How to Prevent the Spread of Multiple-Resistant Gram-Negative Bacteria in the Hospital Setting

Abstract

Infections caused by multi-resistant Gram-negative bacteria are thought to cause increased morbidity, longer length of hospital stay, and higher treatment costs when compared to infections caused by susceptible strains. Successful control of healthcare-associated, multi-resistant Gram-negative bacteria bacteria is relying on several complementary control strategies. Clearly, there is no level of antibiotic resistance where control measures are not warranted any more. First, early detection of resistance carriage may allow rapid contact isolation of identified carriers and improve the adequacy of antibiotic prophylaxis and treatment, especially in critically ill patients. Several recent outbreak reports have shown the importance of surveillance and screening cultures in order to prevent transmission and infection by multi-resistant Gram-negative bacteria in the critical care setting. Although the most efficient screening strategy depends on the local situation and type of resistance and is therefore still a matter of debate, most affected acute care hospitals should install a screening policy for patient groups at high risk of carriage of pan-resistant Acinetobacter spp or carbapenem-resistant Klebsiella spp (e.g. roommates of newly identified carriers) and apply specific preventive measures (contact isolation) applied to identified carriers, especially in the critical care setting. Second, eradicating carriage of multi-resistant bacteria may reduce the rates of infection. However, no controlled studies are available indicating that this approach may work. Third, strict compliance with standard precautions and hand hygiene could prevent most cases of cross-transmission, even without the need for recognition of individual carriers of resistant microorganisms. Unfortunately, many studies have shown that compliance of healthcare workers with hand hygiene recommendations remains low. Implementing alcohol-based hand rinses can improve compliance and decrease cross-infection. Finally, antibiotic selection pressure contributes to the increase in prevalence of multi-resistant Gram-negative bacteria. Data from several recently published studies suggest that restriction of certain classes of antibiotics may decrease rates of multi-resistant Gram-negative bacteria in the hospital setting. Other well-designed investigations are needed to confirm that reduction in antimicrobial overuse has a favorable effect on infection rates caused by multi-resistant Gram-negative bacteria.