Abstract in English:

Diphtheria, a severe respiratory infection, was a major killer of children until the early years of the 20th century. Although diphtheria is now largely controlled globally thanks to vaccination, it is still endemic in some world regions and large epidemics can occur where vaccination coverage is insufficient. The pathological effects caused by its main virulence factor, diphtheria toxin, can be diminished by passive transfer of antibodies. Equine diphtheria antitoxin (eDAT), the cornerstone of treatment against toxinic complications of diphtheria, was invented more than 130 years ago, in 1890, and is still in use today. A method to concentrate anti-diphtheria antibodies from hyperimmune equine serum was described in the first issue of Memórias do Instituto Oswaldo Cruz in 1909. On this historic occasion, we present recent knowledge on taxonomic, epidemiological and clinical aspects of diphtheria agents that produce diphtheria toxin, and provide a historical perspective on eDAT treatment, adverse effects, threats on its scarce international supply, and current avenues for alternative therapeutic strategies.

Abstract in English:

Haemosporida research started in the 19th century with the description of Plasmodium and other related parasites infecting mammals and birds. Here, we highlight the pioneering contributions of Henrique Aragão and Arthur Neiva in describing the first two Plasmodium species in lizards from the New World, Plasmodium diploglossi and Plasmodium tropiduri, published in the first printed issue of Memórias do Instituto Oswaldo Cruz in April 1909. We use these discoveries as a background to explore some historical and taxonomic aspects of Plasmodium species infecting reptiles, with a particular emphasis on the advancements made over the past 115 years in the Neotropics. Our review underscores the complexities and persistent challenges in the taxonomic classification of reptile haemosporidians and discusses some scientific advances in the field that improved our understanding of the biology and evolution of these parasites.

Abstract in English:

BACKGROUND The works of Lutz & Neiva, published 115 years ago in the Memórias do Instituto Oswaldo Cruz, are pioneering for the study of Neotropical Tabanidae. These studies emphasised the importance of biological collections and the description of species from the exploration of South American areas. Dasybasis Macquart, 1847 has traditionally been considered a large genus of tabanids restricted to the Australasian, Neotropical, and Andean regions. Dasybasis species exhibit a high degree of morphological similarity, making specific differentiation challenging. Moreover, some of these features are also present in other taxa, suggesting that they may not be homologous characters and should not be used to define the genus. OBJECTIVES This study aimed to assess the monophyly of Dasybasis and establish its major monophyletic groups. METHODS We conducted an implied weighting analysis using morphological characters, and wing landmarks from 91 terminal species. FINDINGS For the total evidence analyses, aligning with either Tabanus Linnaeus or Dasybasis appendiculata Macquart yielded slightly different trees. Classical morphology and total evidence topology aligned with D. appendiculata are the same, while differing from the total evidence topology aligned with Tabanus in two nodes. MAIN CONCLUSIONS Our results indicate that Dasybasis was not a monophyletic group, and that this name should be restricted to species with a distribution in Australasia; while Neotropical Dasybasis species are recovered in different clades. The genera Archiplatius, Pseudoselasoma, and Stypommia are revalidated. This study provides a revised phylogenetic framework for “Dasybasis” and related taxa, highlighting the need for a more nuanced understanding of morphological character evolution within the tribe Diachlorini.

Abstract in English:

Free-living amoebas (FLA) are ubiquitous protists found in the environment. They have shown exceptional resistance to environmental challenges and play significant roles in controlling microbial populations through their predatory behaviour and microbicidal activity in both soil and aquatic ecosystems environments. However, although rare, a limited group of FLA can cause serious infections in the central nervous system and other diseases, particularly in immunocompromised individuals with high mortality rates. They can also cause keratitis in otherwise healthy individuals. This review offers a comprehensive overview of freshwater naked amoebae but does not cover all aspects in detail. Its goal is to provide a historical context for our current understanding while addressing the most critical elements of FLA biology, their pathogenic potential, and their interactions with important human pathogens.

Abstract in English:

The 2015-16 Zika virus (ZIKV) epidemic has posed unprecedented concern for maternal-infant health, mainly due to the substantial risk of microcephaly and other neurological birth abnormalities associated with congenital ZIKV syndrome (CZS). As licenced vaccines and effective antivirals are still unavailable, attention has been focused on post-delivery in vitro or translational in vivo studies to understand the impact of maternal ZIKV infection on placentation and neurodevelopmental consequences for the foetus. Here, we review clinical and translational studies highlighting ZIKV-induced maternal-foetal interface dysfunction, adding to our previous observations of experimental ZIKV vertical transmission to pregnant rhesus monkeys and newly published post-epidemic findings about the theme. This comparative review focuses on the mechanisms by which the virus has a cytopathic effect on trophoblasts and macrophages during placentation in humans, nonhuman primates, and rodent transgenic models, crosses the placental barrier, replicates, and establishes a persistent uteroplacental infection. When considering the mechanism of ZIKV-induced birth defects in humans and other susceptible hosts, it becomes apparent how the various stages of the ZIKV cycle in the host (both the parent and offspring) unfold. This understanding presents specific opportunities for pharmacological intervention and the development of preventative vaccines.

