IDMM Week 5 Lectures Flashcards
Provincial level health bodies in Canada
Ministry of health
BC CDC
Provincial Lab
Regional health bodies in Canada
5 Regional Health Authorities
First Nations Health Authority
Provincial Health Services Authority
Describe a paradigm for infection control
Agent-Host-Environment triangle as methods for prevention and control
Targets for improved Public Health at the host level
- immunobiologics (vaccines)
- Passive antibody treatment–rabies immune globin
- improving general health–nutrition, rest
- chemoprophylaxis–antimalarial drugs
- treatment to prevent progression to active disease–HIV Tx
- Prevention behaviours–sexual, drug use, eating
- Measures for infected persons–isolation, quarantine, activity, etc.
Targets for inactivation of infectious agent
- Physical methods: heat, cold, radiation, cleaning
2. Chemical methods–chlorination, disinfection, sterilization
Targets for Public Health in the environment
- Sanitation–water, food, feces
- Engineering measures–design of facilities, bed nets
- Administrative measures–cleaning protocols
What is primary prevention
prevention before acquisition of disease/illness/infection (immunization)
What is secondary prevention
prevention for those who have the disease/illness/infection but before apparent/aware of illness (i.e screening for Hep B in pregnancy)
What is tertiary prevention
prevention of those with known disease to prevent complications/progression/spread (ie HAART in HIV)
INfectivity
infected/#exposed
Pathogenicity
clinical cases/#infected
Virulence
severe/fatal / #clinical cases
Case fatality ratio
deaths/#clinical cases
Attack rate
new cases in time ‘x’/population exposed
Reproductive rate
average number of secondary cases (in a susceptible population) that will be generated from each contagious disease
a function of:
- duration of contagiousness
- number of contacts in that period
- probability of transmission given exposure
What virus appears characteristically as “dew drop on a rose petal”
Varicella
Control measures for varicella
- report to public health
- isolation of cases while infectious (until rash has crusted over)
- quarantine of exposed susceptibles if in high risk environment
- protect contacts: immunoprophylazis–vaccine within 3 days of exposure, varicella zoster immune globin (VZIG) within 4 days–can prevent or lessen symptoms
List some reportable diseases
AIDS Campylobacteriosis Anthrax Botulism Chlamydia Cholera C. difficile associated diarrhea Cryptosporidiosis Diptheria Giardiasis Gonorrhea Group B Strep Hep A, B, C HIV Influenza, lab confirmed Listeriosis Lyme disease malaria Measles Mumps Norovirus Pertussis Polio Rabies Rubella Tetanus TB Typhoid fever West Nile
What infection accounts for 60-80% of primary liver cancer globally?
Hepatitis B
Primary prevention of Hep B
immunization, education on risks of transmission, infection control
Secondary prevention of Hep B
routine screening for HBV in pregnancy
perinatal HBimmunoglobin and vaccination at time of delivery if mom is HBV +
Post exposure prophylaxis for exposed individuals
Tertiary prevention for HBV
screening for complications (cirrhosis, HCC)
Discuss HBV immunization
- routine childhood immunizations at 2, 4, 6 months (catch up grade 6)
- adult indications for vaccine: IVDU, infected partner, multiple sex partners, Hx of STIs, travel, healthcare workers, chronic liver disease, end stage renal disease, HIV
What accounts for 40% of all chronic liver disease
Hep C–most common reason for a liver transplant
Passive immunity
short-term, Igs introduced (can be from mom, human donors)
Active immunity
long term
your own immune system stimulation to produce Igs
What is a live attenuated vaccine
“weakened” live agent produces an immune response
Benefits to live attenuated vaccines
closer to natural infection, fewer doses required
Considerations regarding live attenuated vaccines
can have sever reaction in immunocompromised patients
less effective if patient has circulating Igs already (passive immunity from mom)
CONTRA INDICATED IN PREGNANCY
Examples of live attenuated vaccines
MMR, varicella, rotavirus, intranasal flu, yellow fever, oral typhoid, oral polio, herpes zoster
What are inactivated vaccines
live agents grown then inactivated through heat or chemical
Are inactive vaccines ok in pregnancy
yes
Examples of inactivated vaccines
Hep A/B polio rabies influenza HPV pertussis pneumococcal meningococcal H. influenza type B tetanus diptheria
List vaccine components
- immunogenic proteins and polysaccharides–fewer proteins now that vaccines are better targeted
- inactivating agents–formaldehyde
- adjuvants–stimulate immune response (i.e aluminum salts)
- antibiotics–prevent contamination during production
- preservatives–inhibit bacterial/fungal growth (thimerol)
- stabilizers–protect against freeze-drying or heat (gelatin)
What is the role of adjuvants in vaccines?
stimulate immune response–i.e aluminum salts
Grade 6 vaccines
hep B, HPV, meningococcal C, varicella (catch up)
Grade 9 vaccines
TdaP, HPV (catch up)
How effective is the flu vaccine
about 70%
Which has higher safety standards, vaccines or drugs?
vaccines
List 5 antibiotic resistant organisms
MRSA VRE ESBL CRO Macrolide resistant S. Pneumonia
What is MRSA
Methicillin-resistant S. Aureus
Cloxacillin-resistant S. aureus
resistant to all B-lactam antibiotics
S. aureus is one of most important human pathogens–specific screening and infection-prevention approaches in hospitals
What is VRE
vancomycin resistant enterococcus
initially very worrisome because vanco was “last line” antibiotic
fears of resistance spread to staph
largely not a clinical issue now and efforts to ID and control spread have been relaxed
What is ESBL
extended spectrum Beta-lactamase–can cleave up cephalosporins
gram (-) bacilli
mostly in Enterobacteriaciae (some of most important mircoorgs in the biome)
Many human diseases are caused by own own bacteria
E. coli and L. pneumonia
What is CRO
carbapenem resistant organisms
carbapenems are last line antibiotics that have been reserved
NDM1–large amount of antibiotics resistance from India
We are :re-entering the pre-antibiotic era”
Mortality HIGH for these bugs
What is macrolide resistant S. pneumonia
macrolides are used widely for Tx of outpatient respiratory tract infections
Strep. pneumo is largest cause of CAP
resistance is >25% in many parts of Canada
What other conditions have been associated as adverse effect wth over prescription of antibiotics?
asthma
inflammatory bowel disease
changes in gut flora immediately
What is the provincial “antimicrobial clinical expert group” in BC called
PACE
What are some diagnostic aids that can be used to differentiate bacterial from viral and thus prevent over prescription of antibiotics
- Procalcitonin–help differentiate bacterial from viral infections in several settings (more used in Europe)
- Rapid Group A strep tests
“Specialized antibiotic clinical pharmacists are the backbone of acute care stewardship programs”
blah
list 4 adverse effects associated with antibiotics
- promoting and selecting for antimicrobial resistance
- C. difficile infection
- allergic reactions
- links with other diseases (asthma, inflamm bowel)
