Israel Medical Association Journal

Background: Skin colonization of microorganisms in blood cultures (BCs) are generally considered clinically non-significant and can be the source of a true infection, particularly in immunosuppressed patients.

Objectives: To study the epidemiology and risk factors for bacteremia caused by contaminants.

Methods: This retrospective, descriptive study is based on adult BCs collected (2004–2013) and categorized as positive (True bacteremia [TrueB] or contamination) or negative. Clinical, demographic, and laboratory characteristics of BCs positive for the six most common potential contaminant pathogens (PCPs) that can cause TrueB and contamination (Coagulase-negative Staphylococcus [CoNS], Streptococcus viridans, Propionibacterium acnes, Corynebacterium spp., Bacillus spp., Clostridium spp.) were assessed. Ninety-two TrueB were identified vs. 196 contaminations (1:2 ratio).

Results: From 74,014 BCs, PCPs were found in 3735 samples, of which 3643 (97.5%) were contaminations and 92 (2.5%) were TrueB. The overall rate of BC contamination decreased during the study period from 6.7% to 3.8%. CoNS was the most common PCP. Bacillus spp. were only contaminants. Clostridium spp. and Streptococcus viridans were more often TrueB. In a multivariate model, predictors of TrueB included high creatinine levels, Streptococcus viridans in BC, and multiple positive BCs. A single culture of CoNS was strongly predictive of contamination.

Conclusions: Ten years of data on BCs, focusing on six PCPs, demonstrates a significant, yet insufficient reduction in the rate of contamination. High creatinine level, isolation of Streptococcus viridans, and multiple positive BCs were predictors of TrueB, while growth of CoNS was strongly predictive of contamination. This model could assist in diagnostic and therapeutic decision making.

Background: Recent studies show that vaccination of health care workers (HCW) might reduce influenza transmission and mortality among hospitalized patients. No studies have compared the incidence of laboratory-proven influenza in vaccinated versus unvaccinated hospital HCW. 

Objectives: To evaluate the effectiveness of influenza vaccination among hospital HCW and to examine the attitudes of this population towards influenza vaccination.

Methods: We performed a prospective cohort study between 1 January and 30 April 2014 of 1641 HCW at our medical center; 733 were vaccinated and 908 not vaccinated. A random sample of 199 subjects was obtained: 97 vaccinated and 102 non-vaccinated. Participating individuals were contacted on a weekly basis during the flu season and were asked to report any respiratory or flu symptoms and, if positive, to undergo a polymerase chain reaction (PCR) test for influenza. 

Results: In the general HCW population, vaccination was more frequent among physicians 298/498 (58%) than among nurses (324/862 (38%) and among males than females. Flu symptoms were reported by 20 of 199 participants, 13 in the non-vaccinated group (12.7%) and 7 in the vaccinated group (7.2%). A positive PCR test for influenza A virus was present in 4 of 20 people tested (20%). All positive cases were from the non-vaccinated group (P = 0.0953). 

Conclusions: Non-vaccinated HCW showed a higher, although not statistically significant, tendency for contracting laboratory-proven influenza than the vaccinated population. The main reasons for vaccination and non-vaccination were personal beliefs and habits. Education efforts are needed to improve compliance. Larger studies could further clarify this issue.

 

Background: Due to increasing antimicrobial resistance, there has been renewed interest in old drugs that have fallen into disuse because of toxic side effects. One such drug is chloramphenicol. Data on the use and susceptibility patterns to chloramphenicol in developed countries in recent years are limited.

Objectives: To assess the susceptibility of bacteria to chloramphenicol, and evaluate the use of chloramphenicol in Israeli hospitals as influenced by infectious disease specialists’ attitudes with regard to its potential harms.

Methods: A national survey was conducted in all Israeli hospitals. Questionnaires were sent to the directors of infectious disease units and included items on chloramphenicol susceptibility in clinical isolates, use of chloramphenicol for the treatment of inpatients, local recommendations for use of chloramphenicol, and concerns regarding side effects.

Results: Chloramphenicol is used in 83.3% of hospitals, mostly for the treatment of aspiration pneumonia. While 22.2% of infectious disease unit directors believe that chloramphenicol should be avoided because of dangerous side effects, 88.9% believe there is a place for chloramphenicol in the treatment of patients in this era of increasing antibiotic resistance. Chloramphenicol susceptibility is routinely assessed in 44.4% of hospitals, with high susceptibility rates found among gram-positive, gram-negative and anaerobic bacteria.

