Strategies for the Prevention and Containment of Antibiotic Resistance

Strategies for the Prevention and Containment of Antibiotic Resistance Antibiotic resistance may emerge by antibiotic selection pressure but is perpetuated by diverse risk factors and maintained within environments as a result of poor infection control. Population-specific drug pharmacokinetics and pharmacodynamics also play a role. The WHO, US, UK and EU have initiated strategies for the containment of resistance, with surveillance and delineation of the cause(s) cited as essential. Surveillance of antibiotic efficacy should be disease-based, establishing sensitivity profiles of common causative organisms to inform the development of or amendment to standard treatment guidelines and essential drugs lists adopted within the national drug policy. The manner of antimicrobial use (overuse, underuse, inadequate dosing) associated with resistance should be established for appropriate intervention in terms of rational drug use, a reduction in use and dosing regimens based on population-specific pharmacokinetics and pharmacodynamics. Risk factors unique to South African communities (poverty, HIV) and hospitals (duration of hospitalisation, location within the hospital, intensive care unit stay, surgery, wounds, previous and current antimicrobial therapy, mechanical ventilation, urinary catherterisation, nasogastric intubation, central venous and peripheral catheters, previous hospitalisation and transfer from another unit or hospital) must be determined and due vigilance exercised in patients exhibiting classical risk factors for the acquisition of or colonisation with resistant pathogens. Hygiene and sanitation (in communities) and infection control (in hospitals) status must be determined and interventions initiated to prevent the spread of resistance. Pharmacokinetics and pharmacodynamics specific to diverse populations must be devised to optimise antimicrobial therapy. South Africa has unique needs in the antimicrobial resistance arena, needs to be addressed in the context of severe financial, human resources and technological challenges. SA Fam Pract 2006;48(1):50 Introduction Antimicrobial resistance is currently the greatest challenge to the effective treatment of infections globally. Resistance adversely affects both clinical and financial therapeutic outcomes with effects ranging from the failure of an individual patient to respond to therapy and the need for expensive and/or toxic alternative drugs to the social costs of higher morbidity and mortality rates, required and/or longer durations of hospitalisation, increased health care costs and the need for changes in empirical therapy. 2 Surveillance Study in State Hospitals in Kwazulu-Natal, South Africa A recent study evaluated the appropriateness of national standard treatment guidelines (STGs) and the essential drugs list (EDL) for infections within the public health care system in Kwazulu-Natal, South Africa in the context of antibiotic resistance. A multicentre survei l lance study was undertaken in 16 hospitals at 3 levels of health care (district, regional, tertiary – a system of referral with services ranging progressively from general medical services in district hospitals to highly specialised care in tertiary hospitals) where each hospital was requested to submit 100 consecutive, non-repetitive isolates. Identification and susceptibil i ty testing were accomplished using the API system (bioMérieux sa, Lyon, France) and NCCLS disc sensitivity method on antibiotic test panels of up to 19 antibiotics for Gram-negative and 11 for Gram-positive organisms. Isolates were grouped according to their natural resistance profiles and percentage sensitivity to each antibiotic was stratified per hospital level. The total sample of 1270 isolates consisted of 24 different species. Sensitivities ranged from 14-100% with a general trend of highest sensitivity in district hospitals followed by regional and tertiary hospitals consistent with the referral system where health conditions become increasingly severe/complex requiring greater antibiotic use and broader spectrum agents at progressive hospital levels. The study concluded that resistance profiles amongst bacteria vary too much to allow a national