Infection Prevention Flashcards
Many infection are transmissible, what are the 3 methods of transmission?
From non-human source to humans
From person to person- directly
From person to person- indirectly
Give some examples of infections that can transmitted on (2)
Food poisoning organism
Rabies
Give some examples of infections that can be transmitted from person to person (3)
Influenza
Norovirus
Neisseria gonorrhoea
Give an example of a person to person indirect infection/disease, name the vector
Malaria
Mosquitos
What are the 4 consequences of transmission?
Endemic diseases
Outbreak
Epidemic
Pande
What is a endemic disease?
The usual background rate
What is an outbreak of disease?
Two or more cases linked in time and place (linked with incubation period)
What is an epidemic?
Give an example
A rate of infection greater than usual background rate
Eg Influenza cases increases during the winter
What is a pandemic?
Give an example
Very high rate of infection spreading across many region, countries and continents. Caused by an antigen shift- completely new pathogen therefore no immunity.
Swine flu
What are the reasons for outbreaks, epidemics and pandemics?
New pathogens
New hosts
New practice
How does a new pathogen cause outbreaks/epidemics/pandemic?
There can be a shift/change in the antigens (eg influenza)/virulence factors (clostridium difficile)/ antibacterial resistance
How does a new host cause outbreaks/epidemics/pandemics?
New patients may be: Non immune (from HIV/ cancer patients/ those who are immunocompromised/ immunosuppressive do) or there may be healthcare effects
How does a new practice cause outbreaks/epidemics/pandemic?
There can be changes in social customs (tattoos/piercings/sexual promiscuity) or changing in healthcare
What is the infectious dose?
amount of pathogen (measured in number of microorganisms) required to cause an infection in the host.
Varies between:
- micro-organism
- presentation of micro-organism
- immunity of potential host
What effect does infectious dose have on determine transmissibility?
The smaller the infectious dose, the more likely transmission is because people can become ill from minimal contact and transmission.
What sort of graphs do epidemic diseases created?
Bell shaped (from susceptible to infection to recovered)
What sort of graphs do outbreak diseases produce?
Short Sharp peaks because the disease is coming and going. rarely regular
Eg norovirus comes every winter and levels die down during the summer
What are the methods of interventions to deal with infections in terms of pathogens, patients, practice and place?
Pathogen (+vector): reduction or eradication (disinfection body wash- reduce pathogenic organism/decontamination/sterilisation/destroy animals natural habitat and limit vector numbers)
Patient: improved health (nutrition and medical treatment) and immunity (passive eg maternal antibody, intravenous immunoglobulin (antibodies in blood diffusion) and active- vaccinations-herd immunity)
Practice: avoidance of pathogen or its vector (geographical-not going there/protective clothing and equipments) and behavioural (safe sex/safe disposal of sharps/food and drink preparation)
Place: environmental engineering (safe water/safe air/good quality housing/well designed healthcare facilities)
Give some examples of organism that are extinct/ close to extinction due to better control (3)
- smallpox
- polio
- dracunculiasis
What are the negative consequences of controlling pathogenic outbreaks?
Decreases exposure to pathogen=decreased immune stimulus=decreased antibody=increased susceptibles=outbreak
Later average age of exposure=increased severity
Eg getting infections like polio, hepatitis A, chicken pox, congenital rubella syndrome at an older age are more severe
Give an example of pathogens that cause increased severity with age of host (4)
- polio
- hep A
- chicken pox
- congenital rubella syndrome (particularly bad in pregnant-affects baby)
