Nosocomial bloodstream infections in a nationwide study: comparison between solid organ transplant patients and the general population.

BACKGROUND: The incidence of bloodstream infection (BSI) varies according to the transplanted organ. Mortality can be as high as 24%, with a significant impact on graft survival. Transplantation is a risk factor for multidrug-resistant (MDR) organisms, but comparison with a non-transplanted population in a single large cohort has not been described. METHODS: This is a prospective nationwide study (16 centers) reporting data on 2364 monomicrobial nosocomial BSIs, comparing 83 episodes in solid organ transplant patients with 2447 BSIs occurring in the general hospital population. RESULTS: The prevalence of groups of infecting organisms (gram-positive, gram-negative, and fungi) was similar between transplant patients and the general population and a similar crude mortality rate was observed (34.9% in transplant vs. 43.3% in non-transplant patients). Staphylococcus aureus was the single most frequently isolated organism in both groups, and Acinetobacter species was more frequently isolated in the general population. Regarding MDR organisms, Klebsiella species, and Enterobacter species resistant to cefepime, as well as Acinetobacter species resistant to meropenem, were significantly more frequent in transplant patients. CONCLUSION: Antimicrobial resistance is higher, particularly among gram-negative bacteria in the transplant population, although the overall mortality rate between transplant and non-transplant patients with nosocomial BSI is similar.

Health care-related infections in solid organ transplants.

The health care-related infections are well-known in a critical care setting, but reports of those infections in solid organ transplanted patients are scarce. We developed a study of retrospective cohort in a tertiary teaching hospital for 14 months. Eighty-one patients underwent solid organ transplants. The global incidence of health care-related infection was 42.0%. Fifteen percent of the cases were occurrences of surgical site infections, 14.0% pneumonias, 9.0% primary blood stream infections, 4.0% urinary tract infections and 2.0% skin infection. The most prevalent etiologic agents were K. pneumoniae (8.6%), P. aeruginosa (7.4%); A. baumannii (5.0%) and S. aureus (2.5%). Mortality was 18.0%, none of then related to health care infections. The high rate of those infections, mainly surgical site infections, suggests a demand for stricter measures to prevent and control health care-related infections.

A multicenter evaluation of tuberculin skin test positivity and conversion among health care workers in Brazilian hospitals.

SETTING: Four general Brazilian hospitals. OBJECTIVE: To assess the occupational risk of Mycobacterium tuberculosis (TB) in participating hospitals. DESIGN: In phase one of this longitudinal study, a cross-sectional survey documented baseline tuberculin skin test (TST) positivity rates. In phase two, TST conversion rates were evaluated in participants with an initial negative two-step TST. TST conversion data were analyzed to determine risk factors for TB infection using an increase of > or = 10 mm compared to baseline TST. RESULTS: The initial TST positivity rate was 63.1%; the follow-up TST conversion rate was 10.7 per 1000 person-months (p-m). Hospital of employment, recent bacille Calmette-Guerin (BCG) vaccination, nosocomial TB exposure, and employment as a nurse were independent risk factors for TST conversion. Hospitals without TB infection control measures had higher conversion rates than those with control measures (16.0 vs. 7.8/ 1000 p-m, P < 0.001). CONCLUSIONS: This study indicates an important occupational risk of infection in health care settings with a high TB incidence. Longitudinal TST studies are a valuable tool to assess the occupational risk of TB, even in BCG-vaccinated populations, and should be used to direct limited resources for infection control.

TST reversion in a BCG-revaccinated population of nursing and medical students, São Paulo, Brazil, 1997-2000.

SETTING: A major university in São Paulo, Brazil, where vaccination against tuberculosis (TB) with bacille Calmette-Guerin (BCG) was routinely offered to first-year medical and nursing students. OBJECTIVES: To estimate the probability of negative tuberculin skin test (TST) results over a 4-year period following BCG revaccination, and to evaluate the effect of factors associated with reversion. DESIGN: Students were enrolled in 1997, initially given a two-step TST, and were retested annually or biannually for the duration of the study. Data on TB exposures and potential risk factors for TST negativity and reversion were collected through annual surveys. A linear mixture survival model was used to estimate the probability of negative TST results over time. RESULTS: Of 159 students, an estimated 20% had a negative TST result despite revaccination, and a further 31% reverted to negative over 4 years of follow-up. No cofactors significantly affected the probability of reversion. CONCLUSION: Overall, in the absence of reported exposure to Mycobacterium tuberculosis, 51% of students revaccinated upon entering nursing or medical school would have a negative TST result by the time they begin their internships. In this recently vaccinated population, reversion was common, suggesting that annual TST screening may remain a useful tool.

