Lesson 4 Flashcards
What are Health Protection Services?
- Surveillance and control of new and re-emerging infections (e.g. TB)
- Surveillance and control of STIs and blood borne viruses
- Infection control and anti-microbial resistance
- Control of epidemics & pandemics
- Working with other specialists; national and international
Who are ‘key players’ in Health Protection?
Specialists in communicable disease control and health protection
Director of Public Health and Public health specialists
Infection control teams
Emergency planning advisers
Microbiologists – who study the organisms that cause infectious diseases
Clinicians (GPs, A&E Doctors, Community Nurses, Midwives… etc)
What are the three levels of organisation and delivery of Health Protection in the UK?
Nationally - UK Health Security Agency (UKHSA)
Regionally - HSA Regional Centres
Locally - Health Protection Teams
What is the global burden of infectious disease?
• Infectious Diseases cause over 20% of all deaths, globally
• 1,000,000 children each year die from diseases that could have
been prevented by vaccination
• 1,300,000 deaths in 2015 were attributable to viral hepatitis
• 1,400 children die each day from infectious diarrhoeal diseases
(Pre-covid)
What is the burden of infectious disease in the UK?
- £30 billion per year
- over 10% of deaths
- one in three GP consultations
- In 2012 - 8,741 cases of TB, high compared to most Western European countries
- ~25% of the population is affected by GI infection each year -> ~1 million GP visits /~29 million days lost from school or work
- In 201, 21% of all days of work were lost because of coughs, cold and flu.
State the special features of infectious disease epidemiology
- A case of disease may also be a risk factor (even if not recognised as a case)
- Immunity can occur
- Speed of intervention can be critical
Define infectious agent (pathogen)
A viral, bacterial, protozoan or fungal substance that causes disease.
Define infection
The entry and development or multiplication of an infectious agent in the body – the result may or may not be apparent
Define infectious disease (communicable disease)
An illness due to a specific infectious agent or its toxic products that arises through transmission of the agent/ products to a susceptible host
Define contagious
Transmitted by contact
What is passive surveillance (method of surveillance)?
A system by which a designated body (e.g. the local authority or the HPA in England) receives reports of infectious diseases or other illnesses submitted from hospitals, clinics, public health units, or other sources. Cheap, but with reduced quality and completeness.
What is active surveillance (method of surveillance)?
A system whereby staff members of a designated body (e.g. the HPA in England) regularly contact health care providers or the population to seek information about health conditions. Relatively more expensive, but it provides more accurate and timely information
What is routine surveillance (types of surveillance)?
Involves collection of a basic minimum data set, often from one source of data.
Examples include statutory notification of infectious diseases (e.g. NOIDs, laboratory surveillance)
What is enhanced surveillance (type of surveillance)?
Involves collection of a more detailed data set from informants, may combine epidemiological and microbiological data, and may include multiple sources of data.
Examples include meningococcal disease, tuberculosis, listeriosis, enteric fevers, antimicrobial resistance and travel associated legionella infection
Where are the main places we get information from?
Primary Care reporting systems e.g. GPs, Pharmacists, NHS Direct, NPFS
Hospital information systems
Laboratories
What happens with a disease notification?
Consultant in Communicable Disease Control (CCDC) can respond to a notification by:
• Tracing contacts of the index case infected person to:
a) identify source of the infection
b) prevent further dissemination, e.g. tuberculosis
• Interviewing affected people to identify the source of infection, e.g. in a food poisoning outbreak
• Confirming the diagnosis by further testing the infected person, e.g. measles
What are some limitations of surveillance?
Under reporting
Lack of representativeness of reported cases
Trends are difficult to interpret
Lack of denominators
Define reservoir
The reservoir is a host which allows the pathogen to live, and possibly grow, and multiply. Humans, animals and the environment can all be reservoirs for microorganisms.
Define vector
A host that carries a pathogen without injury to itself and spreads the pathogen to susceptible organisms
Define sporadic
Occasional cases occurring at irregular intervals
Define endemic
Continuous occurrence at an expected frequency over a certain
period of time and in a certain geographical location
Define epidemic
Occurrence in a community or region of cases of an illness with
a frequency clearly in excess of normal expectancy
Define pandemic
Epidemic involves several countries or continents, affecting a large population
Compare the transmission and number of cases for an endemic, epidemic and pandemic
Endemic - Transmission occur, but the number of cases remains constant
Epidemic - The number of cases increases
Pandemic - When epidemics occur in several continents – global epidemic
State what the four phases are for UK’s response to COVID 19
- Contain: Early case detection, intense contact tracing to prevent disease from embedding in the community.
- Delay: Slow the spread, delay the peak and push it away from winter (13/03/20)
- Research: Diagnostics, drugs and vaccines
- Mitigate: Focus on those critically unwell and maintain essential services
What are some recognised sources of infections?
- Animal-to-person – primarily a zoonosis
- Meat (e.g. ground beef)
- Waterborne
- Cross-contamination in food preparation
- Person-to-person
- Other foods of animal origin
- Contamination of produce with ruminant faeces
What is a general pathway for the transmission of infectious agents?
Reservoir -> immediate source -> mode of transmission -> susceptible host
What is HCAI?
HCAIs cover any infection contracted:
• as a direct result of treatment in/contact with, a health/social care setting
• as a direct result of healthcare delivery in the community
• as a result of an infection acquired outside a healthcare setting -> brought into a healthcare setting by patients, staff or visitors -> transmitted to others within that setting
Provide statistics on Hospital Acquired Infection (HAI)
- Approx 1 in 10 admissions
- Average increase in stay – 11 days
- Prevalence of 6.4% in 2011 vs 8.2% in 2006
- Respiratory tract, urinary tract and SSIs commonest
- Prevalence of national antimicrobial use was 34.7%
What can be done to allow for source isolation?
Patient with ID should be accommodated in
- a single room on a general ward, or - an isolation unit with negative pressure ventilation, anterooms and en-suite facilities.
What does it mean for a patient to be put into protective isolation
Patient with increased vulnerability to infection should be accommodated in
- A protective isolation room with positive pressure - A general side room with the door kept closed
What are examples of infection prevention and control programs?
- Hand hygiene
- IPC Policies
- Education and training
- Surveillance of infections
- Precautions including PPE, isolation,
- Environmental hygiene
- Decontamination
- BREAK THE CHAIN
How can an investigation of hospital infection cluster/outbreak be implemented?
- Emphasis of IPC programmes is on prevention -> robust cluster outbreak plan for the hospital
- Control activities may include cohorting, isolation, extensive patient screening and restrictions on admissions and discharges all of which can have a major impact on the functioning of the hospital and the wider health economy – think Influenza !
What are control measures that can be implemented within hospitals to limit the spread of infection?
- Close affected bays to admission and transfers
- Stringent hand hygiene
- Personal Protective Equipment
- Enhanced cleaning (environment, equipment, linen, spillages)
- Isolation
- Exclusion
What are ways to protect the general public from infectious agents?
- Handhygiene
- Decontaminationofsoiledmaterials
- Properautoclavinganddisposalofmedicalwaste
- Reporting–ThinkNOIDs
