Antibiotic Resistance prevention Content History of Antibiotic resistance

Antibiotic Resistance & prevention

Content History of Antibiotic resistance The consequences of Antibiotic resistance Reasons for Antibiotic resistance Prevention

The start of antibiotic resistance: Penicillin Fleming 1928 Florey & Chain 1940

History of resistance

“There are two major effects of an antibiotic: therapeutically, it treats the invading infectious organism, but it also eliminates other, or non-disease producing, bacteria in its wake. The latter do, in fact, contribute to the diversity of the ecosystem and the natural balance between susceptible and resistant strains. …

“The consequence of antibiotic use is, therefore, the disruption of the natural microbial ecology. This alteration may be revealed in the emergence of types of bacteria which are very different from those previously found there, or drug resistant variants of the same ones that were already present. ” Levy, 1997

". . . the mounting use of antibiotics, not only in people, but also in animals and in agriculture, has delivered a selection unprecedented in the history of evolution. " Levy, 1997

DRUG RESISTANCE THREATENS TO REVERSE MEDICAL PROGRESS Curable diseases – from sore throats and ear infections to TB and malaria -- are in danger of becoming incurable A new report warns that increasing drug resistance could rob the world of its opportunity to cure illnesses and stop epidemics.

The consequences of antibiotic resistance Increased morbidity & mortality l l “best-guess” therapy may fail with the patient’s condition deteriorating before susceptibility results are available no antibiotics left to treat certain infections Greater health care costs l l l more investigations more expensive, toxic antimicrobials required expensive barrier nursing, isolation, procedures, etc. Therapy priced out of the reach of some third-world countries

Therapy priced out of the reach of the poor A decade ago in New Delhi, India, typhoid could be cured by three inexpensive drugs. Now, these drugs are largely ineffective in the battle against this life-threatening disease. Likewise, ten years ago, a shigella dysentery epidemic could easily be controlled with cotrimoxazole – a drug cheaply available in generic form. Today, nearly all shigella are non-responsive to the drug. The cost of treating one person with multidrug-resistant TB is a hundred times greater than the cost of treating nonresistant cases. New York City needed to spend nearly US$1 billion to control an outbreak of multi-drug resistant TB in the early 1990 s; a cost beyond the reach of most of the world's cities.

Bacterial evolution vs mankind’s ingenuity • Adult humans contains 1014 cells, only 10% are human – the rest are bacteria • Antibiotic use promotes Darwinian selection of resistant bacterial species • Bacteria have efficient mechanisms of genetic transfer – this spreads resistance • Bacteria double every 20 minutes, humans every 30 years • Development of new antibiotics has slowed – resistant microorganisms are increasing

Antibiotic Failures are NOT all due to Resistance Lack of effectiveness in vivo may not be due to bacterial resistance; the antibiotic may not be able to reach the microorganisms: cannot go through blood brain barrier be too toxic at doses required to be effective against targeted microorganisms. . .

Sustained Antibiotic Use Contributes to Resistance initial 3 -month: use of AMI restricted, TOB & GEN unrestricted then 12 months when AMI was primary aminoglycoside Muscato JJ 1991. An evaluation of the susceptibility patterns of gramnegative organisms isolated in cancer centres with aminoglycoside usage. Journal of Antimicrobial Chemotherapy. 27 Suppl C: 1 -7.

Antibiotics overuse creates ‘Superbugs’ 50 million tons antibiotics per year ‘Superbugs’ resistant to most antibiotics Example: Tuberculosis 2. 5 million deaths Mycobacterium tuberculosis increasingly resistant

Resistance Seems to Develop Mostly in ICU Project ICARE (Intensive Care Antibiotic Resistance Epidemiology) by CDC and Emory U SPH to collect data on 8 US hospitals: For 8/10 pathogens considered, resistance was higher among in hospital isolates

How does animal use of antibiotics contribute to resistance? Animals consume and excrete antibiotics (approximately 2 trillion lbs of manure generated in USA annually) Animals can transmit resistant bacteria in food § Food of animal origin most common cause of food-borne infections due to: l l Salmonella Campylobacter Yersinia E Coli 0157, H 7 Genetic transfer to human specific organisms (avoparcin in pigs and chickens). This can also occur with plant bacteria.

