4/30 Fungal Infections and Immunizations Ch 18, 19, 20 Flashcards
(57 cards)
GIve an example of herd immunity
Rates of disease in adults going down after most children were given vaccines.
Live vaccines can be transmitted from person to person - this is not usually a problem except in what circumstances?
Among immunologically vulnerable hosts
define passive immunization
How long does the protective effect last?
Giving a patient immunoglobulins from an already immune individual
Protectin lasts only a few weeks
define active immunization
stimulation longer-lasting immune responses via injection of something that stimulates an immune response in the host
examples of live attenuated vaccines?
is a single dose sufficient for immunity? explain
Examples: Polio, rotavirus, typhoid, BCG (for TB)
single dose may be sufficient; this type of vaccine can elicit broad immunity
example of inactivated vaccines; inactivated whole organisms?
-tetanus, diptheria, Hep B recombinant protein antigen, pneumococcal polysaccharide vaccine (PPV23)
example of vaccine given as viral-like particles?
HPV
Example of vaccines given as inactivated: bacterial capsular polysaccharide conjugated to an immunogenic protein?
comment on this type of vaccine?
- pneumococcal conjugate vaccine. H flu, meningococcal conjugate
- induce only B cell responses without conjugate; often require booster doses to be protective
what do we measure to determine if a vaccine has been “immunogenic”?
measure antibody responses.
define vaccine efficacy (what does it measure)?
how is it expressed?
Vaccine efficacy = measures the ability of the vaccine to prevent disease or disease-related events (death, hospitalization)
expressed as a percentage: # protected/#at risk
Determine efficacy via prospective randomized trial
adverse reactions to vaccines: generally mild or severe?
examples of reactions?
generally mild
can range from local injection site reactions to low grade temps
in immunocompromized pts, more severe systemic infection is possible
reports of febrile seizures, Guillian-Barre syndrome: hard to prove causality!
define universal vaccination
one approach to immunization; aim is to prevent all individuals from getting disease, commonly administered in childhood (unless there are reasons to give later in life)
example when would we vaccinate only risk groups rather than universally?
ex: giving Hep A immunization to travelers or others at particular risk
define underlying risk
can signify risk such as pneumococcal vaccination for immunocompromised and elderly hosts.
his notes don’t make much sense here.
for what diseases can we provide post-exposure prophylaxis?
rabies, measles, Hep B, HIV
for what disease do we only vaccinate after a disease outbreak?
menincococcus
2 contraindications to immunization with live vaccines?
- pregnancy
- immunodeficiency
most vaccination is voluntary or not?
are there any mandated immunizations?
most vaccination is voluntary
some are mandated by school requirements, military requirements, for healthcare workers
reason: unvaccinated people can be a risk to those around them.
Dimorphic fungi: what makes them dimorphic? why do we care?
organisms that live in the environment in one form, and in infected tissue in another.
In environment: filaments with hyphae and septae. In tissue: yeast form (round/oval structures that divide by budding)
The diseases they cause (that we need to know about) are called Deep Mycoses - meaning that they are not limited to skin or mucosa.
Histoplasmosis: geographic distribution?
what types of places will you find histo?
In US: misissippi/ohio river valleys
Global: Central/South america
Find it in caves, soils that have bird/bad droppings, chicken coops, renovating old houses
Remember the CF patient who went cave exploring? This must be why everyone was so horrified.
Patient visited a cave in Belize. has a fungal infection in his lungs. what is it? what med?
Histoplasmosis (based on cave, S america)
Itraconazole
Histoplasmosis: Pathogenesis?
Tiny little yeasts grow within macrophages.
causes reaction resembling TB - fibrosis, caseating necrosis
cytokines activated macrophages to kill yeasts.
Histoplasmosis: clinical sx?
initial: flu-like (cough, fever, malaise).
upon reinfection, may get acute pulm infiltrates; febrile illness
Chronic: fibrosis and cavitary infiltrates
all these fungi have what general presentation in immunocompromised?
cell-mediated reaction -> granulomas. the granulomas may disseminate and allow live fungi into other tissues
–> meningitis, bone granulomas, other organ lesions.
Kind of like TB that then spreads widely
