Polarization of HIV-1- and CMV-Specific IL-17-Producing T Cells among People with HIV under Antiretroviral Therapy with Cannabis and/or Cocaine Usage.

OBJECTIVE: This study evaluated the influence of cannabis and/or cocaine use in human immunodeficiency virus (HIV)- and cytomegalovirus (CMV)-specific T-cell responses of people with HIV (PWH). RESULTS: There was a higher percentage of IL-17-producing HIV-Gag-specific CD8+ T-cells in all drug users than that in PWH non-drug users. Stratifying the drug-user groups, increased percentages of IL-17-producing HIV-Gag-specific CD4+ and CD8+ T-cells were found in PWH cannabis plus cocaine users compared to PWH non-drug users. In response to CMV, there were higher percentage of IL-17-producing CMV-specific CD8+ T-cell in PWH cocaine users than that in PWH non-drug users. Considering all drug users together, there was a higher percentage of SEB-stimulated IL-17-producing CD4+ T-cells than that in PWH non-drug users, whereas cannabis users had higher percentages of IL-17-producing CD4+ T-cells compared to non-drug users. METHODS: Cryopreserved peripheral blood mononuclear cells from 37 PWH undergoing antiretroviral therapy (ART) using cannabis (10), cocaine (7), or cannabis plus cocaine (10) and non-drug users (10) were stimulated with HIV-1 Gag or CMV-pp65 peptide pools, or staphylococcal enterotoxin B (SEB) and evaluated for IFN-γ- and/or IL-17A-producing CD4+ and CD8+ T-cells using flow cytometry. CONCLUSIONS: Cannabis plus cocaine use increased HIV-specific IL-17 producing T-cells and cocaine use increased IL-17 CMV-specific CD8+ T-cell responses which could favor the inflammatory conditions associated with IL-17 overproduction.

Distinct anti-NP, anti-RBD and anti-Spike antibody profiles discriminate death from survival in COVID-19.

Introduction: Infection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) induces rapid production of IgM, IgA, and IgG antibodies directed to multiple viral antigens that may have impact diverse clinical outcomes. Methods: We evaluated IgM, IgA, and IgG antibodies directed to the nucleocapsid (NP), IgA and IgG to the Spike protein and to the receptor-binding domain (RBD), and the presence of neutralizing antibodies (nAb), in a cohort of unvaccinated SARS-CoV-2 infected individuals, in the first 30 days of post-symptom onset (PSO) (T1). Results: This study included 193 coronavirus disease 2019 (COVID-19) participants classified as mild, moderate, severe, critical, and fatal and 27 uninfected controls. In T1, we identified differential antibody profiles associated with distinct clinical presentation. The mild group presented lower levels of anti-NP IgG, and IgA (vs moderate and severe), anti-NP IgM (vs severe, critical and fatal), anti-Spike IgA (vs severe and fatal), and anti-RBD IgG (vs severe). The moderate group presented higher levels of anti-RBD IgA, comparing with severe group. The severe group presented higher levels of anti-NP IgA (vs mild and fatal) and anti-RBD IgG (vs mild and moderate). The fatal group presented higher levels of anti-NP IgM and anti-Spike IgA (vs mild), but lower levels of anti-NP IgA (vs severe). The levels of nAb was lower just in mild group compared to severe, critical, and fatal groups, moreover, no difference was observed among the more severe groups. In addition, we studied 82 convalescent individuals, between 31 days to 6 months (T2) or more than 6 months (T3), PSO, those: 12 mild, 26 moderate, and 46 severe plus critical. The longitudinal analyzes, for the severe plus critical group showed lower levels of anti-NP IgG, IgA and IgM, anti-Spike IgA in relation T3. The follow-up in the fatal group, reveals that the levels of anti-spike IgG increased, while anti-NP IgM levels was decreased along the time in severe/critical and fatal as well as anti-NP IgG and IgA in several/critical groups. Discussion: In summary, the anti-NP IgA and IgG lower levels and the higher levels of anti-RBD and anti-Spike IgA in fatal compared to survival group of individuals admitted to the intensive care unit (ICU). Collectively, our data discriminate death from survival, suggesting that anti-RBD IgA and anti-Spike IgA may play some deleterious effect, in contrast with the potentially protective effect of anti-NP IgA and IgG in the survival group.