Abstract in English:

Visceral Leishmaniasis in the Americas is primarily associated with Leishmania (Leishmania) infantum. This parasite is non-native and was imported during the colonisation era. The constitutive instability of the Leishmania genome allows this parasite to express flexibility in adapting to environmental fluctuations and different selective pressures, such as those the parasite faced when arrived in the New World. Therefore, genetic diversity is expected among the populations of L. infantum in the Americas, despite the bottle neck of importation route. Indeed, subpopulation of strains of L. infantum carrying a homozygous deletion in the genome was detected exclusively in the continent. These strains are more spread across Brazilian territory to the detriment of the non-deleted; the locus includes four genes, two of which encode the enzyme ecto-3’-nucleotidase/nuclease (3’NT/NU), a virulence factor in L. infantum. In this review, we highlight the sub estimated genetic complexity of L. infantum populations in Brazil, addressing the biological importance of the 3’NT/NU enzyme and the possible phenotypic impacts of its deletion, pointing out how it may configure an adaptive strategy for L. infantum. Finally, we raise the discussion of how the genome of L. infantum might be shaped in a unique way under the ecological conditions of Brazil.

Abstract in English:

The history of the plague, caused by Yersinia pestis, is marked by some of the most devastating pandemics. Its arrival in Brazil on the turn of the 19-20th century led to significant public health challenges and responses. Here, we discuss a comprehensive perspective on the history of the plague in Brazil, emphasising epidemiological trends, public health responses and scientific advances. Understanding the history of the plague in Brazil provides valuable insights into infectious disease control. The study highlights the importance of early detection, robust public health infrastructure, and ongoing research, emphasising the lasting influence of epidemic diseases on society.

Abstract in English:

In 1909, Arthur Neiva published an article titled “Contribuição para os estudos dos dipteros. Observação sobre a biolojia e sistematica das anofelinas brasileiras e suas relações com o impaludismo”, highlighting the biology, ecology, and distribution of Anophelinae mosquitoes and the need for more taxonomic studies in Brazil. This came 11 years after Ronald Ross and Grassi demonstrated mosquito roles in transmitting Plasmodium to birds and humans. Despite considerable advances in the understanding of Anophelinae species, knowledge remains insufficient given the complexity of Brazil’s ecosystems, the intensified anthropogenic environmental changes since the mid-20th century, and the persistent public health challenges posed by malaria. This perspective article presents the distribution of Plasmodium vectors and potential vector species in Brazil using climate variables and a maximum entropy model. Geographical distribution maps of Anophelinae species, including putative species, are provided. The article also discusses the current knowledge of vector species distribution in relation to Brazil’s malaria elimination plan, along with the ecological and anthropogenic factors influencing vector distribution.

Abstract in English:

Malaria, caused by Plasmodium spp., remains a major public health problem. Cerebral malaria is its deadliest form, with a 15-25% mortality rate, despite artemisinin-based treatments. In addition, the World Health Organization (WHO) strictly defines cerebral malaria as the presence of coma, 1 h after a seizure or the correction of hypoglycemia, in patients with P. falciparum parasitemia. Consequently, 25% of survivors experience neurocognitive and behavioral sequelae, particularly in children. However, more recently, neurocognitive and behavioral impairments were also reported in severe non-cerebral malaria, non-severe malaria, and even during asymptomatic Plasmodium infection. Such impairments have been observed in school-aged children, the elderly, and in animal models without classic cerebral malaria pathology. Additionally, mild vasogenic edema has been detected in neuroimaging of patients with severe non-cerebral and non-severe P. falciparum malaria. Therefore, given that approximately 98% of malaria cases in the world are non-severe, neurocognitive and behavioral sequelae may account for a significant proportion of global malaria morbidity. Taken together, these observations suggest that systemic inflammation from malaria, even without traditional cerebral malaria signs, can disrupt brain function and lead to long-term sequelae. We propose that the current definition of cerebral malaria may not fully capture the observed evidence and a new conceptualization is necessary to encompass these findings.