Social factors fuelling resistance Poverty encourages the development of resistance through under use of drugs l l Patients unable to afford the full course of the medicines Sub-standard & counterfeit drugs lack potency In wealthy countries, resistance is emerging for the opposite reason – the overuse of drugs. l l Unnecessary demands for drugs by patients are often eagerly met by health services and stimulated by pharmaceutical promotion Overuse of antimicrobials in food production is also contributing to increased drug resistance. Currently, 50% of all antibiotic production is used in animal husbandry and aquiculture Globalization, increased travel and trade ensure that resistant strains quickly travel elsewhere. So does

Prevention

1 -Vaccinate Influenza vaccine S. pneumoniae vaccine § 7 vaccine serotypes are also most resistant § So vaccine reduces incidence of infections due to the 7 serotypes and incidence of resistant strains

2 - Diagnose & Treat Infection Effectively Target the pathogen Target empiric therapy to likely pathogens Culture the patient Target definitive therapy to known pathogens Optimize timing, regimen, dose, route and duration Monitor response and adjust treatment when needed

3 - Treat infection, not contamination Blood cultures Use proper antisepsis for blood cultures Avoid culturing vascular catheter tips Avoid culturing through temporary vascular catheters

4 -Treat infection, not colonization Treat pneumonia § not the tracheal aspirate § not endotracheal tube Treat urinary tract infection § not the indwelling catheter § not simple bacteriuria Treat bacteremia § not the catheter tip or hub Treat bone infection § not the skin flora

5 - Follow Established Guidelines Consult Specialist Follow Guidelines

6 -Use Local Data Know your antibiogram Know your formulary Know your patient population

7 -Stop Antimicrobial Treatment When infection is treated When infection is not diagnosed When infection is unlikely

8 -Prevent Person to Person Transmission Health Care Facility: § Use standard infection control precautions § Follow airborne, droplet and contact precautions § When in doubt, consult infection control experts Community Setting § Stay home when you are sick § Keep your hands clean § Set an example

9 -Prevent Transmission from Environment Get the Catheters out § Use catheters only when essential § Use the correct catheter § Use proper insertion and catheter- care protocols § Remove catheters when they are no longer essential Follow disinfection protocols § From stethoscopes § … to endoscopes

10 - Use Hospital Controls Educational & Persuasive Approaches: minor effect Facilitative Strategies § clinical specialist or pharmacy clinician to advise § computer help screens when ordering Power Strategies § Formulary Control § Monitor usage with time limits on prophylactic, empiric, therapeutic uses § Restriction of Drugs classified as: l Uncontrolled: available for all physicians, l Monitored: usage monitored thru system l Restricted: ID specialist only

Hospital Control: Power 1 -Formulary Control l most common method l pharmacy and therapeutics committee l selects ab in hospital formulary l based on the ab medical usefulness, cost, relevance to epidemiologic situation l no duplication

Hospital Control: Monitor 2 -Monitor and evaluate empiric, therapeutic & prophylactic use l prescriptions include type of rx: E/T/P l Time limits § Empiric: § Prophylactic: § Therapeutic: l 3 days 2 days 7 days extension requires justification written by the prescribing physician l requiring MD to justify prescriptions proper usage.

Hospital Control: Restrict 3 -Restriction of Drugs classified as: · Uncontrolled: available for rx by all physicians · Monitored: available but usage monitored through system · Restricted: available only after consultation with ID specialist or limited list of MD

Hospital Control 4 - Antimicrobial form l l l forms consume time to be filled act as a deterrent for casual prescriptions information obtained on form used to monitor proper usage 5 - Laboratory reporting l l l focus on formulary non formulary ab. S reported when multiple resistance occurs reporting of ab. S prompt to allow rapid switching to more appropriate and narrow spectrum ab

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