for the RESBt 7.7%. Most of the fragments found showed a shorter repeat pattern, located in mono- and trinucleotide motifs. Among the 128 types of SSR motifs, it was possible to notice a large amount of adenine and thymine in relation to guanine and cytosine, which was also seen in chromosomes after staining with base-specific fluorochromes DAPI/CMA3, highlighting DAPI-positive regions. Although the participation of microsatellites in the resistance mechanism of A. gemmatalis to Bt is not clear, the results obtained in this work contribute to a better understanding of the repetitive DNA found in transcribed regions of a non-model organism.

Transcriptional profiling analysis of susceptible and resistant strains of Anticarsia gemmatalis and their response to Bacillus thuringiensis.

Anticarsia gemmatalis is one of the main defoliators of soybean in Brazil. Bacillus thuringiensis (Bt) transgenic crops are used for their management. In this paper we used RNA-seq to explore the response of A. gemmatalis to Bt HD73, as well as to detect transcriptional differences after Bt infection between resistant and susceptible strains. A total of 3853 and 6224 differentially expressed genes (DGEs) were identified in susceptible and resistant larvae after Bt exposure, respectively. We identified 2143 DEGs between susceptible and resistant larvae and 1991 between susceptible and resistant larvae Bt exposed. Immunity-related genes, Bt toxins receptors, proteases, genes involved in metabolic processes, transporters, cuticle proteins and mobile elements have been identified. qRT-PCR data demonstrated upregulation of five genes in susceptible strain after Bt exposure. These results provide insights to understand the molecular and cellular mechanisms of response to Bt that could be used in strategies to control agricultural pests.

A strategy for designing of customized electromechanical actuators of blood pumps.

Congestive heart failure is a pathology of global incidence that affects millions of people worldwide. When the heart weakens and fails to pump blood at physiological rates commensurate with the requirements of tissues, two main alternatives are cardiac transplant and ventricular assist devices (VADs). This article presents the design strategy for development of a customized VAD electromagnetic actuator. Electromagnetic actuator is a brushless direct current motor customized to drive the pump impeller by permanent magnets located in rotor-stator coupling. In this case, ceramic pivot bearings support the VAD impeller. Electronic circuitry controls rotation switching current in stator coils. The proposed methodology consisted of analytical numerical design, tridimensional computational modeling, numerical simulations using Maxwell software, actuator prototyping, and validation in the dynamometer. The axial flow actuator was chosen by its size and high power density compared to the radial flow type. First step consisted of estimating the required torque to drive the pump. Torque was estimated at 2100 rpm and mean current of 0.5 A. Numerical analysis using finite element method mapped vectors and fields to build stator coils and actuator assemblage. After tests in the dynamometer, experimental results were compared with numerical simulation and validated the proposed model. In conclusion, the proposed methodology for designing of VAD electromechanical actuator was considered satisfactory in terms of data consistency, feasibility, and reliability.

Pulmonary Embolism and Gas Exchange.

Acute pulmonary embolism (PE) impairs hemodynamics, gas exchange, and lung mechanical capacity. Considering PE pathophysiology, most attention has been paid to hemodynamic impairment. However, the most prevalent symptoms in PE patients come from gas exchange alterations, which have not been in the spotlight for many years. Pulmonary physiology and consequent gas exchange impairment play a pivotal role in the high risk of death from PE. In this review, we will look at the pathophysiology of PE, from the vascular occlusion to the resultant heterogeneity in pulmonary perfusion and gas exchange impairment, discussing in detail its causes and consequences.

Functional annotation and distribution overview of RNA families in 27 Streptococcus agalactiae genomes.

BACKGROUND: Streptococcus agalactiae, also known as Group B Streptococcus (GBS), is a Gram-positive bacterium that colonizes the gastrointestinal and genitourinary tract of humans. This bacterium has also been isolated from various animals, such as fish and cattle. Non-coding RNAs (ncRNAs) can act as regulators of gene expression in bacteria, such as Streptococcus pneumoniae and Streptococcus pyogenes. However, little is known about the genomic distribution of ncRNAs and RNA families in S. agalactiae. RESULTS: Comparative genome analysis of 27 S. agalactiae strains showed more than 5 thousand genomic regions identified and classified as Core, Exclusive, and Shared genome sequences. We identified 27 to 89 RNA families per genome distributed over these regions, from these, 25 were in Core regions while Shared and Exclusive regions showed variations amongst strains. We propose that the amount and type of ncRNA present in each genome can provide a pattern to contribute in the identification of the clonal types. CONCLUSIONS: The identification of RNA families provides an insight over ncRNAs, sRNAs and ribozymes function, that can be further explored as targets for antibiotic development or studied in gene regulation of cellular processes. RNA families could be considered as markers to determine infection capabilities of different strains. Lastly, pan-genome analysis of GBS including the full range of functional transcripts provides a broader approach in the understanding of this pathogen.

