Mountain View
biomedical and healthCAre Data Discovery Index Ecosystem
help Advanced Search
Title: MRSA and deprivavtion study : Evidence For Community-Based Transmission Of Community-Associated But Not Health-Care-Associated-MRSA Lineages Linked To Social And Material Deprivation      
Background Community-associated- (CA-) MRSA strains have emerged as a cause of hospital infection in some parts of the world challenging definitions of health-care-associated- (HA-) - and CA-MRSA based on where the disease manifests. The overall burden of MRSA in Europe is declining due to decline of HA-MRSA lineages, but CA-MRSA continues to emerge worldwide and is predicted to displace HA-MRSA in hospitals. CA-MRSA has long been associated to socio-economic deprivation in America and Oceania. Meanwhile, in Europe, addressing the social determinants of infectious diseases has become a Public Health priority following recognition that individuals with lower socio-economic status are disproportionately affected by infections in every European Union Member State. Our understanding of the current epidemiology of MRSA is blurring, but spatial models can shed light to present transmission dynamics. Here, we apply these models and adjust for area-level hospital attendance to identify what the current transmission niches of genotypic CA- and HA-MRSA are in the UK and to address the significance of social determinants. Methods and Findings All MRSA isolates identified over four months at three NHS hospital microbiology laboratories serving three boroughs of South East London were analysed. Isolates were classified as HA- or CA-MRSA based on whole genome sequencing. MRSA cases were mapped to small geographies and linked to area-level aggregated socio-economic and demographic data. Ecological regression models adjusted by area-level hospital attendance were used to describe the spatial epidemiology of MRSA in relation to social determinants. 471 MRSA cases were identified; 83.2% (392/471) were categorised into HA- or CA-MRSA. 71.7% (281/392) were HA-MRSA and 26.3% (103/392) were CA-MRSA. In adjusted models, both CA-and HA-MRSA were associated with household deprivation, which was spatially correlated with hospital attendance (spatial correlation coefficient = 0.76). HA-MRSA was also associated with poor health and residence in communal care homes whilst CA-MRSA to household overcrowding, low income, homelessness and recent immigration to the UK. Following area-level adjustment for hospital attendance and deprived households, the relative risk (RR) of HA-MRSA across the three boroughs ranged from 0.818 to 12.462 depending on the area. The RR of CA-MRSA ranged from 0.994 to 1.007. Only 0.09% variation in area-level relative risk (RR) of HA-MRSA was attributable to the spatial arrangement of target geographies compared to 28.67% variation in RR for CA-MRSA. A limitation of the study was the low number of CA-MRSA cases (n=103) compared to HA-MRSA (n=281), which could deter characterisation of geographical variation of CA-MRSA. Conclusions This study identifies HA-MRSA as the dominant genotypically-defined lineages in South East London. An association between HA-MRSA and household deprivation could be explained by more persons in high risk areas attending hospital. There was no evidence of community-based transmission of HA-MRSA suggesting that the community reservoir originates from hospitals. There was also a significant reservoir of CA-MRSA associated with household deprivation, overcrowding, homelessness, low income and recent immigration to the UK. Importantly, communities adjacent to these high risk CA-MRSA areas were themselves at greater risk of CA-MRSA, indicating that regional spread of CA-MRSA is ongoing. Together, these findings have implications for maintaining control of MRSA in the UK. They suggests that recent importation and community spread of CA-MRSA from deprived areas across the whole community will likely result in CA-MRSA strains overtaking HA-MRSA strains, particularly if success of hospital-based infection control programmes is maintained. Future control measures should target prevention of CA-MRSA strains in the community and ensure that hospital admission screening programmes take account of the emerging threat of importation of CA-MRSA lineages into hospitals.
National Center for Biotechnology Information
NCBI BioProject