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.

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.

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.

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.

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.

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.

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.

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.

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.

BACKGROUND Bat-borne hantaviruses have been identified worldwide but little is known about neotropical bats in the megadiverse biomes of the American continent. Although serological evidence has hinted at hantavirus circulation in Brazil, the scarce number of genomic detection represents a gap to understand viral diversity, prevalence, and ecology of bat-borne hantaviruses. OBJECTIVE We aim to investigate and evaluate the presence and prevalence of bat-borne hantavirus in the Brazilian Atlantic Forest. METHODS Here in, 97 lung and kidney tissue samples from bats captured in the Brazilian Atlantic Rainforest were submitted to hantavirus-specific nested reverse transcription-polymerase chain reaction (RT-PCR) targeted the hantaviral L segment and metagenomic analysis. FINDINGS Hantavirus RNA was detected in five tissue fragments of 20 Seba’s short-tailed bats (Carollia perspicillata). Phylogenetic analysis, based on partial L-segment sequence using maximum likelihood method, demonstrated that the identified virus formed a monophyletic clade and a highly divergent bat-borne lineage comprising other recent strains found in the genus Carollia from South America. MAIN CONCLUSIONS Our findings suggest the presence of a novel bat-borne hantavirus in Brazil, tentatively named Mamanguape virus (MGPV). Additional genomic data will help to extend our knowledge about the classification of MGPV within the Hantaviridae family and the evolution origins of new world bat-borne hantaviruses. Batborne Bat borne continent Brazil diversity batborne bat Forest 9 hantavirusspecific specific transcriptionpolymerase transcription polymerase RTPCR RT PCR (RT-PCR analysis 2 Sebas Seba s shorttailed short tailed perspicillata. perspicillata . perspicillata) Lsegment method America MGPV. (MGPV) (MGPV

BACKGROUND Strigomonas culicis is a monoxenic trypanosomatid parasite of insects that naturally contains an endosymbiotic bacterium. The aposymbiotic strain can be obtained, making this strain a model for evolutive research about organelle origins. In addition, S. culicis contains homologues of virulence factors of pathogenic trypanosomatids, which functions are waiting for further analysis. In this sense, the publication of S. culicis proteome makes feasible additional investigations regarding the differential expression of peptidases from the wild-type (WT) and the aposymbiotic (APO) strains. OBJECTIVES Here, we analysed two proteomic data from S. culicis WT and APO strains screening for peptidases differentially expressed and assessed the differential expression of cysteine and metallopeptidases. METHODS A comparative proteomic screening between WT and APO identified 43 modulated peptidases. FINDINGS Cysteine and metallopeptidases, such as calpains and GP63, were the major classes, highlighting their significance. GP63 exhibited an increased proteolysis in a specific metallopeptidase substrate, an up-modulation gene expression in RT-PCR, and a higher protein identification by flow cytometry in the aposymbiotic strain. Notwithstanding, the wild-type strain showed enhanced cysteine peptidase activity. MAIN CONCLUSION Our study highlighted the endosymbiont influence in S. culicis peptidase expression, with GP63 expression and activity raised in the aposymbiotic strain, whereas cysteine peptidase levels were reduced. bacterium obtained origins addition S trypanosomatids analysis sense wildtype wild type (WT (APO Here metallopeptidases 4 GP classes significance GP6 substrate upmodulation up modulation RTPCR, RTPCR RT PCR, PCR RT-PCR Notwithstanding reduced

