Estimating enhanced prevaccination measles transmission hotspots in the context of cross-scale dynamics.

A key question in clarifying human-environment interactions is how dynamic complexity develops across integrative scales from molecular to population and global levels. Apart from its public health importance, measles is an excellent test bed for such an analysis. Simple mechanistic models have successfully illuminated measles dynamics at the city and country levels, revealing seasonal forcing of transmission as a major driver of long-term epidemic behavior. Seasonal forcing ties closely to patterns of school aggregation at the individual and community levels, but there are few explicit estimates of school transmission due to the relative lack of epidemic data at this scale. Here, we use data from a 1904 measles outbreak in schools in Woolwich, London, coupled with a stochastic Susceptible-Infected-Recovered model to analyze measles incidence data. Our results indicate that transmission within schools and age classes is higher than previous population-level serological data would suggest. This analysis sheds quantitative light on the role of school-aged children in measles cross-scale dynamics, as we illustrate with references to the contemporary vaccination landscape.

Potential burden of antibiotic resistance on surgery and cancer chemotherapy antibiotic prophylaxis in the USA: a literature review and modelling study.

BACKGROUND: The declining efficacy of existing antibiotics potentially jeopardises outcomes in patients undergoing medical procedures. We investigated the potential consequences of increases in antibiotic resistance on the ten most common surgical procedures and immunosuppressing cancer chemotherapies that rely on antibiotic prophylaxis in the USA. METHODS: We searched the published scientific literature and identified meta-analyses and reviews of randomised controlled trials or quasi-randomised controlled trials (allocation done on the basis of a pseudo-random sequence-eg, odd/even hospital number or date of birth, alternation) to estimate the efficacy of antibiotic prophylaxis in preventing infections and infection-related deaths after surgical procedures and immunosuppressing cancer chemotherapy. We varied the identified effect sizes under different scenarios of reduction in the efficacy of antibiotic prophylaxis (10%, 30%, 70%, and 100% reductions) and estimated the additional number of infections and infection-related deaths per year in the USA for each scenario. We estimated the percentage of pathogens causing infections after these procedures that are resistant to standard prophylactic antibiotics in the USA. FINDINGS: We estimate that between 38·7% and 50·9% of pathogens causing surgical site infections and 26·8% of pathogens causing infections after chemotherapy are resistant to standard prophylactic antibiotics in the USA. A 30% reduction in the efficacy of antibiotic prophylaxis for these procedures would result in 120,000 additional surgical site infections and infections after chemotherapy per year in the USA (ranging from 40,000 for a 10% reduction in efficacy to 280,000 for a 70% reduction in efficacy), and 6300 infection-related deaths (range: 2100 for a 10% reduction in efficacy, to 15,000 for a 70% reduction). We estimated that every year, 13,120 infections (42%) after prostate biopsy are attributable to resistance to fluoroquinolones in the USA. INTERPRETATION: Increasing antibiotic resistance potentially threatens the safety and efficacy of surgical procedures and immunosuppressing chemotherapy. More data are needed to establish how antibiotic prophylaxis recommendations should be modified in the context of increasing rates of resistance. FUNDING: DRIVE-AB Consortium.

Global trends in antimicrobial use in food animals.

Demand for animal protein for human consumption is rising globally at an unprecedented rate. Modern animal production practices are associated with regular use of antimicrobials, potentially increasing selection pressure on bacteria to become resistant. Despite the significant potential consequences for antimicrobial resistance, there has been no quantitative measurement of global antimicrobial consumption by livestock. We address this gap by using Bayesian statistical models combining maps of livestock densities, economic projections of demand for meat products, and current estimates of antimicrobial consumption in high-income countries to map antimicrobial use in food animals for 2010 and 2030. We estimate that the global average annual consumption of antimicrobials per kilogram of animal produced was 45 mg⋅kg(-1), 148 mg⋅kg(-1), and 172 mg⋅kg(-1) for cattle, chicken, and pigs, respectively. Starting from this baseline, we estimate that between 2010 and 2030, the global consumption of antimicrobials will increase by 67%, from 63,151 ± 1,560 tons to 105,596 ± 3,605 tons. Up to a third of the increase in consumption in livestock between 2010 and 2030 is imputable to shifting production practices in middle-income countries where extensive farming systems will be replaced by large-scale intensive farming operations that routinely use antimicrobials in subtherapeutic doses. For Brazil, Russia, India, China, and South Africa, the increase in antimicrobial consumption will be 99%, up to seven times the projected population growth in this group of countries. Better understanding of the consequences of the uninhibited growth in veterinary antimicrobial consumption is needed to assess its potential effects on animal and human health.