P. J. van den Broek

Infection control measures to limit the spread of Clostridium difficile

Clostridium difficile-associated diarrhoea (CDAD) presents mainly as a nosocomial infection, usually after antimicrobial therapy. Many outbreaks have been attributed to C. difficile, some due to a new hyper-virulent strain that may cause more severe disease and a worse patient outcome. As a result of CDAD, large numbers of C. difficile spores may be excreted by affected patients. Spores then survive for months in the environment; they cannot be destroyed by standard alcohol-based hand disinfection, and persist despite usual environmental cleaning agents. All these factors increase the risk of C. difficile transmission. Once CDAD is diagnosed in a patient, immediate implementation of appropriate infection control measures is mandatory in order to prevent further spread within the hospital. The quality and quantity of antibiotic prescribing should be reviewed to minimise the selective pressure for CDAD. This article provides a review of the literature that can be used for evidence-based guidelines to limit the spread of C. difficile. These include early diagnosis of CDAD, surveillance of CDAD cases, education of staff, appropriate use of isolation precautions, hand hygiene, protective clothing, environmental cleaning and cleaning of medical equipment, good antibiotic stewardship, and specific measures during outbreaks. Existing local protocols and practices for the control of C. difficile should be carefully reviewed and modified if necessary.

Aetiology of community-acquired pneumonia: a prospective study among adults requiring admission to hospital.

BACKGROUND--The prevalence of microorganisms causing community-acquired pneumonia in patients who required admission to hospital was investigated and the percentage of cases whose aetiology remained unknown due to the study design and logistical problems estimated. METHODS--Between January 1991 and April 1993 all patients with community-acquired pneumonia admitted to six hospitals were included in the study. Aetiological diagnosis, categorised as definite, probable and possible, was based on the results of routine microbiological and serological tests. RESULTS--Three hundred and thirty four patients with a median age of 65 (range 17-92) years were enrolled in the study. The diagnosis of community-acquired pneumonia was definite in 108 cases, and probable or possible in 73 and 27 cases, respectively, including dual infections. Streptococcus pneumoniae was the predominant pathogen (27%) followed by viruses and Haemophilus influenzae (both about 8%) and Mycoplasma pneumoniae (6%). Chlamydia spp (3%) and Legionella pneumophila (2%) were less frequently detected. No diagnosis was made in 45% of the cases. With adjustment for anti-microbial therapy before admission and for other logistical considerations, it is estimated that the aetiology could have been ascertained in 65% of the cases. CONCLUSIONS--Streptococcus pneumoniae is the most frequently detected cause of community-acquired pneumonia. The inability to detect a micro-organism results mainly from the use of routine diagnostic tests and, to a lesser extent, from logistical problems or the use of antibiotics before admission.

Interaction of povidone-iodine compounds, phagocytic cells, and microorganisms.

The interaction between povidone-iodine, phagocytic cells, and microorganisms was studied. Three preparations of povidone-iodine were investigated: commercially available povidone-iodine solution Betadine, pure high-molecular-weight povidone-iodine as used in Betadine, and a low-molecular-weight povidone-iodine. Low concentrations of povidone-iodine (approximately 0.005%) have considerable activity in vitro. The concentrations used clinically (0.1 to 20%) are toxic for granulocytes and monocytes. Leukocytes reduce the in vitro microbicidal activity of povidone-iodine. No differences of any importance were found between the three preparations of povidone-iodine.

Persistent Acinetobacter baumannii? Look inside your medical equipment.

Two outbreaks of multidrug-resistant Acinetobacter baumannii occurred in our hospital. The outbreak strains were eventually isolated from respiratory ventilators, an apparatus used to cool or warm patients, and four continuous veno-venous hemofiltration machines. Removing dust from the machines and replacing all dust filters brought the outbreaks to an end.

Endemic and Epidemic Acinetobacter Species in a University Hospital: an 8-Year Survey

ABSTRACT The prevalence of the currently known Acinetobacter species and related trends of antimicrobial resistance in a Dutch university hospital were studied. Between 1999 and 2006, Acinetobacter isolates from clinical samples were collected prospectively. Isolates were analyzed by amplified fragment length polymorphism fingerprinting. For species identification, a profile similarity cutoff level of 50% was used, and for strain identification, a cutoff level of 90% was used. Susceptibility for antimicrobial agents was tested by disk diffusion by following the CLSI guideline. The incidences of Acinetobacter isolates ranged from 1.7 to 3.7 per 10,000 patients per year, without a trend of increase, during the study years. Twenty different species were distinguished. Acinetobacter baumannii (27%) and Acinetobacter genomic species (gen. sp.) 3 (26%) were the most prevalent. Other species seen relatively frequently were Acinetobacter lwoffii (11%), Acinetobacter ursingii (4%), Acinetobacter johnsonii (4%), and Acinetobacter junii (3%). One large cluster of A. baumannii, involving 31 patients, and 16 smaller clusters of various species, involving in total 39 patients, with at most 5 patients in 1 cluster, occurred. Overall, 37% of the A. baumannii isolates were fully susceptible to the tested antibiotics. There was a borderline significant (P = 0.059) trend of decreasing susceptibility. A. baumannii was the Acinetobacter species causing the largest burden of multiple-antibiotic resistance and transmissions in the hospital.

