Infectious Disease Prevention & Immunoprophylaxis Flashcards
A biological attack with intentional release of viruses, bacteria, or other germs that can sicken or kill people, livestock, or crops
Bioterrorism
the processing of microbes or toxins in a manner that would ensure a devastating effect following release
Weaponization
Features of Biologic Agents Used as Bioweapons
10
1. High morbidity and mortality rates
2. Potential for person-to-person spread
3. Low infective dose and highly infectious by aerosol
4. Lack of rapid diagnostic capability
5. Lack of universally available effective vaccine
6. Potential to cause anxiety
7. Availability of pathogen and feasibility of production
8. Environmental stability
9. Database of prior research and development
10. Potential to be “weaponized”
- Easily spread person - person
- High mortality and morbidity
- Requires special action for public health preparedness
- Potential for public panic and social disruption
is what category
category A - high priority
- Moderately easy to spread
- Low to moderate morbidity and mortality
what category?
category B - mid priority
- readily available
- Could be engineered for mass spread in the future
- Potential for major health impact
what category?
category C - lowest priority
what are the category A organisms
6
- Anthrax -(Bacillus anthracis)
- Botulism - (Clostridium botulinum toxin)
- Plague - (Yersinia pestis)
- Smallpox - (Variola major)
- Tularemia - (Francisella tularensis)
- Viral Hemorrhagic Fevers
* Arenaviruses: Lassa, New World (Machupo, Junin, Guanarito, and Sabia)
* Bunyaviridae: Crimean-Congo, Rift Valley
* Filoviridae: Ebola, Marburg
what are the category B organisms
13
- Brucellosis (Brucella spp.)
- Epsilon toxin of Clostridium perfringens
- Food safety threats (e.g., Salmonella spp.,
- Escherichia coli 0157:H7, Shigella)
- Glanders (Burkholderia mallei)
- Melioidosis (Burkholderia pseudomallei)
- Psittacosis (Chlamydophila psittaci)
- Q fever (Coxiella burnetii)
- Ricin toxin from Ricinus communis (castor beans)
- Staphylococcal enterotoxin B
- Typhus fever (Rickettsia prowazekii)
- Viral encephalitis (alphaviruses [e.g., Venezuelan, eastern, and western equine encephalitis])
- Water safety threats (e.g., Vibrio cholerae, Cryptosporidium parvum)
what diseases are category C
Emerging infectious diseases threats such as Nipah, hantavirus, SARS or MERS coronavirus, and pandemic influenza
what are the 3 forms of anthrax
-
GI
* Contaminated meat; unlikely result of bioterrorism
2.Skin / Cutaneous
* Spores enter skin ⇾ papule ⇾ painless vesicle ⇾ necrotic eschar -
Resp
* Most likely due to bioterrorism
* Fever, fatigue, malaise, N/V, cough, SOB ⇾ pneumonia ⇾ pleural effusions ⇾ death
how do you diagnose anthrax
- Prompt recognition key
- Culture blood, skin lesion, resp secretions
- Antibodies
tx for anthrax
- Antitoxin
- cipro, clinda
post-exposure/prophylaxis of anthrax
- vaccination available
- cipro, doxy, amoxicillin
how long is tx and proyphylaxis for anthrax and why?