Distribution of Divo in Coffea genomes, a poorly described family of angiosperm LTR-Retrotransposons.

Coffea arabica (the Arabica coffee) is an allotetraploid species originating from a recent hybridization between two diploid species: C. canephora and C. eugenioides. Transposable elements can drive structural and functional variation during the process of hybridization and allopolyploid formation in plants. To learn more about the evolution of the C. arabica genome, we characterized and studied a new Copia LTR-Retrotransposon (LTR-RT) family in diploid and allotetraploid Coffea genomes called Divo. It is a complete and relatively compact LTR-RT element (~5 kb), carrying typical Gag and Pol Copia type domains. Reverse Trancriptase (RT) domain-based phylogeny demonstrated that Divo is a new and well-supported family in the Bianca lineage, but strictly restricted to dicotyledonous species. In C. canephora, Divo is expressed and showed a genomic distribution along gene rich and gene poor regions. The copy number, the molecular estimation of insertion time and the analysis at orthologous locations of insertions in diploid and allotetraploid coffee genomes suggest that Divo underwent a different and recent transposition activity in C. arabica and C. canephora when compared to C. eugenioides. The analysis of this novel LTR-RT family represents an important step toward uncovering the genome structure and evolution of C. arabica allotetraploid genome.

Platelet activation and apoptosis modulate monocyte inflammatory responses in dengue.

Dengue is the most prevalent human arbovirus disease in the world. Dengue infection has a large spectrum of clinical manifestations, from self-limited febrile illness to severe syndromes accompanied by bleeding and shock. Thrombocytopenia and vascular leak with altered cytokine profiles in plasma are features of severe dengue. Although monocytes have been recognized as important sources of cytokines in dengue, the contributions of platelet-monocyte interactions to inflammatory responses in dengue have not been addressed. Patients with dengue were investigated for platelet-monocyte aggregate formation. Platelet-induced cytokine responses by monocytes and underlying mechanisms were also investigated in vitro. We observed increased levels of platelet-monocyte aggregates in blood samples from patients with dengue, especially patients with thrombocytopenia and increased vascular permeability. Moreover, the exposure of monocytes from healthy volunteers to platelets from patients with dengue induced the secretion of the cytokines IL-1ß, IL-8, IL-10 and MCP-1, whereas exposure to platelets from healthy volunteers only induced the secretion of MCP-1. In addition to the well-established modulation of monocyte cytokine responses by activated platelets through P-selectin binding, we found that interaction of monocytes with apoptotic platelets mediate IL-10 secretion through phosphatidylserine recognition in platelet-monocyte aggregates. Moreover, IL-10 secretion required platelet-monocyte contact but not phagocytosis. Together, our results demonstrate that activated and apoptotic platelets aggregate with monocytes during dengue infection and signal specific cytokine responses that may contribute to the pathogenesis of dengue.

Platelets mediate increased endothelium permeability in dengue through NLRP3-inflammasome activation.

Dengue is the most frequent hemorrhagic viral disease and re-emergent infection in the world. Although thrombocytopenia is characteristically observed in mild and severe forms of dengue, the role of platelet activation in dengue pathogenesis has not been fully elucidated. We hypothesize that platelets have major roles in inflammatory amplification and increased vascular permeability during severe forms of dengue. Here we investigate interleukin (IL)-1ß synthesis, processing, and secretion in platelets during dengue virus (DV) infection and potential contribution of these events to endothelial permeability during infection. We observed increased expression of IL-1ß in platelets and platelet-derived microparticles from patients with dengue or after platelet exposure to DV in vitro. We demonstrated that DV infection leads to assembly of nucleotide-binding domain leucine rich repeat containing protein (NLRP3) inflammasomes, activation of caspase-1, and caspase-1-dependent IL-1ß secretion. Our findings also indicate that platelet-derived IL-1ß is chiefly released in microparticles through mechanisms dependent on mitochondrial reactive oxygen species-triggered NLRP3 inflammasomes. Inflammasome activation and platelet shedding of IL-1ß-rich microparticles correlated with signs of increased vascular permeability. Moreover, microparticles from DV-stimulated platelets induced enhanced permeability in vitro in an IL-1-dependent manner. Our findings provide new evidence that platelets contribute to increased vascular permeability in DV infection by inflammasome-dependent release of IL-1ß.

