Klaris Riesenberg

Attributable Mortality Rate for Carbapenem-Resistant Klebsiella pneumoniae Bacteremia

OBJECTIVE To determine the attributable (direct) mortality and morbidity caused by carbapenem-resistant Klebsiella pneumoniae bacteremia. DESIGN A matched retrospective, historical cohort design, using a stepwise procedure to stringently match the best control subjects to the best case subjects. SETTING A 1,000-bed tertiary-care university teaching hospital. PATIENTS Case subjects were defined as adult patients with carbapenem-resistant K. pneumoniae bacteremia during the period from October 2005 through October 2008. Control subjects were defined as patients who were very similar to case subjects except that they did not have bacteremia. METHODS Matching potential control subjects to case subjects was performed at a 1:1 ratio using a computerized record system. The criteria used included same hospitalization period, similar Charlson comorbidity index, same underlying disease, same age within 10 years, and same sex. Demographic and clinical characteristics were collected from medical records. RESULTS During the study period, 319 patients developed an infection due to carbapenem-resistant K. pneumoniae. Of these 319 patients, 39 (12.2%) developed a bloodstream infection, for an overall rate of 0.59 episodes of carbapenem-resistant K. pneumoniae bacteremia per 10,000 patient-days. We excluded 7 patients from our study, leaving a total of 32 case subjects in our cohort. Case subjects were significantly more likely than control subjects (n = 32) to require care in an intensive care unit (12 case subjects [37.5%] vs 3 control subjects [9.4%]), ventilator support (17 case subjects [53.1%] vs 8 control subjects [25%]), and use of a central venous catheter (19 case subjects [59.4%] vs 9 control subjects [28.1%]). For case subjects, the crude mortality rate was 71.9% (ie, 23 of the 32 case subjects died); for control subjects, the crude mortality rate was 21.9% (ie, 7 of the 32 control subjects died) (P < .001. For case subjects, the attributable mortality was 50% (95% confidence interval [CI], 15.3%-98.6%). A mortality risk ratio of 3.3 (95% CI, 2.9-28.5) was found for case subjects with carbapenem-resistant K. pneumoniae bacteremia. CONCLUSIONS Patients with carbapenem-resistant K. pneumoniae require more intensive and invasive care. We have shown that the crude and attributable mortality rates associated with carbapenem-resistant K. pneumoniae bacteremia were striking.

Nosocomial multi-drug resistant Acinetobacter baumannii bloodstream infection: risk factors and outcome with ampicillin-sulbactam treatment

The emergence of multidrug-resistant (MDR) Acinetobacter baumannii poses a therapeutic problem. The aim of this study was to assess the risk factors for nosocomial MDR-A. baumannii bloodstream infection (BSI) and the efficacy of ampicillin-sulbactam (A/S) in its treatment. Of 94 nosocomial A. baumannii BSI during the year 2000, 54% involved MDR strains, 81% of which were genetically related. Various risk factors for MDR-A. baumannii were found, of which intensive-care unit admission and prior aminoglycoside therapy were independently associated with MDR-A. baumannii acquisition on multivariate analysis. Of MDR-A. baumannii BSI cases, 65% received A/S and 35% inadequate antibiotic therapy, whereas of 43 non-MDR cases, 86% were treated according to susceptibility and 14% inappropriately with antibiotics to which these organisms were resistant. Crude mortality was comparable in the adequately treated groups. Respective mortalities among patients treated adequately and inadequately were 41.4 and 91.7% (p<0.001). Among severely ill patients, A/S therapy significantly decreased the risk of death (P=0.02 OR=7.64). MDR-A. baumannii has become highly endemic in our institution. A/S appears to be one of the last effective and safe empirical resorts for treatment of MDR A. baumannii BSI.