lasts up to 60 days due to persistence of ungerminated spores in the resp tract
what is the only bioterrorism agent that is non-living but one of the most potent toxins in existence and extremely poisonous
Botulism
which toxin has 7 forms and prevents the release of acetylcholine, leading to flaccid paralysis of muscles
botulism
pt comes in with multiple cranial nerve palsies leading to descending flaccid paralysis
Diplopia, dysphagia, dysarthria, dry mouth, ptosis, dilated pupils, fatigue, extreme weakness
what could they been infected with
Botulism
diagnosing Botulism
Toxin immunoassay
tx for botulism
Supportive
* Intubation, mechanical ventilation, parenteral nutrition
* Equine antitoxin if dx early in disease
* Weeks to months of regeneration of new motor neuron synapses w/in the muscle cell
NO approved FDA vaccine
2 main types of plague, including presentations
-
Bubonic plague - results from bite of plague-infected rat flea
* Painful LAD w/ necrosis, fever, bacteremia ⇾ septicemia ⇾ death
* buboes
* Extensive ecchymosis and necrosis of digits and nose -
Pneumonic plague - inhalation of the bacteria
* Fever, cough, hemoptysis, and GI Sx
* Pneumonia ⇾ pleural effusion ⇾ lung consolidation ⇾ death
* Mortality 84%
diagnosing the plague
- Blood cultures and / or cultures of buboes, sputum
- Antibodies
tx for plague
- gentamicin
- streptomycin
- doxycycline
- chloramphenicol
prophylaxis of plague
- doxycycline
- levofloxacin
course of smallpox
- Exposure from aerosolized droplets from close contact w/ infected person
- Virus infects host
⇾ spreads to lymphoid tissue
⇾ localized infection of skin dermis
⇾ 2-14 days later ⇾ fever, malaise, HA, N/V, back pain, rash (maculopapular to face and extreme
⇾ spreading to trunk ⇾ turn to vesicles, then pustules, then scabs), mouth ulcers - Like varicella, pt is assumed no longer contagious when all lesions have formed scabs
- Death usually from severe systemic illness
how to diagnose smallpox
- Culture, PCR
- Antibodies
tx for smallpox
Strict isolation
Supportive measures only
Antivirals have not really been studied
which bioterrorism agent is Weaponized through either aerosol or in drinking water
Tularemia
microbiology of Tularemia
- Non-spore forming, but may survive weeks on surfaces
- Not spread person ⇾ person, but as little as 10 organisms may infect the host
-
Infection from insect bites or environment contamination - ticks and fleas bite an infected host and pass along to humans
also known as “rabbit fever” or “deer fly fever”
s/s of tularemia
1-14 days post exposure
1. Inflammation of the airways
* Pharyngitis, pleuritis, bronchopneumonia
2. Fever, HA, chills, fatigue, malaise
3. Conjunctivitis and exanthems possible
4. 50% - infiltrate on CXR; hilar adenopathy w/o infiltrate also possible
how do you diagnose tularemia
Gram stain or cultures of infected tissues or blood
tx for tularemia
- streptomycin or doxycycline
- also gentamicin, chloramphenicol, ciprofloxacin
no vaccines
s/s of viral hemorrhagic fevers
Fever, myalgia, prostration, DIC w/ thrombocytopenia and capillary hemorrhage
diagnosing viral hemorrhagic fevers
- > 38.3 ℃ (or 101 ℉) for at least 3 wks with at least 2 of the following (in the absence of another cause)
* Hemorrhagic or purpuric rash
* Epistaxis
* Hematemesis
* Hemoptysis
* Hematochezia - Serological testing for antigen and antibody; PCR - sent to the CDC
tx for viral hemorrhagic fevers
No approved treatment or vaccine
Experimental - antibody cocktails and ribavirin
3 main categories for transmission-based precautions
-
Contact precautions
* Gown and gloves required for pt or environment contact
* Sometimes above needed to even enter patient room -
Droplet precautions
* Surgical mask required w/in 3 feet of patient -
Airborne infection isolation
* Negative pressure isolation room
* Respirator must be worn
what are the types of PPE
-
Gloves
* blood, body fluids, secretions, excretions, mucous membranes, non-intact skin, or contaminated equipment -
Gowns
