I read a recent review in Clinical Infectious Diseases (the second-ranked premier ID journal, depending on ranking criteria) on the World Health Organization’s (WHO’s) ranking of antibiotics a couple of days ago. The WHO has ranked antimicrobial agents according to their importance for human medicine since 2007, and has updated the list every 3 years or so. The committee that performs the review is the WHO Advisory Group on Integrated Surveillance of Antimicrobial Resistance (AGISAR), which comprises experts in both human and veterinary medicine. A new committee has been formed since April this year to update the list again.

The concept – particularly given the current global problem of antimicrobial resistance – is to incorporate such a list as part of risk management strategies to ameliorate human health risks associated with the use of antibiotics in food production systems (i.e. food animals). Antimicrobial agents are assigned to 3 categories of importance (“critically important”, “highly important” or just “important”) based on 2 criteria:

• The antibiotic (or class of antibiotic) is the sole therapy or one of few alternatives to treat serious human disease.
• The antibiotic (or class) is used to treat diseases caused by microbes that may be transmitted via non-human sources (or that may acquire resistance from non-human sources).

The list of critically important antibiotics as determined in the third revision of WHO’s ranking in 2011 is shown below (I have made certain changes according to antibiotics that are available in Singapore):

A further prioritization at the WHO-AGISAR Copenhagen meeting in 2007 resulted in the quinolones, macrolides and 3rd and 4th generation cephalosporins being listed as the three classes of antibiotics where risk management strategies were most urgently required (most critical of the critically important list!).

Personally, I feel such a ranking is a good start. But as has been evident for the past decade, it is insufficient without the weight of public and political support to address the growing issue of antimicrobial resistance.