Staphylococcus aureus bacteremia: what is the impact of oxacillin resistance on mortality?

In order to analyse the impact of oxacillin resistance on the mortality of Staphylococcus aureus bacteremia, and to assess the antimicrobial susceptibility of community-acquired strains in two large university hospitals (the Instituto do Coração do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo and the Instituto Central do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo), we carried out a four-month-long prospective cohort study, which included 163 consecutive cases of S. aureus bacteremia. Of these, 140 (85.9%) were hospital-acquired, 9 (5.5%) were community-acquired and 14 (8.6%) were of indeterminate origin. No cases of community-acquired infection by oxacillin-resistant S. aureus was identified. Among hospital-acquired infections, oxacillin-resistant S. aureus was responsible for 64.3% of cases. Mortality up to 15 days after diagnosis of bacteremia was 27% (18/67) for infections caused by susceptible strains and 33% (32/96) for infections caused by oxacillin-resistant strains (p=0.10). The following independent risk factors for the acquisition of oxacillin-resistant S. aureus were identified in multiple logistical regression analysis: age over 60 years, use of corticoids; presence of a central vascular catheter, and previous use of antibiotics.

Induction of interleukin-10 by HIV antigens in peripheral mononuclear cells of health care workers after occupational exposure to HIV-1-positive blood.

Evaluation of HIV-induced IL-2 production by peripheral blood mononuclear cells (PBMC) and HIV-specific T helper and cytotoxic T lymphocyte (CTL) responses in health care workers (HCW) occupationally exposed to HIV reveals a high rate of response to HIV among non-seroconverters. IL-10 is also known to interfere with HIV infection in vitro. To evaluate the induction of IL-10 by HIV antigens in HCW occupationally exposed to HIV, 18 HCW with percutaneous injury were enrolled in this study, 9 of them exposed to HIV-contaminated blood, and 9 exposed to HIV-negative blood. PBMC were incubated on plates coated with HIV-1 antigens, and IL-10 was measured in supernatants by ELISA. Five of nine HCW exposed to HIV-contaminated blood presented HIV-induced IL-10. Two of nine HCW exposed to HIV-negative source patients also had detectable levels of HIV-induced IL-10, one of them in the sample obtained on the day of accidental exposure. There was a relationship between the type of device involved in injury and IL-10 production. Individuals exposed to hollow needles or scalpels presented HIV-induced IL-10, whereas those exposed to solid needles and to digital puncture did not, suggesting a relationship between infectious load and IL-10. Although occupational exposure to HIV leads to a low rate of seroconversion, these individuals can develop an antigen-specific immune response characterized in our study by induction of IL-10 in PBMC in vitro.

Incidence and risk factors for surgical site infection after simultaneous pancreas-kidney transplantation.

A simultaneous pancreas-kidney transplantation (SPKT) is the best treatment option for type I diabetic patients with advanced chronic renal failure. Infectious complications affect 7-50% of the patients receiving this procedure. We conducted a nested case-control study to assess the risk factors for surgical site infection (SSI) in patients receiving SPKT at our centre between 2000 and 2006. Of the 119 evaluated transplant recipients, 55 (46.2%) developed SSIs and the 30 day mortality was 11.8%. Gram-negative organisms were the predominant organisms isolated from SSIs. After multivariate logistic regression, the variables independently associated with SSI were: acute tubular necrosis, post-transplant fistula and graft rejection. This study demonstrated a high incidence of SSI in this patient cohort and variables related to the surgical procedure were closely associated with the development of SSI.

Seven-year trend analysis of nosocomial candidemia and antifungal (fluconazole and caspofungin) use in Intensive Care Units at a Brazilian University Hospital.