Abstract in English:

BACKGROUND Non-O1 and non-O139 Vibrio cholerae (NOVC) that cause bacteraemia have attracted the attention of the public health community around the world, mainly due to the prospect of outbreaks and the way to treat such infections. OBJECTIVES To identify V. cholerae lineages and their antibiotic resistance and virulence factors associated with bacteraemia. METHODS Vibrio cholerae genomes associated with strains isolated from blood were retrieved and subjected to core genome-based phylogenomic analysis with Roary. The virulome and resistome were searched with abricate using the VFDB and CARD databases. FINDINGS Analysis showed that, in addition to V. cholerae, Vibrio paracholerae also causes bacteraemia. The NOVC group was highly diverse, although genomes from different countries were related. Most bacteraemic Vibrios came from countries not affected by epidemic/endemic cholera. The NOVCs virulome presented factors, such as type III and VI secretion systems, HapA, HlyA, RTX, and TLH. Importantly, no resistance to third-generation cephalosporin has been identified in the resistome of NOVCs. MAIN CONCLUSIONS The presence of multiple NOVC lineages that cause bacteraemia in different parts of the world shows that there is no geographic and socioeconomic restriction for these cases. Therefore, healthcare systems need to be aware of this uncommon but deadly Vibrio infection.

Abstract in English:

BACKGROUND The nematode Angiostrongylus cantonensis, which is endemic to Southeast Asia and adjacent Pacific Islands, has already been recorded in more than 30 countries, including Brazil and other South American nations. It is one of the principal etiological agents of the zoonosis Eosinophilic Meningitis (EoM), which has a number of different species of terrestrial gastropods that act as its intermediate hosts. OBJECTIVE The present study investigated the occurrence of the larvae of this nematode in specimens of terrestrial molluscs collected in half of the municipalities of the Brazilian State of Rio de Janeiro. METHODS The study is based on the surveillance of this nematode in the Brazilian State of Rio de Janeiro, where terrestrial snails and slugs were collected in more than half of the state’s municipalities (46 in all), and examined for parasitological infections. The nematode larvae retrieved from these specimens were identified based on their morphology and cytochrome oxidase I (COI) mitochondrial DNA sequences. FINDINGS Angiostrongylid larvae were found in 230 (8.8%) of the 2,600 terrestrial molluscs examined, collected from 26 municipalities. Overall, 14 terrestrial gastropod species were identified, including both native and exotic taxa, and six were found to be infected naturally by A. cantonensis. The natural infection rates by Angiostrongylus in the different terrestrial molluscs species were 12.5% in Angustipes erinaceus, 9.7% in Achatina fulica, 6.8% in Bradybaena similaris, 6.3% in Sarasinula linguaeformis, 3.9% in Leptinaria unilamellata, and 4.6% in Subulina octona. A. fulica was the most frequent and extensively distributed species, with infected snails being found in 22 municipalities. MAIN CONCLUSIONS The data from this first comprehensive survey of A. cantonensis in Rio de Janeiro highlights the potential epidemiological risk of human infection in this state. Mapping the spread of infected molluscs will also provide essential information for the evaluation of the risk of human infection, and should help local health authorities to provide a faster and more accurate diagnosis whenever neuroangiostrongyliasis is suspected.

Abstract in English:

BACKGROUND The neglected illness Chagas disease is treated with limited efficacy and adverse effects by old drugs. Due to the low interest of pharmaceutical industry in targeting economically depressed-patients, repurposing is a tool that should be applied because it can introduce new anti-Chagas entities into the clinic at reduced costs. OBJECTIVES To investigate the repurposing/combination of medicines strategies as anti-Chagas treatment. METHODS Epimastigotes, trypomastigotes and amastigotes of Trypanosoma cruzi were in vitro exposed to 28 Uruguayan-approved medicines not previously tested, 28 FDA-approved medicines previously evaluated, and three reference agents. Parasite inhibition was assessed and for the best drugs, in pairs-isobolographic studies, looking for synergism/additivity/antagonism, were done. Macrophages were used to study selectivity. For some relevant agents, we analysed whether medicines mammals´ action mechanisms are operative in epimastigotes-T. cruzi. FINDINGS From the anti-epimastigotes monotherapy-screening, we found that 18% of them showed better/comparable activities than references. Additionally, for the binary-combinations 8% were additive, 4% were synergic and the rest showed antagonism. Favourably, in macrophages-cytotoxicity four of the binary-combinations were antagonists. Naftazone and pinaverium bromide, not previously tested against T. cruzi, maintained their activity against trypomastigotes and amastigotes. The identified action mechanisms open the door to new strategies designing anti-T. cruzi drugs. MAIN CONCLUSIONS Using approved-medicines is a good strategy for new anti-Chagas treatments.

