Public Health Flashcards
What are the aims of immunisation
To control communicable diseases
Prevent the onset of disease through primary prevention
Interrupt transmission of disease
Alter disease progression or limit consequences through secondary prevention
How are vaccines used in primary prevention
Given pre-exposure to antigen to develop immunity
Helps those who are currently healthy to reduce their risk of a specific disease
E.g. childhood schedule, given to older people, travel vaccines, high risk groups, occupational
How do vaccines work
They teach the immune system to recognise bacteria and viruses before the person encounters them naturally
This allows the body to effectively fight the pathogens
What is active immunity
The person has been exposed to the pathogen in the environment or artificially and produced an immune response
What are antigens
Parts of bacteria and viruses, which are recognised by the immune system
Usually proteins or polysaccharides
What are antibodies
Proteins which bind to antigens - very specific
When they bind it alerts other immune cells
Describe B cells
Mature in bone marrow
Triggered to produce antibodies when they encounter a foreign antigen
Describe T cells
Mature in thymus
Exist as CD4 and CD8
Orchestrate response of immune system by binding to other cells and sending out signals
What is passive immunity
Transfer of pre-formed antibodies from one person to another
How can passive immunity occur
Mother to unborn baby via placenta - lasts up to 1 year
From another person or animal - blood donors, human Ig or specific Ig
What are the advantages of passive immunity via immunoglobulin transfers
Rapid action
Can be given post exposure
Can control outbreaks
Used if vaccine is contraindicated
What are the disadvantages of passive immunity via immunoglobulin transfers
Short term protection Short time window Blood derived May trigger hypersensitivity reaction expensive
What is the preferred means of immunisation
Active immunity through vaccination
List the different types of vaccines
Live virus - attenuated so less effective at causing disease but still triggers immune response Inactivated: Killed organism Subunit vaccines Conjugate
What are the benefits of inactivated vaccines
Safer
Suited to bacterial pathogens
List contraindications to vaccines
Confrimed anaphylaxis in response to previous dose
Cannot give live vaccines to immunosuppressed or pregnant patients
Egg allergy - used in production of some vaccines
Severe latex allergy
Acute illness (until resolves)
What is herd immunity
Protect unvaccinated individuals, through having sufficiently large proportion of population vaccinated
Those who are vaccinated stop transmission
Which diseases are routinely vaccinated against in the UK
Diphtheria Whooping cough Tetanus Polio Hib Meningococcal Measles Mumps Rubella Flu Pneumococcal HPV Hep B
What are notifiable diseases
When there is clinical suspicion or a health risk state associated with this specific disease and the doctors have a legal duty to report it to the health board
How do you notify a health board of a disease
In writing within 3 days
Notify ASAP via phone if deemed urgent
What is diphtheria
URTI characterized by sore throat, low grade fever
Get a white membrane of tonsils, pharynx etc
Caused by gram + bacterium
For which meningococcal disease serogroups is a vaccine available
A C W Y135 B
How are meningococcal diseases spread
Spread by person-to-person contact through respiratory droplets of infected people (close contact)
In some people it is part of normal flora
How do the boards decide which vaccines are needed
Is there a need for it (epidemiological factors)?
Does it work?
Costs
Acceptability - any safety issues
What is the under 5 mortality rate
Probability of a child born in a specific year or period dying before reaching the age of 5
(per 1000 live births)
What is the infant mortality rate
Probability of a child born in a specific year or period dying before reaching the age of 1
(per 1000 live births)
What are the top 5 causes of under 5 mortality globally
Preterm birth complications Pneumonia Intrapartum-related complications - obstructed labour/asphyxia Diarrhoea Neonatal sepsis
What are the top 5 causes of under 5 mortality in Africa
Diarrhoea Pneumonia Malaria Preterm birth complications Intrapartum-related complications
what percentage of child deaths are linked to malnutrition
45%
What is considered the most dangerous period of a child’s life
The first 24 hours
Many babies die in this window
What simple measures can be used to decrease neonatal death
Proper antenatal care: tetanus vaccine and treatment of maternal infection (HIV, syphilis)
Steroids for pre-term labour
Skilled birth attendant
Clean delivery, warm baby and able to resuscitate
How do you prevent neonates dying of syphilis that they got from mum
Give a single dose of penicillin to mum when she is pregnant
Why do you give steroid in pre-term births
Helps the lungs develop sufficiently
What are the risk factors for developing pneumonia in kids
Malnutrition
Over-crowding
Indoor air pollution
Parental smoking