Surveillance and outbreaks Flashcards
What is the public health definition of surveillance?
The ongoing systematic collection, analysis and interpretation of health-related data essential to planning, implementation and evaluation of public health practice
What are the goals of public heath surveillance?
Acquire information to guide public health policy and programs
Estimate magnitude and scope of health problems
Measure trends in data and characterise nature of disease
Monitor changes in infectious and environmental agents
Detect epidemics, health problems, changes in health behaviours
Identify patients and their contacts for treatment and intervention
Assess effectiveness of programs and control measures
Develop hypotheses and stimulate further research
What is the overall process from problem to response?
Surveillance - to identify problem
Risk factor identification - identify the cause
Intervention evaluation - identify what works
Implementation - identify how to put interventions in place
How is surveillance of infectious diseases done?
Determine current burden and epidemiology of disease
Monitor trends in disease over time or following interventions
Identify outbreaks and new pathogens
What does determining the current burden and epidemiology of a disease entail?
Prevalence of disease plus seasonality, geographic distribution, age groups, etc.
Evidence for interventions such as vaccines or antibiotic administration
Determine antimicrobial resistance and identify currently circulating strains
How are trends in disease over time monitored in surveillance?
Determining the impact of a vaccine on levels of disease, circulating strains or etiology of cases
Assess control, elimination or eradication of disease following control measures
How are outbreaks and new pathogens identified in surveillance?
Early detection, rapid response and mitigation of disease outbreaks or epidemics
Identify risk of newly emerging or re-emerging pathogens in population
Describe passive surveillance
Diseases reported as standard by GPs, hospitals or diagnostic laboratories
Routine reporting of notifiable diseases to public health agency for analysis
May incorporate administrative data, healthcare seeking activity, internet searches
Limited by incompleteness of reporting and variability in data quality
Relatively simple and inexpensive approach for key pathogens and diseases
Describe active surveillance
Public health agencies actively engage to seek reports of disease cases
Ensures more complete reporting of cases with active follow-up and review
Most accurate and timely, aiming to detect ever case with defined case definitions
More comprehensive but expensive due to human and financial resources required
What are notifiable diseases?
Diseases that are important to public health
Diseases that cause severe risk to human health
Diseases prone to outbreaks or epidemics
Emerging or re-emerging diseases
Diseases with interventions for their control
How are diseases confirmed in the diagnostic lab?
Microbiological culture - identifying clinical isolate
Serology - biomarker antibodies
Molecular methods - PCR, LAMP, NAAT, MLST
Typing - PFGE, antibiogram, serotyping
Whole genome sequencing - virulence factors, SNPs
What are examples of passive surveillance?
Monitoring pandemic response and rates of other seasonal diseases
Informing content of vaccine formulations and tracking impact of roll-out
Assessing circulating resistance determinants and evolution of multi-drug resistant pathogens
Triggering further investigation of unusual spikes or trends in data
What is an outbreak?
Two or more people experiencing similar illnesses linked in time or place
Greater than expected rate of infection compared to the usual rate for the time/place
Single case for certain rare diseases such as diphtheria, botulism, rabies, viral haemorrhagic fever or polio
Suspected, anticipated or actual event involving microbial or chemical contamination of food or water
How are outbreaks managed?
Initial incident notified
Response and investigation
Outbreak declared
Outbreak control team - coordinate and direct investigations, enact and monitor control measures, communicate actions and progress
Agencies involved
End of outbreak
What are examples of active surveillance?
Food poisoning - source of disease linked to food processing, supply chain or outlet
Environmental contamination - exposure to natural pathogen or accidental release
Hospital acquired infection - transmission due to breakdown in infection control
Travel - infection following return from endemic area and onwards transmission
