CD Flashcards
A 77 year old recently immigrated from Pakistan to Canada. He is previously healthy and presents with 2 months of a new cough, hoarse voice, and weight loss. He has been diagnosed with TB. He has a positive sputum specimen by AFB smear, 2+, positive NAAT. Culture is still pending. CXR reveals small lesions in the left upper lobe, though no cavitary lesions. CT neck/chest reveals bilateral diffuse thickening of the vocal cords. He lives with 5 family members in a 3-bedroom house in a suburban neighborhood of a large multicultural city. He does not work.
1. List 4 factors that make this case highly infectious.
2. How should this individual be managed (4 items)?
3. You determine that close contacts should be followed up. List 6 factors that should be considered for contact investigations and management.
4. The WHO End TB strategy seeks to reduce the prevalence of TB to less than 10 per 100,000 globally by 2035. List 5 elements of TB elimination and control that can help Canada achieve this goal.
- List 4 factors that make this case highly infectious.
Smear positive
NAAT positive
Respiratory symptoms including a cough
Upper lobe involvement seen on x-ray
Laryngeal TB - How should this individual be managed (4 items)?
Treatment with rifampin, isoniazid, pyrazinamide, ethambutol x 2 months, then isoniazid and rifampin for another 4 months
Weekly sputum samples
Home isolation until smear negative
Monthly follow-up appointments with TB services
Airborne precautions in healthcare settings - You determine that close contacts should be followed up. List 6 factors that should be considered for contact investigations and management.
Age of the contact, specifically if 5 years or younger
If they are immunocompromised, for example taking a TNF inhibitor
If they have HIV
History of BCG vaccination
Any symptoms of active TB such as a new cough
Duration of exposure
Exposure setting, such as indoor versus outdoor, proximity to the case, and air quality or ventilation - The WHO End TB strategy seeks to reduce the prevalence of TB to less than 10 per 100,000 globally by 2035. List 5 elements of TB elimination and control that can help Canada achieve this goal.
Primary prevention - improved access to adequate housing for Inuit, First Nations, and newcomer populations
Secondary prevention - screening programs with chest x-ray for higher risk population such as immigrants
Tertiary prevention - early diagnosis and treatment by improving access to primary care and specialist TB clinics, to reduce transmission to others
Timely contact tracing and contact investigation/management
Strengthening the Canadian TB Reporting System for ongoing surveillance
Public education on the symptoms and risks of TB
Improved adherence to treatment for active and latent TB through DOT or community-led initiatives
Other Categories for TB Control
- Prevention
- Diagnosis
- Treatment
- Contact Tracing
- Surveillance
- Targeted programs (CXR on IMEs)
- SDOH
There is a new lab-confirmed hep B case
1. List 6 important elements to include in the case investigation
2. List 4 elements of case management
3. List 4 criteria for identifying close contacts
- List 6 important elements to include in the case investigation
Risk factors
Was their mother hep B positive when pregnant with the case?
Any hep B positive household contacts (acute or chronic carrier)
Any unprotected sexual contact with someone who is hep B positive or multiple sexual partners?
gbMSM?
Injection drug use? Sharing needles or other supplies i.e. cookers, straws, pipes
Current or past incarceration?
Receipt of blood/tissue/organ donation?
Invasive medical or dental procedure in an endemic country?
Frequent recipient of blood products?
Skin piercings, tattoos, or acupuncture with unsterile equipment or technique?
Invasive medical or dental procedure? E.g. hemodialysis
Immigration from or to a hep B endemic country (prevalence 8%)
Determine co-infection with other blood borne infections
Determine immunization history
Determine pregnancy status
Determine history of blood, tissue, or organ donation
Determine occupation - List 4 elements of case management
Education on signs and symptoms, modes of transmission, and ways to reduce risk of transmission
Refer to hepatology or ID
Routine IPC precautions for hospitalized cases
Re-check HBsAg and anti-HBs in 6 months - List 4 criteria for identifying close contacts
Living in the same household
Sharing needles
Sexual partners
People who have shared personal care items (e.g. razors, toothbrushes)
- List 5 elements of an animal exposure rabies risk assessment.
- What is the regimen for rabies post-exposure prophylaxis from a high risk exposure? How does this change if the victim received an adequate pre-exposure prophylaxis series? For immunocompromised people?
- List 4 possible interventions for a rabies control program in an area endemic for human and animal rabies
- List 5 elements of an animal exposure rabies risk assessment.