Abstract in English:

BACKGROUND Chagas disease (CD) is a neglected tropical disease caused by Trypanosoma cruzi. The current drugs used to treat these diseases have limited efficacy and produce severe side effects. 4-aminoquinoline derivatives were shown to be a promising class of inhibitors of cysteine proteases cruzain and TbrCATL. OBJECTIVES To evaluate the trypanocidal activity of a new series of aminoquinolines as potential inhibitors of cruzain and TbrCATL. METHODS Three aminoquinolines were synthesised and their in vitro activity was evaluated against cruzain and TbrCATL as well as against amastigotes and trypomastigotes forms of T. cruzi. In silico studies were also carried out to try to understand the experimental results. FINDINGS Compound 5 showed promising activity against cruzain and TbrCATL, with better performance than E60, the reference drug. Compound 5 inhibited cruzain and TbrCATL at IC50 of 23 µM ±3 and 29 µM ±1, respectively, but this inhibition showed characteristics of promiscuous inhibition by colloidal aggregation. On the other hand, the compound 4 showed to be more promising activity against T. cruzi with IC50 2.57 µM ± 0.03 lower than the reference drug benznidazole 3.8 µM. MAIN CONCLUSIONS The results of this study can guide new drug development for the treatment of trypanosomiasis.

Abstract in English:

BACKGROUND Benznidazole (BNZ) is the primary treatment for Chagas disease. While pharmacokinetic studies of BNZ began in the 1970s, its metabolism and excretion are not fully understood. Alternatives like Benznidazol Lafepe® and Abarax® have replaced the original Radanil®. OBJECTIVES To compare the pharmacokinetic profiles of both currently available formulations of BNZ in adults with chronic Trypanosoma cruzi infection. METHODS The study involved 13 subjects each one receiving 100 mg of both presentations one week apart. Blood samples were collected over 48 hours post-administration to analyse BNZ concentration and calculate pharmacokinetic parameters. FINDINGS The analysis showed that both presentations had similar maximum plasma concentration and time to reach maximum plasma concentration values. Area under curve (AUC) values were slightly lower in Abarax® than Benznidazol Lafepe®. High intra-individual variability was observed, attributed to erratic absorption patterns with multiple peaks in concentration-time curves. The half-life values for both formulations were 9.1 and 8.0 h, respectively, with a significant intra-individual variability over 30%. MAIN CONCLUSIONS The mean difference in the AUC was lower than 10%, but exceeded the 90% confidence interval for the higher bioequivalence limit. Despite the high variability that confirms erratic absorption, the pharmacokinetic parameters of both formulations were within expected ranges.

Abstract in English:

BACKGROUND Bacillus Calmette-Guérin (BCG) is one of the most successful vaccines in the world and evidence suggests it can be used as a bacterial vector to deliver heterologous antigens. OBJECTIVES We evaluated whether BCG could be biotinylated and used as a carrier of Schistosoma mansoni antigen tetraspanin-2 (TSP-2) fused with rhizavidin, an avidin analog. METHODS BCG was grown and biotinylated. The recombinant protein Rzv:TSP-2 was produced and purified from Escherichia coli. The biotinylation and antigen coupling was analysed by flow cytometry, enzyme-linked immunosorbent assay (ELISA) and Western blot. Vaccine immunogenicity was tested in immunised mice by the assessment of lung and splenic T cells. FINDINGS BCG can be biotinylated, which in turn, can be coupled with Rzv:TSP-2. After a series of optimisations which involved molarity of the biotin, ratio of BCG:reagent and the concentration of Rzv:TSP-2 used, almost 50% of the bacteria were biotinylated and 35% coupled with antigen. Although a clear adjuvant effect of BCG was observed, evaluation of immune response in immunised mice demonstrated an overall low immunogenicity of the BCG-Rzv:TSP-2. MAIN CONCLUSION These results demonstrated the use of BCG as a carrier of avidin-tagged antigens. Further optimisations are needed in order to strengthen the stability of tagged proteins in order to produce antigen-specific immune responses.

