Revista do Instituto de Medicina Tropical de São Paulo
To publish articles dealing with research on tropical diseases and related sciences.
Universidade de São Paulo. Instituto de Medicina Tropical de São Paulo
Weil's disease: rapid recovery following corticosteroid treatment: a case report
Leptospirosis is a zoonotic infection with a range of clinical findings, ranging from a mild, self-limited illness to a severe, life-threatening disease known as Weil's disease. The role of adjunctive corticosteroid therapy in severe leptospirosis remains controversial. We report a 41-year-old male with a history of intravenous drug use, regular alcohol consumption, and exposure to contaminated freshwater, who presented with fever, myalgia, vomiting, jaundice, thrombocytopenia, and acute kidney injury. Serological testing via the microagglutination test (MAT) was negative at admission, and empirical antibiotic therapy with ceftriaxone was initiated. Despite appropriate antimicrobial treatment and supportive care, including hemodialysis, the patient developed progressive hyperbilirubinemia and persistent thrombocytopenia. A repeat MAT performed one week later confirmed infection with Leptospira interrogans serovar Pomona. Due to ongoing clinical deterioration, methylprednisolone (1 mg/kg/day) was initiated, resulting in a dramatic clinical and laboratory improvement within 24 h. This rapid response suggests a potential role for corticosteroid therapy in selected patients with severe leptospirosis; however, further studies are required to establish its efficacy and safety.
Copyright (c) 2026 Ahmet Melih Şahin, İrem Atçı-Koç, Sinan Çetin https://creativecommons.org/licenses/by-nc/4.0
Rare fungal bloodstream infections in pediatric patients: a case series
Fungemia caused by rare fungal species has been increasingly recognized in both immunocompromised and immunocompetent children. Our aim is to characterize the clinical and microbiological features of rare fungal bloodstream infections in hospitalized pediatric patients. A retrospective, descriptive study was conducted including all cases of fungemia due to rare yeasts in patients admitted to two tertiary pediatric hospitals between 2021 and 2025. Fungal species identification, anatomical sites of infection, antifungal therapeutic regimens, and clinical outcomes were systematically analyzed. In total, 13 cases of rare fungal bloodstream infections were identified among 13 patients from 2,555 blood cultures obtained during the study period, representing an incidence of 0.5%. The predominant species isolated were Saccharomyces cerevisiae (n=5), Wickerhamomyces anomalus (n=3), Candid orthopsilosis (n=2), Yarrowia lipolytica (n=1), Meyerozyma guilliermondii (n=1), and Trichosporon asahii (n=1). The median age at infection was 31 months (range: 0–178 months), with 92.3% (12/13) of patients presenting underlying medical conditions. The median interval from hospital admission to fungemia onset was 19 days (range: 0–73 days). Amphotericin B deoxycholate was the most frequently employed initial antifungal agent (n=5), followed by liposomal amphotericin B (n=4). Modification of antifungal therapy was required in five cases (38.5%). Microbiological clearance was achieved in all patients on subsequent blood cultures. The 30-day all-cause mortality rate was 15.4% (2/13). We concluded that rare fungal bloodstream infections occurred predominantly in patients with underlying comorbidities and prolonged hospital stays; nevertheless, the majority showed favorable clinical responses with appropriate antifungal therapy and achieved fungal eradication from the bloodstream.
Copyright (c) 2026 Nicole Feitosa Ximenes Ferreira, Giovana Fernandes Zorzan, André Ricardo Araújo da Silva https://creativecommons.org/licenses/by-nc/4.0
Open-access The diagnostic value of fine-needle aspiration cytology in the early diagnosis of pulmonary cryptococcosis
Pulmonary cryptococcosis, an invasive fungal infection caused by Cryptococcus spp., is often misdiagnosed as tuberculosis or lung cancer due to overlapping clinical and radiological features, leading to treatment delays. In this descriptive study, we aim to characterize the diagnostic findings and clinical utility of fine-needle aspiration cytology (FNAC) in a series of patients with pulmonary cryptococcosis, within the context of other available diagnostic modalities. We retrospectively analyzed 10 patients with pulmonary cryptococcosis who underwent imaging-guided percutaneous lung aspiration. Wright-Giemsa-stained cytology smears were examined under oil immersion, enabling clear visualization of the characteristic morphological features of Cryptococcus. In this case series, FNAC provided a rapid cytological diagnosis within two hours in all 10 cases, consistent with the results obtained by metagenomic next-generation sequencing (mNGS) and serological testing. In contrast, conventional smear microscopy showed lower detection rates, and histopathology required longer processing times. The use of FNAC facilitated early diagnosis, enabling timely initiation of antifungal therapy and helping to avoid unnecessary surgical interventions. Our findings suggest that cytomorphological evaluation by FNAC is a rapid and valuable diagnostic tool in the early clinical management of pulmonary cryptococcosis, effectively complementing existing diagnostic methods.
Copyright (c) 2026 Dongxia Wang, Ning Wang, Jiejing Liu, Chengyan Zhao, Xue Xing https://creativecommons.org/licenses/by-nc/4.0
Treatment of brucellosis in pregnant women: a systematic review and analysis of current gaps and future perspectives
Human brucellosis is a globally prevalent bacterial disease with significant implications during pregnancy due to obstetric complications. Despite the importance of early diagnosis and treatment, the lack of therapeutic consensus and robust evidence underscores the need for systematic evaluation to guide clinical practice. This study systematically reviewed the literature to identify and summarize available drug therapy options for brucellosis in pregnant women, focusing on efficacy, safety, and obstetric outcomes. The review followed PRISMA and Cochrane Handbook guidelines. Searches were conducted in MEDLINE, Embase, Cochrane Library, LILACS, and gray literature for references indexed up to September 15, 2025. Eligible studies reported therapeutic interventions in pregnant women with brucellosis. Risk of bias was assessed using the JBI Critical Appraisal tool, and data on participants, interventions, and outcomes were extracted. Of 737 records screened, six studies met the inclusion criteria, comprising retrospective and prospective reports published between 1991 and 2020, totaling 403 pregnant women. Therapeutic regimens varied, with sulfamethoxazole–trimethoprim (SMX–TMP) plus rifampicin being the most frequently used combination. Adverse obstetric outcomes associated with this regimen occurred in 16% (95%CI: 8%–30%) of cases. Overall, abortion occurred in 94 (23.3%) women, 20 preterm births were reported, and 10 newborns had low birth weight. Recurrence was observed in only 3% of cases. Heterogeneity in outcomes and definitions limited comparability. In conclusion, there is no standardized treatment for brucellosis during pregnancy. Adverse obstetric outcomes remain frequent, highlighting the need for controlled studies to establish safe and effective therapeutic protocols.