Integrated Metabolic and Inflammatory Signatures Associated with Severity of, Fatality of, and Recovery from COVID-19.

Severe manifestations of coronavirus disease 2019 (COVID-19) and mortality have been associated with physiological alterations that provide insights into the pathogenesis of the disease. Moreover, factors that drive recovery from COVID-19 can be explored to identify correlates of protection. The cellular metabolism represents a potential target to improve survival upon severe disease, but the associations between the metabolism and the inflammatory response during COVID-19 are not well defined. We analyzed blood laboratorial parameters, cytokines, and metabolomes of 150 individuals with mild to severe disease, of which 33 progressed to a fatal outcome. A subset of 20 individuals was followed up after hospital discharge and recovery from acute disease. We used hierarchical community networks to integrate metabolomics profiles with cytokines and markers of inflammation, coagulation, and tissue damage. Infection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) promotes significant alterations in the plasma metabolome, whose activity varies according to disease severity and correlates with oxygen saturation. Differential metabolism underlying death was marked by amino acids and related metabolites, such as glutamate, glutamyl-glutamate, and oxoproline, and lipids, including progesterone, phosphocholine, and lysophosphatidylcholines (lysoPCs). Individuals who recovered from severe disease displayed persistent alterations enriched for metabolism of purines and phosphatidylinositol phosphate and glycolysis. Recovery of mild disease was associated with vitamin E metabolism. Data integration shows that the metabolic response is a hub connecting other biological features during disease and recovery. Infection by SARS-CoV-2 induces concerted activity of metabolic and inflammatory responses that depend on disease severity and collectively predict clinical outcomes of COVID-19. IMPORTANCE COVID-19 is characterized by diverse clinical outcomes that include asymptomatic to mild manifestations or severe disease and death. Infection by SARS-CoV-2 activates inflammatory and metabolic responses that drive protection or pathology. How inflammation and metabolism communicate during COVID-19 is not well defined. We used high-resolution mass spectrometry to investigate small biochemical compounds (<1,500 Da) in plasma of individuals with COVID-19 and controls. Age, sex, and comorbidities have a profound effect on the plasma metabolites of individuals with COVID-19, but we identified significant activity of pathways and metabolites related to amino acids, lipids, nucleotides, and vitamins determined by disease severity, survival outcome, and recovery. Furthermore, we identified metabolites associated with acute-phase proteins and coagulation factors, which collectively identify individuals with severe disease or individuals who died of severe COVID-19. Our study suggests that manipulating specific metabolic pathways can be explored to prevent hyperinflammation, organ dysfunction, and death.

Mortality Risk Factors for Coronavirus Infection in Hospitalized Adults in Brazil: A Retrospective Cohort Study.

BACKGROUND: The COVID-19 pandemic has presented high morbidity and mortality, with associated high socioeconomic costs. Brazil ranks third in the number of COVID-19 cases, behind only India and the United States. OBJECTIVE: To analyze risk factors for mortality in adults hospitalized with COVID-19 in Brazil. METHODS: Observational retrospective cohort study including data from all Brazilian states and regions. The study included information from 468,226 in-hospital patients from all regions of Brazil from 1 January 2021 to 31 July 2021. Data from the influenza epidemiological surveillance system were used. The participants were adults hospitalized with COVID-19. A Cox regression model was used to analyze factors associated with mortality in adults with COVID-19. RESULTS: The in-hospital mortality lethality was 37.5%. The risk factors associated with COVID-19 mortality were older age, with a linear increase with increments in age, male sex, black or mixed race, low education level, comorbidities, use of ventilatory support, and living in the southeast, north, or northeast regions of the country. CONCLUSIONS: Our results illustrate the severity of the COVID-19 pandemic in Brazil and reinforce that policies and practices to deal with this disease should focus on groups and regions with higher risk, whereas public policies should promote nonpharmacological measures and vaccination in the Brazilian population.

SARS-CoV-2 loads in urine, sera and stool specimens in association with clinical features of COVID-19 patients.

