ANTIMICROBIAL USE AND RESISTANCE SURVEILLANCE PILOT PROJECT – LESSONS
FROM THE DURBAN SITEGray AL, Essack SY, Deedat F, Pillay T,
van Maasdyk J, Holloway K, Sorensen TL, Sturm AW
Dept. Pharmacology and Dept. Medical Microbiology, Nelson R Mandela School of Medicine, School of Pharmaceutical Sciences,
Univ. KwaZulu-Natal, Durban, South Africa,
WHO/EDM, Geneva
Abstract Problem Statement: The World Health Organization’s global strategy for containing antimicrobial resistance
recommends the development of methodologies that will enable developing countries to identify and track resistance trends in specific infections and geographical locations. Standard methods for such surveillance systems do not exist for resource-constrained settings.
Objectives: To investigate the association between antibiotic use and resistance over time in respiratory tract infections in the Inner West metropolitan area of Durban.
Design: Retrospective, time series analysis of antimicrobial use data and antimicrobial resistance of selected isolates.Setting and population: 7 randomly selected private pharmacies, 7 convenience sampled private dispensing
practitioners and 7 randomly selected state-operated nurse-managed primary health care clinics.Methods: Antimicrobial use data were obtained from prescription records at sites representing a broad spectrum of socio-
economic conditions and prescriber types. Sputum specimens were obtained from consenting patients presenting with self-reported cough with or without fever at 4 sites in the selected geographical locale. Cultures positive for Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis were subjected to MIC determinations against ampicillin, erythromycin, chloramphenicol, cotrimoxazole and ciprofloxacin by means of agar dilution. NCCLS breakpoints were applied to determine resistance.
Outcome measures: Percentage of patients seen (or prescriptions dispensed) in which an antimicrobial was prescribed; antimicrobial usage in Defined Daily Doses per 100 patients seen; percentage susceptibility of selected isolates.
Results: High usage of older antimicrobial agents was seen in public sector clinics and lower usage of a wide range of agents, including newer broad-spectrum antimicrobials, in the private sector. Percentage resistance of selected isolates by time series per quarter showed an decreasing level of resistance amongst pneumococci to ampicillin and erythromycin, but continuously total resistance to cotrimoxazole. Increasing trends in resistance to ampicillin were shown amongst H influenzae, but decreasing trends in resistance to cotrimoxazole.
Conclusions: Although no direct relationship between resistance levels and antimicrobial usage could be shown, the feasibility of establishing a system to generate data of this sort was demonstrated. Further analysis over time is planned.
Study funded by: World Health Organization.
Background• In September 2001 the WHO released
the Global Strategy for Containment of Antimicrobial Resistance (WHO/CDS/CSR/DRS/2001.2)– This document identified 67 interventions
targeted at different groups – It also identified the need for linked
surveillance of antimicrobial resistance and use, in order to assess these interventions
• Not clear how to achieve this in resource-constrained setting
Objectives• To investigate the association between
antibiotic use and resistance over time in respiratory tract infections in the Inner West metropolitan area of Durban, South Africa
Methods – resistance• Sputum specimens
• consenting patients with self-reported cough, with or without fever
• 4 convenience sampled sites• Public and private sector
• Standard laboratory work-up– Selective cultures for:
• Streptococcus pneumoniae• Haemophilus influenzae • Moraxella catarrhalis
– MIC determinations • ampicillin, erythromycin, chloramphenicol, cotrimoxazole and
ciprofloxacin • agar dilution• standard NCCLS breakpoints
Methods – antimicrobial use• Retrospective prescription audit
(2 weeks’ Rx per month)– 7 randomly selected private pharmacies (stratified by socio-
economic status of area; data from original prescriptions)– 7 convenience sampled private dispensing practitioners
(stratified by socio-economic area; data from clinical records)
– 7 randomly selected primary health care clinics (stratified by size; data from daily clinic registers)
• Data analysis – % patients seen (or prescriptions dispensed) in which an
antimicrobial was prescribed– antimicrobial usage in Defined Daily Doses per 100 patients
seen (clinics and doctors) or prescriptions dispensed (pharmacies)
– % susceptibility of selected isolates - all by time series
S. pneumoniae – resistance(ciprofloxacin not tested)
0
20
40
60
80
100
% re
sist
ance
Q4 '02 Q1 '03 Q2 '03 Q3 '03 Q4 '03
Cotrimoxazole Ampicillin RifampicinChloramphenicol Erythromycin
H. Influenzae – resistance(no resistance to erythromycin or ciprofloxacin)
0
20
40
60
80
100
% re
sist
ance
Q4 '02 Q1 '03 Q2 '03 Q3 '03 Q4 '03
Cotrimoxazole Ampicillin Rifampicin Chloramphenicol
Antimicobial use – overallFacility type Total
patients seen or
prescriptions dispensed
Antimicrobial-containing
prescriptions
% AM Rx
Pharmacies (prescriptions)
19 979 2 400 12.0
Clinics 84 390 14 096 16.7
Dispensing practitioners
23 420 3 003 12.8
Antimicrobial use - cotrimoxazole
05
101520253035
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Months (Q4 '02 = 1-3)
Cotr
imox
azol
e D
DD/1
00pt
Pharmacies Clinics Doctors
Winter
Antimicrobial use - quinolones
02468
10121416
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Months (Q4 '02 = 1-3)
Qui
nolo
ne D
DD
/100
pt
Pharmacies Clinics Doctors
Winter
Antimicrobial use – all antimicrobials
0
50
100
150
200
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Months (Q4 '02 = 1-3)
All
AM
DD
D/10
0pt
Pharmacies Clinics Doctors
Winter
Conclusions and Acknowledgements• Although no direct relationship between resistance
levels and antimicrobial usage could be shown, the feasibility of establishing a system to generate data of this sort was demonstrated
• Given the differences in antimicrobial use patterns in different settings, interventions to contain the development of resistance will have to be carefully tailored for each setting
Thanks to: WHO/EDM for funding this pilot project, the fieldworkers and laboratory staff, the staff at the facilities, for allowing us access to their patients and their data, the patients who provided sputum samples