communicable disease control Flashcards
Childhood vaccinations
DTP (diphtheria, tetanus, pertussis)
polio
Hib
hep B
men B
men C
Rotavirus
Pneumococcal
MMR
HPV
Men ACWY
influenza for children aged 2-3 and school age + children with long term conditions
older adults vaccination
COVID-19
Flu
Pneumococcal
shingles
RSV
targeted vaccination
pregnancy - RSV, pertussis, influenza
TB - infants from areas of high TB incidenc or with parent or grandparent from there
children in clinical risk group - flu
adults in clinical risk groups (CKD, diabetes, COPD) - flu, pneumococcal
occupational groups - e.g. BBVs, TB
what to consider in designing immunisation strategy
aim - control, eliminate, eradicate, prevent severe disease, high risk groups?
who - define population, age
inform - comms - provide information, increase uptake
vaccine - type, cost, adverse effects, how many doses, cost effectiveness, evidence
implementation - where to deliver
monitoring and evaluation - cost effectiveness, uptake, adverse effects, disease incidence, inequalities
types of vaccine
live attenuated - weakened form of live pathogen e.g. oral polio
inactivated - dead pathogen but can still cause immune response. e.g. hep A or rabies
subunit - conjugate, polysaccharide, protein-based - made from a piece of the pathogen like a surface proteins. e.g. men acwy
toxid - inactivated toxin produced by the pathogen e.g. pertussis
viral vector = delivers antigen genetic code e.g. ebola
mRNA vaccine = insoluable capsule deliver viral mRNA e.g. covid-19
outbreak
2 or more people experiencing a similar illness linked in time and place. OR
* a greater than expected rate of infection compared to background for that place or time
* a single case of disease of PH importance
* a suspected or actual contamination event of food or water
cluster
refers to an aggregation of cases grouped in place and time that are suspected to be greater than the number expected, even though the expected number may not be known.
epidemic
epidemic = refers to an increase, often sudden, in the number of cases of a disease above what is normally expected in that population in that area. Usually over a wider geographic area than an outbreak
pandemic
refers to an epidemic that has spread over several countries or continents, usually affecting a large number of people.
endemic
refers to the constant presence and/or usual prevalence of a disease or infectious agent in a population within a geographic area. Hyperendemic refers to persistent, high levels of disease occurrence.
framework for outbreak control
Disease Outbreak (CCDCs Do Help To Control Cholera Deaths)
o Confirm outbreak exists – collect information (inc NOIDs), compare to that expected, definitions of outbreak. Establish OCT / IMT
o Confirm Diagnosis – specimens
o Case Definition – time/person/place, symptoms, possible/probable/confirmed
o Collect data – determine background rate of disease, find cases, microbiological data, genetics, environmental samples
o Describe data – time/person/place – plot the epi curve, population at risk, risk factors
o Generate Hypothesis – pathogen, source, transmission
o Test Hypothesis – cohort/case-control,
o Control – control source, transmission mode, host defences, protect at risk.
o Communication/– Must agree comms strategy – accuracy and timeliness, proactive/reactive. Internal (shared situational awareness): OCT members. External: healthcare professionals, social care, public health teams (regional/national if appropriate), epidemiologists, virologists/microbiologists, environmental health, industry, the public
o Declare outbreak is over –once returned to background rate. Outbreak report + Evaluation and learning to prevent future incidents.
emergency
= An event or situation threatening serious damage to human welfare (e.g., disruption to health services, food, water, energy, or transport) or the environment. Emergencies might be natural (extreme weather, wild fires, earthquakes, volcanic eruptions) or man-man (CBRN, shootings)
EPRR cycle
prevention - assess and anticipate risks
mitigation - reduce size of impact
preparedness - plans and training and exercising
response - mobilise resources, contain source
recovery - decontamination, lessons, long term consequences
what is IPC and the key measures
= a practical, evidence-based approach preventing patients and health workers from being harmed by avoidable infections. All hospitals are required to have an IPC team who a responsible for providing expert advice, training, implementing systems and processes, surveillance and controlling HCAIs. NHSE produces the national IPC manual for NHS settings. CQC inspects against standards for IPC
measures:
- PPE
- handwashing
- cough hygiene
- management of equipment and environment
- laundry management
- spills of bodily fluids
- reducing exposure
- waste management
- training
role of local gov in infection control
DPH - duty to prepare for and lead response to PH incidents (cat 1 responder)
ICB also cat 1 responder
health protection powers
environmental health teams - food premises, water, air, noise issues, contaminated sites
work with HPTs in outbreak response
Port health =
monitoring and control of PH risks at ports of entry, ensuring safety of imported goods, preventing entry of infectious diseases of epidemic potential, and protecting public health.
tradition microbiological techniques (4)
● Microscopy = identification of microorganisms using direct visualisation of morphology - stains, probes with coloured tags (fluorescence microscopy), electron microscopy for high resolution images of microorganism structures.
● Culture = isolate and amplify microorganisms under controlled conditions – identify using specific mediums, drug sensitivity
● Serology and immunological tests – detect and identify antigens and antibodies in the host. Including ELISA (immunoassay), lateral flow assays (point of care))
● Mass spectrometry - Identify microorganisms based on protein profiles. Microorganisms produce a unique spectral pattern when hit with a fixed pulse laser beam which can be compared against a database to identify it.
molecular techniques used in labs
● Polymerase Chain Reaction (PCR): Amplifying specific DNA/RNA sequences. Real-time PCR (qPCR) is used for for rapid pathogen detection and quantification.
● Next-Generation Sequencing (NGS): Whole-genome sequencing for identifying pathogens, strain typing, outbreak investigations, or metagenomics.
● Fluorescence in situ hybridisation (FISH): fluorescent probes used to detect RNA or DNA sequences in cells e.g. detected pathogen in clinical samples
● Nucleic Acid Hybridization: Techniques like Southern blot or microarrays which measure the expression of multiple genes simultaneously
Risk comms CERC model (CDC
- Be First: Crises are time-sensitive. Communicating information quickly is almost always important. For members of the public, the first source of information often becomes the preferred source.
- Be Right: Accuracy establishes credibility. Information can include what is known, what is not known, and what is being done to fill in the gaps.
- Be Credible: Honesty and truthfulness should not be compromised during crises.
- Express Empathy: perceived severity and perceived susceptibility. Crises create harm, and the suffering should be acknowledged in words. Addressing what people are feeling, and the challenges they face, builds trust and rapport.
- Promote Action: Giving people meaningful things to do calms anxiety, helps restore order, and promotes a restored sense of control.
- Show Respect: Respectful communication is particularly important when people feel vulnerable.
types of outbreak curve
Point source – Persons are exposed to the same common source over a brief period of time, such as through a single meal or event attended by all cases; number of cases rise rapidly to a peak and falls off gradually; majority of cases occur within one incubation period.
Continuous source – persons are exposed to the same source but exposure is prolonged over a period of days, weeks, or longer. The epi curve rises gradually and might plateau. e.g., contaminated food product sold over period of time
Propagated source – does not have a common source but spreads person to person. tends to have a series of irregular, progressively larger peaks; multiple peaks separated by approx. one incubation period; e.g., person-to-person spread of shigellosis
Intermittent source – similar to continuous but exposure is intermittent; multiple peaks – length: no relation to the incubation period (reflects intermittent times of exposure) e.g. water contamination which reduces as water quality improves then re-emerges