Copyright (c) 2026 Endi Lanza Galvão, Diêgo Mendes Xavier, Glaciele Maria de Souza, Gláucia Cota, Sarah Nascimento Silva https://creativecommons.org/licenses/by-nc/4.0
Clostridioides difficile infections in seven Brazilian hospitals during the COVID-19 pandemic: hand hygiene and antimicrobial consumption
This study aimed to evaluate the incidence density of Clostridioides difficile infections (CDIs), hand hygiene adherence, and antimicrobial consumption across Brazilian hospitals during the COVID-19 pandemic. An ecological study was conducted in seven Brazilian hospitals from June 2018 to December 2019 (pre-pandemic) and from June 2020 to December 2021(pandemic). Data on CDI incidence density, hand hygiene adherence, and antimicrobial consumption were collected. CDI incidence was assessed based on the number of monthly cases and the incidence density rate per 10,000 patient-days. This study involved hospitals from four states and included three public and four private institutions. Statistical analyses were performed using the Mann-Whitney U test in R (p < 0.05). Time series analysis used joinpoint regression to determine monthly percent change, average monthly percent change, and 95% confidence intervals. Although statistically insignificant, an upward trend occurred in CDI incidence (p = 0.081) from the pre-pandemic to the pandemic periods. Consumption of azithromycin (p < 0.01) and levofloxacin (p < 0.01) increased significantly, whereas ceftriaxone use decreased (p = 0.0038). The joinpoint regression analysis of antimicrobial consumption trends during the pandemic showed trend changes for vancomycin and meropenem defined daily dose, with higher consumption during the second wave of COVID-19 in Brazil. Hand hygiene adherence failed to differ significantly but showed a downward trend in 2020 and 2021. The dynamics of the COVID-19 pandemic and changes in protective measures may have influenced CDI incidence and antimicrobial consumption patterns across the study period.
Copyright (c) 2026 Luiza Arcas Gonçalves, Ivan Lira dos Santos, Ana Paula Matos Porto, Antônio Brazil Viana Junior, Julia Herkenhoff Carijo, Claudia Dantas de Maio Carillho, Brunno Cesar Batista Cocentino, Luciana Neves Passos, Glaucia Fernanda Varkulja, Thais Guimarães, Silvia Figueiredo Costa https://creativecommons.org/licenses/by-nc/4.0
Molecular biomarkers associated with ATLL and HAM progression in HTLV-1 infection: a systematic review
Human T-lymphotropic virus type 1 (HTLV-1) infects approximately five to 10 million individuals worldwide, although only a minority develop severe outcomes such as adult T-cell leukemia/lymphoma (ATLL) or HTLV-1-associated myelopathy (HAM). Proviral load (PVL), while widely used, shows limited sensitivity and specificity, reinforcing the need for complementary biomarkers. Omics-based approaches have emerged as promising tools to improve risk prediction. We conducted a systematic review following PRISMA guidelines, searching PubMed, Web of Science, Virtual Health Library (BVS), and CAPES Periodicals databases for studies published between May 2020 and May 2025. Eligible studies included original observational designs investigating genomic, proteomic, and metabolic biomarkers associated with progression to ATLL or HAM. Methodological quality was assessed using tools from the National Heart, Lung, and Blood Institute (NHLBI). In total, 35 studies met the inclusion criteria, most conducted in Brazil, Japan, and Iran. A total of 67 biomarkers were identified: 37 genomic, 27 proteomic, and three metabolic with potential clinical applications in risk stratification, prognosis, and therapeutic monitoring of HTLV-1 infection. PVL remained the most frequently investigated marker but lacked predictive power in isolation. Additional candidates with strong potential included IFN-γ, CXCL10, Neopterin, AnxA1, and sTNFR2. This review highlights the potential of integrated multiparametric panels—combining PVL with omics-derived biomarkers—as a promising strategy to improve risk stratification, prognosis, and therapeutic monitoring in people living with HTLV-1 (PLHTLV-1). However, further longitudinal and clinically validated studies are needed to confirm their applicability and support their translation into early intervention strategies, particularly during the asymptomatic phase.
Copyright (c) 2026 Theo Leite, Marcos Eduardo Souza Abreu, Alex Ap. Rosini Silva, Rubens de Assis Santos Sebastião, Lucas Araujo Romão, Jorge Casseb, Tatiane Assone, Fabio Eudes Leal, Sheila de Oliveira Garcia Mateos https://creativecommons.org/licenses/by-nc/4.0
Mycobacterium kansasii in cancer patients: a 13-case series
Mycobacterium kansasii comprises one of the most common and most pathogenic nontuberculous mycobacteria, particularly in immunocompromised individuals. This retrospective observational study aimed to describe the epidemiology, clinical characteristics, and outcomes of M. kansasii infections in 13 cancer patients from Instituto do Cancer do Estado de Sao Paulo, Brazil, from January 2011 to September 2023. Of the 19 initial positive cultures, 13 fully met diagnostic criteria for M. kansasii infections. Solid tumors occurred the most (69.2%), and only 38.4% of patients were undergoing chemotherapy at diagnosis. Smoking was the most frequent previous characteristic in these cases (76.9%). Fever (53.4%), cough (46.1%) and dyspnea (30.7%) were the most common symptoms. Multiple nodules (46.1%) and cavities (46.1%) were the most common radiological findings. Overall, seven patients (53.8%) received at least 12 months of therapy. One-year overall mortality totaled 38.4-22.2% in patients with solid tumors and 75% in patients with hematologic malignancies. In conclusion, M. kansasii infections were predominantly pulmonary in this series of cancer patients, which showed a high frequency of other respiratory comorbidities, especially smoking. Mortality occurred in several patients, particularly among those with hematological malignancies.
Copyright (c) 2026 Patrícia Rodrigues Bonazzi, Giovanni Mollo Baia, William Kazunori Sekiguchi, Adriana Satie Gonçalves Kono Magri, Raquel Keiko de Luca Ito, Karim Yaqub Ibrahim, Odeli Nicole Encinas Sejas, Edson Abdala https://creativecommons.org/licenses/by-nc/4.0
Epidemiological study of hantavirus in Southern Brazil, 2009-2019
Brazil has the highest number of hantavirus cardiopulmonary syndrome cases on the American continent, with Santa Catarina being the state with the most notifications. This retrospective longitudinal study aimed to describe the epidemiological profile of 177 hantavirus cases reported in Santa Catarina from 2009 to 2019, using data from the Notifiable Diseases Information System (SINAN). Statistical analyses of socio-demographic, clinical, and epidemiological data revealed that the typical patient was a male of working age with low educational attainment, living in a rural area. The highest incidence occurred in the Santa Catarina West, Midwest, and Mountain regions, strongly associated with agricultural activities. The case fatality rate (CFR) was highest among the 15-19-year age group. Clinical risk factors for death included respiratory signs, increased hematocrit, and the need for mechanical ventilation. Patients who sought early care had a higher CFR, possibly due to the initial difficulty of differentiating hantavirus from other viral diseases. Conversely, regions with higher notification rates showed lower CFRs, suggesting better surveillance. This study highlights critical areas for public health intervention and the key characteristics of hantavirus patients (males in rural areas and adolescents aged 15-19 years in regions with low notification rates) and areas for public health intervention. Training for medical professionals in regions with low notification rates should aim to reduce lethality, especially in regions with low reported cases (Itajai river delta and South), where underreporting may be occurring. Furthermore, the high lethality in adolescents and in patients with non-specific initial symptoms requires greater awareness. This study shows the utility of a governmental database in identifying epidemiological patterns and creating public health strategies tailored to regional specificities.