Abstract in English:

BACKGROUND The Atlantic Forest harbours a rich mosquito assemblage, including vectors for diverse arbovirus. Mosquito species adapt to urban-forest landscape changes, acting as bridge vectors for pathogens. OBJECTIVES This study evaluated different collection methods for immature and adult mosquitoes combined with improving field personnel qualifications in a transition area between urbanised and sylvatic environments. METHODS Immature and adult mosquitoes were collected from 33 collection points established in urban and peri-urban, sylvatic and transitional areas using different capture methods. During the course, 107 professionals were qualified. FINDINGS Vectors (Anophelinae and Culicinae) were dominant in the urban/peri-urban environment (51.49%), followed by the transitional (26.69%) and sylvatic (21.82%) environments. Aedes (Stegomyia) albopictus (Skuse), Ae. (Ochlerotatus) scapularis (Rondani), Ae. (Stg.) aegypti (Linnaeus), Haemagogus (Conopostegus) leucocelaenus (Dyar & Shannon), undetermined Culex, Cx. (Melanoconion) pilosus (Dyar and Knab), Cx. (Carrollia) urichii (Coquillett), and Sabethes (Sabethes) albiprivus Theobald were most abundant, with Ae. albopictus collected from all ecotopes. Ovitrap provided a robust sample of the immature stages (92.8%), whereas other methods contributed 3.59% of total immatures, but greatest species richness (14 species). For adult mosquitoes, Shannon light trap resulted in greatest abundance (86.16%). MAIN CONCLUSIONS The use of varied sampling techniques led to collection of a high mosquito species richness, which, combined with programs for training local professionals, should be an integral part of health surveillance for monitoring the risk of vector-borne diseases.

Abstract in English:

BACKGROUND Toxocariasis is a neglected global zoonosis. The immunological diagnosis has setbacks that hinder further knowledge about its pathology, epidemiology, and public control measures, and lack of financial support and attention prevents innovative research. Although studies on synthetic peptides are common for several infectious pathologies, none evaluated chemically synthetic peptides for toxocariasis diagnosis. OBJECTIVE This study aimed to identify potential synthetic peptides from C-type lectin 1 (Tc-CTL-1) from Toxocara canis. METHODS In silico analyses were made by five B-cell peptide prediction programs, 3-D modelling, BLASTp homology analysis, and signal-peptide identification. SPOT-synthesis was used for epitope mapping and assessed by dot-blot. Sera from non-infected and T. canis, Strongyloides venezuelensis, Ascaris suum, or Schistosoma mansoni-infected animals were used to assess the peptide’s immunogenicity and cross-reactivity. The selection of potential immunogenic epitopes included the most immunogenic peptides with the least cross-reactivity. FINDINGS Fifty-five peptides were selected by in silico analysis. Dot-blot showed intense recognition by anti-Toxocara IgG and cross-reactivity with A. suum-infected mice. Selection criteria identified four epitopes with diagnostic potential. MAIN CONCLUSIONS The findings demonstrate that synthetic peptides should be explored for innovation of toxocariasis diagnosis, and suggest the adaptation of dot-blot using the SPOT-synthesis technique as a potential immunodiagnostic platform.

Abstract in English:

BACKGROUND Efflux pumps represents one of the most important mechanisms of antibiotic resistance. They allow bacteria to expel antibiotics from their cells before they reach the target site. OBJECTIVES The main objective of this work was to examine how cultivation temperature and its variations affect the activity of efflux pumps in Acinetobacter junii, Bacillus cereus, and Enterobacter cloacae isolated from a skin swab. METHODS The isolation and purification of bacterial colonies were done through the streak plate method. For the identification of bacterial species, MALDI-TOF was utilised. To detect the activity of efflux pumps, agar-ethidium bromide cartwheel method was implemented. FINDINGS The accumulation of ethidium bromide (EtBr) in bacterial cells was higher at 43ºC than at 30ºC, so the activity of efflux pumps was reduced at 43ºC in all isolates. A temperature of 7ºC also caused increased cumulation of EtBr in the cells, hence decreasing the activity of efflux pumps in isolated bacteria. Moreover, B. cereus was more sensitive to meropenem at 43ºC than at 36ºC. MAIN CONCLUSIONS The activity of efflux pumps and antibiotic resistance can be strongly affected by changes in incubation temperature in vitro in tested human opportunistic bacterial pathogens.

Abstract in English:

BACKGROUND Rickettsia is a genus of Gram-negative bacteria that causes various diseases, including epidemic typhus, Rocky Mountain spotted fever, and Mediterranean spotted fever. Ticks transmit these diseases and commonly found in developing regions with poor sanitation. As a result, it is difficult to estimate the number of these diseases cases, making it challenging to create prevention and diagnostic mechanisms. OBJECTIVES Thus, this study aimed to develop an in silico multi-epitope vaccine against Rickettsia. METHODS Eight proteins were previously identified as potential vaccine candidates through reverse vaccinology and were screened for epitopes that bind to MHC class I and II molecules. The epitopes were then analysed for antigenicity, allergenicity, and toxicity. The selected epitopes were linked with AAY and GPGPG sequences peptide and a known adjuvant, the B-chain of Escherichia coli heat-labile enterotoxin, to form a chimeric multi-epitope protein. The protein’s three-dimensional structure was predicted, and molecular docking analysis was performed against the toll-like receptor 4 (TLR4). Finally, the immune response to the protein was simulated using C-ImmSim tool. FINDINGS A total of 26 immunogenic epitopes, formed the multi-epitope vaccine RGME-VAC/ATS-1. The vaccine showed excellent immunogenic parameters and was predicted to do not be toxic or allergenic to the host. It also showed good potential stimulation of immune cells, with a propensity to generate memory cells and elicit IFN-γ secretion. MAIN CONCLUSIONS The in silico validations suggest that our study successfully designed an innovative multi-epitope vaccine against Rickettsia, addressing the challenges posed by the elusive nature of diseases caused by this genus. We provide a promising potential for further experimental exploration and the development of targeted prevention and diagnostic strategies for these diseases.

Abstract in English:

BACKGROUND Heterochromatin protein 1 (HP1) is widespread in several organisms playing a role in control of gene expression by heterochromatin formation and maintenance of silent chromatin. Schistosoma mansoni is a human parasite that is responsible for Schistosomiasis, a tropical neglected disease in the tropical and subtropical areas in the world, where the intermediate host Biomphalaria glabrata is present. OBJECTIVES In this study we attempted to investigate if the SmHP1 is enriched in S. mansoni chromatin in cercariae larvae stage, compared with another larvae stage sporocysts and its importance for S. mansoni life cycle progression and parasite oviposition. METHODS We used ChIPmentation with commercial antibody ab109028 that passed in-house quality control. We also used RNA interference, mice infection and histology. FINDINGS Our data show that S. mansoni HP1 enrichment is non-canonical with a peak at the transcription end sites of protein coding genes. We did not find strong differences in SmHP1 chromatin landscapes between sporocysts and cercariae. Knock- down of SmHP1 in schistosomula and in vivo experiments in mice unexpectedly increased parasite oviposition. MAIN CONCLUSIONS Our results suggest that SmHP1 may influence chromatin structure in a non-canonical way in S. mansoni stages and may play a role in regulation of parasite oviposition.

Abstract in English:

BACKGROUND The importance of the mosquito Aedes aegypti as a vector of arboviruses like dengue, Zika, and chikungunya justifies the interest in investigating this species’ physiology and reproductive biology. For the maintenance and expansion of Ae. aegypti populations, copulation, oogenesis, female oviposition capacity, embryo development and larval hatching are crucial processes regulated by biological clocks. Many of these parameters have currently been investigated under environmental and laboratory conditions. However, there are specific gaps regarding the effect of light on these critical reproductive aspects. In this study, the influence of light on some aspects of Ae. aegypti biology was evaluated. OBJECTIVES We investigated, in laboratory conditions, the effects of constant light on Ae. aegypti reproductive features: spermathecal content, embryo morphology, females’ fecundity, and egg viability. METHODS Morphological and physiological assays were performed using Ae. aegypti females and eggs obtained from forced egg laying. The reproductive aspects were analysed under constant light (LL = light/light) and light/dark cycles (LD12:12 = 12 h of light and 12 h of dark). FINDINGS and MAIN CONCLUSIONS Our results proved the negative effect of constant light on egg production (decreasing the fecundity) and embryonic development (causing a drop in egg viability and perceptive damage in the embryos). The results presented here bring new information on the impacts that a source of constant light may have on the reproductive biology of Ae. aegypti.

Abstract in English:

BACKGROUND The HTLV-1 affects 5 to 10 million people worldwide. It is estimated that 5 to 10% of the infected individuals develop severe diseases, such as HTLV-Associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP) or Adult T-Cell Leukaemia/Lymphoma (ATLL). HTLV-1 transmission can occur mainly through unprotected sexual contact and from mother to child during breastfeeding. No vaccines can contain this infection, and strategies to prevent transmission become a priority. Therefore, it is important to know the main dissemination routes of each region to design the best public health strategies for controlling the spread of this virus. OBJECTIVES This study aimed to evaluate the prevalence of family aggregation in HTLV-1 infection among patients treated at a reference centre in Brazil. METHODS A cross-sectional study was conducted with patients between July 2021 and August 2022. A total of 67 individuals were attended, of which 17 were classified as index cases due to a history of family aggregation, with 120 family contacts. FINDINGS We found a prevalence of 36% of individuals positive for HTLV-1 and the same for HTLV-1 negative, while 28% of the family members had unknown serology. The possible transmission routes were identified, and the familial transmission histories within each family were hypothesised. MAIN CONCLUSIONS These data can support specific decisions regarding the local reality, such as a better health strategy, especially in preventing new HTLV-1 cases.