Maternal physical activity, cervical length and its relation to spontaneous vaginal birth at term.

OBJECTIVE: Physical activity during pregnancy is known to be beneficial, however there are controversies about the risk of preterm labor, and there is no published data to assess the association between cervical length and maternal physical activity during pregnancy. Therefore, the objective of the study was to describe the cervical length in the second and third trimesters, correlating with physical activity, anthropometric characteristics, and obstetric results. METHODS: Prospective cohort with 56 pregnant women, allocated in two groups according to the answers obtained by a validating questionnaire on physical activity. It was considered significant p < 0.05. RESULTS: The length of the uterine cervix was similar between active and sedentary women, from the 22nd to the 24th week of pregnancy (p = 0.58), and from the 32nd to the 34th week (p = 0.59). Gestational age at delivery was lower among active women than among sedentary ones, although without clinical repercussion, 38.2 ± 1.2 vs. 39.1 ± 1.2 weeks, respectively (p = 0.02). Among active women, 33 (89.1 %) had natural labor, while among sedentary ones, only 13 (68.4 %) (p = 0.05). The Apgar score was higher among children of active mothers (p = 0.04). CONCLUSION: Despite being the data still to small to allow final conclusions, maternal physical activity, cervical length and its relation to spontaneous vaginal birth at term is a relevant topic for the information of women in early pregnancy. More investigations directly after specific activities such as riding, walking, and biking are needed to answer the questions we receive from our pregnant patients.

Differential Gene Expression in Contrasting Common Bean Cultivars for Drought Tolerance during an Extended Dry Period.

Common beans (Phaseolus vulgaris L.), besides being an important source of nutrients such as iron, magnesium, and protein, are crucial for food security, especially in developing countries. Common bean cultivation areas commonly face production challenges due to drought occurrences, mainly during the reproductive period. Dry spells last approximately 20 days, enough time to compromise production. Hence, it is crucial to understand the genetic and molecular mechanisms that confer drought tolerance to improve common bean cultivars' adaptation to drought. Sixty six RNASeq libraries, generated from tolerant and sensitive cultivars in drought time sourced from the R5 phenological stage at 0 to 20 days of water deficit were sequenced, generated over 1.5 billion reads, that aligned to 62,524 transcripts originating from a reference transcriptome, as well as 6673 transcripts obtained via de novo assembly. Differentially expressed transcripts were functionally annotated, revealing a variety of genes associated with molecular functions such as oxidoreductase and transferase activity, as well as biological processes related to stress response and signaling. The presence of regulatory genes involved in signaling cascades and transcriptional control was also highlighted, for example, LEA proteins and dehydrins associated with dehydration protection, and transcription factors such as WRKY, MYB, and NAC, which modulate plant response to water deficit. Additionally, genes related to membrane and protein protection, as well as water and ion uptake and transport, were identified, including aquaporins, RING-type E3 ubiquitin transferases, antioxidant enzymes such as GSTs and CYPs, and thioredoxins. This study highlights the complexity of plant response to water scarcity, focusing on the functional diversity of the genes involved and their participation in the biological processes essential for plant adaptation to water stress. The identification of regulatory and cell protection genes offers promising prospects for genetic improvement aiming at the production of common bean varieties more resistant to drought. These findings have the potential to drive sustainable agriculture, providing valuable insights to ensure food security in a context of climate change.

Acute effects of transcranial direct current stimulation combined with physical therapy on the balance and gait in individuals with Parkinson's disease: A randomized controlled trial.