Copyright (c) 2026 Felipe Manoel Gimenez de Oliveira, Paulo Augusto Esteves, Ricardo Evandro Mendes https://creativecommons.org/licenses/by-nc/4.0
Candidemia in a tertiary hospital in Southern Brazil
<span style="color: #393939; font-family: 'Noto Sans', sans-serif; font-size: 18px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: #ffffff; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; display: inline !important; float: none;">Invasive bloodstream infections caused by <em style="box-sizing: border-box; color: #393939; font-family: 'Noto Sans', sans-serif; font-size: 18px; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: #ffffff; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;">Candida<span style="color: #393939; font-family: 'Noto Sans', sans-serif; font-size: 18px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: #ffffff; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; display: inline !important; float: none;"> spp. significantly impact global health and are associated with high mortality rates. This study describes a five-year retrospective analysis conducted in a tertiary hospital with 213 beds in Rio Grande, Rio Grande do Sul State, Brazil, aiming to provide clinical-epidemiological data on candidemia and the susceptibility profile of isolates in this region. From January 2019 to December 2023, 44 patients (26 adults, 15 neonates, and three pediatric individuals) were diagnosed with candidemia at our hospital and included in this study. <em style="box-sizing: border-box; color: #393939; font-family: 'Noto Sans', sans-serif; font-size: 18px; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: #ffffff; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;">Candida<span style="color: #393939; font-family: 'Noto Sans', sans-serif; font-size: 18px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: #ffffff; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; display: inline !important; float: none;"> species accounted for 4.5% of all sepsis-causing agents (44/971). The overall incidence was 2.2 cases per 1,000 hospitalizations; however, when stratified by hospitalization unit, this rate reached 26 per 1,000 hospitalizations in the neonatal intensive care unit (NICU), followed by 13 per 1,000 hospitalizations in the intensive care unit (ICU). The mortality rate reached 92% among ICU patients and 40% among NICU patients. <em style="box-sizing: border-box; color: #393939; font-family: 'Noto Sans', sans-serif; font-size: 18px; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: #ffffff; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;">C. albicans<span style="color: #393939; font-family: 'Noto Sans', sans-serif; font-size: 18px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: #ffffff; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; display: inline !important; float: none;"> was the most prevalent species (57%), while <em style="box-sizing: border-box; color: #393939; font-family: 'Noto Sans', sans-serif; font-size: 18px; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: #ffffff; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;">C. parapsilosis<span style="color: #393939; font-family: 'Noto Sans', sans-serif; font-size: 18px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: #ffffff; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; display: inline !important; float: none;"> was the most common non-<em style="box-sizing: border-box; color: #393939; font-family: 'Noto Sans', sans-serif; font-size: 18px; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: #ffffff; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;">albicans<span style="color: #393939; font-family: 'Noto Sans', sans-serif; font-size: 18px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: #ffffff; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; display: inline !important; float: none;"> species (∼30%). Resistance to at least one of the three antifungal classes tested was detected in 13% of the isolates. This study underscores the substantial impact of candidemia in ICU settings in a tertiary hospital in Southern Brazil, emphasizing the importance of improved awareness and surveillance to enhance diagnosis, control, prevention, and monitoring of antifungal resistance, aiming to reduce incidence and mortality rates.
Copyright (c) 2026 Leandre Carmem Wilot, Bianca dos Santos Blan, Vanice Rodrigues Poester, Cecília Bittencourt Severo, Karine Ortiz Sanchotene, Mônica Campos dos Santos, Mariana Rodrigues Trápaga, Melissa Orzechowski Xavier https://creativecommons.org/licenses/by-nc/4.0
A rare case of oral myiasis in a non-tropical region: the role of systemic vulnerability
Myiasis is a rare parasitic infection caused by the larvae of Diptera flies, which infest the tissues of humans or animals and are typically found in warm, humid climates. Oral myiasis is uncommon in healthy individuals and typically occurs when adult flies lay eggs or larvae near the mouth or on open wounds. Malnutrition, immunodeficiency, poor oral hygiene, dental problems, neurological or psychiatric conditions, and alcoholism are the main risk factors. In this report, we present a case of oral myiasis that occurred in a patient with multiple comorbidities, including malnutrition, immunological and neurological dysfunction (lung carcinoma, cirrhosis, cachexia, Parkinson's disease). The patient was admitted to our intensive care unit while intubated because of confusion, respiratory failure, and sepsis, in which oral myiasis was identified. Due to the patient's comorbid conditions, ivermectin could not be administered. A conservative approach was used, including daily cleaning with diluted hydrogen peroxide and povidone–iodine, together with mechanical removal of the larvae. The infestation was completely resolved within three days. This case shows that oral myiasis may develop in non-tropical settings when systemic vulnerability exists. It highlights the importance of regular oral exams and mouth care for high-risk patients.
Copyright (c) 2026 Gökçe Kızılkale Kayıkcı, Ayşe Yılmaz, Furkan Arabacı, Hale Ahsen Yardibi Demir, Mesut Özsoy https://creativecommons.org/licenses/by-nc/4.0
Genotypic virulence profiles and mobile genetic elements related to invasiveness in Neisseria gonorrhoeae strains
Neisseria gonorrhoeae (NG) has become an increasing global health threat due to drug resistance and potentially invasive disease. In this study, we assessed the genotypic profile in both invasive and non-invasive NG strains from patients at University of Sao Paulo Faculty of Medicine Clinics Hospital, Brazil. We analyzed the NG genotypic profiles and clinical data from 25 patients hospitalized at Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo (HC-FMUSP) from January 2017 to March 2020. A total of 25 isolates underwent whole genome sequencing, of which 10 (40%) were collected from sterile sites like blood and classified as invasive. Invasive and noninvasive specimens were clustered in 5 STs and 11 STs, respectively, sharing 3 STs in common. We identified resistance markers for macrolides (mtrR) in 40% of isolates and 92% exhibited at least one resistance marker for beta-lactams (penA, blaTEM-1B, or blaTEM-135), predominantly PBP1 and PBP2 alterations. Resistance genes blaTEM-1B (7%vs.50%, p=0.023) and tetM (13%vs.80%, p=0.002) were more frequently found in invasive disease isolates, always accompanied by the mobile genetic elements pJD4 and pEP5289, respectively. Associated with these elements were two toxin encoding genes (vapD and zeta1/2) previously described as possible virulence factors and resistance genes for beta-lactams and tetracyclines. Results revealed that invasive strains of NG are genotypically clustered and frequently harbor two plasmids which may be associated with invasive disease. Resistance markers for beta-lactam as PBP1 and PBP2 alterations warn against a future potential resistance to this class.