Background: COVID-19 pandemic continues to be a priority in public health worldwide, and factors inherent to SARS-CoV-2 pathogenesis and genomic characteristics are under study. Investigations that evaluate possible risk factors for infection, clinical manifestations, and viral shedding in different specimens also need to clarify possible associations with COVID-19 prognosis and disease outcomes. Study design: In this study, we evaluated SARS-CoV-2 positivity and estimated viral loads by real-time RT-PCR in stool, sera, and urine samples from 35 patients, with a positive SARS-CoV-2 RNA molecular test in respiratory sample, attended at a University COVID-19 referral hospital in Goiania, Goias, Brazil. Whole-genome sequencing was also performed in samples with higher viral load. Results: The positivity index was 51.43%, 14.28%, and 5.71% in stool, sera, and urine specimens, respectively. The median viral load was 8.01 × 106 GC/g, 2.03 × 106 GC/mL, and 1.36 × 105 GC/mL in stool, sera, and urine, respectivelly. Of all patients, 88.57% had previous comorbidities, and 48.39% of them had detectable SARS-CoV-2 RNA in at least one type of clinical specimen evaluated by this study (stool, sera or urine). A higher viral load was observed in patients with more than two previous comorbidities and that were classified as severe or critical conditions. Samples with the highest viral loads were sequenced and characterized as B.1.1.33 variant. Conclusion: We conclude that SARS-CoV-2 RNA is present in more than one type of clinical specimen during the infection, and that the most critical patients had detectable viral RNA in more than one clinical specimen at the same time point.

Spondylodiscitis associated with skin lesions caused by Rhizopus in a patient with systemic lupus erythematosus.

Mucormycosis is a serious and rare fungal disease caused by opportunistic fungi of the zygomycete class, order Mucorales. The main clinical presentations are rhinocerebral, pulmonary, cutaneous, gastrointestinal, and disseminated infections. There are few reports in the literature of spondylodiscitis caused by mucormycosis. We report a 53-year-old male patient presenting with subcutaneous nodules and severe low back pain radiating to the lower limbs. The patient had systemic lupus erythematosus (SLE) for 8 years and corticoid-induced diabetes. He had been using 60 mg/day of prednisone in the last year, with a recent pulse therapy regimen with methylprednisolone and cyclophosphamide to control the renal dysfunction. Nuclear magnetic resonance (NMR) of the spine showed spondylodiscitis. The patient underwent spinal arthrodesis and lesion biopsy. The histopathological study of the vertebra reported a necro suppurative inflammation with numerous fungal structures described as a wide range of hyaline hyphae. The histopathology of the cutaneous nodule exhibited an extensive suppurative lesion centered on the subcutaneous tissue, associated with a large amount of hyphae, similar to that found in the spinal lesion, suggestive of mucormycosis. The fungal culture showed the growth of Rhizopus spp. Treatment was performed with amphotericin B lipid complex 5 mg/kg/day for 60 days. After antifungal treatment, there was a progressive reduction in the number of subcutaneous nodules and total improvement of the patient's low back pain, with recovery of his gait. At the 18-month outpatient visit follow-up, the patient was stable and without recurrence. In our case, timely diagnosis enabled the removal of the osteoarticular focus and the targeted therapy resulted in a satisfactory clinical response, without sequelae or complications, despite the patient's underlying immunosuppressed status.

Clinical practice in COVID-19: The most frequently asked questions to infectious diseases specialists.

Since the emergence of the disease caused by the severe respiratory syndrome coronavirus 2 (SARS-CoV-2) - COVID-19 - in late December 2019, a vast number of publications on the subject appeared in peer-reviewed journals and preprints. Despite the significant amount of available information, infectious disease physicians are requested to solve questions from colleagues, patients, and relatives on a daily basis. Here, we aim to describe the evidence supporting the answers for frequently asked questions, based on a literature review. We created a web-based questionnaire which was distributed to a group of 70 infectious disease specialists and medical residents, asking what questions and issues they most frequently faced. The 10 most frequent questions guided the topics for a narrative review. We provide evidence and consensus-based information on subjects such as infection and transmission, isolation, management of COVID-19 confirmed cases, reinfection, clinical-therapeutic management, vaccination, and antibodies post-infection/vaccination. Correctly clarifying doubts and providing clear information to physicians, patients, and family members helps to better manage COVID-19 in the community and the hospital settings.

AIDS-related progressive multifocal leukoencephalopathy

Abstract INTRODUCTION: Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system caused by reactivation of JC virus (JCV). METHODS: We described the profile of laboratory-confirmed PML cases among AIDS patients. RESULTS: A total of 43 HIV patients with clinical conditions compatible with PML were obtained; 5 cases were confirmed by JCV testing. The main clinical finding was mental confusion. Median CD4 count was 54 cells/mm³. CONCLUSIONS: Three of the five confirmed PML cases died; the time between diagnosis and death was 2, 5, and 6 months. It is important to consider JCV infection as a differential diagnosis.