Candidemia is associated with high morbidity and mortality resulting in significant increases in the length of patients' hospitalization and in healthcare costs. Critically ill patients are at particular risk for candidemia because of their debilitated condition and frequent need for invasive procedures. The aim of this study was to characterize the incidence and epidemiology of candidemia over a seven-year period in intensive care units (ICUs) and the use of fluconazole and caspofungin in a large university-affiliated hospital. All cases of candidemia were identified by surveillance, using the Centers for Diseases Control and Prevention criteria. Demographic variables, use of antifungal (fluconazole and caspofungin) and patient outcomes were evaluated. The chi2 test for linear trend was employed to evaluate the distribution of Candida spp. and the use of fluconazole and caspofungin by defined daily dose (DDD) per 1,000 patients-days during the study period. One hundred and eight episodes of candidemia were identified. The overall incidence of candidemia (P=0.20) and incidence of non-Candida albicans Candida infections (P=0.32) remained stable over the study period and ranged from 0.3-0.9 episodes per 1,000 catheter-days and 0.39-0.83 episodes per 1,000 patients-days. However, the use of fluconazole and caspofungin increased significantly (P<0.001). While there were no reports of the use of fluconazole for prophylaxis in 1999, its use for this purpose increased from 3% in 2000 to 7.0% (P=0.07) in 2006. C. albicans was the most frequent specie isolated and burns and cancer were the most frequent underlying conditions. The overall mortality was 76%. There was no difference between C. albicans and non-C. albicans Candida infections when the crude and 14-day mortality rates were compared. Our data demonstrated that C. albicans is still the most frequent species causing candidemia in our intensive care units. Our rates of candidemia are lower than those reported from the region and similar to American and European hospitals. Although the incidence of blood stream infections (BSI) and candidemia remained stable, the use of fluconazole and caspofungin increased significantly over the years included in this study but had no impact on the incidence of infections caused by non-C. albicans Candida species.

Immunophenotypic characterization of peripheral T lymphocytes in Mycobacterium tuberculosis infection and disease.

The cellular immune response probably plays a pivotal role in determining the clinical outcome after exposure to Mycobacterium tuberculosis. We used multi-parameter flow-cytometry to evaluate the distribution of T-lymphocyte subsets during infection and disease caused by M. tuberculosis. Samples were obtained from 71 volunteers to identify the T CD4+ and CD8+ lymphocyte numbers, and the activation plus memory/naïve phenotypes, as defined by CD38, HLA-DR, CD45RA and CD27 markers. Subjects were divided into 18 healthy volunteers without detectable reaction to purified protein derivative (PPD-), 18 health care workers with a recent conversion to PPD, 20 patients with active pulmonary tuberculosis (TBC) and 15 patients with treated TBC at 6 months of therapy. By multiple-comparison analyses, the T CD4+ lymphocyte number of the TBC group was lower than the PPD- group (P < 0.05). This difference was apparently lost after treatment. The higher and the lower number of naïve T CD4+ cells was observed in the PPD- and TBC group, respectively. CD8+ T lymphocytes were also statistically different among the four groups (P = 0.0002), lower in the TBC group (P < 0.05). CD8+ T lymphocyte activation was evaluated by the CD38 and HLA-DR surface expression. The percentage distribution of these markers was statistically different between the four groups (P = 0.0055). TBC patients had a higher percentage of CD38+ cells and mean fluorescence index, suggesting an overall increase of cell activation. These results suggest that peripheral T lymphocytes reflect cellular activation during TBC, along with possible redistribution of naïve, memory/effector and late differentiated memory/effector phenotypes in the peripheral blood after infection and disease caused by M. tuberculosis.

Health care-related infections in solid organ transplants

The health care-related infections are well-known in a critical care setting, but reports of those infections in solid organ transplanted patients are scarce. We developed a study of retrospective cohort in a tertiary teaching hospital for 14 months. Eighty-one patients underwent solid organ transplants. The global incidence of health care-related infection was 42.0 percent. Fifteen percent of the cases were occurrences of surgical site infections, 14.0 percent pneumonias, 9.0 percent primary blood stream infections, 4.0 percent urinary tract infections and 2.0 percent skin infection. The most prevalent etiologic agents were K. pneumoniae (8.6 percent), P. aeruginosa (7.4 percent); A. baumannii (5.0 percent) and S. aureus (2.5 percent). Mortality was 18.0 percent, none of then related to health care infections. The high rate of those infections, mainly surgical site infections, suggests a demand for stricter measures to prevent and control health care-related infections.

