Theme 4- health improvement Flashcards
What is health protection?
“The protection of individuals, groups and populations through expert advice and effective collaboration to prevent and mitigate the impact of infectious disease, environmental, chemical and radiological threats”
What does PHE protect the public from?
- Chemicals and poisons
- Radiation
- Communicable disease
- And about emergency response – being prepared for major disasters
Why public health not under control?
- Societal events- war, migration, urban decay
- Human behaviour- travel, diet , recreation
- Health care- new devices, transplants, immunosuppresion
- Environmental changes- deforestation, flood, climate change
- Public health infrastructure- organisation, trained personnel
- Microbiological adaptation- antibiotic resistance, mutation
What is an outbreak?
Two or more associated cases- By definition, you need to find a link
A higher than expected incidence of cases- By definition, you need to know how many cases you expect
What is a hazard?
A hazard is a potential source of harm
A hazard in health protection terms is any substance or agent that poses a threat to health
What is the difference between a hazard and a risk?
Hazard is the potential to cause harm
Risk is the likelihood of harm
So in health protection we try to eliminate or mitigate the risks of harm from exposure to hazards
What are hazards categorised into?
- Radiation, chemical and environmental hazards
- Infectious agents that cause disease
Infectious agents fall into six groups what are they?
- Bacteria
- Viruses
- Protozoa
- Helminths
- Fungi
- Prions
What is the epidemiological triad of disease causation?
- Environment
- Host
- Agent
What are the agent factors?
- Infectivity
- Pathogenicity
- Virulence
- Minimal Infective Dose
What is infectivity?
Infectivity- The ability to enter and replicate in a host
What is patheogenicity?
Pathogenicity- The ability to cause disease in a host
What is virulence?
Virulence- The extent of disease an agent can cause in a host
What is the minimal infective dose?
Minimal Infective Dose- The amount of a pathogen that is required to establish an infection
What is opportunity of an infection influenced by?
Opportunity is influenced by level of exposure and host susceptibility
What are host factors?
- Genetics
- Age
- Lifestyle
- General health- better immune systems, co-morbidities lower the immune system and medication lead to pathogenic disease
- Nutritional status
- Psychological health- can increase exposure by taking risky behaviour, depression lowers the immune system
- Immune status
What are types of immunity?
- Innate immunity- The defensive system you were born with
- Adaptive/acquired immunity- Exposure to a pathogen triggers immune system to develop antibodies- natural or vaccine induced
- Passive immunity- Given antibodies rather than produced them oneself
What are environmental factors?
- Geography
- Climate
- Agriculture
- Infrastructure
- Social conditions
- Economic conditions
What is a communicable disease?
Communicable disease- An infectious disease transmissible by direct contact with an affected individual or the individuals discharges or by indirect means through a vector
E.g. Anthrax from exposure to a pathogen, not communicable as cannot be passed between humans
What is transmission?
Transmission- The process by which an infectious agent passes from an infected host to a susceptible host
What is transmissibility?
Transmissibility- The ability of an infectious agent to pass from an infected host to a susceptible host
What is the chain of infection?
Sequence by the infectious agent leaves its host or reservoir is conveyed by some mode of transmission and enters through an appropriate port of entry to infect the susceptible host
How do you control the communicable disease?
Controlling communicable disease requires breaking this chain of infection through interventions eliminate or reduce the infectious agent, prevent the infectious agent entering new susceptible hosts or reducing the susceptibility of potential hosts
What is a reservoir?
Reservoir- A location where an infectious agent can survive and multiply
What is a colonised reservoir?
Colonised (by bacteria)- bacteria surviving and multiplying (reservoir) but have not infected the host. Reservoir capable of being in chain of infection but are not affected at that point themselves
Human reservoirs- asymptomatic carrier?
Asymptomatic carriers- those infected but have not gone on to develop disease or those infected and incubating the disease but are not symptomatic
Human reservoir- symptomatic carrier?
Symptomatic carriers- shows symptoms
Human reservoir- convalescent carrier?
Convalescent carriers- those that have the disease and recovered but still have some infectious agent
Human resevoir- chronic carrier?
Chronic carriers- continue to harbour pathogen months and years after initial infection
Animal reservoir- zoonosis?
Zoonosis- An infection that is transmissible under natural conditions from vertebrate animals to humans
What is an environmental reservoir?
- Soil- can get cholera from soil and water
- Water
- Plants
What si mode of transmission?
how to get from reservoir to host