Antibiotic resistance and COVID-19, the growing infectious disease pandemics of the 21st century: Modelling the burden and transmission of antibiotic resistance and prevention of COVID-19

Antibiotic resistant bacteria (ARB) and COVID-19 are both important infectious diseases of the 21st century. During my PhD I firstly summarized the available knowledge on ARB transmission pathways, I studied whether ARB increase the total number of infections or whether they replace infections with susceptible bacteria and I explored a new method to estimate the ARB disease burden. I identified a knowledge gap between the frequency of exposure to ARB and the probability of ARB acquisition. Certain exposure events may be high-risk, but if exposure is infrequent, the contribution of a more frequent, low-risk exposure may be higher. Furthermore, I found that for Escherichia coli, replacement of susceptible infections with resistant infections is more likely than an increase in the total number of infections. This implies that only different characteristics of resistant E. coli, e.g. a higher mortality, can cause an increase of the disease burden, rather than an increasing number of infections. Secondly, I investigated which measures are effective in inhibiting further spread of COVID-19. Self-initiated measures, such as hand washing, distancing and face masks can reduce infections by more than 50% and postpone the peak number of infected, if virus awareness is quickly raised. In addition, we found that the spread of other infectious diseases is influenced by corona measures. For example, Dutch heterosexuals indicated that not being able to make an appointment with the general practitioner or the sexual health center was the main reason that they were unable to take a test for sexually transmitted diseases

Antibiotic resistance and COVID-19, the growing infectious disease pandemics of the 21st century: Modelling the burden and transmission of antibiotic resistance and prevention of COVID-19

Antibiotic resistant bacteria (ARB) and COVID-19 are both important infectious diseases of the 21st century. During my PhD I firstly summarized the available knowledge on ARB transmission pathways, I studied whether ARB increase the total number of infections or whether they replace infections with susceptible bacteria and I explored a new method to estimate the ARB disease burden. I identified a knowledge gap between the frequency of exposure to ARB and the probability of ARB acquisition. Certain exposure events may be high-risk, but if exposure is infrequent, the contribution of a more frequent, low-risk exposure may be higher. Furthermore, I found that for Escherichia coli, replacement of susceptible infections with resistant infections is more likely than an increase in the total number of infections. This implies that only different characteristics of resistant E. coli, e.g. a higher mortality, can cause an increase of the disease burden, rather than an increasing number of infections. Secondly, I investigated which measures are effective in inhibiting further spread of COVID-19. Self-initiated measures, such as hand washing, distancing and face masks can reduce infections by more than 50% and postpone the peak number of infected, if virus awareness is quickly raised. In addition, we found that the spread of other infectious diseases is influenced by corona measures. For example, Dutch heterosexuals indicated that not being able to make an appointment with the general practitioner or the sexual health center was the main reason that they were unable to take a test for sexually transmitted diseases

New methodology to assess the excess burden of antibiotic resistance using country-specific parameters: a case study regarding E. coli urinary tract infections

Objectives Antimicrobial resistant (AMR) infections are a major public health problem and the burden on population level is not yet clear. We developed a method to calculate the excess burden of resistance which uses country-specific parameter estimates and surveillance data to compare the mortality and morbidity due to resistant infection against a counterfactual (the expected burden if infection was antimicrobial susceptible). We illustrate this approach by estimating the excess burden for AMR (defined as having tested positive for extended-spectrum beta-lactamases) urinary tract infections (UTIs) caused by E. coli in the Netherlands in 2018, which has a relatively low prevalence of AMR E. coli, and in Italy in 2016, which has a relatively high prevalence.Design Excess burden was estimated using the incidence-based disability-adjusted life-years (DALYs) measure. Incidence of AMR E. coli UTI in the Netherlands was derived from ISIS-AR, a national surveillance system that includes tested healthcare and community isolates, and the incidence in Italy was estimated using data reported in the literature. A systematic literature review was conducted to find country-specific parameter estimates for disability duration, risks of progression to bacteraemia and mortality.Results The annual excess burden of AMR E. coli UTI was estimated at 3.89 and 99.27 DALY/100 0000 population and 39 and 2786 excess deaths for the Netherlands and Italy, respectively.Conclusions For the first time, we use country-specific and pathogen-specific parameters to estimate the excess burden of resistant infections. Given the large difference in excess burden due to resistance estimated for Italy and for the Netherlands, we emphasise the importance of using country-specific parameters describing the incidence and disease progression following AMR and susceptible infections that are pathogen specific, and unfortunately currently difficult to locate