Staphylococcus aureus bacteremia: what is the impact of oxacillin resistance on mortality?

In order to analyse the impact of oxacillin resistance on the mortality of Staphylococcus aureus bacteremia, and to assess the antimicrobial susceptibility of community-acquired strains in two large university hospitals (the Instituto do Coração do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo and the Instituto Central do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo), we carried out a four-month-long prospective cohort study, which included 163 consecutive cases of S. aureus bacteremia. Of these, 140 (85.9 percent) were hospital-acquired, 9 (5.5 percent) were community-acquired and 14 (8.6 percent) were of indeterminate origin. No cases of community-acquired infection by oxacillin-resistant S. aureus was identified. Among hospital-acquired infections, oxacillin-resistant S. aureus was responsible for 64.3 percent of cases. Mortality up to 15 days after diagnosis of bacteremia was 27 percent (18/67) for infections caused by susceptible strains and 33 percent (32/96) for infections caused by oxacillin-resistant strains (p=0.10). The following independent risk factors for the acquisition of oxacillin-resistant S. aureus were identified in multiple logistical regression analysis: age over 60 years, use of corticoids; presence of a central vascular catheter, and previous use of antibiotics.

Tratamento de pneumonia em pacientes hospitalizados: resultado de um estudo clínico multicêntrico utilizando uma cefalosporina de quarta geraçäo (cefepima) / Treatment of pneumonia in hospitalized patients: results of a multicenter study using a fourth-generation cephalosporin (cefepime)

Objetivo. Avaliar a eficácia e a segurança do cefepima no tratamento de pneumonia grave em pacientes hospitalizados. Casuística e Métodos. Realizamos um estudo perspectivo, multicêntrico, nao comparativo envolvendo 148 pacientes (62 com pneumonia hospitalar, 34 com pneumonia comunitária e 52 formas indefinidas). A cefepina foi administrada por via intravenosa (1.000 a 2.000mg cada 12 horas), sendo que as doses também foram ajustadas para a funçao renal. A resposta clínica foi avaliada 48 horas após o término da terapêutica com cefepina. Resultados. A média de idade foi de 56,4 + 20,31 anos. As bactérias mais comuns isoladas nos pacientes com pneumonia hospitalar foram: 5 Pseudomonas aeruginosa (8,06 por cento); 7 Pseudomonas sp. (11.29 por cento); 6 Klebsiella sp. (9,68 por cento); 3 E. coli (4,84 por cento); 2 Acinetobacter baumannii (3,23 por cento); 3 Staphylococcus aureus (4,84 por cento); 3 Streptococcus pneumoniae (4,84 por cento); 5 outras (8,06 por cento). Os mais comuns isolados nos pacientes com pneumonia adquirida na comunidade foram: 2 Streptococcus pneumoniae (5,88 por cento); 1 S. aureus (2,94 por cento); 2 P. aureginosa (5,88 por cento) e 2 K. pneumoniae (5,88 por cento). A eficácia clínica foi observada em 137/148 dos casos (92,56 por cento) sendo que a resoluçao parcial foi obtida em 20,27 por cento e cura em 72,29 por cento. Falha de tratamento foi encontrado em 10 pacientes (6,75 por cento) e um caso foi avaliado. Eventos adversos foram observados em 5/148 pacientes (3,38 por cento). Conclusao. Nosso estudo sugere que o cefepina é seguro e efetivo no tratamento de pneumonia grave em pacientes hospitalizados.

Efeito da infecçäo hospitalar da corrente sanguínea por Staphylococcus aureus resistente à oxacilina sobre a letalidade e o tempo de hospitalizaçäo / The effect of bloodstream hospital infection by Staphylococcus aureus resistant to oxacillin on the mortality and the length of hospitalization