Date and time of exposure
Location of exposure
Type of animal
Based on local epidemiology, is the type of animal a known reservoir for rabies?
If not a known reservoir, could the animal have come into contact with a rapid animal?
Was the attack provoked?
Did the animal have clinical signs of rabies i.e. encephalopathy, self-mutilation, coma
Is the animal available for observation?
Has the victim previously received rabies vaccine?
Do we know the victim’s RFFIT titre (greater than 0.5 IU/mL?)? - What is the regimen for rabies post-exposure prophylaxis from a high risk exposure? How does this change if the victim received an adequate pre-exposure prophylaxis series? For immunocompromised people?
4-dose regimen for immunocompetent unvaccinated patient: vaccine 1.0mL IM on days 0,3,7,and 14
2-dose regimen if previously vaccinated on days 0 and 3, then check titres
5-dose regimen if immunocompromised on days 0,3,7,14, and 28
Note: PrEP regime is 3 doses on days 0,7,and 28 - List 4 possible interventions for a rabies control program in an area endemic for human and animal rabies
Public education campaigns on animal safety and management for animal bites
Pre-exposure vaccination
Post-exposure vaccination
Animal vaccination
Timely access to healthcare following an animal bite
Surveillance for rabies cases
- Your local influenza surveillance systems indicate that seasonal influenza cases are much higher this year compared to average cases in previous years. List 4 possible reasons for this.
- List 3 types of influenza surveillance used in Canada and give an example of each
- Your local influenza surveillance systems indicate that seasonal influenza cases are much higher this year compared to average cases in previous years. List 4 possible reasons for this.
Agent - Mismatch between the circulation strain and vaccine strain
Host - Lower vaccination compared to previous years
Physical Environment - Unseasonably cold weather leading to respiratory viruses surviving longer on surfaces and people spending more time together indoors
Social Environment - Mass gatherings or holidays with many social gatherings
Increased testing
Change in test sensitivity
Increased surveillance
Change in case definition - List 3 types of influenza surveillance used in Canada and give an example of each
Syndromic - FluWatch, school absenteeism, LTC respiratory illness monitoring
Passive - lab reporting
Sentinel - FluWatch, Sentinel Practitioner Surveillance Network for vaccine effectiveness, Tarrant (AB)
A lab-confirmed case of measles has been identified in a 30 year old male.
- List 5 steps of your case investigation.
- What are your next steps for case management (3)
- What are the criteria for a susceptible contact? (6)
- Household contacts have been identified: (i) case’s 30 year old wife who is 16 weeks pregnant and received all childhood vaccines in Canada , (ii) a 2 year old child who is unvaccinated, (iii) a 6 year old child who received 1 measles containing vaccine at age 14 months, (iv) and the case’s 58 year old mother who has a diagnosis of hypertension but otherwise healthy with childhood vaccination is unknown. What type of post-exposure prophylaxis do you offer each contact?
- What criteria do you consider for exclusion orders for contacts?
- What variables do you need to know to calculate critical vaccination coverage against measles? (2)
- List 5 steps of your case investigation.
Are there clinical symptoms consistent with measles such as fever, maculopapular rash on the head that spreads inferiorly, cough, conjunctivitis, coryza, Koplik spots?
Are there signs or symptoms of severe illness such as encephalitis or seizure?
Any travel during the incubation period (21 days prior to onset of fever)
What is the case’s occupation?
Any contact with a known or probable case of measles?
Has the case previously received any measles-containing vaccines?
Did the case attend any healthcare settings during the period of communicability (4 days prior to rash until 4 days after rash onset)? - What are your next steps for case management (3)
Isolation until 4 days after the rash appeared
If hospitalized or seeking healthcare, ensure airborne, droplet IPC precautions are used
Initiate contact tracing - What are the criteria for a susceptible contact? (6)
Shared airspace for any length of time with the case, including 2 hours after the case left the airspace and
No measles-containing vaccines
Less than 2 doses of measles-containing vaccine for adults who are healthcare workers, military personnel, or students
Less than 2 valid doses of measles-vaccine for children and adolescents ages 1-17 (2 doses administered after 12 months old at least 4 weeks apart (MMR) or 6 weeks apart (MMRV)
No history of lab-confirmed measles
No prior serologic evidence of immunity (IgG >200 U/mL) - Household contacts have been identified: (i) case’s 30 year old wife who is 16 weeks pregnant and received all childhood vaccines in Canada , (ii) a 2 year old child who is unvaccinated, (iii) a 6 year old child who received 1 measles containing vaccine at age 14 months, (iv) and the case’s 58 year old mother who has a diagnosis of hypertension but otherwise healthy with childhood vaccination is unknown. What type of post-exposure prophylaxis do you offer each contact?