During procedures when contact of clothing, exposed skin w/ blood/body fluids, secretions, excretions, or body fluid is anticipated -
Mask / Goggles or Face shield
Any activity which may result in splashes or sprays of blood, body fluids, secretions, or excretions
what are the types of immnunity
-
Active immunity - induced by vaccines prepared from bacteria or their products
* Capsular polysaccharides, inactivated protein exotoxins (toxoids), killed bacteria, or live-attenuated bacteria -
Passive immunity - administration of preformed antibodies in preparations called immunoglobulins
* May be used as prevention or treatment of certain bacterial disease
* Examples: tetanus antitoxin, botulinum antitoxin, diphtheria antitoxin - used for tx and prevention
what are the types of vaccinations
-
Inactivated - dead virus
* More stable
* Safest form
* Weaker immune response
* Often requires multiple doses or boosters
* Examples: seasonal influenza, polio -
Live, attenuated - live but weakened virus
* Does not cause active disease (typically)
* Provides greatest immunity
* Examples: measles, mumps, varicella -
Subunit Vaccines
* Contain only antigens
* Less risk of adverse reactions
* Very time-consuming to make
* Example: Hep B -
Toxoid Vaccines
For bacterial infections that secrete toxoids
Inactivated toxoids
Examples: tetanus, diphtheria, pertussis -
Conjugate Vaccines
* Works against bacteria w/ a cell wall
* Produce synthetic product containing cell wall similar to the bacteria
* Examples: HIB type B vaccine, Pneumococcal (Prevnar) -
Once Experimental, now Realistic
* DNA vaccines / RNA vaccines - Covid-19 vaccines
* Recombinant vector vaccines
* Use a live bacteria as a vector
CI for vaccines
- Severe allergic reaction - anaphylaxis
- Pregnancy and severe immunosuppression - no LIVE vaccines, including live-attenuated vaccines
precautions for vaccines
- Acute illness that is moderate to severe - with or without fever
- Delay and vaccinate after illness resolves
what are the 4 variations of Diphtheria / Tetanus / Pertussis
1. DTaP - Diphtheria, tetanus, and pertussis
* Approved for ages 6 weeks ⇾ 7 years of age
* Made up of inactivated forms of the toxins produced by these bacteria, as well as acellular antigens of pertussis
* Brand names: Daptacel, Infanrix
2. Tdap - Tetanus, diphtheria, and pertussis
* Lower dose of the toxin components used for booster doses only
* Indicated for those 7 years of age and older
* Brand names: Boostrix, Adacel
3. Td - Tetanus and diphtheria
* Same as the Tdap w/o the pertussis component
4. DT - Diphtheria and tetanus
MOA of Diphtheria, Tetanus, Pertussis
- Protects against: Corynebacterium diphtheriae, Clostridium tetani, and Bordetella pertussis
- Produces an active immune response by developing antibodies and antigens against the toxoids and acellular pertussis antigens
what is the dosing route and schedule for Diphtheria / Tetanus / Pertussis
- DTaP - 5 part series given at WCC
* 2 months, 4 months, 6 months, 15 months, 4 years
* Usually given as a combo vaccine
* Pediarix - DTaP, Hep B, IPV or
* Pentacel - DTaP, HIB, IPV - Tdap
* Booster at age 11 or 12 and every 10 years - Td
* Given for a dirty wound if it’s been > 5 years since last tetanus
CI for Diphtheria, Tetanus, Pertussis
- Hx of encephalopathy - coma or prolonged seizures w/in 7 days of administration of the vaccine w/ pertussis components
- Progressive, unstable neurological d/o, uncontrolled seizures, etc. - hold off on vaccine until controlled
MOA of MMR
Live-attenuated vaccine
90% prevention of rubella after a single dose; 99% measles and 95% mumps prevention after a second dose
dosing for MMR
- Given SQ
- 2-part series given at WCC
* 12 months
* 4 y/o - typically combined w/ varicella - ProQuad vaccine
* MMRV combo not given under 23 months due to febrile seizure risk - leaving country to an endemic area
* Given between 6-11 months
* Second dose - 28 d after
* Adults born before 1970 - 1 dose;
* HCW - both doses
Prophylaxis of MMR
May be administered w/in six days of exposure
CI of MMR
- Pregnancy
- Severe immunodeficiency
