Transmission routes of antibiotic resistant bacteria : a systematic review

Background: Quantification of acquisition routes of antibiotic resistant bacteria (ARB) is pivotal for understanding transmission dynamics and designing cost-effective interventions. Different methods have been used to quantify the importance of transmission routes, such as relative risks, odds ratios (OR), genomic comparisons and basic reproduction numbers. We systematically reviewed reported estimates on acquisition routes’ contributions of ARB in humans, animals, water and the environment and assessed the methods used to quantify the importance of transmission routes. Methods: PubMed and EMBASE were searched, resulting in 6054 articles published up until January 1st, 2019. Full text screening was performed on 525 articles and 277 are included. Results: We extracted 718 estimates with S. aureus (n = 273), E. coli (n = 157) and Enterobacteriaceae (n = 99) being studied most frequently. Most estimates were derived from statistical methods (n = 560), mainly expressed as risks (n = 246) and ORs (n = 239), followed by genetic comparisons (n = 85), modelling (n = 62) and dosage of ARB ingested (n = 17). Transmission routes analysed most frequently were occupational exposure (n = 157), travelling (n = 110) and contacts with carriers (n = 83). Studies were mostly performed in the United States (n = 142), the Netherlands (n = 87) and Germany (n = 60). Comparison of methods was not possible as studies using different methods to estimate the same route were lacking. Due to study heterogeneity not all estimates by the same method could be pooled. Conclusion: Despite an abundance of published data the relative importance of transmission routes of ARB has not been accurately quantified. Links between exposure and acquisition are often present, but the frequency of exposure is missing, which disables estimation of transmission routes’ importance. To create effective policies reducing ARB, estimates of transmission should be weighed by the frequency of exposure occurrence

A preview of COVID-19 vaccination and treatment

Vaccination or recent exposure to infection with SARS-CoV-2 currently grants the vast majority of the population considerable immunity and thereby protection against severe disease. It is yet unknow how long this protection lasts. Continuous changes of the viral genotype and phenotype herein play an important role, in particular the variant-specific alterations of the spike protein. Protection by T-cell immunity seems to be more preserved in the event of changes in the virus as compared to antibody-mediated host defences. Furthermore, the continuous succession of virus variants also directly and indirectly affects the effectiveness of medical treatment. Regarding immune-modulating as well as anti-viral therapy, the viral characteristics of the circulating SARS-CoV-2 variant in combination with the level of host immunity will determine whether their use makes sense, and for which patients. The number of patients needed to treat to prevent a clinically negative outcome herein represents an important figure.</p

A preview of COVID-19 vaccination and treatment

Vaccination or recent exposure to infection with SARS-CoV-2 currently grants the vast majority of the population considerable immunity and thereby protection against severe disease. It is yet unknow how long this protection lasts. Continuous changes of the viral genotype and phenotype herein play an important role, in particular the variant-specific alterations of the spike protein. Protection by T-cell immunity seems to be more preserved in the event of changes in the virus as compared to antibody-mediated host defences. Furthermore, the continuous succession of virus variants also directly and indirectly affects the effectiveness of medical treatment. Regarding immune-modulating as well as anti-viral therapy, the viral characteristics of the circulating SARS-CoV-2 variant in combination with the level of host immunity will determine whether their use makes sense, and for which patients. The number of patients needed to treat to prevent a clinically negative outcome herein represents an important figure.</p

Global Spread of Vancomycin-resistant Enterococcus faecium from Distinct Nosocomial Genetic Complex

Vancomycin-resistant enterococci (VRE) have caused hospital outbreaks worldwide, and the vancomycin-resistance gene (vanA) has crossed genus boundaries to methicillin-resistant Staphylococcus aureus. Spread of VRE, therefore, represents an immediate threat for patient care and creates a reservoir of mobile resistance genes for other, more virulent pathogens. Evolutionary genetics, population structure, and geographic distribution of 411 VRE and vancomycin-susceptible Enterococcus faecium isolates, recovered from human and nonhuman sources and community and hospital reservoirs in 5 continents, identified a genetic lineage of E. faecium (complex-17) that has spread globally. This lineage is characterized by 1) ampicillin resistance, 2) a pathogenicity island, and 3) an association with hospital outbreaks. Complex-17 is an example of cumulative evolutionary processes that improved the relative fitness of bacteria in hospital environments. Preventing further spread of this epidemic E. faecium subpopulation is critical, and efforts should focus on the early disclosure of ampicillin-resistant complex-17 strains

Prevention of infections with highly resistant microorganisms:Maximizing transparency by using outcome indicators

In the Netherlands the quality of health care is supervised by the Health Care Inspectorate. Since 2013 the Health Care Inspectorate has been specifically checking hospital practices for reducing transmission of highly resistant microorganisms. Its mode of operation, using process indicators, has been criticised. Here, it is proposed that this quality control be based on relevant outcome parameters of infection prevention strategies. This would also maximise transparency regarding the occurrence of infections caused by highly resistant microorganisms in Dutch hospitals.</p

Prevention of infections with highly resistant microorganisms:Maximizing transparency by using outcome indicators

In the Netherlands the quality of health care is supervised by the Health Care Inspectorate. Since 2013 the Health Care Inspectorate has been specifically checking hospital practices for reducing transmission of highly resistant microorganisms. Its mode of operation, using process indicators, has been criticised. Here, it is proposed that this quality control be based on relevant outcome parameters of infection prevention strategies. This would also maximise transparency regarding the occurrence of infections caused by highly resistant microorganisms in Dutch hospitals.</p