Wife who is 16w pregnant - Ig up to 6 days after initial exposure
2 year old child unvaccinated - 1 dose MMR(V) at anytime, Ig up to 6 days after initial exposure
6 year old child 1 vaccine - 1 dose MMR(V) at anytime
58 year old mother with hypertension assumed to not have received a measles containing vaccine previously - 1 dose MMR(V) anytime, Ig up to 6 days after initial exposure - What criteria do you consider for exclusion orders?
Consider exclusion orders for contacts who do not receive PEP for the duration of 5 days after first exposure to 21 days after last exposure or until immunization with measles-containing vaccine, administration of immunoglobulin, or documented lab-confirmed immunity
Exclude any healthcare workers exposed who only have 1 dose of measles-containing vaccine until there is lab-confirmed immunity and administer 1 dose of measles-containing vaccine immediately - What variables do you need to know to calculate critical vaccination coverage against measles? (2)
R0 (15-17)
Vaccine effectiveness (99% with 2 doses)
* Critical vaccine coverage = (Herd immunity threshold)/(Vaccine effectiveness)
= [1-(1/R0)]/VE
There is a vaccine shortage; list 3 methods for pivoting a vaccine program to deal with this resource scarcity
There is a vaccine shortage; list 3 methods for pivoting a vaccine program to deal with this resource scarcity
Eligibility - restrict to the highest risk populations (risk of exposure and risk of severe illness)
Scheduling - increase the time interval between doses or provide an incomplete series to a large number of people in the the target population before offering complete series (i.e. mpox 1 dose as PrEP)
Dosing - offer dose-sparing regimens via alternate routes of administration (e.g. lower volumes are usually administered when IM vaccines are given ID, for example mpx, rabies)
Eliminate waste/ manage clinic flow - create plans for unused doses that remain in multidose vials at the end of a clinic due to no-shows or incompletely booked clinics (e.g. offer to workers, call clients from a waitlist, outreach)
Describe each of the following hep B serological markers: HBsAg, Anti-HBs, anti-HBc, HBeAg, HBV DNA
HBsAg: first detectable marker of infection; indicates acute or chronic infection if present for 6+ months
Anti-HBs: immunity from infection or vaccine
anti-HBc IgM: immunity from recent infection (<6 months); occasionally can be detected with exacerbations of chronic infections
HBeAg: indicates acute or chronic infection; associated with level of infectiousness and viral replication
HBV DNA: associated with level of infectiousness; helps determine the need for treatment
List 5 elements of a possible syphilis control strategy and give an example for each element.
Pan-Canadian STBBI Framework for Action 4 pillars
Prevention - sex education in schools, low barrier access to condoms (i.e. free distribution in public spaces), public awareness campaigns including banners on dating/hook up apps and websites
Testing - increase lab capacity for higher volumes of syphilis tests; collaborate with primary care providers, emergency departments, STI clinics, and prenatal care providers to increase routine and opportunistic syphilis screening; change screening guidelines to be more inclusive (additional prenatal screening, newborn screening, youth and young adults); upscale point of care test and treat clinics and dried blood spot testing for areas that do not have resources to support phlebotomy or swabbing
Initiation of Care and Treatment - encourage point-of-care test and treat programs to reduce the potential for loss to follow-up; create care environments that are culturally safe and gender affirming; reduce the barriers to testing and treatment in emergency departments by creating a standardized order set and stocking benzathine penicillin kits in emerg with instructions; increase capacity for complex case management and partner notification
Ongoing Care and Support - Find ways of building trust and encouraging an ongoing care relationship with clients/patients (e.g. peer support workers, collaborate with outreach programs or community-based organizations, incentive programs such as gift cards, communicating via text or social media instead of phone calls)
On a foundation of enabling environment, research and surveillance, knowledge mobilization, and monitoring and evaluation (e.g. reflex lab reporting to Public Health; required reporting from point-of-care testing)
You decide to focus on increasing point-of-care testing test & treat programs, expanding beyond the centralized STI clinic to operate at community health centres, through mobile outreach clinics, and supplying education and supplies to primary care and emergency rooms. List and describe 5 possible indicators that can be used to evaluate this program, with the goal of reducing infectious syphilis rates and eliminating congenital syphilis.