Conclusions: In an era of increasing antibiotic resistance, many Israeli infectious disease unit directors believe that chloramphenicol has a role in the treatment of respiratory tract and other infections in hospitalized patients.

Background: Community-acquired pneumonia is a common infection and is associated with high rates of morbidity and mortality. Most patients with CAP[1] are treated empirically.

Objectives: To identify common pathogens causing CAP in hospitalized patients in northern Israel and to evaluate the correlation between etiology and disease severity.

Methods: We conducted a prospective study of patients with CAP hospitalized at HaEmek Medical Center, Afula. We collected demographic, clinical and laboratory data (blood and sputum cultures, serology, pneumococcal urinary antigen test, and respiratory multiplex-polymerase chain reaction from nasopharyngeal swab), and radiologic evaluation was performed.

Results: A total of 126 patients and 24 controls were enrolled. At least one pathogen was identified in 84 cases (66.7%), more than one in 43 patients (34.1%), and no pathogens in 42 (33.3%). Typical bacteria were found in 23 (18.3%), atypical bacteria in 66 (52.4%), and viruses in 42 (33.3%). The number (%) of patients with pathogens isolated was: Chlamydophila pneumoniae 26 (20.6%), Streptococcus pneumoniae 23 (18.3%), Mycoplasma pneumoniae 23 (18.3%), influenza virus A-B 20 (15.9%), Coxiella burnetti 8 (6.3%), and parainfluenza and adenovirus 13 (10.3%) each. A correlation was found only between a high PORT score on admission and S. pneumoniae, although atypical pathogens did not show class predominance.

Conclusions: S. pneumoniae, M. pneumoniae and C. pneumoniae were the most common pathogens isolated, while co-infection was very frequent. PORT score did not predict any of the pathogens involved. The choice of empiric antimicrobial treatment for CAP should be made according to local epidemiologic data.

Background: Due to increasing antimicrobial resistance there has been renewed interest in old drugs that have fallen into disuse because of toxic side effects.

Objectives: To evaluate the susceptibility profile, in our hospital, of Enterobacteriaceae and Streptococcus pneumoniae isolates to chloramphenicol and to compare them with the susceptibility to amoxicillin-clavulanate.

Methods: All isolates of Enterobacteriaceae and S. pneumoniae recovered in our lab during a one year period were tested for susceptibility to chloramphenicol and amoxicillin-clavulanate or penicillin, respectively.

Results: Of 413 Enterobacteriaceae isolates, 182 (44.1%) were resistant to amoxicillin-clavulanate, but only 76 (18.4%) were resistant to chloramphenicol. Of 189 isolates of S. pneumoniae, 4 (2.1%) were highly resistant to penicillin and 73 (38.8%) were partially resistant, while only 2 (1.1%) were resistant to chloramphenicol. None of the 24 S. pneumoniae isolates causing invasive diseases exhibited resistance to chloramphenicol.

Conclusions: In an era of increasing resistance to many antibiotic preparations, chloramphenicol might have a role in the treatment of intraabdominal and respiratory tract infections.

Background: Identification of pathogens and their susceptibility to antimicrobials is mandatory for successful empiric antibiotic treatment.

Objectives: To compare the clinical characteristics of patients with bacteremia, as well as the bacterial distribution and antimicrobial susceptibility in community, hospital and long-term care facilities during two periods (2001–2002 and 2005–2006).

Methods: The study was conducted at the HaEmek Medical Center, a community 500-bed teaching hospital in northern Israel serving a population of ~500,000 inhabitants. All episodes of bacteremia (n=1546) during two 2 year periods (2001–2 and 2005–6) were prospectively recorded, evaluated and compared (755 in 2001–2 and 791 in 2005–6).

Results: In both periods the urinary tract was the main port of entry in community and long-term care facility bacteremia, while the urinary tract – primary and catheter-related – were similar in frequency as sources of hospital bacteremia. Escherichia coli was the most frequent pathogen isolate. No significant changes in the frequency of methicillin-resistant Staphylococcus aureus and extended-spectrum beta-lactamase-producing bacteria were seen between the two 2 year periods (2001–2 and 2005–6). The susceptibility of non-ESBL[1]-producing E. coli decreased for some antibiotics while non-ESBL-producing Klebsiella pneumoniae susceptibility profile improved in the same period. A non-statistically significant trend of increased resistance in gram-negative isolates to quinolones, piperacillin and piperacillin-tazobactam was observed, but most isolates still remained highly susceptible to carbapenems. There was a small increase in mortality rate in hospital bacteremia during the second period.

Conclusions: Continuous surveillance is imperative for monitoring the local epidemiology and for developing local treatment guidelines.