Estimates of antibiotic resistance in Italy and Western Europe in 2019: a MICROBE-based comparative analysis

antimicrobial resistance (AMR) will cause 10 million deaths per year worldwide by 2050, with economic costs of up to 100 trillion dollars. Antibiotic resistance (ABR) constitutes the majority of this health threat. Globally, 1.27 million people died in 2019 as a direct result of ABR. One in 5 deaths occurred in children under five, and 6 bacterial pathogens accounted for more than 70% of ABR-associated deaths.

to compare ABR estimates in terms of death and disability-adjusted life-years (DALYs) in 2019 in Italy and in Western Europe (WE) by grading the infectious syndromes and the bacterial pathogens involved, with the aim to identify the most urgent healthcare needs in Italy.

the estimates of the burden of ABR in 2019 in WE and Italy, extracted from the Measuring Infectious Causes and Resistance Outcomes for Burden Estimation (MICROBE) tool by the Institute for Health Metrics and Evaluation (IHME; Seattle, USA), reported deaths and DALYs associated with 33 bacterial pathogens across 12 infectious syndromes, as well as deaths and DALYs associated with and attributable to ABR for 23 bacteria and 86 pathogen-drug combinations. The comparison between WE and Italy was performed in steps. First, among the 12 groups of infectious syndromes from the Global Burden of Diseases (GBD) study 2019, the most impacting in terms of deaths and DALYs were ranked based on the magnitude of rates, and the corresponding ABR-associated burden was reported. Then, the burden of the leading pathogens (bacteria, viruses, fungi, and polymicrobial infections) for all infectious syndromes was compared between the two areas. Death and DALY rates associated with ABR were reported for each bacterium, together with the percentage of ABR-attributable burden. Although it is known that Italy is one of the WE countries with the largest share of elderly, crude rates were reported instead of age-standardized rates, in order to quantify the actual burden of ABR in the two areas.

Italy and Western Europe.

death and DALYs rates per 100,000 inhabitants.

the largest difference between ABR-associated death rates in the two areas was found for bloodstream infections (25.2 and 18.8 per 100,000 in Italy and WE, respectively), followed by peritoneal and abdominal infections (15.1 and 12.2 in Italy and WE, respectively). However, the percentages of deaths and DALYs attributable to ABR were always higher in Italy for all the infections considered. Regarding pathogens, Escherichia coli accounted for the greatest burden associated to ABR, in terms of both deaths and DALYs, in both areas. The highest ABR-attributable percentage of deaths was found for Acinetobacter baumannii (28.4% in WE and 31.9% in Italy), accounting also for the highest percentage of ABR-attributable DALYs (28.4% in WE and 31.7% in Italy). The pathogen-drug combination with the highest burden associated with AMR was Escherichia coli-Aminopenicillin, while the greatest AMR-attributable burden was found for Staphylococcus aureus-Methicillin (MRSA). On average, 55.4% of Escherichia coli was resistant to Aminopenicillin in WE, with Italy ranking third (67.6%). Nordic countries showed smaller values, with Sweden in last place (32.8%). The average percentage of MRSA in WE was 16%, with Italy exceeding it by more than 13 pointsConclusions: despite similar sepsis mortality rates in Italy and other WE countries, the proportion of ABR-associated and attributable deaths was higher in Italy. Targeted strategies aimed at reducing the circulation of bacteria and resistant microorganisms together with other interventions could lead to an overall reduction in deaths associated with ABR.