You decide to focus on increasing point-of-care testing test & treat programs, expanding beyond the centralized STI clinic to operate at community health centres, through mobile outreach clinics, and supplying education and supplies to primary care and emergency rooms. List and describe 5 possible indicators that can be used to evaluate this program, with the goal of reducing infectious syphilis rates and eliminating congenital syphilis.
Number of partner sites (process indicator/output)
Number of kits distributed (process indicator/output)
Test positivity
Percent of positive tests that receive adequate treatment within 2 weeks (process indicator)
Percent change in syphilis incidence from baseline (outcome indicator)
Incidence of congenital syphilis (outcome indicator)
Define “outbreak”
Outbreak: an increase in the number of cases of a disease above what is normally expected in a population, usually in a limited geographic area
Define PHEIC and list 4 criteria for declaring a PHEIC
PHEIC (WHO): “an extraordinary event which is determined to constitute a public health risk to other States through the international spread of disease and to potentially require a coordinated international response”.
Must report if 2/4 criteria are met:
The public health impact is serious
The event is unusual or unexpected
There is significant risk of international spread
There is significant risk of international travel or trade restrictions
List 3 reasons why outbreaks might occur
Agent: Increased virulence, Increased amount of the infectious agent
Host: Change in host susceptibility
Environment: Enhanced mode of transmission leading to more susceptible people being exposed, Increased host exposure or new portals of entry
List 8 of the 13 criteria of the Erikson-De Wals framework for deciding if a vaccine should be incorporated into a publicly funded program.
Disease factors
Does the burden of disease justify a control program?
Vaccine factors
Is the vaccine safe and effective?
Is the vaccine licensed for the proposed use, or will it be off-label?
Are there important research questions that have not been answered? E.g. how long does the vaccine confer immunity?
Program factors
What is the goal? What is the delivery strategy? E.g universal, targeted
Can it be evaluated?
Is it cost effective?
Legal
Ethical
Feasibility
Societal factors
Acceptability
Equity
Conformity - is the program implemented elsewhere?
Political landscape - is there political gain or risk from implementing the program?
List the 5 C’s of vaccine hesitancy
Confidence - the confidence that vaccines are effective
Constraints - barriers to accessing vaccination
Complacency - perception that VPDs are not an imminent threat
Collective responsibility - willingness to benefit minimally
Risk Calculation - Individual decision making on if benefits (i.e. protection against hospitalization) outweigh the risks of the vaccination (i.e AEFI)
List and describe 6 stakeholders involved in vaccine licensing and programs
Health Canada Biologics Radiopharmaceuticals and Genetic Therapies Directorate - license and regulate vaccines in Canada
NACI (National Advisory Committee on Immunization) - Provide recommendations on vaccine programs to provinces and territories
CIC (Canadian Immunization Committee) - evaluate the cost effectiveness of vaccination programs
PHAC / CAEFISS - surveillance on adverse effects following immunization
Brighton Collaborative - sets the international standards for AEFIs
Provincial and territorial governments - make decisions on vaccine policy
Health authorities or local public health - operate vaccine clinics
Primary care providers - administer vaccines
List and describe 2 types of AEFI surveillance systems in Canada
CAEFISS - passive surveillance of AEFIS in Canada, submitted via patient or healthcare providers
IMPACT - active surveillance of pediatric hospitalization data for possible AEFIs in 12 pediatric hospitals.
List 5 categories of vaccine components and their purpose
Antigen - induces immune response against the pathogen of interest
Adjuvant - improves immunogenicity and duration of protection e.g aluminum hydroxide
Antibiotics - prevent bacterial contamination during manufacturing
Preservative - prevents microbial contamination in multidose vials e.g. thimerosal, formaldehyde
Stabilizers - improve stability and the delivery of the antigen e.g. lactose, gelatin, albumin
List 5 types of vaccines and one example of each
Live attenuated - MMR, varicella, intranasal influenza, BCG, small pox, oral polio, rotavirus, yellow fever
Inactivated - IPV, Hep A, Rabies
Subunit (Can be further categorizes into protein, conjugate, or polysaccharide subcategories)
Protein based subunit - acellular pertussis
Conjugate subunit - Hib, pneumococcal conjugate
Polysaccharide subunit - quadrivalent meningococcal ACYW-135, pneumococcal 23-valent
Recombinant - Hep B, HPV
Toxoid - tetanus, diphtheria
mRNA - COVID spikevax (moderna)
Viral vector - COVID vaxzevira (AZ)
