Communicable diseases- public health Flashcards
The 3 key domains of public health practice
- Health improvement
- Improving services
- Health protection
Goal of public health
“Protection of people from infectious diseases and preventing harm from non-communicable diseases and preventing harm from non-communicable environmental hazards involving chemicals, poisons or radiation.”
Areas of public health concern for the UK:
- Healthcare acquired infections
- Antimicrobial resistance
- Sexually transmitted infections- overall rates falling but gonorroea increasing
- Emerging infections- ebola, zika, COVID-29, polio
Chain of infection (6)
- Portals of entry- e.g., mucous membrane
- Susceptible host- Immune deficient
- Infectious agent- e.g, Bacteria
- Reservoirs- people, water
- Portals of exit- blood, secretions
- Modes of transmission- physical contact
Incubation period defintition
time period between initial contact with an infectious agent and the appearance of the first sign or symptom of disease
Infectious period (period of communicability)
the time during which an infectious agent may be transferred directly or indirectly from an infected person to another person etc.”
Transmissibilty of infection can be described with which values
Reproduction number
Basic reproduction number R0
Effective reproduction numer R
Definition of reproduction number
the average number of new people infected by each infectious case
Bsic reproduction number R0
the mean number of secondary cases a typical single infected case will cause in a population with no immunity to the disease, in the absence of interventions to control the infection.
Effective reproduction number - R
The number of secondary infections produced by a typical infective case
Takes into account the fact that some poeple are already immune, because of previous infection or vaccination
Definition of sporadic disease occurance
irregular pattern, occasionally cases at irregular intervals
e.g, typhoid
Endemic disease occurance
persistent, low or moderate level of disease
e.g., malaria, Tb
Hyper endemic
A higher persistent level
e.g., hep B
Epidemuc
occurance exceeds the expected level for a givem time period
e.g., measles outbreak
pandemic
epidemic spreadinf over several countries or continents
Suspected case definition
any febrile (showing symptoms of fever) illness accompanied by a rash
Probable case definition
A case that meets the clinical case definition, has non-contributory or no serologic or virologic testing, and is not epidemiologically linked to a confirmed case
Principles of communicable diseases control
- Control the source
- Interrupt transmission- vector control, needle exchange, hand washing
- Protect the suceptible population by immunisation or chemoprophylaxis
Management of suspected outbreak (typhoid)
- Check antibiotic resistance of the organism isolated from the culture
- Ensure cases are isolated
- Observe enteric precautions and give personal hygiene advice
- Obtain food and travel history
- Investigate household and other close contacts with a faecel specimen for culture- those who are positive should be treated as cases
Is this an outbreak?
2 or more cases arising within the same 48 hour window OR 3 or more within the same 72 hour window which meet the same clinical case definition where an epidemiological link can be established.
Principles of outbreak management
Immediate control measures
Incident/ outbreak control team
Case finding
Data collection and analysis
Hypothesis generation and testing
Further control measures