Abstract in English:

BACKGROUND Tanychlamys indica (Godwin-Austen, 1883) was reported as a serious pest in India. The snails are voracious and feed on a wide range of commercial crops. It has also been identified as an intermediate nematode host of Angiostrongylus cantonensis in Bombay, India. T. indica was recently introduced in Brazil by international trade of citrus fruit seedlings. First in the State of Santa Catarina and then in Paraná. Recently, it has been detected in the city of São Paulo threatening to spread to other Brazilian states. OBJECTIVES We report the first record, in Brazil, of the natural infection by L3 larvae of A. cantonensis isolated from T. indica collected in the Vila Leopoldina neighbourhood, located in the west zone of São Paulo city. METHODS In January 2023, a team from LABFAUNA and UVIS Lapa collected 36 molluscs identified as T. indica in Vila Leopoldina, São Paulo city. Of these, 20 molluscs were subjected to individual parasitological analysis at the Instituto Adolfo Lutz, using the modified Rugai methodology. FINDINGS A total of 145 larvae were identified morphologically and classified according to Ash’s criteria. These larvae were identified as third - stage larvae (L3) of A. cantonensis by real time polymerase chain reaction (PCR). MAIN CONCLUSIONS It is evident that further research is imperative to map the distribution of T. indica in Brazil and to assess its potential as an intermediate host for the nematode A. cantonensis, as well as the economic risks to agriculture. Over the past two decades, human cases of neuroangiostrongyliasis have been documented in the Southeast, North, Northeast, and South regions of Brazil. Additionally, there are records of natural infection with A. cantonensis in molluscs and rodents.

Abstract in English:

BACKGROUND The malaria control strategy of the Brazilian Ministry of Health involves the classification of transmission contexts into special areas based on the distinct determinants of malaria in each location. OBJECTIVE To search, find, organise, and map data about special areas using Brazilian databases and show their distribution among the states of the Brazilian Amazon. METHODS A search related to the socioenvironmental determinants of malaria was conducted in Brazilian databases using the special areas of the Ministry of Health as a reference. Data were compiled by states in the Brazilian Amazon. FINDINGS Indigenous areas occupy a significant portion of the Amazon territory and exhibit high incidence rates of malaria. Rural settlements also cover large areas of the Amazon, and in some states, more than 10% of malaria cases are associated with this typology. Legal and illegal mining areas, despite occupying small portions of the Amazon territory, contribute to the malaria caseload. In contrast, urban areas cover smaller regions, with low incidence rates. MAIN CONCLUSIONS Despite the progress represented by the typological structure of special areas by the Ministry of Health’s, our findings reveal limitations related to them because of their complexities and emphasise the need to further substratify these areas to devise control strategies more adapted to them.

Abstract in English:

BACKGROUND Chronic Chagas cardiomyopathy (CCC) is the most severe clinical form of the Chagas disease. There is a strong correlation between soluble tumor necrosis factor receptors (sTNFR1 and sTNFR2) and cardiac and functional parameters in CCC, but their prognostic value remains unknown. OBJECTIVE To verify the prognostic value of sTNFR1 and sTNFR2 in CCC. METHODS A longitudinal study was conducted. Sixty-nine patients with CCC (53.70 ± 9.66 years, NYHA I-II) were submitted to blood collection and echocardiography, and followed for 43.81 ± 1.21 months. The outcome was determined by the combination of cardiac death, heart transplantation, or stroke. FINDINGS After the follow-up, 15 patients (22%) presented adverse cardiovascular events. Only left ventricular ejection fraction (LVEF) [heart rate at rest (HR): 0.935, 95% CI 0.878 to 0.994; p = 0.033] and sTNFR2 (HR: 1.002, 95% CI 1.001 to 1.003; p = 0.006) remained as independent predictors of adverse cardiovascular events. The optimal cutoff point to identify these patients was the value of 1784.00 pg/mL. There was a significant difference between the groups with lower and higher sTNFR2 levels (long-rank < 0.001). MAIN CONCLUSIONS High serum levels of sTNFR2, together with lower LVEF, are strong independent predictors of adverse cardiovascular events in CCC, making them valuable for risk stratification.