- Postpone a month if pt has been on long-term (>14 days) of steroids
- Immediate hypersensitivity reaction to gelatin or neomycin - components of the vaccine
MOA of polio
Inactivated vaccine (IPV)
The only type of polio vaccine given in the US since 2000
90% effective after the first dose, 99-100% effective after the third dose
dosing route and schedule for polio
- Given IM or SQ
- 4-dose series given at WCC
* 2 months
* 4 months
* 6 months
* 4 years - Usually in combinations w/ other vaccine:
* Pentacel - DTaP-IPV/Hib / Pediarix -DTaP-IPV-HepB / Kinrix -DTaP-IPV - Modified schedule given to any child leaving country to travel to an endemic area
* First dose given between 6-11 months of age, followed by 3 more doses
CI for polio
Previous reaction to IPV
Allergy or sensitivities to streptomycin, polymyxin B, and neomycin
precautions = pregnancy
MOA of hep A vax
Inactivated / killed virus
- activates lymphocytes to attack the antigen = releases inflammatory mediators signaling B and T-cells = produces new B and T-cells against hep A antigen
dosing route and schedule of hep A
- Given IM
- 2-dose schedule given at WCC
* 12 months
* 2 years
* Second dose sometimes given at 18 month visit - just needs to be 6 months apart
MOA of hep B
- Subunit vaccine - recombinant vaccine containing hepatitis B virus surface antigen only
- Produced in yeast or mammalian cells (Chinese hamster ovaries)
- HBsAg proteins in the vaccine are recognized by antigen presenting cells process the antigen and introduce it to the T-helper cells. B-cells now recognize the antigen causing a weak immune response which then produces neutralizing antibodies
dosing route and schedule of hep B
Given IM
4-dose vaccine given at WCC
* Birth - 1 month
* 2 months
* 4 months
* 6 months
Usually used in combination w/ other vaccines
Pediarix - DTaP, Hep B, IPV
CI of hep B vax
- Hypersensitivity to yeast
- Severe allergic reaction to latex
MOA of rotavirus
Live-attenuated vaccine
Issue w/ different strains of RV in geographical regions
2 are licensed in the US
1. Rotarix - live-attenuated G1P human RV vaccine
2. RotaTeq - live pentavalent bovine-reassortant vaccine containing G1,2,3,4 and P1
dosing route and schedule for rotavirus
- Given PO
- 2 or 3-dose vaccine given at WCC
- Rotarix - 2-dose vaccine
* 2 months
* 4 months - RotaTeq - 3-dose vaccine
* 2 months
* 4 months
* 6 months - Dose of either of the above should be given before 15 weeks of age and all doses given before 8 months of age
CI of rotavirus
Severe immunodeficiency
Previous h/o intussusception
Severe illness - wait until recovery to give vaccine
how does Haemophilus Influenzae - HIB vax work?
Attaches a polyribosylribitol phosphate (PRP) capsule to a protein, which will recruit T-cells and lead to the formation of sufficient numbers of anti-PRP antibodies
dosing and route for haemophilus influenzae (HIB)
- Given IM
- Individual vaccine or combo vaccine
* Pentacel - DTaP/HIB/IPV - Given at WCC
* 2 months
* 4 months
* 6 months
* 12-15 month - booster
CI and precautions for haemophilus influenza (HIB)
CI:
* Same w/ all other vaccine
* Do no give to infants < 6 weeks of age
Precautions:
* Moderate to severe illness with or w/o fever
how long is immunity from pneumococcal vax
- Active against Streptococcus pneumoniae
- Immunity in 2-3 weeks after vaccine, lasting around 5 years
what are the 4 pneumococcal vaccines
1. PCV13 - Prevnar 13
* Produces better immunity in children
* stimulates mucosal immunity, decreasing colonization, providing some herd immunity
* 4-dose series given at WCC
* 2 months
* 4 months
* 6 months
* 12 - 15 months
* >6 y/o - single dose
2. PPSV23 - Pneumovax 23
* 1-dose
* Indicated in adult population of those >65 y/o w/ Prevnar 13
* 3. PCV 15 - Vaxnuvance
* Includes serotype from PCV 13 and some from PCV 23
* 1-dose
* Indicated in adult population of those who >65 who have not received either PCV 13 or PPSV23
4. PCV 20 - Prevnar 20
* Includes serotype from PCV 13 and additional from PCV 23
* Same as PCV15
CI for pneumococcal
none!