Copyright (c) 2026 José Victor Bortolotto Bampi, Saidy Vásconez Noguera, Sania Alves dos Santos, Ana Paula Marchi, Marina Farrel Côrtes, Joyce Vanessa da Silva Fonseca, Ivan Lira dos Santos, Flávia Rossi, Maria Luiza Bazzo, Gwenda Hughes, Igor Borges, Silvia Figueiredo Costa https://creativecommons.org/licenses/by-nc/4.0
The COVID-19 pandemic in the hotel industry: the application of hygiene and safety protocols by hotel employees
This study sought to understand how the application of hygiene and safety protocols by hotel companies in Sao Paulo city, Brazil, occurred during the COVID-19 pandemic. The first objective of the study was to find, based on the information provided by employees who worked in certain hotels via questionnaires from March 2020 to December 2022, which protocols were applied in the studied period and which measures were definitively incorporated into the hygiene schemes of these hotels. Secondly, this study aimed to assess how the interaction and adaptations to the implemented hygiene protocols took place to find the measures that have become hygiene habits in everyday life. The literature on the applied health protocols during the pandemic was reviewed. A cross-sectional descriptive study was conducted with 421 respondents. This study found a significant association between sex and the adoption of protective measures during the pandemic. Women adhered more to protective measures than men, and this association remained after the pandemic. Employees who worked in the food and beverage area contracted COVID-19 more often than employees in other hotel areas. Those with higher education levels received more doses of COVID-19 vaccines than those with lower levels of education. Finally, this study found a direct relationship between the quality standard of the hotels and the frequency of training received by employees and a high adherence to vaccination against COVID-19 that was lower at higher educational levels.
Cláudia Regina Rodrigues Sarralheiro Butuhy
Copyright (c) 2026 Cláudia Regina Rodrigues Sarralheiro Butuhy, Expedito José de Albuquerque Luna https://creativecommons.org/licenses/by-nc/4.0
Plasmidial virulence of Rhodococcus equi and its implications of livestock infections for human health: a possible foodborne pathogen?
Rhodococcus equi, a versatile and adapted opportunistic in nature bacterium, infects animals and humans. This soil-borne microorganism widely occurs in farms. Its dissemination occurs by feces from domestic animals (particularly horses, cattle, and pigs). In the last decades, bacterial virulence has been strongly attributed to plasmid-encoded virulence-associated proteins (VAPs). To date, three virulence plasmid types have been recognized: pVAPA, pVAPB, and pVAPN, which are considered host- or livestock-adapted. The pVAPA type is related to equine isolates (horse-type), the pVAPB type is associated with pig isolates (porcine-type), whereas the pVAPN type occurs in domestic ruminants (bovine and caprine) (ruminant-type). Nonetheless, pathogenic R. equi possessing the three virulent plasmid types can infect humans. Inhaling aerosol particles from the environment of equids represents the first route traditionally considered for the transmission of R. equi to humans, although an epidemiological lack of transmission remains in human infections because some patients with rhodococcosis have no history of contact with livestock or their environment on farms. However, all pVAPs types have been found in humans infected by R. equi (predominantly living with HIV), which could be presumably transmitted to patients by the ingestion of contaminated undercooked or raw meat from slaughtered pigs, cattle and, occasionally, horses, representing a probably route of the transmission of the pathogen from livestock-to-humans that could partially explain infections in humans without a history of contact with cattle, pigs, horses, or their farm environments.
Copyright (c) 2026 Márcio Garcia Ribeiro, Alexandre Naime Barbosa, Juliano Gonçalves Pereira, Fábio Sossai Possebon, José Paes de Almeida Nogueira Pinto, Fábio Vinícius Ramos Portilho, Thaís Spessotto Bello, Patrik Júnior de Lima Paz, Marcelo Fagali Arabe Filho, Letícia Colin Panegossi, Alec Utida Reznik, Larissa Onuki Zeferino, Maria Clara Trindade, Nícolas Garcia Ribeiro, Shinji Takai https://creativecommons.org/licenses/by-nc/4.0
A fatal case report of sepsis caused by Robinsoniella sp.
Robinsoniella species are anaerobic, spore-forming, Gram-positive bacilli that are rarely associated with human infections because of their slow growth and the limitations of conventional identification methods. We describe a fatal case of sepsis in an 84-year-old woman with hypertension, diabetes, and chronic renal insufficiency. During hospitalization, she developed impaired consciousness, polymicrobial infections, and multiple organ failure. Despite aggressive antimicrobial and supportive treatment, her condition deteriorated, leading to death. This study identified a Robinsoniella isolate (designated Rp5645) by 16S rRNA gene sequencing, showing 98.35% similarity to R. peoriensis PPC31. As this value falls below the accepted species-level threshold, Rp5645 may represent a novel Robinsoniella species. Unfortunately, the isolate lost viability before further genomic or phenotypic studies could be performed. This outcome illustrates the technical challenges in recovering and preserving fastidious anaerobes and underscores the crucial role of rapid molecular identification in confirming rare pathogens. This case broadens the clinical spectrum of Robinsoniella infections and highlights its potential pathogenic capacity, particularly in older or immunocompromised patients. It also emphasizes the need for timely molecular characterization to prevent the loss of valuable data from uncommon clinical isolates.
Copyright (c) 2026 Meijia Huang, Hongjuan Zhang, Xinyue Li, Xiangchentao Zhang, Yunmin Xu https://creativecommons.org/licenses/by-nc/4.0
Dengue haemorrhagic fever: an evaluation of host innates immune factors in hepatic lesions and their correlation with immunopathogenesis
Dengue fever challenges public health worldwide. The numerous factors associated with dengue fever severity and mortality risk include host characteristics such as patient age, comorbid conditions, previous dengue virus (DENV) infections, and biochemical biomarkers. Type I IFNs are essential cytokines in orchestrating innate and adaptive immune responses against viral invasion, and their regulation is mediated by IRF-2, which prevents excessive IFN expression. In vitro studies have shown DENV evasion strategies that affect IFN-I production but few have considered the in-situ interrelationship between IFN-I and the virus. This study aims to find elements of innate immunity that induce the anti-viral response and their correlation with the detected alterations in liver lesions. Liver specimens from individuals who died due to dengue were selected according to clinical and laboratory data and serological diagnosis. The specimens were subjected to histological and immunohistochemical evaluation of cells expressing IFN-I, RIG-1, IRF-2, and STING. Viral antigens were detected by an anti-DENV. A high number of cells expressed RIG-1 and IRF-2 when compared to IFN-I and STING. In severe cases of dengue, DENV may play a role in its pathogenesis with properties that induce non-effective immune responses. The virus can evade effective immune responses by impairing the early activation of innate immunity. This immune dysregulation may contribute to the progression of more severe manifestations and seems to play a role in the pathogenesis of hepatic involvement.