YOKENELLA REGENSBURGEI osteoarticular infection: a case report

okenella regensburgei belongs to the family Enterobacteriaceae and is an opportunistic agent rarely associated with infections in humans. We report a case of osteoarticular knee infection caused by Y. regensburgei in a patient under treatment for rheumatoid arthritis, using corticosteroids, with complication in primary total arthroplasty of the knee. Y. regensburgei was identified using the VITEK2 system. Antimicrobial susceptibility testing was performed using the disk-diffusion method, according to the guidelines from the Clinical and Laboratory Standards Institute. The patient presented favorable clinical evolution after the second debridement, with complete removal of the prosthesis and antibiotic therapy with sulfamethoxazole/trimethoprim. This is the first case of Y. regensburgei infection described d in Brazil.

AIDS-related progressive multifocal leukoencephalopathy.

INTRODUCTION: Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system caused by reactivation of JC virus (JCV). METHODS: We described the profile of laboratory-confirmed PML cases among AIDS patients. RESULTS: A total of 43 HIV patients with clinical conditions compatible with PML were obtained; 5 cases were confirmed by JCV testing. The main clinical finding was mental confusion. Median CD4 count was 54 cells/mm³. CONCLUSIONS: Three of the five confirmed PML cases died; the time between diagnosis and death was 2, 5, and 6 months. It is important to consider JCV infection as a differential diagnosis.

Meningoencephalitis and optical neuritis caused by CRYPTOCOCCUS GATTII in an immunocompetent patient

The following case is of a 59-year-old man, undergoing no medication, with no pathological history or others risk factors, who presented dizziness, fever and asthenia twenty days before admission. The patient was admitted for investigation when the asthenia intensified, followed by seizures. On admission, blood count, biochemical tests and chest computed tomography were normal, a serological test for anti-HIV proved negative, while the magnetic resonance of the brain showed signs suggestive of meningoencephalitis. Cerebrospinal fluid (CSF) analysis suggested bacterial meningitis due to increased leukocytes with a predominance of polymorphonuclear cells, reduced glucose and increased proteins as well as positive Gram cocci in pairs by Gram and negative fungi by India ink test. Treatment with ceftriaxone was started. Since there was no significant improvement, CSF analysis was repeated on the seventh day of treatment. Intracranial pressure was measured by manometry (29 mmHg) and CSF analysis showed the presence of encapsulated yeasts similar to Cryptococcus neoformans by the India ink test. The treatment was modified to liposomal amphotericin B and flucytosine; the intracranial hypertension was controlled by repeated CSF punctures. After fourteen days of antifungal treatment, the patient presented visual turbidity and bilateral papillar edema, so corticosteroid therapy was prescribed. The evolution was favorable, with progressive resolution of symptoms, improvement of CSF parameters and visual acuity. The patient was discharged eight weeks after admission, with outpatient guidance. Corticosteroid therapy associated with antifungal therapy proved to be beneficial in this case, since following the introduction of corticosteroids there was progressive visual improvement.

Distinct inflammatory profiles in HIV-infected individuals under antiretroviral therapy using cannabis, cocaine or cannabis plus cocaine.