2 forms of vaccines for influenza
1. Inactivated / killed vaccine
* Derived from hybrid strain mixed w/ laboratory strain and grown in eggs
2. Live-attenuated vaccine
* Donor virus is mated w/ an anticipated epidemic wild strain
* Induces nasal IgA antibodies
what are the 2 types of inactived influenza vaccines
- Quadrivalent vaccine - protects against 4 different strains
- Trivalent vaccine - protects against 3 different strains - egg-based
what are the 3 main types of Quadrivalent vaccines
- Egg-based - Fluzone
* Fluzone - 6 months and older for standard dose of Fluzone - Cell-culture based - Flucelvax - egg-free and grown in cells of mammals
* 4 years and older - Recombinant - Flublok - uses recombinant technology and is egg-free as well
* 18 years and older
what are the 2 trivalent vaccines
- Fluzone high dose
* 65<
* 4x the antigen = better protection - FLUAD - formulated with the adjuvant MF59
* 65<
* Standard dose
CI for LAIV live-attenuated vaccine
flu
must be Ages 2 - 49
1. Pregnancy
2. Children 2-17 receiving ASA therapy
3. Immunosuppression
4. Children 2-4 w/ asthma or wheezing in past 12 months
5. People who have taken influenza antiviral meds in the past 48 hrs
6. People who care for immunosuppressed individuals
7. Chronic medical conditions, such as DM, chronic kidney dz, etc.
precautions with LAIV live-attenuated vaccine
flu
- Asthma in those 5 years and older
- Moderate, acute illness w/ or w/o fever
- Guillain-barré w/in 6 weeks following last influenza vaccine
dosing route and schedule of infleunza
- 6 months ⇾ 8 years of age - 2 doses in the same season if they have never had two in one season previously
- 9+ - 1 dose regardless of previous vaccination hx
CI and caution of inactivated influenza vaccine
- Severe latex allergy
- Precautions - GBS infection w/in 6 wks of previous influenza vaccine
MOA of varicella
Live-attenuated vaccine
Produces an IgG humoral immune response = cell-mediated immune response by varicella-zoster-specific activation of both CD4+ T-helper and CD8+ T-lymphocyte cells
dosing route and schedule for varicella
- Given SQ
- 2-dose series at WCC
* 12 month WCC
* 4 year WCC - usually in combo w/ MMR vaccine
CI of varicella
- Hx of allergy to neomycin
- Blood dyscrasias (leukemia, lymphoma - anything that affects the bone marrow)
- Moderate to severe illness
- Anyone who has received blood products w/n 3-11 months
- Immunocompromised or pregnant
MOA of meningococcal
- Protects against Neisseria meningitidis
* A, B, C, W, X, and Y are responsible for majority of invasive disease - Conjugated polysaccharide vaccines - protects against serotypes A,C,W, and Y
* Menactra
* Menveo - Recombinant vaccines - protect against serotype B
* Bexsero
* Trumenba
CI of meningococcal
Severe allergic reaction to latex
MOA of HPV
- Subunit vaccine
- Recombinant DNA was used to generate virus-like particles capable of mimicking the natural virus and eliciting high-titers of virus neutralizing antibodies
* They resemble authentic virions
* Are not infectious
* Induce high levels of antibodies
which vaccine protects against strains 6, 11 (genital warts) and 16, 18 (cervical cancers) and now 31, 33, 45, 52, and 58
Gardasil 9
Gardasil 4 and Cervarix (no longer in production)
dosing route and schedule for HPV
- Given IM
- Indicated in ages 9-45, but most have no benefit over age 26
- 2 or 3-dose series dependent upon timing of administration of the vaccine
* If administered before age 15 - only 2 doses needed
* 11 years old
* Next dose in 6-12 month
CI of HPV
- Immediate hypersensitivity to yeast
- Severe latex allergy
- Precaution - Pregnancy
MOA of yellow fever vaccine
- The 17D vaccine is a live-attenuated vaccine
- Live vaccine is introduced into system and patient produces a low-level viremia
* IgM antibodies are produced against YF
* Virus may be passed through blood products so no blood donations allowed in pts who have received YF vaccine w/in 14 days
dosing route and schedule for yellow fever vaccine
- Given SQ or IM
- indicated for 9 months - 59 years of age for those traveling to or living in at risk for YF
* Africa and South America - Also indicated for lab personnel