Abstract in English:

BACKGROUND Leprosy, a neglected tropical disease caused by Mycobacterium leprae, presents significant public health challenges in Brazil due to its slow progression, dermato-neurological manifestations, and potential for disability. Understanding leprosy’s spatial distribution and temporal trends is important for effective control and elimination strategies. OBJECTIVES This study aimed to identify clusters of leprosy in Brazilian states using agglomerative hierarchical clustering and to analyse their temporal trends from 2012 to 2022. METHODS An ecological study was conducted using data from the National System of Notifiable Diseases (SINAN). The agglomerative hierarchical clustering method was used to group states using the new case detection rate (NCDR) of leprosy per 100,000 inhabitants, the proportion of new cases of leprosy with grade 2 physical disability at the time of diagnosis (G2R), and the Gini index, a measure of socioeconomic inequality. Temporal trends within the clusters were assessed using Prais-Winsten regression analysis. FINDINGS In the period 2012-2022, 293,030 new cases of leprosy were reported in Brazil. Five distinct clusters were identified. Cluster 4, comprising Mato Grosso and Tocantins, had the highest NCDR and stable temporal trends (APC: 3.2%, 95% CI: -0.1%, 6.7%). Clusters 1 and 3 had the highest proportions of grade 2 disability, indicating late diagnosis. Clusters 4 and 5 had the lowest percentages of individuals with incomplete/complete higher education (7.6% and 7.4%, respectively). Cluster 4 had the highest percentage of individuals with the Diforma clinical form (69.8%) and with cases classified as multibacillary (84.5%). MAIN CONCLUSIONS The use of agglomerative hierarchical clustering, a novel application of a non-supervised algorithm in this context, highlighting the integration of multiple epidemiological and socioeconomic variables for a better understanding the dynamics of leprosy transmission in Brazil. Significant variations in the spatial distribution and temporal trends of leprosy were observed across Brazilian states. To improve leprosy surveillance and control in Brazil, targeted interventions are needed, particularly in high-endemicity regions with late diagnosis.

Abstract in English:

BACKGROUND Coronavirus disease 2019 (COVID-19) is caused by the new coronavirus 2 (severe acute respiratory syndrome coronavirus 2 - SARS-CoV-2). Long COVID is a new condition associated with persistent COVID-19 symptoms and/or new emerging symptoms. Telomeres are specialised structures for genome protection at the end of chromosomes and telomerase is the enzyme that synthesises telomere DNA. OBJECTIVES Patients with Long COVID symptoms were recruited at the Pedro Ernesto University Hospital (HUPE) in Rio de Janeiro, Brazil, with the main purpose of investigating the association between telomere length and Long COVID. METHODS Leukocyte telomere length (LTL) was determined by quantitative real-time polymerase chain reaction (qPCR) in 34 Long COVID patients compared to a control group (n = 122). Telomerase activity was determined by qPCR assays using the commercial kit from ScienCell. A questionnaire on symptoms, vaccine doses and blood count was completed. FINDINGS The Long COVID patients were found to have an increase in LTL. Telomerase activity was also examined in a smaller number of patients and found to be reactivated in the blood. MAIN CONCLUSIONS It will be necessary to conduct further studies and monitor Long COVID patients to determine if future health issues could be linked to telomerase activity and elongated telomeres.

Abstract in English:

BACKGROUND Escherichia coli is a commensal organism but may become pathogenic by the acquisition of virulence factors involved with intestinal (IPEC) or extraintestinal (ExPEC) infections. Some strains, known as hybrids, may harbour virulence determinants of both IPEC and ExPEC pathotypes, increasing their virulence potential. Reports of hybrid E. coli in Brazil are rare, and the associated lineages were poorly explored. OBJECTIVES This study characterised ExPEC E. coli strains focusing on the occurrence of hybrid pathotypes. METHODS Fifteen clinical ExPEC strains were submitted to multilocus sequence typing (MLST), susceptibility test, and polymerase chain reaction (PCR) targeting IEC/ExPEC virulence markers. FINDINGS All strains were multidrug-resistant, and 11 STs were determined among the 15 ExPEC strains, including local/new and pandemic lineages, such as ST69 and ST131. Twelve/15 isolates were classified as hybrids, due to the presence of virulence markers of both Enteroaggregative E. coli (EAEC) and ExPEC or UPEC pathotypes. These UPEC/EAEC (n = 10) and ExPEC/EAEC (n = 2) hybrid strains were found among distinct phylogroups and lineages, including new STs. Interestingly, most hybrids belonged to the pandemic ST131 lineage, and this genotype had never been previously reported in the ST131 circulating in Brazil. MAIN CONCLUSIONS Therefore, this study provides new information on the epidemiological scenario of hybrid E. coli, contributing to a better understanding of the occurrence and pathogenic potential of these organisms.