BURDEN

Accurate data on the burden that AMR places on the national health and economy are important for governments to reliably and prudently prioritize their public health spending.  Furthermore, reliable data are valuable for campaigns to raise public awareness of AMR and to obtain funding for research and surveillance networks. However, to date, most estimates of the impact of AMR on human health have been based on fragmented, very limited data, mainly derived from retrospective epidemiological studies in high-income countries and often conducted using very different methodological approaches.

The health impact of a disease can be measured by using different metrics (for example, mortality, prevalence, incidence) and is generally a combination of different measures that offers the clearest picture. To harmonize the approach and yield more robust estimates of the impact of AMR, and by beginning with one of the key needed metrics, GLASS has published the “GLASS method for estimating attributable mortality of AMR bloodstream infections” in May 2020. It is a master template protocol aimed at estimating in-hospital mortality - and optionally mortality at 28 days after confirmed infection - attributable to AMR bloodstream infections, the latter being among the most serious life-threatening infectious diseases. The protocol is targeting at a minimum E. coli resistant to 3rd generation cephalosporin and methicillin-resistant Staphylococcus aureus bloodstream infections, both for community and hospital origin infections, but it can be applied to other pathogen-antimicrobial combinations, based on the local epidemiology and availability of resources. The study design proposed is a prospective cohort study including up to three patient cohorts (patients with AMR bloodstream infections of each target species, drug-susceptible bloodstream infections of each target species, and patients without bloodstream infections of the target pathogen) to be followed up until hospital discharge and optionally after discharge. The protocol includes the collection of a large number of variables, which will allow for adjustment of confounders and risk factor analysis.

This new methodology offers a great opportunity for countries to carry out an estimation of AMR attributable mortality using a standardized and robust epidemiological approach that will facilitate the comparability and pooling of estimates at the global level. Moreover, the significant advances made in AMR surveillance in recent years, including increased participation in GLASS, and the momentum gained from the development and implementation of AMR national action plans could be leveraged to prioritize these efforts to inform policy and AMR action.