Objetivo. Determinar a letalidade atribuída à infecçao hospitalar da corrente sangüínea (IHCS) por Staphylococcus aureus resistente à oxacilina (SARO) e seu efeito sobre o tempo de hospitalizaçao. Casuística e Métodos. Estudo tipo caso controle envolvendo 71 pares de pacientes adultos internados em hospital de ensino no período de janeiro de 1991 a setembro de 1992, pareados para os seguintes critérios: idade, sexo, doença de base, procedimento cirúrgico, mesmo período de risco e data de admissao. Resultados. A incidência de pacientes com sepses hospitalar por SARO representou 73,22 por cento entre aqueles que desenvolveram bacteremia por Staphylococcus aureus. A taxa de letalidade dos casos foi de 56,33 por cento (40/71). Oito controles morreram, o que corresponde à taxa de letalidade de 11,26 por cento (8/71). A letalidade atribuída à infecçao hospitalar da corrente sangüínea por SARO foi de 45,07 por cento (OR=17,0; IC 95 por cento=3,58 - 202,26; p=0,000001). Os casos permaneceram, em média, 32,5 dias internados no hospital, enquanto que os controles 29,7 dias (p=0,32). Conclusoes. Observou-se elevada proporçao de sepses por SARO entre todas as bacteremias por Staphylococcus aureus. A IHCS por SARO acarreta, por si só, uma alta taxa de letalidade, independentemente da doença que causou a internaçao, sem contudo, aumentar o tempo de permanência hospitalar.

Induction of interleukin-10 by HIV antigens in peripheral mononuclear cells of health care workers after occupational exposure to HIV-1-positive blood

Evaluation of HIV-induced IL-2 production by peripheral blood mononuclear cells (PBMC) and HIV-specific T helper and cytotoxic T lymphocyte (CTL) responses in health care workers (HCW) occupationally exposed to HIV reveals a high rate of response to HIV among non-seroconverters. IL-10 is also known to interfere with HIV infection in vitro. To evaluate the induction of IL-10 by HIV antigens in HCW occupationally exposed to HIV, 18 HCW with percutaneous injury were enrolled in this study, 9 of them exposed to HIV-contaminated blood, and 9 exposed to HIV-negative blood. PBMC were incubated on plates coated with HIV-1 antigens, and IL-10 was measured in supernatants by ELISA. Five of nine HCW exposed to HIV-contaminated blood presented HIV-induced IL-10. Two of nine HCW exposed to HIV-negative source patients also had detectable levels of HIV-induced IL-10, one of them in the sample obtained on the day of accidental exposure. There was a relationship between the type of device involved in injury and IL-10 production. Individuals exposed to hollow needles or scalpels presented HIV-induced IL-10, whereas those exposed to solid needles and to digital puncture did not, suggesting a relationship between infectious load and IL-10. Although occupational exposure to HIV leads to a low rate of seroconversion, these individuals can develop an antigen-specific immune response characterized in our study by induction of IL-10 in PBMC in vitro

Infecçäo causada por Mycobacterium tuberculosis com resistência primária a múltiplas drogas: relato de caso em paciente com AIDS / Infection caused by Mycobacterium tuberculosis with primary resistance to multiple drugs: a case report of a patient with AIDS

Mycobacterium tuberculosis, primariamente resistente a múltiplas drogas, é problema de crescente importância nos Estados Unidos. No Brasil, näo existem relatos, pelo menos em literatura formal, de infecçäo por este patógeno. Relato de caso. Os autores relatam caso de paciente do sexo masculino que teve diagnóstico de tuberculose ganglionar cervical por meio de baciloscopia. Adicionalmente, anti-HIV feito por método ELISA resultou positivo. O paciente iniciou esquema terapêutico com isoniazida, rifampicina e pirazinamida. Segundo o paciente e seus familiares, os medicamentos foram administrados corretamente, mas näo foi observada melhora clínica. Após 75 dias de tratamento, o paciente foi internado no Hospital do Servidor Público Estadual de Säo Paulo com piora clínica caracterizada por aumento de gânglio submandibular, insuficiência respiratória e dor abdominal, vindo a falecer seis dias após a admissäo. Cultura do aspirado ganglionar, colhida no dia da internaçäo, mostrou crescimento de M. tuberculosis sensível ao etambutol e resistente à isoniazida, rifampicina, pirazinamida, etionamida e estreptomicina. Discussäo. O isolamento de M. tuberculosis multirresistente, mesmo que em paciente com forma extra-pulmonar da doença, traz à tona discussäo da necessidade da prevalência do patógeno em nosso meio mediante realizaçäo de cultura e antibiograma, e ressalta problemas inerentes à MTB-MDR, como a alta letalidade em pacientes com infecçäo clinicamente manifesta e a transmissäo intra-hospitalar, já demonstrada em outros países. É discutida a necessidade de cumprimento rigoroso das medidas de isolamento