Application methods of transcranial direct current stimulation (tDCS) in Parkinson's disease (PD) are quite divergent making it difficult to define the clinical effectiveness of the tDCS on PD. Thus, the aim of this study was to verify the acute effects of tDCS when applied to different targets (Cz or C3-Cz-C4) combined to physical therapy to improve balance and gait in individuals with PD. A randomized controlled trial was conducted, with 50 individuals who were separated into four groups: 1) Real tDCS (Cz) + physical therapy, 2) Real tDCS (C3-Cz-C4) + physical therapy, 3) Sham tDCS + physical therapy and 4) Educational lecture + physical therapy. The current intensity was 2 mA, applied for 20 min. For the instrumental assessment of balance and gait, the 3D motion analysis system was used. For the biomechanical analysis of gait, three different conditions were performed: normal gait, dual task gait and obstacle gait. For balance analysis, the following positions were utilized: Romberg with eyes opened, Romberg with eyes closed, Tandem with eyes opened and Tandem with eyes closed. All evaluations were performed pre-intervention, post-intervention (immediately at the end of the intervention) and were followed-up on (24 h after the end of the intervention). No statistically significant differences were found for all gait and balance outcomes when considering the interaction between time (pre, post and follow-up assessments) versus group (Education, Sham, Cz and C3-Cz-C4). In conclusion, it was found that one session of tDCS, stimulating Cz or C3-Cz-C4 combined with physical therapy, was not effective in improving the balance and gait in people with PD as compared to sham tDCS or educational lecture plus physiotherapy.

Influence of temperature variation on gene expression and cocoon production in Bombyx mori Linnaeus, 1758 (Lepidoptera: Bombycidae).

Silkworms (Bombyx mori) are lepidopterans of economic importance for global silk production. However, factors that directly affect the yield and quality of silkworm cocoon production, such as diseases and temperature fluctuations, cause great economic losses. Knowing how they respond to rearing temperature during the most critical stage of their life cycle (i.e., fifth instar) could provide information on their adaptation and improve silk production. In the current work, we analyzed transcriptional data from two groups of B. mori that were reared at 26 °C and 34 °C throughout the fifth instar. The silkworms and cocoons were weighed. In total, 3115 transcripts were differentially expressed (DE; including 1696 down-regulated and 1419 up-regulated) among the 29,157 sequences found by transcriptome assembly. We emphasize the genes associated with immunological response, transcription factors, silk biosynthesis, and heat shock proteins, among the DE transcripts in response to the temperature conditions. Silkworms reared at 34 °C presented a reduced mean body weight (-0.944 g in comparison to the 26 °C group), which had a direct impact on the weight of cocoons formed and the silk conversion rate. These changes were statistically significant when compared to silkworms reared at 26 °C. Mortality rates (6 and 9 %, at 26 °C and 34 °C, respectively) were similar to those obtained in breeding fields. The findings provide information on the biological processes involved in the temperature response mechanism of silkworms, as well as information that may be used in future climatization processes at rearing facilities and in breeding for improved thermotolerance.

Challenges of acute febrile illness diagnosis in a national infectious diseases center in Rio de Janeiro: 16-year experience of syndromic surveillance.

INTRODUCTION: Acute febrile illnesses (AFI) are a frequent chief complaint in outpatients. Because the capacity to investigate the causative pathogen of AFIs is limited in low- and middle-income countries, patient management may be suboptimal. Understanding the distribution of causes of AFI can improve patient outcomes. This study aims to describe the most common etiologies diagnosed over a 16-years period in a national reference center for tropical diseases in a large urban center in Rio de Janeiro, Brazil. METHODS: From August 2004-December 2019, 3591 patients > 12 years old, with AFI and/or rash were eligible. Complementary exams for etiological investigation were requested using syndromic classification as a decision guide. Results. Among the 3591 patients included, endemic arboviruses such as chikungunya (21%), dengue (15%) and zika (6%) were the most common laboratory-confirmed diagnosis, together with travel-related malaria (11%). Clinical presumptive diagnosis lacked sensitivity for emerging diseases such as zika (31%). Rickettsia disease and leptospirosis were rarely investigated and an infrequent finding when based purely on clinical features. Respiratory symptoms increased the odds for the diagnostic remaining inconclusive. CONCLUSIONS: Numerous patients did not have a conclusive etiologic diagnosis. Since syndromic classification used for standardization of etiological investigation and presumptive clinical diagnosis had moderate accuracy, it is necessary to incorporate new diagnostic technologies to improve diagnostic accuracy and surveillance capacity.

Telehealth For Individuals with Parkinson's Disease During Covid-19 In Brazil: A Prospective Case Series.

