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.