What does Antimicrobial Resistance Mean for Human Health?
Robert Cunney
Temple Street Children’s University Hospital and
HSE/RCPI HCAI/AMR Clinical Programme
Deaths due to infection among US soldiers in four wars
Source: US Army Medical Department, Office of Medical History
Beneficial impact of antibiotics
• Average life span USA extended by 10 years
– Curing all forms cancer: extend by 3 years*
• Control of primary infectious diseases
• Control of opportunistic infections
– Allow cytotoxic chemotherapy, radical surgery etc.
*McDermott 1982, Johns Hopkins Med J 151: 302-12
Bacterial cervical adenitis
• Common childhood infection
• “Antibiotics should be targeted against S. aureus and group A streptococcus, and should include a 10-day course of oral cephalexin (Keflex), amoxicillin/clavulanate (Augmentin), or clindamycin (Cleocin).”*
*Dulin M, Leach L, Am Fam Physician. 2008 Nov 1;78(9):1097-1098
Image source: Meier J, Grimmer J, Am Fam Physician. 2014 Mar 1;89(5):353-358
The first antibiotic guideline?
“Penicillin should only be used if
there is a properly diagnosed
reason and, if it needs to be
used, use the highest possible
dose for the shortest time
necessary. Otherwise antibiotic
resistance will develop”
Alexander Fleming, 1945
Scale of Antibiotic Use
• >100,000 million kg antibiotics produced since
1941
– 50% human use
• 20% hospitals
• 80% community
– 50% agricultural use
• 20% therapeutic
• 80% prophylactic/growth promotion
– 75% questionable therapeutic value
Harrison and Lederberg, Antimicrobial Resistance 1998
0%
5%
10%
15%
20%
25%
30%
35%
40%
45%
50%
Pro
po
rtio
n r
esi
stan
ce
Year
ESBL-producing E. coli
Multiple-ResistantE. coli
ESBL-producingKleb. pneumoniae
Multiple-ResistantKleb. pneumoniae
Multiple-ResistantPseud. aeruginosa
Meticillin-ResistantStaph. aureus
Vancomycin-ResistantEnterococcus faecium
Penicillin-ResistantStrep. pneumoniae
Summary of resistance trends (selected drug/bug combinations)
EARS-Net data on Antimicrobial Resistance in Ireland, Q1-2 2016
*2016 data are provisional to the end of Q2 only
Monitoring trends over time: changing epidemiology
*2015 data is projected total assuming 100% coverage (instead of 97%) by laboratories
EARS-Net data on Antimicrobial Resistance in Ireland, Q1-2 2016
0
500
1000
1500
2000
2500
3000
Nu
mb
er
of
iso
late
s re
po
rte
d
Year
sau eco
Extended-spectrum beta-lactamase (ESBL)
• Most important resistance determinant among Gram-negative bacteria
– Originated in non-pathogenic Kluyvera sp.
– Rapid emergence and evolution since 1990
• Global distribution via uropathogenic E. coli clones
• 40% of E. coli causing abdominal infections in Asia-Pacific and Latin America*
– Geographical distribution of ESBL types
• Wider distribution of types in human vs. animal strains
*Data source: Global Study for Monitoring Antimicrobial Resistant Trends (SMART) 2003-2007,
Flow of antibiotic resistance genes in E. coli in the biosphere
Hawkey P M , Jones A M J. Antimicrob. Chemother. 2009;64:i3-i10
Global distribution of CTX-M genotypes
Hawkey P M , Jones A M J. Antimicrob. Chemother. 2009;64:i3-i10
Carbapenem-resistant Klebsiella (CRE) in Italy
Data source: GM Rossolini, ARHAI Network Meeting, Berlin, Dec 2012