Copyright (c) 2026 Carla Pagliari, Geovanna Menezes Marcoli, Luciane Kanashiro-Galo, Evandro Sobroza de Mello, Leda Viegas de Carvalho, Ricardo Penny, Juarez Simões Quaresma, Pedro Fernando da Costa Vasconcelos, Mirian Nacagami Sotto https://creativecommons.org/licenses/by-nc/4.0
Rezafungin in fluconazole-resistant and refractory candidiasis: the first Brazilian experience
Invasive candidiasis is associated with high morbidity and mortality, and the rising of antifungal resistance underscores the need for new therapies. Rezafungin, a second-generation echinocandin, enables once-weekly dosing, achieves high plasma concentrations, and shows potent in vitro activity. We report two Brazilian cases showing its clinical utility: (i) fluconazole-resistant Candida tropicalis bloodstream infection in a patient with colorectal cancer and chronic kidney disease and (ii) azole-refractory C. albicans esophagitis in a patient with autoimmune polyglandular syndrome type 1. Both achieved rapid clinical response and microbiological clearance. These are the first documented cases of rezafungin use for invasive candidiasis in Brazil.
Copyright (c) 2026 Wdson Luis Lima Kruschewsky, Jeanne Aiko de Souza Nakagawa, Lumena Pereira Machado Siqueira, Mariane Taborda, Vítor Falcão de Oliveira, Edson Abdala, Adriana Satie Gonçalves Kono Magri, Marcello Mihailenko Chaves Magri https://creativecommons.org/licenses/by-nc/4.0
Streptococcus suis infection as an emerging zoonotic threat in Brazil: a One Health-based review
Streptococcus suis infection is an emerging zoonotic pathogen of growing concern in Brazil, particularly in the Northeast—a region lacking swine-focused surveillance. Although human contamination remains rare, they have been increasingly reported among individuals exposed to pigs or pork products, and most commonly present as central nervous system infections. Diagnostic challenges persist, especially related to culture-based methods, highlighting the need for advanced molecular tools like polymerase chain reaction and metagenomic Next-Generation Sequencing. Veterinary data reveal a high diversity of serotypes and concerning rates of antimicrobial resistance. These studies remain scarce in regions with reports of human infection. This review highlights the clinical, epidemiological, and microbiological aspects of S. suis in Brazil and underscores the importance of One Health approaches to enhance detection and prevention.
Copyright (c) 2026 Luís Arthur Brasil Gadelha Farias, Osvaldo Mariano Viana Neto, Ednaldo Pereira Lima Sobrinho, Antonio Gutierry Neves Dantas de Melo, Isabela Melo Pontes, Bruna Batista Schmid Gonçalves, Helena Pinheiro Benevides, Susana Pereira de Oliveira Maia, Jorge Luiz Nobre Rodrigues, Lauro Vieira Perdigão Neto https://creativecommons.org/licenses/by-nc/4.0
Molecular identification of Bartonella henselae in dogs with clinical suspicion of visceral leishmaniasis
The genus Bartonella includes species responsible for severe infections. Bartonella henselae, commonly linked to human disease, also infects dogs with or without symptoms. In Brazil, visceral leishmaniasis (VL) caused by Leishmania infantum is prevalent in Mato Grosso State, Brazil, particularly in Rondonopolis city, affecting both humans and dogs. Although reports of co-infection with Bartonella spp. and L. infantum exist in other countries, Brazilian studies are scarce. This study investigates the presence of B. henselae using culture and molecular methods in dogs suspected of having VL in Rondonopolis, while also assessing potential co-infections and evaluating diagnostic limitations of VL. Results showed B. henselae DNA in 53.75% (43/80) of these dogs, with Leishmania spp. DNA found in 65.11% (28/43) of them. Of the 80 dogs, 43.75% (35) lacked VL serological confirmation, yet 48.57% (17/35) were positive for B. henselae. This is the first report of B. henselae bacteremia in dogs from Rondonopolis. The high occurrence of dogs with clinical VL suggests a need for further research to understand the bacterium's role in VL-suspected cases, regardless of diagnostic confirmation. The study highlights a significant finding: approximately half of the dogs suspected of zoonotic parasitosis, with or without serological confirmation, were infected with B. henselae. Additionally, the detection of Leishmania sp. DNA in dogs not confirmed by Brazil's Health Department serological criteria suggests that these diagnostic standards may need reevaluation by health authorities, though caution is warranted due to the limitations of blood-based PCR for Leishmania sp. detection.
Copyright (c) 2026 Verônica Domingos Miranda, Luciene Silva dos Santos, Mariana Medeiros Torres, Osvaldo Campos dos Santos Nonato, Adriano Cappellazzo Coelho, Paulo Eduardo Neves Ferreira Velho, Marina Rovani Drummond https://creativecommons.org/licenses/by-nc/4.0
Eosinophilic meningitis caused by Angiostrongylus cantonensis: case report in a patient with false-positive immunological test result for Neisseria meningitides
Eosinophilic meningitis caused by Angiostrongylus cantonensis is an uncommon disease in Brazil that occurs by ingesting slugs, water or food contaminated with the parasite. Here we report a case of a 64-year-old patient with neck stiffness, headache, fever, and peripheral and cerebrospinal fluid (CSF) eosinophilia, compatible with eosinophilic meningitis. He had a false-positive result for Neisseria meningitides and received unsuccessful treatment with antibiotics. After extensive investigation, DNA and anti-A.cantonensis antibodies were detected and the patient was successfully treated with prednisone and albendazole. Diagnosis of neuroangiostrongyliasis relies on epidemiological data, as well as clinical and laboratory examinations such as detection of antibodies and DNA of the parasite in CSF. Its timely treatment with corticosteroid therapy reduces damage to neural tissues and manages headache.