A Randomized, Double-Blind, Placebo-Controlled Trial of Selective Digestive Decontamination Using Oral Gentamicin and Oral Polymyxin E for Eradication of Carbapenem-Resistant Klebsiella pneumoniae Carriage

OBJECTIVE To assess the effectiveness of selective digestive decontamination (SDD) for eradicating carbapenem-resistant Klebsiella pneumoniae (CRKP) oropharyngeal and gastrointestinal carriage. DESIGN A randomized, double-blind, placebo-controlled trial with 7 weeks of follow-up per patient. SETTING A 1,000-bed tertiary-care university hospital. PATIENTS Adults with CRKP-positive rectal swab cultures. METHODS Patients were blindly randomized (1 :1) over a 20-month period. The SDD arm received oral gentamicin and polymyxin E gel (0.5 g 4 times per day) and oral solutions of gentamicin (80 mg 4 times per day) and polymyxin E (1 x 10(6) units 4 times per day for 7 days). The placebo arm received oral placebo gel 4 times per day and 2 placebo oral solutions 4 times per day for 7 days. Strict contact precautions were applied. Samples obtained from the throat, groin, and urine were also cultured. RESULTS Forty patients (mean age ± standard deviation, 71 ± 16 years; 65% male) were included. At screening, greater than or equal to 30% of oropharyngeal, greater than or equal to 60% of skin, and greater than or equal to 35% of urine cultures yielded CRKP isolates. All throat cultures became negative in the SDD arm after 3 days (P < .0001). The percentages of rectal cultures that were positive for CRKP were significantly reduced at 2 weeks. At that time, 16.1% of rectal cultures in the placebo arm and 61.1% in the SDD arm were negative (odds ratio, 0.13; 95% confidence interval, 0.02-0.74; P < .0016). A difference between the percentages in the 2 arms was still maintained at 6 weeks (33.3% vs 58.5%). Groin colonization prevalence did not change in either arm, and the prevalence of urine colonization increased in the placebo arm. CONCLUSIONS This SDD regimen could be a suitable decolonization therapy for selected patients colonized with CRKP, such as transplant recipients or immunocompromised patients pending chemotherapy and patients who require major intestinal or oropharyngeal surgery. Moreover, in outbreaks caused by CRKP infections that are uncontrolled by routine infection control measures, SDD could provide additional infection containment.

Risk factors for developing clinical infection with carbapenem-resistant Klebsiella pneumoniae in hospital patients initially only colonized with carbapenem-resistant K pneumoniae.

BACKGROUND This study examined predictors of carbapenem-resistant Klebsiella pneumoniae (CRKP) colonization and risk factors for the development of CRKP infection in patients initially only colonized with CRKP. METHODS A total of 464 patients with CRKP rectal colonization (CRKP-RC) were identified. Two case-control studies were performed, one comparing risk factors for CRKP-RC in patients who did not develop CRKP infection (CRKP-IN) versus patients without CRKP-RC and CRKP-IN, and the other comparing CRKP-RC patients who did not develop CRKP-IN with those who did. RESULTS Forty-two of the 464 colonized patients developed CRKP-IN. Multivariate analysis identified the following predictors for CRKP-RC: antibiotic therapy (odds ratio [OR], 5.76; P ≤ .0001), aminopenicillin therapy (OR, 7.753; P = .004), bedridden (OR, 3.09; P = .021), and nursing home residency (OR, 3.09; P = .013). Risk factors for CRKP-IN in initially CRKP-RC-positive patients were previous invasive procedure (OR, 5.737; P = .021), diabetes mellitus (OR, 4.362; P = .017), solid tumor (OR, 3.422; P = .025), tracheostomy (OR, 4.978; P = .042), urinary catheter insertion (OR, 4.696; P = .037), and antipseudomonal penicillin (OR, 23.09; P ≤ .0001). CONCLUSIONS We suggest that in patients with CRKP-RC, a strategy for preventing CRKP-IN might include limiting antipseudomonal penicillin and carbapenem use and preventing infections by closely following compliance with infection control bundles.