Implementation of an Educational Program and an Antibiotic Order Form to Optimize Quality of Antimicrobial Drug Use in a Department of Internal Medicine

In a study designed to evaluate the effects of an educational program and an antibiotic order form on the quality of antimicrobial drug use, a prospective analysis was conducted in the department of internal medicine of a 948-bed university hospital. Following a quality-of-use review of all consecutive courses of antimicrobial drugs prescribed during four weeks, an educational program was conducted and an antibiotic order form introduced. After four years, an identical review was performed. In the first review, 109 (31%) of 347 patients were prescribed antimicrobial drugs. Only 40% of the prescriptions were considered definitely appropriate, and 13% were considered unjustified. There was a certain degree of underutilization, and only 67% of clinical isolates were susceptible to empirical therapy. In the review performed after intervention, 164 (21%) of 796 patients were given antimicrobial drugs. Defined daily doses per 100 bed days increased from 59.8 to 72.6. Fifty-three percent of the prescriptions were judged optimal, and only 9% were judged unjustified. Ninety percent of the clinical isolates were susceptible to empirical therapy. After one year, compliance with the antibiotic order forms on a voluntary basis reached 77%, documenting 86% of antimicrobial drug costs. As a result, the antibiotic order form will be useful for surveillance, if logistic support is provided by the pharmacy. The combination of several measures leads to improved quality of use. As correctly predicted by the first evaluation, improvement in quality resulted in increased drug consumption by fewer patients and a higher cost per bed day.

Efficacy and safety of azithromycin versus benzylpenicillin or erythromycin in community-acquired pneumonia

Azithromycin, a recently introduced antibiotic, offers the potential advantages of short-course administration and lower toxicity compared to other macrolides. Approved for the treatment of mild pneumonia, this drug was investigated in a study of patients hospitalized for community-acquired pneumonia. In an open-labelled randomized study, oral azithromycin was compared with intravenous benzylpenicillin in patients suspected to have pneumonococcal pneumonia. Azithromycin was also compared with erythromycin, both administered orally, in all other patients. Three hundred thirty-four patients with community-acquired pneumonia were hospitalized, 108 of whom were randomized; 104 could be evaluated. A need for intravenous therapy was the most common reason for exclusion. In the pneumococcal group, 35 patients received azithromycin and 29 benzylpenicillin. The clinical and radiological success rate achieved with azithromycin (83 %) was considerably higher than that achieved with benzylpenicillin (66 %), though the difference was not significant. In the non-pneumococcal group, 19 patients received azithromycin and 21 erythromycin; no differences in the success rate were found (79 % and 76 %, respectively). Eight patients on azithromycin had a blood culture positive forStreptococcus pneumoniae; in three of these patients therapy was changed. None of the five patients with pneumococcal bacteraemia who received benzylpenicillin required a change in therapy. It is concluded that oral azithromycin, administered as short-course therapy, is an appropriate antibiotic for treating patients with community-acquired pneumonia. However, it is not yet certain that azithromycin is a good choice for patients with pneumococcal bacteraemia.

Erysipelas-like skin lesions associated with Campylobacter jejuni septicemia in patients with hypogammaglobulinemia

Three cases are reported of hypogammaglobulinemic males with recurrentCampylobacter jejuni septicemia and erysipelas-like cellulitis without diarrhoea. In one patientCampylobacter jejuni grew from skin biopsy specimens. The findings in another patient were strongly suggestive of osteomyelitis caused byCampylobacter jejuni. Since the susceptibility of hypogammaglobulinemic patients to infection withCampylobacter jejuni is probably related to a lack of serum bactericidal activity againstCampylobacter jejuni due to lack of IgM, two patients in whom previous antimicrobial treatment failed were treated with plasma infusions. This regimen supplemented with imipenem resulted in cure of these relapsing infections.Campylobacter jejuni septicemia must be considered in hypogammaglobulinemic patients who present with periodic fever and cellulitis.

Non-gonococcal infectious arthritis: A retrospective study

In a retrospective study the outcome of non-gonococcal infectious arthritis was evaluated in 76 adult patients admitted to the Leiden University Hospital between 1970 and 1984. The mortality rate was 12%, and complete recovery was achieved in only 19 of the 76 patients (25%). Each of the following had a significantly unfavourable influence on the residual joint function: duration of infection more than 14 days, female sex, presence of rheumatoid arthritis, and presence of a joint prosthesis.

Antistaphylococcal activities of teicoplanin and vancomycin in vitro and in an experimental infection.

The efficacies of vancomycin and teicoplanin in an experimental Staphylococcus aureus infection in granulocytopenic mice were related to their activities in vitro and their pharmacokinetic profiles. In vitro teicoplanin had a higher intrinsic activity than vancomycin did; and it also had a more favorable pharmacokinetic profile, resulting in higher peak concentrations in plasma, a longer elimination half-life, and a larger area under the concentration-time curve than those of vancomycin. To predict the antibacterial efficacies of the drugs in vivo on the basis of their activities in vitro and pharmacokinetics, a mathematical model was applied. In the model the in vitro effect was expressed as the difference in growth rate between control cultures and those in the presence of the antibiotic (ER), and the in vivo effect was expressed as the difference between numbers of CFU in control and antibiotic-treated animals (EN). The integral of ER against time, ERt, was calculated by using the concentrations found in vivo. A significant linear relationship was found between EN and ERt for different dosages at the same times (4 h) after drug administration as well as for the same doses at consecutive times, although at the lowest doses of teicoplanin the observed effect was less than the predicted effect.