OBJECTIVES: To evaluate the effects of cannabis and/or cocaine use on inflammatory, oxidative stress status and circulating monocyte subsets in HIV-infected individuals under antiretroviral therapy. DESIGN: Soluble CD14 (sCD14), intestinal fatty acid-binding protein (IFABP), tumor necrosis factor-alpha (TNF-α), interleukin (IL)-6, IL-8, IL-10, C-reactive protein (CRP) and oxidative stress markers were examined. The monocyte subsets and their activation and cytokine production by peripheral blood mononuclear cells (PBMCs) of HIV-1 infected individuals upon lipopolysaccharide (LPS)-stimulation were also investigated. METHODS: sCD14, IFABP, TNF-α, IL-6, IL-8 and IL-10 levels were evaluated using ELISA, CRP by turbidimetry; lipid peroxidation (TBARS) spectrofluometrically and total thiol levels by using 5-5'-dithio-bis (2-nitrobenzoic acid) reagent. Monocyte subsets and activation were assessed by flow cytometry. RESULTS: All HIV-infected drug user groups showed higher sCD14 levels compared with HIV+ nondrug users. IFABP was increased in HIV+ drug-users in relation to healthy individuals. Cannabis use lowered the percentages of inflammatory, nonclassical, activated-classic and activated-inflammatory monocytes. Cocaine users showed increased plasmatic TNF-α and TBARS levels, decreased thiols content and lower activated-classic and inflammatory-monocyte percentages. Cannabis-plus-cocaine use increased CRP, IL-8 and IL-6/IL-10 ratio, but decreased thiol content, and inflammatory and activated-classic monocyte percentages. PBMCs of cannabis and cannabis-plus-cocaine users showed low-potential cytokine production either spontaneously or under LPS-stimulation. CONCLUSION: In HIV infection, the use of cannabis induces predominantly an anti-inflammatory profile. The use of cocaine and cannabis-plus-cocaine showed a mixed pro-inflammatory and anti-inflammatory profile, with predominance of inflammatory status. Further studies are required to better understand the action of these drugs in HIV infection.

Isoniazid-resistant tuberculous spondylodiscitis associated with scrofuloderma

The extrapulmonary forms of tuberculosis are responsible for about 20% of cases. Scrofuloderma is the cutaneous manifestation secondary to infection in some subcutaneous foci. A 33-year-old patient was admitted to the Clinical Hospital with exudative skin lesions on the back and thorax, initiated 10 months previously, associated with daily fever, and constipation. Spine resonance showed a paravertebral pseudotumoral lesion with T4 and T9 invasion, including vertebral canal and sub-ligament extension. The lesions presented fistulas for paravertebral muscles, lung and skin. Polimerase chain reaction (PCR) proved positive for Mycobacterium tubeculosis in the thorax wound secretion, caracterizing tuberculous spondilodiscitis with scrofuloderma. Treatment was initiated with rifampicin, isoniazid, pyrazinamide and ethambutol with important clinical improvement after the first week. The febrile peaks came to an end and there was improvement in the pattern of the cutaneous lesions. The susceptibility test showed resistance to isoniazid

Infecção urinária multirresistente na gravidez / Multiresistant urinary infection in pregnancy

Os micro-organismos que apresentam mecanismos de resistência aos antimicrobianos, como produção de ß-lactamase de espectro estendido (ESBL), resultam em uma maior dificuldade no tratamento e exigem a utilização de antibióticos de largo espectro com frequência crescente. Assim, este estudo busca revisar a literatura sobre as infecções causadas por micro-organismos multirresistentes na gravidez. Foi realizada uma busca de artigos no PubMed, MedLine e Lilacs usando-se unitermos, incluindo-se os estudos publicados de 2000 a 2016, de línguas portuguesa e inglesa, envolvendo apenas seres humanos. Foram selecionados 59 artigos com força de evidência A e B. Os critérios para inclusão no estudo são: estarem grávidas e terem diagnóstico de infecção do trato urinário. Serão critérios de exclusão: uso de antimicrobiano a menos de duas semanas antes da coleta da amostra e portadoras de doença imunossupressora. A verdadeira prevalência de ITU em gestantes por bactérias multirresistentes é desconhecida. As ITUs por bactérias produtoras de ESBL variam entre 1% e 40%. O tratamento mais aceito para os casos mais graves (pielonefrite ou bacteremia) é com carbapenêmicos. A nitrofurantoína e a fosfomicina têm sido utilizadas para tratar a cistite com patógenos produtores de ESBL com sucesso.(AU)

Microorganisms that have resistance mechanisms to antimicrobial agents, such as production of ß-lactamase extended spectrum (ESBL), result in greater difficulty in treatment and require the use of broad spectrum antibiotics with increasing frequency. This study aims to review the literature on infections caused by multiresistant microorganisms in pregnancy. A search for articles was conducted in PubMed, MedLine and Lilacs are using key words, including published studies from 2000 to 2016, Portuguese and English, involving only human. 59 articles were selected on strength of evidence A and B. The criteria for inclusion was pregnant and having diagnosed of urinary tract infection. The criteria for exclusion was: use of antimicrobial less than two weeks before sample collection and suffering from immunosuppressive disease. The true prevalence of UTI in pregnant women by multiresistant bacteria is unknown. UTIs for ESBL-producing bacteria, ranging from 1% to 40%. The treatment more acceptable for the most serious cases (pyelonephritis or bacteremia) is with carbapenems. Nitrofurantoin and fosfomycin has been used to treat successfully with cystitis ESBL producers pathogens.(AU)

Neurological manifestations of dengue in Central Brazil.