Assessment, Diagnosis, and Treatment of HIV-Associated Neurocognitive Disorder: A Consensus Report of the Mind Exchange Program

Many practical clinical questions regarding the management of human immunodeficiency virus (HIV)-associated neurocognitive disorder (HAND) remain unanswered. We sought to identify and develop practical answers to key clinical questions in HAND management. Sixty-six specialists from 30 countries provided input into the program, which was overseen by a steering committee. Fourteen questions were rated as being of greatest clinical importance. Answers were drafted by an expert group based on a comprehensive literature review. Sixty-three experts convened to determine consensus and level of evidence for the answers. Consensus was reached on all answers. For instance, good practice suggests that all HIV patients should be screened for HAND early in disease using standardized tools. Follow-up frequency depends on whether HAND is already present or whether clinical data suggest risk for developing HAND. Worsening neurocognitive impairment may trigger consideration of antiretroviral modification when other causes have been excluded. The Mind Exchange program provides practical guidance in the diagnosis, monitoring, and treatment of HAND.

Syphilis and HIV co-infection.

Syphilis is a complex disease, which is sexually transmitted. The incidence of syphilis is rising all over the world, partly due to the increased transmission in HIV patients and other high risk groups such as men who have sex with men. Interestingly syphilis itself facilitates HIV infection in several ways. Great importance exists in recognition of both diseases and their complex interactions. This article will review the manifestations of syphilis in the context of HIV infected patients, and the challenging diagnosis and management of these patients.

Clinical significance and impact on mortality of extended-spectrum beta lactamase-producing Enterobacteriaceae isolates in nosocomial bacteremia.

During an 8-month period, 55 episodes of nosocomial bacteremia caused by Enterobacteriaceae species were identified in a tertiary medical center, of which 26 (47%) were caused by extended-spectrum beta lactamase (ESBL)-producing organisms. ESBL production was associated with resistance to aminoglycosides, fluoroquinolones, tetracycline and co-trimoxazole compared with non-ESBL-producing organisms (p < 0.01). By multivariate analysis, infection with ESBL-producing organisms was associated with previous antibiotic therapy and central venous catheter insertion and mortality was associated with heart failure, malignancy and a prolonged hospital stay. Nineteen (73%) patients infected with ESBL-producing organisms received adequate empirical antibiotic therapy and all 26 received adequate definitive therapy. The in-hospital mortality rate did not differ between patients infected with ESBL producers and those infected by non-ESBL-producing Enterobacteriaceae species [13/26 (50%) and 11/29 (38%), respectively] (p > 0.5).During an 8-month period, 55 episodes of nosocomial bacteremia caused by Enterobacteriaceae species were identified in a tertiary medical center, of which 26 (47%) were caused by extended-spectrum beta lactamase (ESBL)-producing organisms. ESBL production was associated with resistance to aminoglycosides, fluoroquinolones, tetracycline and co-trimoxazole compared with non-ESBL-producing organisms (p < 0.01). By multivariate analysis, infection with ESBL-producing organisms was associated with previous antibiotic therapy and central venous catheter insertion and mortality was associated with heart failure, malignancy and a prolonged hospital stay. Nineteen (73%) patients infected with ESBL-producing organisms received adequate empirical antibiotic therapy and all 26 received adequate definitive therapy. The in-hospital mortality rate did not differ between patients infected with ESBL producers and those infected by non-ESBL-producing Enterobacteriaceae species [13/26 (50%) and 11/29 (38%), respectively] (p > 0.5).

Community-Acquired Methicillin-Resistant Staphylococcus aureus in Institutionalized Adults with Developmental Disabilities

Methicillin-resistant Staphylococcus aureus (MRSA) has recently been reported to emerge in the community setting. We describe the investigation and control of a community-acquired outbreak of MRSA skin infections in a closed community of institutionalized adults with developmental disabilities. In a 9-month period in 1997, 20 (71%) of 28 residents had 73 infectious episodes. Of the cultures, 60% and 32% obtained from residents and personnel, respectively, grew S. aureus; 96% and 27% were MRSA. All isolates were genetically related by pulsed-field gel electrophoresis and belonged to a phage type not previously described in the region. No known risk factors for MRSA acquisition were found. However, 58 antibiotic courses had been administered to 16 residents during the preceding 9 months. Infection control measures, antibiotic restriction, and appropriate therapy resulted in successful termination of this outbreak. Selective antibiotic pressure may result in the emergence, persistence, and dissemination of MRSA strains, causing prolonged disease.