- Usually lifelong protection, but given again in 10 years if travelling to high risk areas
CI and precautions of yellow fever
- <6 months
- Immunocompromised
* Thymus d/o, organ transplant recipients, malignancies, other immunodeficiencies
Precautions: 6 - 8 months old, Over 60 yo, Pregnancy / Breastfeeding
MOA of typhoid vax
Protects from gram negative Salmonella enterica serotype typhi (Salmonella typhi)
what are the 2 types of typhoid vax
- Oral, live-attenuated vaccine
* causes lipopolysaccharide biosynthesis inducing a local protective immune response in the intestine
* Due to the build up of lipopolysaccharide intermediates, the bacterial cells lyse before causing a virulent infection - Capsular, polysaccharide vaccine
dosing route and schedule of typhoid
- Oral vaccine
* 1 capsule by mouth every other day totaling 4 pills
* May travel 1 week after last dose
* Given at 6 years of age and older
* Booster every 5 years - IM injection
* One dose
* May travel 2 weeks after vaccination
* Given at 2 years of age and older
* Booster every 2 years
CI of typhoid
- Oral vaccine
* Pregnancy
* Immunocompromised - IM injection
* No real contraindication except as w/ all vaccinations, but best to delay until 2nd trimester of pregnancy
The person infected must receive passive and active immunization:
what are the vaccines
- Rabies immunoglobulin - passive immunization
* Binds to the RV preventing it from invading the CNS
* Also builds up antibodies to allow the vaccine to work more proactively - Rabies vaccine - active immunization
* Inactivated antigen vaccine
* Builds antibodies against the RV
dosing route and schedule of rabies vax
- HRIG - Human rabies immunoglobulin
* Injected around the wound up to 7 days after first dose of vaccine
* If full amount not used, inject the rest at a different site from rabies vaccine
* Is not given to those who have had previous vaccination - Vaccine
* 1 mL given IM (deltoid) on days 0, 3, 7 and 14
* If previously immunized, it’s given only on days 0 and 3
* Immunocompromised persons should receive a fifth dose on day 28
* In 2013, the vaccine age indication was dropped to 2 months of age
vaccine for botulism
- no FDA approved
- Antitoxin for those exposed
* Will neutralize all 7 botulinum neurotoxin serotypes
* Approved by FDA in 2013
* For use in those over 12 months of age
MOA of synagis
- Immunoglobulin only - Synagis /palivizumab
* Humanized monoclonal anti-RSV antibody
* Bind RSV F protein, which plays a role in virus attachment and mediates fusion
* Does not inhibit virus attachment
* Does inhibit viral transcription
dosing routine and schedule for synagis
- Must be given monthly to high-risk individuals during respiratory season (Sept - May)
- 55% reduction in RSV admissions in premature infants
MOA of antivenoms
- Attaches to and neutralizes the poisonous venom proteins causing it to be released from the receptor site
- Antibodies or antibody fragments derived from the plasma of large mammals (generally horses, but also sheep, goats, or rabbits) that have been previously immunized with non-lethal venomous doses
dosing route and indications for antivenoms
- The sooner initiated, the more effective - typically w/in 4 hours of bite
- Indicated for progressive local tissue findings, hematologic laboratory abnormalities, and/or evidence of systemic toxicity
* Airway swelling, neurological toxicity, cardiovascular collapse
dosing schedule of administering antivenoms
- Initial dose
* 4-6 vials IV over 1 hour - Subsequent doses
* An additional 4-6 vials - Maintenance dose
* 2 vials every 6 hours up to 3 doses
* This is started 6 hours after control achieved
* Decreases recurrence of symptoms - “Control” is defined as
* Systemic symptoms resolved
* Hematologic abnormalities are improving
* Local effects have begun to improve
cautions with antivenoms
- Sensitivity should be tested first and watching for any localized reaction over the next 30 min
- Epinephrine and antihistamine should be at the bedside
- Serum sickness
* Hypersensitivity reaction to the alien immunoglobulin
* Anaphylactic and pyrogenic reactions
* Fever, chills, rigor, headache and tachycardia
* Skin rash, generalized allergic reaction