Copyright (c) 2026 Marcela Nataly Parra Alvarez, Juan Sebastián Sánchez León, Tassiane Moreira da Silva, Renato Dumba Monteiro de Castro, Arlete Hilbig, Leyva Cecilia Vieira de Melo, Carlos Graeff-Teixeira, Alessandro Comarú Pasqualotto https://creativecommons.org/licenses/by-nc/4.0
Non-feline transmission of sporotrichosis: a systematic review of published cases
Sporotrichosis is a subcutaneous mycosis caused by species belonging to the genus Sporothrix. While zoonotic transmission has been primarily associated with cats, reports have pointed to sporotrichosis transmission by various non-feline animals, albeit infrequently compared with the aforementioned. These reports suggest the potential for zoonotic or environmentally mediated transmission routes with clinical and epidemiological relevance that have yet to be extensively explored. This systematic review organizes the current knowledge on sporotrichosis acquired by non-feline zoonotic transmission. A comprehensive literature review was conducted from January 1980 to March 2025, leveraging prominent databases like PubMed, SciELO, Web of Science, and EBSCO to identify cases of sporotrichosis transmitted by non-feline animals. A total of 78 cases of sporotrichosis transmitted by non-feline animals were identified in 26 articles. Most cases (76%) were transmitted by vertebrate animals, primarily dogs, whereas 24% were transmitted by invertebrates, such as mosquitoes. Lymphocutaneous presentation predominated among clinical manifestation in 80.7% of cases. Most frequently isolated species was Sporothrix schenckii, whereas Sporothrix brasiliensis was isolated only in infections caused by vertebrate animals. Most patients were young adult males, mainly related with hunting activities. Itraconazole was the most frequently used treatment. Sporotrichosis transmission route via non-feline animals is significant and frequently underestimated. Further research is needed to improve our understanding of the transmission mechanisms, focusing on distinguishing between direct zoonotic transmission and environmental exposure mediated by animal contact. Such enhanced understanding is crucial for improving diagnostic procedures in hyperendemic regions and strengthening epidemiological surveillance.
Copyright (c) 2026 Pamela Rodríguez-Salgado, Andrés Tirado-Sánchez, Valeria Lyzzete Diaz-Molina, Max Carlos Ramírez-Soto, Flavio Queiroz-Telles, Alexandro Bonifaz https://creativecommons.org/licenses/by-nc/4.0
Fulminant hepatitis secondary to dengue in pediatric patients: a series of four cases
This study reports a case series of four pediatric patients with dengue who developed fulminant hepatitis and acute liver failure requiring transplantation. This study aims to enhance early recognition of dengue-related complications, particularly fulminant hepatitis. The series includes two previously healthy girls, aged one and six years; and two boys, aged 12 and 15 years, with pre-existing hemoglobinopathies. A review was conducted to contextualize these cases with prior reports of dengue-associated fulminant hepatitis in children, focusing on diagnosis and management. All four patients underwent liver transplantation, yet their clinical courses and outcomes were varied. Patient 1, a six-year-old girl, had early warning signs and underwent cadaveric liver transplantation nine days after onset. Patient 2, a one--year-old girl, developed severe disease and received living-donor transplantation 20 days after onset. Both had favorable postoperative outcomes. Patient 3, a 12-year-old boy with SC hemoglobinopathy, underwent transplantation on day seven of illness but died on the fifth postoperative day. Patient 4, a 15-year-old boy with sickle cell anemia, underwent transplantation on day four of symptoms but suffered multiple cardiorespiratory arrests during recovery and died on postoperative day 24. Although rare, dengue can lead to fulminant hepatitis in previously healthy children, with worse outcomes in those with comorbidities. Early recognition of severe manifestations is critical for appropriate management. Larger studies are warranted to identify prognostic factors and optimize decision-making for pediatric patients requiring liver transplantation.
Copyright (c) 2026 Isabelly Victoria Simões Melchiori, Mariana Favero Elias, Jhonny Richard de Sousa, Leonardo Labbate Kalil, João Pedro de Mattos Anacleto, Victor Fernandes Rosa, Ana Cristina Aoun Tannuri https://creativecommons.org/licenses/by-nc/4.0
Comparative performance of Filamentous Fungi 4.0 and Mass Spectrometry Identification 2.0 databases for Aspergillus spp.: identification using a simplified protein extraction method
Aspergillus spp. are major agents of pulmonary aspergillosis, posing diagnostic challenges in clinical laboratories due to morphological similarity among species. This study compared the performance of two spectral databases, Filamentous Fungi v4.0 (Bruker Daltonics) and Mass Spectrometry Identification v2.0 (MSI 2.0), for Aspergillus species identification by MALDI-TOF MS, and evaluated the applicability of the simplified protein extraction method from solid culture medium for routine use in hospital laboratories. Overall, 46 clinical isolates from patients with pulmonary aspergillosis were cultured on Sabouraud Dextrose Agar (SDA) at 37 °C for 48 h. Proteins were extracted directly from colonies and analysed using the Bruker MALDI Biotyper system. Spectra were compared against FF_4.0 and MSI_2.0 databases, and results were correlated with molecular identification by benA, cmd5, and ITS gene sequencing. The extraction method yielded high-quality spectra with peaks between 2–15 kDa. The FF_4.0 database identified 52.17% of isolates at the section level and none at the species level, reflecting limited spectral compatibility and taxonomic coverage. Conversely, MSI_2.0 correctly identified 82.6% of isolates at the species level, 15.23% at the section level, and only 2.17% were not identified. Concordance between MSI_2.0 and sequencing reached 44.7%, without statistical significance (p = 0.627). The simplified solid-medium extraction method combined with MSI 2.0 proved efficient, reproducible, and suitable for clinical routine, offering faster identification of Aspergillus species compared to conventional methods. In contrast, FF_4.0 showed limited applicability for hospital workflows.
Copyright (c) 2026 Gustavo Giacon Damiani, Vivian Caso Coelho, Juliana Possato Fernandes Takahashi, Ingrid Gonçalves Costa Leite, Marcia Regina von Zeska Kress, Marcello Mihailenko Chaves Magri, Valdes Roberto Bollela, Roberto Martínez, Gil Benard, Tiago Alexandre Cocio https://creativecommons.org/licenses/by-nc/4.0
Yellow fever virus resurgence in Sao Paulo State, Brazil, 2024–2025
We report the detection of yellow fever virus in Campinas and Ribeirao Preto city areas (two geographic areas within Sao Paulo State, Brazil) from September 2024 to February 2025. Phylogenetic analysis of six new genomes showed a re-introduction in 2022 from Midwest Brazil followed by persistence in Sao Paulo State. Continued surveillance in neotropical primates is required to prevent cases in humans.
