EPIDEMIOLOGIC SURVEILLANCE AND EPIDEMIC OUTBREAK INVESTIGATION (PART 1) Flashcards
○ From a source common to all
Common-vehicle exposure
○ Exposed only once
Single Exposure
○ Exposed several times
Multiple Exposures
○ Intermittent contamination
Periodic Contamination
○ Persistent contamination
Continuous Contamination
○ Characterized by signs and symptoms
Clinical Disease
Non-clinical Disease
Preclinical
Subclinical
Persistent (Chronic)
Latent
- symptoms not yet apparent but the disease is biologically present and destined to progress to clinical
Preclinical
- symptoms not yet apparent but seropositive
Subclinical
- manifestation of symptoms for years
Persistent (Chronic)
- no active multiplication of the agent
Latent
○ Harbors organism, can be asymptomatic and seronegative
Carrier
Factors that affect incubation period
○ Time of replication
○ Site of replication
○ Dose of infectious agent
○ Detention period of animal or human
Quarantine (quarante giomi)
○ A person who acquires the disease from exposure
○ E.g. from contaminated food
Primary Case
○ A person who acquires the disease through exposure to primary case
Secondary Case
○ Factors such as sex, age, race, and other host characteristics
WHO
○ Certain diseases occur with a certain periodicity
WHEN
○ Diseases are NOT randomly distributed in time or place
WHERE
● A very helpful method for determining which of the possible agents is likely to be the cause of the certain outbreak.
CROSS TABULATION
● Establishment of Baseline data
● Evaluation of Time trend’s
● Identification and documentation of Outbreaks
● Evaluation of Public Health and Disease Interventions
● Setting of Disease Control Priorities
● Study of Changing Patterns of Disease
SURVEILLANCE OF DISEASE
○ The occurrence of disease or unexpected, elevated frequency
Epidemics (disease outbreaks)
○ Entire process of collecting, analyzing, interpreting, and reporting data on the incidence of death, diseases, and injuries and the prevalence of certain conditions, for promoting and safeguarding public health.
Surveillance
○ United States Federal Agency responsible for surveillance.
Centers for Disease Control and Prevention (CDC)
Development of surveillance system requires:
Clear objectives
Standardized reporting procedures
Identify the etiology or cause of a disease and the relevant risk factors Determine the extent of disease found in the community
Study the natural history and prognosis of disease
Evaluate both existing and newly developed preventive, therapeutic measures, and modes of health care delivery
Provide the foundation for developing public policy
Case definition based on clinical findings
Determination of intensity of surveillance (Active vs passive)
Determination of duration of surveillance (ongoing vs time-limited)
Types of analysis (e.g. incidence, prevalence, case fatality ratio, etc.) Plans for information dissemination (internet, publication, broadcast)
Pilot test performed and evaluated first before full system attempt
Continuous evaluation when full system is operational
METHODS AND FUNCTIONS OF DISEASE SURVEILLANCE
Process of collecting, analyzing, interpreting, and reporting data concerning incidence of death, diseases, and injuries and the prevalence of certain conditions
Physicians, clinics, labs, and hospitals are instructed to record all cases of reportable disease that they encounter.
Passive (Ongoing)
Surveillance body (e.g., CDC) makes periodic phone calls, e-mails, and visits to reporting individuals/ institutions to obtain data
Active (As needed)
○ Detect deviations from the usual pattern of data
○ Prompts epidemiologist to explore
Continued surveillance