Objective: To implement a telerehabilitation prevention, treatment, and follow-up physical therapy protocol for monitoring individuals with Parkinson's disease (PD) and to verify its effectiveness in minimizing the deleterious effects of the COVID-19 pandemic. Design: Prospective case series, involving 40 participants with mild to moderate PD recruited from a specialized neurorehabilitation group. The study was divided into four parts: (1) Phone calls to assess the feasibility of participating in remote physical therapy. (2) Social media training. (3) Baseline and post-intervention assessment for functional lower extremity strength, fear of falling, quality of life, depression, anxiety, activities of daily living, verbal fluency. (4) Intervention protocol consisting of 20 remote weekly physical therapy sessions, graphic material for physical and cognitive training, social activities, and education. Conclusion: The telerehabilitation protocol was viable and effective for patients with PD as an alternative to in-person treatment during the COVID-19 pandemic.

Severe Sporotrichosis Treated with Amphotericin B: A 20-Year Cohort Study in an Endemic Area of Zoonotic Transmission.

Although rare, disseminated sporotrichosis is increasing in several countries. Despite its limiting toxic potential, amphotericin B is the only intravenous antifungal available to treat severe sporotrichosis. We aimed to describe the effectiveness and safety of amphotericin B treatment for severe sporotrichosis. Clinical records of patients with disseminated sporotrichosis at a reference center were reviewed. This study included 73 patients. Most (53.4%) were men and non-white. HIV coinfection was the main comorbidity (52.1%). Most reported contact with cats (76.7%). Sporothrix brasiliensis was the causative species. Affected sites were skin (98.6%), osteoarticular system (64.4%), upper airway (42.5%), central nervous system (20.5%), eyes (12.3%), and lungs (8.2%). Median doses of amphotericin B used were 750 mg and 4500 mg for deoxycholate and lipid complex formulations, respectively. Amphotericin B discontinuation occurred in 20.5% due to adverse events, mainly azotemia. The outcomes included cure (52.1%), death due to sporotrichosis (21.9%), death due to other causes (9.6%), and loss to follow-up (8.2%). Survival analysis showed an association between cure and the absence of bone, upper airway, and central nervous system involvement. Amphotericin B is the first-choice treatment for disseminated sporotrichosis; however, the severity of systemic dissemination might predict its response. Favorable clinical results depend on prompt diagnosis, investigation of fungal dissemination, and early therapy initiation.

Beyond arboviruses: A multicenter study to evaluate differential diagnosis of rash diseases and acute febrile illness cases in Rio de Janeiro, Brazil.

INTRODUCTION: A wide variety of viruses can cause rash diseases (RDs) or acute febrile illness (AFIs) in children, adolescents and adults; however, approximately 19% of RD cases and 40% of AFI cases remain without a defined etiology. Parvovirus B19 (B19V) and herpesvirus infection can also cause RD and/or AFI, and in some risk groups, these infections can become persistent (or latent) and may require hospital treatment. Since these infections do not have mandatory reporting, they can be hidden by other diseases, such as those caused by arboviruses (e.g., dengue virus). In this context, the aim of this study was to pursue the differential laboratory diagnoses of B19V and herpesvirus infections in patients with RD and AFI, without a defined etiology, seen in hospitals and/or reference centers for infectious diseases in Rio de Janeiro. METHODS: A total of 114 participants were enrolled in the study, including 54 children and 60 adults. B19V infection was assessed by real-time PCR (qPCR) and ELISA (anti-B19V IgM and IgG). EBV was assessed through qPCR, and betaherpesviruses (HCMV, HHV-6 and HHV-7) were assessed through multiplex qPCR. Sociodemographic and clinical data were obtained from the medical record data of these participants. RESULTS: The median age of children with RD was 2 years (interquartile range (IQR): 5), and 55.6% were male. Among adults with AFI, the median age was 38 years (IQR: 21), and 56.7% were female. Regarding RD patients, viral prevalence (and load) were 5.5%(104IU/mL), 3.4%(104IU/mL), 5.5%(104IU/mL) and 11.1%(105IU/mL) for B19V, EBV, HCMV and HHV-6 infection, respectively, and in AFI patients they were 6.6%(105IU/mL), 1.6%(103IU/mL), 3.3%(104IU/mL) for B19V, HCMV and HHV-6, respectively. HHV-7 was not detected in RD or AFI patients. CONCLUSION: These results suggest the importance of including B19V and herpesviruses in the differential laboratory diagnoses for patients with RD and AFI, not only for epidemiological purposes but also for the proper management of the patient.