infection prevention Flashcards
on what basis does infection prevention work on
memory from adaptive immunity
first exposure to Ag -> primary immune response develops -> proliferation of activated B and T cells into effector cells and some into memory T and B cells -> reexposure to same Ag -> activation of memory T and B cells -> generates secondary immune response with shorter lag time and heightened activity (aka more Ab produced)
what are the considerations when wanting to give live, attenuated vaccines
- avoid in pregnant women (no evidence of birth defects but may have fetal infection)
- avoid in infancy <1 yr (mother’s circulating Ab will neutralise so become less effective)
- avoid in severely immunocompromised
- avoid giving another live vaccine within 28d (circulating Ab can interfere with replication process and minimise response to vaccine)
- space 3-10m apart from administration of Ab containing products
what are examples of immunocompromised patients
hematologic/ solid organ malignancies, immunosuppressive meds, chemo tx, HIV with CD4 <200
what is herd immunity
protecting both vaccinated and unvaccinated individuals
percentage of population that needs to be vaccinated for herd immunity depends on how contagious the disease is
what is the childhood immunisation schedule
BCG (1, 0)
HepB (3, 0)
DTap (3, 1)
Tdap (0, 1)
IPV (3, 1)
Hib (3, 1)
PCV10/PCV13 (2, 1)
PPSV23 (1 or 2 if indicated, 0)
MMR (2, 0)
Varicella (2, 0)
HPV2/HPV4 (2, 0)
influenza (annual)
what is the adult immunisation schedule
HepB (all take 3 if not yet taken or not immune)
Tdap (all take 1 if pregnancy indicated)
PCV13 (1 if indicated, 1 if indicated, 1)
PPSV23 (1-2 doses depending on indication, 1-2 doses depending on indication, 1)
MMR (all take 2 if not yet taken or not immune)`
Varicella (all take 2 if not yet taken or not immune)
HPV2/HPV4 (all take 2 if not yet taken or not immune)
influenza (1 annually if indicated, 1 annually if indicated, 1)
what are the considerations for vaccine use
effectiveness
adverse effects
c/i and precautions
simultaneous administration and missed doses
what are uncommon and severe but rare adverse effects
uncommon: fever, hematoma
severe but rare: anaphylaxis, hypersensitivity
what happens if theres a missed dose
administer dose asap, usually do not need additional doses
what are the medical considerations before international travel
- risk assessment (medical history, prior travel experience, specific itinerary, activities, type of accommodation, traveler’s risk tolerance, financial challenges)
- standard in-office interventions (administration of immunisations, malaria chemoprophylaxis if at risk. traveler’s diarrhoea)
- focused education before the trip (vectorborne diseases if at risk, other travel related illnesses as applicable, medical kit and medical care abroad)
when does pre travel consultation happen
4-6w before departure
what are examples of other travel related illnesses
altitude illness, travelers’ thrombosis, motor vehicle injury, bloodborne and STI, swimming, water exposure and marine hazards, transportation associated illnesses, respiratory infections and TB, rabies and animal associated illness, skin conditions and wounds
what are the contents to cover regarding medical kit and medical care abroad
personal health kit, available medical facilities, evacuation insurance, supplemental health insurance
what are the necessary information for risk assessment during pre travel consultations
medical history, special conditions, immunisation history, prior travel experience, itinerary, timing, reason for travel, travel style, activities
what are the major routes of infection and examples of common vaccines used
- food or waterborne pathogens spread via fecal oral contamination -> cholera, hepA, typhoid, poliomyelitis
- insect vectorborne -> yellow fever, japanese encephalitis
- transcutaneous spread through bites and cuts -> tetanus, rabies
- respiratory spread -> influenza, MMR, varicella, BCG for TB, pneumococcus, meningococcus, diphtheria, haemophillus influenzae, pertussis
- blood and bodily fluids spread -> hepB, HPV
what are examples of vaccines and their type of vaccine and corresponding trip characteristics that suggests high risk
- cholera (live attenuated) -> poor sanitation and hygiene practices, humanitarian work
- Hep A (inactivated) -> poor sanitation and hygiene practices, adventurous eating habits, men who have sex with men
- Hep B (recombinant) -> adventure travel, medical tourism, possibility of sexual contact at destination
- influenza (recombinant/ inactivated) -> mass gatherings, exposure to live poultry
- japanese encephalitis (inactivated) -> adventure travel in agricultural areas, open air accommodations, rural home stays
- MMR (live attenuated) -> antivaccine communities, mass gatherings, travel to one or more areas with current outbreaks
- meningococcal (conjugate, quadrivalent) -> mass gatherings, sub saharan africa
- poliovirus (inactivated)
- rabies (inactivated)
- Tdap (toxoid) -> activities that are injury prone, humanitarian aid
- yellow fever (live attenuated)
what are the considerations for immunisation for travelers
- review routine vaccinations
- choice of travel vaccines
- last minute travel
- giving more than 1 vaccine on same day
- minimum intervals between vaccines
- missed doses
what are the steps to take for last minute travel
advice for accelerated immunisation schedules, counselling on risk avoidance, drug prophylaxis if applicable and referrals to health services at their desitination
which mosquito breed is responsible for malaria transmission
anopheles
what bacteria species and which species is responsible for transmission of malaria
plasmodium (p. falciparum, p. malariae, p. ovale, p. vivax, p. knowlesi)
what are the clinical symptoms of malaria
fever, chills, sweat, N/V/D, headache, body ache and weakness, cough, abdominal pain, may progress to organ failure and sepsis without timely treatment
what are the modes of transmission of malaria
primarily through the bites of infected female anapheles but can also be transmitted through contaminated blood products, organ transplantation and vertical transmission from mother to fetus
what are the factors that increases risk of transmission of malaria
increase between dusk and dawn
decrease during colder season/ region
decrease in deserts
large urban areas usually free of transmission
decrease at high altitudes of at least 1500m above sea level
increase at end of or soon after rainy season
what are the three sub cycles in the plasmodium life cycle
- human liver (exo-erythrocytic cycle)
- human blood (erythrocytic cycle)
- mosquito (sporogenic cycle)