Exposure of Hospital Personnel to Brucella melitensis and Occurrence of Laboratory-acquired Disease in an Endemic Area

In 1997, 7 cases of laboratory-acquired Brucella melitensis infections were detected among the hospital personnel of a medical centre serving an endemic area in southern Israel. Although the onset of symptoms in 6 of the 7 patients occurred during a 2-week period, suggesting a point source exposure, biotype analysis showed that the outbreak was caused by 3 different B. melitensis serovars, indicating multiple exposures. Review of the laboratory records showed that during 1997, the microorganism was recovered from 146 blood and synovial fluid cultures, and that during the 2 months in which the laboratory-acquired cases occurred (April and June), 53 of 530 positive aerobic blood culture bottles (10.0%) grew B. melitensis. The epidemiological investigation did not reveal the source of the outbreak, and no noticeable breaches in laboratory safety practices could be demonstrated. It is concluded that in areas endemic for brucellosis, hospital personnel are frequently exposed to Brucella microorganisms. Under these circumstances, significant morbidity may occur despite observance of recommended safety practices. Biotyping of Brucella isolates may contribute to the elucidation of complex epidemiological situations.In 1997, 7 cases of laboratory-acquired Brucella melitensis infections were detected among the hospital personnel of a medical centre serving an endemic area in southern Israel. Although the onset of symptoms in 6 of the 7 patients occurred during a 2-week period, suggesting a point source exposure, biotype analysis showed that the outbreak was caused by 3 different B. melitensis serovars, indicating multiple exposures. Review of the laboratory records showed that during 1997, the microorganism was recovered from 146 blood and synovial fluid cultures, and that during the 2 months in which the laboratory-acquired cases occurred (April and June), 53 of 530 positive aerobic blood culture bottles (10.0%) grew B. melitensis. The epidemiological investigation did not reveal the source of the outbreak, and no noticeable breaches in laboratory safety practices could be demonstrated. It is concluded that in areas endemic for brucellosis, hospital personnel are frequently exposed to Brucella microorganisms. Under these circumstances, significant morbidity may occur despite observance of recommended safety practices. Biotyping of Brucella isolates may contribute to the elucidation of complex epidemiological situations.

The Many Faces of Human-to-Human Transmission of Brucellosis: Congenital Infection and Outbreak of Nosocomial Disease Related to an Unrecognized Clinical Case

BACKGROUND Because person-to-person transmission of brucellosis is exceptional, physicians who care for patients with this disease are not considered to be at increased risk. A woman in her 24th week of pregnancy who had received a diagnosis of placenta previa presented to the hospital with massive vaginal bleeding and hypovolemic shock, requiring performance of an emergency Cesarean delivery. Two physicians who assisted the surgical delivery developed culture-proven Brucella melitensis infection. The organism was also recovered from cultures of blood samples obtained from the mother and the premature newborn. The mother had been observed since early pregnancy because of an undiagnosed febrile hepatitis, but no specific tests for brucellosis had been performed. Retrospective testing of serum samples obtained at the onset of disease were positive for Brucella antibodies, indicating that the disease could have been diagnosed earlier. METHODS Hospital records of the obstetric, intensive care, and surgical departments were examined to identify all staff members who took care of the mother and her offspring. The identified personnel were interrogated about exposure to potentially infective blood and fomites and were screened by blood cultures and serologic tests for Brucella species. RESULTS An additional physician who assisted in the resuscitation of the newborn had a blood culture positive for B. melitensis and a positive result of a diagnostic serological test. Ninety-five other members of the hospital staff, who were potentially exposed to the organism, were found to be uninfected. CONCLUSIONS Although rare, transmission of B. melitensis from patients to medical personnel may occur. Strict adherence to universal precautions, especially during performance of medical procedures characterized by massive blood exposure, should be reinforced.