INTRODUCTION:: The incidence of dengue has increased throughout the 2000s with a consequent global increase in atypical clinical forms. METHODS:: This study reports a series of cases of neurological dengue out of 498 confirmed cases of laboratory dengue in Goiânia, Brazil. Cases were confirmed based on viral RNA detection via polymerase chain reaction or IgM antibody capture. RESULTS:: Neurological symptoms occurred in 5.6% of cases, including paresthesia (3.8%), encephalitis (2%), encephalopathy (1%), seizure (0.8%), meningoencephalitis (0.4%), and paresis (0.4%). DENV-3 was the predominant circulating serotype (93%). CONCLUSIONS:: We reported dengue cases with neurological manifestations in endemic area.

Neurological manifestations of dengue in Central Brazil

Abstract INTRODUCTION: The incidence of dengue has increased throughout the 2000s with a consequent global increase in atypical clinical forms. METHODS: This study reports a series of cases of neurological dengue out of 498 confirmed cases of laboratory dengue in Goiânia, Brazil. Cases were confirmed based on viral RNA detection via polymerase chain reaction or IgM antibody capture. RESULTS: Neurological symptoms occurred in 5.6% of cases, including paresthesia (3.8%), encephalitis (2%), encephalopathy (1%), seizure (0.8%), meningoencephalitis (0.4%), and paresis (0.4%). DENV-3 was the predominant circulating serotype (93%). CONCLUSIONS: We reported dengue cases with neurological manifestations in endemic area.

Acinetobacter baumannii strains isolated from patients in intensive care units in Goiânia, Brazil: Molecular and drug susceptibility profiles.

Resistance to antimicrobial agents is increasing worldwide and imposes significant life-threatening risks to several different populations, especially those in intensive care units (ICUs). Bacteria can quickly develop or acquire resistance to antimicrobial drugs, and combined with their intrinsic potential to cause disease in humans, these bacteria can become deadly. Among Gram-negative bacteria, Acinetobacter baumannii is notorious as a frequent opportunistic pathogen associated with critically ill patients, and understanding the genetic basis of A. baumannii resistance to beta-lactams among patients in ICUs will result in better protocols to prevent the development of resistance as well as improved treatment regimens. In this study, we assessed 1333 patients in five ICUs, 56 of whom developed A. baumannii infections. Most of the A. baumannii isolates were resistant to beta-lactam antimicrobial drugs, specifically, 3rd- and 4th-generation cephalosporins and carbapenems, and 91.1% of the isolates were multi-drug resistant (MDR). The most frequent OXA gene present was OXA-23 (55.1%), which is significantly associated with MDR strains. Most of the A. baumannii isolates (76.8%) were capable of forming a biofilm. The antimicrobial drug classes that were effective against most of these isolates were polymyxins and tigecycline. The molecular profile of the isolates allowed detection of 12 different clusters comprising 2 to 8 isolates each. In conclusion, our data indicate a high incidence of resistance to carbapenems as well as MDR strains among the observed A. baumannii isolates, most of which exhibited a high prevalence of OXA-23 gene expression. Only a few selective drugs were effective, reinforcing the notion that bacterial resistance is an emerging problem that should be prioritized in every healthcare facility.

Staphylococcus aureus bacteremia in a Brazilian Midwest teaching hospital

Staphylococcus aureus bacteremia is a frequent and potentially fatal condition. Resistance to methicillin is considered to be a predictive factor for mortality. The purpose of this study was to evaluate the epidemiological behaviour of S. aureus bacteremia in a teaching hospital. The incidence was 5.1 cases per 1,000 admissions. There was a significant improvement in the susceptibility of S. aureus; the incidence of methicillin-resistant S. aureus (MRSA) was 31.3% (95% confidence interval (CI) 24.5-39.1); whereas MRSA bacteremia a decade before had accounted for 55.0% (95% CI 45.2-64.3) of the cases. Overall mortality due to S. aureus bacteremia was 29.3%. MRSA bacteremia was not a risk factor for death