BACKGROUND Although blood transfusion is an essential therapeutic procedure, it can present risks, including transmitting infectious diseases, such as malaria. In Acre, the thick blood smear microscopic examination (TBS) is used to screen infected malaria blood donors. However, TBS has low sensitivity for detecting Plasmodium in situations of low parasitaemia, such as those presented by asymptomatic clinically healthy individuals. OBJECTIVES To investigate the pertinence of using polymerase chain reaction (PCR) to detect malarial infection for screening blood donors in Cruzeiro do Sul, Acre, an endemic high-risk malaria area in the Legal Amazon. METHODS A cross-sectional study was conducted among individuals eligible and ineligible to be blood donors, according to clinical and epidemiological criteria. Besides the mandatory screening of HCV, HBV, and HIV tests, malaria PCR and TBS were also carried out on all blood donor candidates who attended the Cruzeiro do Sul Blood Centre from July to September 2022. FINDINGS Of the 230 participants, 209 (91%) were eligible for blood donation by clinical-epidemiological screening. Surprisingly, no blood donor candidate reported a history of malaria. All TBS microscopic tests were negative at the time of recruitment. However, samples from four blood donor candidates (two eligible by clinical and epidemiological malaria criteria and two ineligible by hypertension and recent tattoo) were positive by Plasmodium and P. vivax molecular tests. MAIN CONCLUSIONS Malaria molecular techniques for screening blood donors should be introduced in the Brazilian Blood Centres to maximise recipient safety. Furthermore, selecting zero-risk donors could pave the way to build a transmissible malaria-free environment in the blood bank context in the near future. procedure risks diseases Acre (TBS However parasitaemia (PCR highrisk high risk Amazon crosssectional cross sectional HCV HBV 2022 23 participants 20 91% 91 (91% clinicalepidemiological Surprisingly recruitment tattoo P safety Furthermore zerorisk zero malariafree free future 202 2 9 (91 (9 (

BACKGROUND Acanthamoebae are causative agents of severe and complicated human infections without a standard effective therapy to date. Therefore, the research is focused on the development of new amoebicidal drugs based on the natural products. Plants of the family Lamiaceae are typical with several phenolic secondary metabolites that make them interesting in medical point of view. OBJECTIVE In this review, we concentrate on anti-Acanthamoeba activities of plant extracts, essential oils, and phytochemicals of Lamiaceae in the published literature. FINDINGS A total of 13 articles in the research field were found. Totally, 16 plant species belonging to family Lamiaceae were studied against trophozoites and cysts of Acanthamoeba in in vitro conditions. Low toxicity of the Lamiaceae plant extracts to tissue cultures enhances their possible potential for clinical use. The research demonstrated promising trophocidal and cysticidal effects against acanthamoebae. Further research is needed with inclusion of more clinical isolates and in vivo studies. MAIN CONCLUSION Reviewing the related literature highlights the promising amoebicidal activities of plant extracts, essential oils and bioactive compounds of family Lamiaceae. Identifying the active components could lead to production new effective and well-tolerated drugs for the Acanthamoeba infections treatment. date Therefore products view review antiAcanthamoeba anti 1 found Totally conditions use acanthamoebae studies welltolerated well tolerated treatment

BACKGROUND Trypanosoma rangeli is a haemoflagellate parasite that infects triatomine bugs and mammals in South and Central America. Trypanosoma cruzi, the etiological agent of Chagas disease, has a partially overlapping geographical distribution with T. rangeli, that leads to mixed human infections and cross-reactivity in immunodiagnosis. Although T. rangeli can be detected long after mammal infection, its multiplicative forms have not yet been described. OBJECTIVES To enhance our understanding of T. rangeli development in mammals, this study assessed various infection parameters in mice over time. METHODS The parasitaemia, body temperature, and weight of Swiss Webster mice were monitored over 120 days after exposing them to the bites of Rhodnius prolixus nymphs containing metacyclic trypomastigotes in their salivary glands. On day 132 post-infection, spleens and mesenteric lymph nodes were analysed for T. rangeli DNA using polymerase chain reaction (PCR) and quantitative PCR (qPCR). FINDINGS Parasites were detectable in mice blood since day 2 post-infection, detection peaking on day 5 and becoming undetectable by day 120. PCR and qPCR detected T. rangeli DNA in the spleens and mesenteric lymph nodes of infected mice. Infected mice showed higher body temperatures and a slower weight gain over time compared to controls. MAIN CONCLUSIONS The study confirmed that T. rangeli establishes a persistent infection in mice, detectable in lymphoid organs long after parasites had disappeared from blood. In addition, infected mice exhibited physiological changes, suggesting potential subclinical effects. These findings highlight the need for further studies on the immune response and potential impacts of T. rangeli infection in mammalian hosts. America cruzi disease T crossreactivity cross reactivity immunodiagnosis described parasitaemia temperature 12 glands 13 postinfection, postinfection post post-infection (PCR qPCR. . (qPCR) controls addition changes effects hosts 1 (qPCR