Quantifying the transmission dynamics of MRSA in the community and healthcare settings in a low-prevalence country

Abstract

Methicillin-resistant Staphylococcus aureus (MRSA) is a primarily nosocomial pathogen that, in recent years, has increasingly spread to the general population. The rising prevalence of MRSA in the community implies more frequent introductions in healthcare settings that could jeopardize the effectiveness of infection-control procedures. To investigate the epidemiological dynamics of MRSA in a low-prevalence country, we developed an individual-based model (IBM) reproducing the population’s sociodemography, explicitly representing households, hospitals, and nursing homes. The model was calibrated to surveillance data from the Norwegian national registry (2008–2015) and to published household prevalence data. We estimated an effective reproductive number of 0.68 (95% CI 0.47–0.90), suggesting that the observed rise in MRSA infections is not due to an ongoing epidemic but driven by more frequent acquisitions abroad. As a result of MRSA importations, an almost twofold increase in the prevalence of carriage was estimated over the study period, in 2015 reaching a value of 0.37% (0.25–0.54%) in the community and 1.11% (0.79–1.59%) in hospitalized patients. Household transmission accounted for half of new MRSA acquisitions, indicating this setting as a potential target for preventive strategies. However, nosocomial acquisition was still the primary source of symptomatic disease, which reinforces the importance of hospital-based transmission control. Although our results indicate little reason for concern about MRSA transmission in low-prevalence settings in the immediate future, the increases in importation and global circulation highlight the need for coordinated initiatives to reduce the spread of antibiotic resistance worldwide.

Rapid nanopore-based DNA sequencing protocol of antibiotic-resistant bacteria for use in surveillance and outbreak investigation

“…Recent surveillance data from European countries show a general trend towards increasing methicillin-resistant S. aureus (MRSA) prevalence from the north to the south of the continent [13,14]. In Norway, a country with low prevalence of MRSA, recent publications have reported that global circulation and import of cases from abroad are related to the increasing rate of MRSA infections [15,16]. Due to the low diversity among some MRSA isolates belonging to the same clone, methods such as multilocus sequencing typing (MLST), multiple locus variable-number tandem repeat analysis (MLVA), pulsed-field gel electrophoresis (PFGE and S. aureus Protein A (spa) typing cannot discriminate all epidemiologically linked cases in certain settings.…”

Insight on the Structure-to-Activity of Carbosilane Metallodendrimers in the Fight against Staphylococcus aureus Biofilms

“…We herein demonstrated that carbosilane metallodendrimers are a promising tool in the fight against Gram-positive bacteria, which cause important nosocomial infections in hospital facilities [ 2 ]. The presence of a thick peptidoglycan layer in these bacteria hampers the effective treatment and other dendrimers, such as PAMAM, reported difficulties to disrupt the crosslinked peptidoglycan layer [ 25 ].…”

“…S. aureus belongs to the Staphylococcaceae family and appears in coconut shape with 0.5 to 1.5 microns diameter, arranged in pairs, clusters or chains [ 1 ]. The widespread dissemination of this microorganism, together with its virulence and antibiotic resistance, produces an important impact on morbidity at community and intra-hospital levels [ 2 ]. This partly arises from its ability to adhere to the surface of permanent medical devices and develop biofilms [ 3 ].…”

Changing epidemiology of methicillin-resistant Staphylococcus aureus in a low endemicity area—new challenges for MRSA control

“…A high risk of MRSA transmission between household members has been noted earlier [ 24 , 25 ]. In a recent Norwegian study, it was estimated that up to 49% of new MRSA colonisation events were among household contacts of MRSA carriers [ 26 ]. Our results as well as findings from other low-prevalence countries support the policy of targeted screening of household members of MRSA carriers prior to or at hospital admission.…”