Natália Coelho Couto de Azevedo Fernandes
Copyright (c) 2026 Mariana Sequetin Cunha, Juliana Mariotti Guerra, Márcio Junio Lima Siconelli, Benedito Antonio Lopes da Fonseca, Jessica Caroline de Almeida Dias, Gisele Dias de Freitas, Ester Cerdeira Sabino, Erika Regina Manuli, Geovana Maria Pereira, Ian Nunes Valença, Patrícia Sayuri Silvestre Matsumoto, Nuno Rodrigues Faria, Natália Coelho Couto de Azevedo Fernandes https://creativecommons.org/licenses/by-nc/4.0
Occlusion body-incorporated SARS-CoV-2 S-RBD via cypovirus polyhedrin-derived peptide: a novel insect cell-expressed antigen for high-accuracy COVID-19 diagnosis, and humoral immune response and hybrid immunity evaluation
Accurate serological assays are critical for monitoring antibody responses to SARS-CoV-2 and for assessing vaccine efficacy. In this study, we engineered a recombinant baculovirus to express the SARS-CoV-2 spike receptor-binding domain (RBD) fused to an N-terminal peptide of cypovirus polyhedrin (S-RBD-POLH), thereby enabling its potential encapsulation within occlusion bodies. The construct was expressed in insect cells and employed to establish an in-house enzyme-linked immunosorbent assay (ELISA-S) for COVID-19 diagnosis and evaluation of the humoral immune response to SARS-CoV-2. We compared the performance of ELISA-S with a commercial lateral flow immunoassay (LFIA), a chemiluminescence immunoassay (CLIA), and an in-house ELISA targeting Escherichia coli-produced nucleocapsid (N) protein (ELISA-N). Both in-house ELISAs had excellent diagnostic performance (overall accuracy = 0.90), with ELISA-S achieving 98.9% sensitivity and 100% specificity. Inter-assay concordance was high (kappa coefficient > 0.92), with near-perfect agreement between ELISA-S and LFIA (kappa = 0.99). Longitudinal analysis revealed increasing anti-RBD IgG titers over time, in contrast to declining anti-N IgG levels, consistent with expected post-infection kinetics. Moreover, ELISA-S reliably detected antibodies in individuals with hybrid immunity across different periods of the pandemic. These findings establish a scalable platform for antigen encapsulation and production in insect cells to enhance antibody detection. The ELISA-S system represents a robust and adaptable approach for evaluating humoral immunity following infection, vaccination, or hybrid immunity, and can be used for all variants.
Copyright (c) 2026 Murilo Barros-Silveira, Fabricio da Silva Morgado, Laurine Lacerda Pigosso, Fernanda Cortez Roriz Pontes, Ethiane Rozo dos Santos, Rosana Pereira Morais, Yves Mauro Fernandes Ternes, Célia Maria de Almeida Soares, Bergmann Morais Ribeiro, Fátima Ribeiro-Dias https://creativecommons.org/licenses/by-nc/4.0
Reflections on the study "Central sterile supply department management on hospital-associated infections: a systematic review and meta-analysis" by Shuai et al
Copyright (c) 2026 Eliane Molina Psaltikidis https://creativecommons.org/licenses/by-nc/4.0
Fatal cerebral myiasis secondary to squamous cell carcinoma: case report and scoping review
Cerebral myiasis is an exceptionally rare condition caused by infestation with dipteran larvae, with only 20 cases reported in the literature to date. A 78-year-old man presented with anorexia, vomiting, and fever. Physical examination revealed a 7 × 8 cm ulcerated scalp lesion with a necrotic base, purulent discharge, a foul odor, and numerous larvae. Computed tomography demonstrated an osteolytic frontal bone defect accompanied by pneumocephalus and subcutaneous emphysema. The larvae were manually removed, an iodoform dressing was applied, and intravenous ceftriaxone therapy was initiated. Progressive neurological decline prompted repeat imaging, which revealed frontal and parietal cerebritis with abscess formation. Surgical debridement was performed to remove necrotic tissue. Histopathological analysis showed moderately differentiated squamous cell carcinoma with acute osteomyelitis, and cultures yielded multidrug-resistant Pseudomonas aeruginosa. Despite targeted antibiotic therapy and intensive supportive care, the patient died. This case highlights the significant morbidity and mortality associated with cerebral myiasis, particularly when complicated by underlying malignancy and multidrug-resistant infection. Early recognition, prompt surgical intervention, and pathogen-directed antimicrobial therapy are crucial, while comprehensive multidisciplinary management remains essential to optimize outcomes in this life-threatening condition.
Copyright (c) 2026 Paulo Henrique Alves Togni Filho, Ernani Alves de Oliveira, Roscicler Pereira de Sousa, André Luís Santos Vaz Leite, Lucas Eiji Adachi Oliveira, Guilherme Augusto Paro, Julia de Campos Preto https://creativecommons.org/licenses/by-nc/4.0
Leptospirosis-associated pulmonary hemorrhagic syndrome: immune mechanisms, clinical manifestations, and experimental models
<span style="color: #393939; font-family: 'Noto Sans', sans-serif; font-size: 18px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: #ffffff; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; display: inline !important; float: none;">Leptospirosis is a neglected zoonotic disease caused by bacteria of the genus <em style="box-sizing: border-box; color: #393939; font-family: 'Noto Sans', sans-serif; font-size: 18px; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: #ffffff; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;">Leptospira<span style="color: #393939; font-family: 'Noto Sans', sans-serif; font-size: 18px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: #ffffff; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; display: inline !important; float: none;">, mainly acquired via direct contact with water and soil contaminated by the urine of infected animals. This is most observed in tropical and subtropical regions, and it is strongly associated with urban population growth in areas lacking adequate sanitation conditions. <em style="box-sizing: border-box; color: #393939; font-family: 'Noto Sans', sans-serif; font-size: 18px; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: #ffffff; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;">Leptospira<span style="color: #393939; font-family: 'Noto Sans', sans-serif; font-size: 18px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: #ffffff; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; display: inline !important; float: none;"> infection can lead to several clinical manifestations in humans, ranging from a nonspecific febrile illness to severe complications such as jaundice, renal failure, and life-threatening pulmonary disease. One of the most severe forms is leptospirosis-associated pulmonary hemorrhagic syndrome (LPHS), characterized by coughing, chest pain, dyspnea, and massive pulmonary hemorrhage. The mortality rate of LPHS is approximately 50%, with death generally occurring within 72 hours after symptom onset. The etiopathogenesis of LPHS remains poorly understood. Some studies suggest that <em style="box-sizing: border-box; color: #393939; font-family: 'Noto Sans', sans-serif; font-size: 18px; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: #ffffff; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;">Leptospira<span style="color: #393939; font-family: 'Noto Sans', sans-serif; font-size: 18px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: #ffffff; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; display: inline !important; float: none;"> spp. may directly damage blood capillaries and alter vascular permeability. Additionally, the host immune response, via the cytokine release, high expression of adhesion molecules, and activation of the Complement System, may further disrupt endothelial integrity, promoting vascular leakage and the systemic dissemination of leptospires. Animal models are essential for a better understanding of <em style="box-sizing: border-box; color: #393939; font-family: 'Noto Sans', sans-serif; font-size: 18px; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: #ffffff; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;">Leptospira<span style="color: #393939; font-family: 'Noto Sans', sans-serif; font-size: 18px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: #ffffff; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; display: inline !important; float: none;"> transmission, colonization, and pathogenesis. This review aims to consolidate current understanding of LPHS, with emphasis on its pathogenesis, immune mechanisms, clinical manifestations, virulence factors, and experimental models.
