The global spread of multi-resistant bacteria, particularly gram-negative bacteria, is a risk for patients. When this type of germ is detected in a hospital, the traditional strategy of “screening, isolation and eradication” usually takes effect. But does evidence prove that this method really is the most effective? A team of researchers asked themselves this question and came to astonishing conclusions.
Professor Sebastian W Lemmen, Head of the Central Department of Hospital Hygiene and Infectiology at University Hospital of RWTH Aachen, and Dr Karl Lewalter, also from RWTH Aachen, compared the traditional strategy for fighting resistant germs with an alternative strategy. The alternative is based on “antibiotic stewardship”– in other words, a strategy for the rational use of antibiotics – in combination with hygiene measures, in particular, correct hand hygiene. The researchers based their comparison on a series of studies that they evaluated and summarised. They published their results in the trade journal “Infection”.
According to the article, the traditional pathogen-specific screening system used by most clinics today has many limitations because the swab materials, frequency and detection methods, as well as screening groups, are not standardised. In addition, the effectiveness of isolation measures as such has not yet been proven. However, the disadvantages of single-room isolation for the successful outcome and the mental state of the patients are very well described. The eradication of multi-resistant pathogens is a major challenge and has not yet been sustainably successful in carriers of vancomycin-resistant enterococci (VRE) or multi-resistant gram-negative bacteria.
For multi-resistant bacteria, many guidelines recommend swab screenings with cotton swabs to identify asymptomatic carriers. Typical smear areas are nose, throat and groin, as well as the perineal area (perineum). However, no details are given in the guidelines, for example, which type of swabs should be used. There are many different materials, and these have a great influence on the detection rate. Furthermore, the optimal frequency of screening is controversial, as is the microbiological detection method itself – using normal culture, special culture media or molecular techniques – although these also have an influence on the detection rate. These shortcomings are known to professionals involved in the healthcare system, but the measures derived from them, such as isolation, are based exclusively on the results of screening under the respective conditions. Furthermore, experts disagree about which patient groups should be tested. The spectrum ranges from screening all patients to concentrating on specific risk groups. With a detection rate of only 1% – 2%, the cost-benefit ratio of the measure is also questionable.
Most guidelines recommend contact isolation measures, as well as isolation in single rooms, and the use of protective gowns and gloves as essential instruments for infection control. In view of the frequent deficits in the study design, it is unclear how useful these measures are. On the contrary, there is increasing evidence that the infection rate with multi-resistant germs does not rise after the isolation has ended. Medical care under isolation measures has disadvantages, which are repeatedly highlighted in studies: errors of treatment, unwanted incidents, as well as depressive, anxious and uncomfortable patients, are more common here than in non-isolated settings. In addition, staff compliance with hygiene measures for isolated patients is low.
Various eradication concepts have been investigated and published in the scientific literature. These include treatment with Mupirocin Nasal Ointment or the administration of various antibiotics. None of these measures reliably leads to sustained eradication of the pathogens. (2)
A current and systematic review that evaluated data of more than nine million patient days between 1960 and 2016 proves the effectiveness of a limited and targeted use of antibiotics on multi-resistant germs, the authors explain in their summary. Antibiotic stewardship has significantly reduced infections and colonisations with MRSA (methicillin-resistant staphylococci), multi-resistant gram-negative bacteria and Clostridium difficile by 37%, 51% and 32%, respectively. In combination with appropriate hygiene measures, the occurrence of multi-resistant germs has been reduced by up to 70%. Hand hygiene proved to be the most effective measure.
In their pioneering work at the Geneva University Hospital, researchers led by the Swiss physician Professor Didier Pittet were able to prove as early as 1997 that consistent hand hygiene reduces infection rates. Despite such evidence, however, compliance in many medical areas is still not optimal. In many subsequent studies, researchers have since investigated how compliance can be improved. These clearly show that this topic must be continuously addressed with the help of courses, during medical training, through motivational activities, process optimisation and availability of appropriate devices.
First of all, it is important to reduce the bacterial count: various studies have shown that washing with 2% chlorhexidine and, in certain cases, in combination with the nasal ointment Mupirocin, significantly reduces the transmission of MRSA and VRE (vancomycin-resistant enterococci), and also reduces the rate of blood stream infections (3). Additional screening and isolation measures have no further effect on the transmission rate of multi-resistant bacteria, according to a comparative study (4).
According to Lemmen and Lewalter, antibiotic stewardship in combination with antiseptic bathing and standard hygiene measures, in particular hand hygiene, significantly reduces the transmission rate of multi-resistant germs. According to the scientists, screening and isolation did not lead to any additional benefit. In practice, they say the above measures should be better implemented to reduce the problem of resistant germs.
Antibiotic stewardship and horizontal infection control are more effective than screening, isolation and eradication, Lemmen SW, Lewalter K, Infection
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, Saidel-Odes L et al., Infect Control Hosp Epidemiol.
Effect of daily chlorhexidine bathing on hospital-acquired infection., Climo MW et al., N Engl J Med.