Transmission of Infection and Infection Control Flashcards
What is the term for living or nonliving material in which infectious agents multiple and develop and depend on for survival?
Reservoir
ex. human (influenza virus)
ex. animal (rabies virus)
ex. inanimate (Clostridium tetani–> spores in soil)
What is the incubation period?
Time from entry of pathogen to first appearance of signs/symptoms of disease.
ex. influenza: 1-3d
ex. common cold virus: 12h-5d
ex. chickenpox (VZV): 2-3 wks
What is the period of communicability?
Time during which pathogen is capable of being transmitted/
ex. influenza virus: clinical onset to 3-5d post onset
ex. common cold virus: 24h before onset to 5d after onset
ex. VZV (chickenpox): 1-2d before onset of rash until all lesions crusted (5d)
What are examples of infectious agents transferred by direct contact?
- HIV (mucous membrane to mucous membrane)
- Herpes virus (muc to muc)
- impetigo due to streptococcus pyogenes (skin to skin)
What are examples of infectious agents transferred via indirect contact?
ex. antibiotic resistant organisms: clostridium difficile, respiratory viruses (via hands, fomites)
ex. norovirus, rotavirus, salmonella spp., shigella spp., campylobacter spp., e.coli (fecal-oral)
- HIV, Hepatitis B, Hepatitis C (needlestick)
What size are ‘droplets’ and how far can they be propelled in the air?
> =5um
2 m distance
What are examples of droplet-transmitted infectious agents?
- respiratory viruses: respiratory syncytial virus, influenza, parainfluenza, adenovirus, rhinovirus
- neisseria meningitidis
What are examples of airborne infectious agents?
- mycobacterium tuberculosis
- measles
- varicella zoster virus (chickenpox)
What are examples of vector-borne infectious agents?
- West Nile Virus
- Malaria
(via mosquitoes)
What is a ‘common vehicle’ of transmission? Give examples.
common vehicle= a single contaminated source that transmits infection to multiple hosts
ex. food, medication, IV fluid, equipment
examples from news: Walkerton drinking water (E coli), EEG electrodes (Hep B), Acupuncture needles (Mycobacterium abscessus)
What are the 6 main arms of ‘public health measures’ to prevent spread of infectious disease?
- Vaccination
- Post-exposure prophylaxis
- Reportable Disease
- Contact Tracing
- Quarantine
- Outbreak investigation
What infections do we vaccinate against in Canada?
- Diphtheria
- Pertussis
- Tetanus
- Polio
- Haemophilus B (Hib)
- Pneumococcal
- Rotovirus
- Meningococcal
- Measles
- Mumps
- Rubella
- Chickenpox (Varicella)
- Hepatitis B
- HPV
- Influenza
What are 7 examples of vaccinations given to travelers (dependent on destination)?
- Hepatitis A
- Yellow fever
- Typhoid
- Cholera
- Neisseria meningitidis
- Japanese encephalitis
- Rabies
List infections that have vaccines and/or immunoglobulins for prophylaxis post-exposure:
- Hep B (vaccine, Ig)
- Hep A (vaccine, Ig)
- Varicella Zoster (vaccine, Ig)
- Rabies (vaccine, Ig)
- Measles (vaccine, Ig)
- Botulism (Ig)
List infections that have post-exposure prophylaxis in the form of antimicrobials/antivirals
- Pertussis
- Invasive Neisseria meningitidis
- Invasive Streptococcus pyogenes
- HIV
According to the ‘Health Protection and Promotion Act’, which individuals/bodies must report suspected occurrences/occurrences of reportable diseases to the local Health Unit?
- physicians
- laboratories
- admins of hospitals
- schools
What is the term for the tracking of all individuals who have been exposed to a person with a communicable disease during its period of communicability?
‘Contact Tracing’
What antibiotic resistant organisms are surveilled for nosocomial infx?
What other organisms can cause hospital-acquired infx?
- Methicillin-resistant Staphylococcus aureus (MRSA)
- Vancomycin-resistant enterococci (VRE)
- Extended-spectrum beta-lactamase producing GN (ESBL)
- Carbapenemase-producing GN (KPC, NDM-1)
- Clostridium difficile and Influenza virus also cause HAI
What are two means of decolonizing a host from antibiotic resistant organisms like MRSA?
- topical or systemic antibiotics
2. photodisinfection
Give examples of prophylactic post-exposure treatments for:
- Invasive Neisseria meningitidis
- Invasive Streptococcus pyogenes
- Needlestick injuries
- Neisseria m. : Rifampin or ciprofloxacin
- Strep p. : Penicillin+rifampin or clindamycin or azithromycin
- Needlestick:
- Antiretroviral rx
- Hep B vaccine/Ig
- Monitoring HIV, Hep B, Hep C seroconversion
What are the 7 steps of an outbreak investigation?
- confirm outbreak exists
- develop a case definition
- create line listing and epicurve
- assemble team
- institute control measures
- evaluate efficacy of control measures
- declare outbreak over
What are 3 types of outbreaks?
- point source (one bad meal at old age home)
- common source (sick chef works for 5 days)
- propagated spread (person to person spread)