Copyright (c) 2026 Lara Rodrigues da Silva, Milena Carvalho Carneiro, Ana Carolina Mikejevs Lorga, Luana Barbosa Rodrigues dos Santos, Leonardo Moura Midon, Amaro Nunes Duarte Neto, Thais Akemi Amamura, Lourdes Isaac https://creativecommons.org/licenses/by-nc/4.0
SARS-CoV-2 lineage-specific disease symptoms and disease severity in a city in southeastern Brazil
In 2020, Sao Caetano do Sul city, located in the metropolitan region of Sao Paulo State, Brazil, established a web-based platform to provide primary care to suspected COVID-19 patients, integrating clinical and demographic data and sample metadata. Here we describe lineage-specific spatiotemporal dynamics of infections, clinical symptoms, and disease severity during the first year of the epidemic, which included circulation of the poorly characterised Gamma variant of concern. From April 6, 2020, to April 30, 2021, we gathered clinical, demographic, spatial and epidemiological data from the city's platform. We selected and sequenced 879 PCR+ swab samples (8% of all reported cases), obtaining a spatially and temporally representative set of sequences. Daily lineage-specific prevalence was estimated with a moving-window approach, allowing inference of cumulative cases and symptom probability stratified by lineage using integrated data from the platform. Most infections were caused by B.1.1.28 (41.3%), followed by Gamma (31.7%), Zeta (9.6%), and B1.1.33 (9.0%). Gamma and Zeta correlated with larger prevalence of dyspnoea (respectively, 81.3% and 78.5%) and persistent fever (84.7% and 61.1%) compared with B.1.1.28 and B.1.1.33. Ageusia, anosmia, and coryza were respectively 18.9%, 20.3%, and 17.8% less commonly caused by Gamma, whereas altered mental status was 108.9% more common in Zeta. Case incidence was spatially heterogeneous and larger in poorer and younger districts. Our study reveals that Gamma was associated with more severe presentation of the disease, emphasising its role in the heightened mortality levels in Brazil.
Copyright (c) 2026 Flavia Cristina da Silva Sales, Carlos Augusto Prete Junior, Leandro Abade, Lewis Fletcher Buss, Darlan da Silva Candido, Ingra Morales Claro, Filipe Romero Rebello Moreira, Erika Regina Manuli, Ligia Capuani, Camila Alves da Silva Maia, Thais Coletti, Heuder Gustavo Oliveira Paião, Silvia Figueiredo Costa, Maria Cassia Mendes Correa, Fabio Eudes Leal, Kris Varun Parag, Vítor Heloiz Nascimento, Nuno Rodrigues Faria, Ester Cerdeira Sabino https://creativecommons.org/licenses/by-nc/4.0
HIV-associated neurological infections in a Brazilian tertiary care center: clinical-epidemiological features and predictors of in-hospital mortality
Neurological manifestations remain a significant cause of hospitalization and in-hospital mortality among people living with HIV (PLWH), even in the era of antiretroviral therapy (ART). This study aims to describe the clinical and epidemiological profile of PLWH with neurological opportunistic infections (nOIs) and to identify factors associated with in-hospital mortality. We conducted a retrospective cohort study with PLWH aged >18 years hospitalized due to nOIs between November 2017 and December 2021 at a tertiary hospital in Brazil. Demographic, clinical, and laboratory data were extracted from electronic medical records. Logistic regression was used to evaluate associations between patient characteristics and in-hospital mortality. Among 237 hospitalized PLWH, 89 (37.6%) had nOIs. The median CD4 count at admission was 55 cells/mm³ (IQR 22.5–149), and 91.7% had previously used ART (only 22.7% used it regularly). The most frequent infections were cerebral toxoplasmosis (50.6%), cryptococcal meningitis (10.1%), and progressive multifocal leukoencephalopathy (9%). A total of 19 in-hospital deaths occurred. In the multivariate analysis, undefined neurological infections (aOR: 8.67; 95%CI: 1.23–61.17) and ICU admission (aOR: 58.61; 95% CI: 10.24–335.49) were independently associated with mortality. In conclusion, severe immunosuppression and low ART adherence were common in this cohort. Cerebral toxoplasmosis was the most prevalent neurological infection. ICU admission and undefined neurological syndromes were strong predictors of in-hospital mortality. Early diagnosis, prompt treatment, and strategies to improve ART adherence are essential to reduce fatal outcomes in this population.
Copyright (c) 2026 Laísa Rivas Dapousa Ramos, Daniel Ayabe Ninomiya, Murilo Freua Sequeira, Olavo Henrique Munhoz Leite, Marcello Mihailenko Chaves Magri https://creativecommons.org/licenses/by-nc/4.0
Circulating cell-free mitochondrial DNA as a candidate marker of hyperinflammation and immune activation in pre-adolescents, adolescents and young adults with COVID-19 and comorbidities
Youth encompasses pre-adolescence (10-14 years), adolescence (15-17 years), and young adulthood (18-24 years). Adolescents in general, particularly those with comorbidities, appear more susceptible to severe COVID-19, a vulnerability also observed in newborns and young infants. The mechanisms underlying this increased risk remain unclear, highlighting the need for early disease biomarkers. Circulating cell-free mitochondrial DNA (ccf-mtDNA), a damage-associated molecular pattern (DAMP), has been linked to systemic inflammation and immune activation during viral infections. This study evaluated plasma ccf-mtDNA levels in pre-adolescents, adolescents, and young adults with and without COVID-19, all presenting respiratory symptoms and predominantly harboring comorbidities, some with coinfections by other respiratory viruses. In this prospective study of 88 participants aged 12-21 years, half tested positive and half negative for SARS-CoV-2 by Reverse-Transcribed Polymerase Chain Reaction (RT-PCR). Comorbidities were present in 75% of COVID-19-positive and 54.5% of COVID-19-negative participants. Coinfections were detected in 52.3% and 25% of tested participants, respectively. Plasma ccf-mtDNA was quantified by a quantitative Real Time PCR (qPCR) targeting the mitochondrial NADH dehydrogenase 2 (ND2) gene or MT-ND2. COVID-19-positive participants exhibited significantly higher ccf-mtDNA levels than both symptomatic COVID-19-negative individuals and healthy controls (p<0.001). Although median levels were numerically higher in severe/critical compared with mild/moderate cases (7,769 vs. 4,649 ccf-mtDNA/mL), the difference was not statistically significant, likely due to limited sample size. In conclusion, elevated ccf-mtDNA distinguishes young individuals with COVID-19 and comorbidities from non-COVID-19 symptomatic participants and healthy controls. Although not linked to disease severity in this preliminary study, ccf-mtDNA may serve as an early biomarker of SARS-CoV-2-induced hyperinflammation and immune activation, supporting further targeted clinical investigations.
Copyright (c) 2026 Gabriella Bayler Novo, Emilly Henrique dos Santos, Karen Alessandra Rodrigues, Gabriel Acca Barreira, Mariana Okay Saippa, Maria Carolina Pires Cruz, Maria Fernanda Baduê Pereira, Heloisa Helena de Sousa Marques, Thelma Suely Okay https://creativecommons.org/licenses/by-nc/4.0