LE1 EPIDEMI

• demo means people
• graphy means writing about or recording something
• Demography means writing about the people
• Demography is the science of populations
• what is the problem - surveillance
• what is the cause - risk factor identification
• what works - intervention evaluation
• how you do it - implementation
• core sciences: surveillance, prevention effectiveness, epidemiology, laboratory, and informatics
• surveillance - monitor public health situation (where and when)
• epidemiology - where diseases originate, how they move through populations, why they are moving and understand how we can prevent them (why some populations choose to become vaccinated and some do not)
• laboratory - support public health by allowing the finding of diagnosis that is being investigated on (diagnose whether the disease caused is influenza or something else)
• laboratory - help in conducting research and testing
• informatics - deals with the methods in collecting, piling and effectively using electronic data to solve public health problems (clinical records)
• Prevention effectiveness - is closely linked to public health policy (To asses whether an influenza vaccination costing hundreds dollar will ultimately result in a savings of over a million of dollars)
• Prevention effectiveness - studies important economic information to decision-makers and allow them to choose from among the options the best option possible
• epidemiology - study of distribution and determinants of health-related states among specified populations and the application of that study to the control of health problems
• Epidemiology Purposes in Public Health Practices:

  • Discover the agent, host, and environmental factors that affect health
  • Determine the relative importance of causes of illness, disability, and death
  • Identify those segments of the population that have the greatest risk from specific causes of ill health
  • Evaluate the effectiveness of health programs and services in improving population health
• Solving Health Problems: Data collection (surveillance - time, place, and person) -> Assessment Inference) -> Hypothesis Testing (determine how and why) -> Action (Intervention)
• Implementation of action should be at a population level
• All of the following illustrates the purpose of epidemiology in public health except

  • identifying populations who are at risk for certain diseases
  • assessing the effectiveness of interventions
  • providing treatment for patients in clinical settings
  • determining the importance of causes of illnesses

  Answer: c
• Epidemiologists use a model for studying infectious disease and its spread that involves the microbe that causes the disease, the organism that harbors the disease, and the external factors that cause or allow disease transmission. This is also known as

  • host, vector, and transmission
  • transmission, host, and environment
  • host, agent, and environment
  • organism, transmission, and environment

  Answer: c
• Epidemic or outbreak: disease occurrence among a population that is in excess of what is expected in a given time and place
• Sporadic: fewer than 10 cases per year; last week, 1 case
• Cluster: group of cases in a specific time and place that might be more than expected
• Outbreak: usually no more than 2-4 cases per week; last week 13 cases
• Endemic: disease or condition present among a population at all times
• Endemic : 40-50 cases per week; last week, 48 cases
• Epidemic or outbreak: usually no more than 2-4 cases per week; last week, 13 cases
• Pandemic: a disaster or condition that spreads across regions
• Rate: number of cases occurring during a specific period; always dependent on the size of the population during that period
• Malaria is present in Africa at all times because of the presence of infected mosquitoes. Malaria is endemic in Africa
• The Ebola virus in parts of Africa is in excess of what is expected for this region. This virus is a/an epidemic
• HIV/AIDS is one of the worst global diseases in history. It is a/an pandemic
• In March 1981, an outbreak of measles occurred among employees at Factory X in Fort Worth, Texas.

  This group of cases in this specific time and place can be described as a cluster
• Rates help us compare health problems among different populations that include two or more groups who differ by a selected characteristic
• To calculate a rate, we first need to determine the frequency of disease, which includes:

  • number of cases of the illness or condition
  • size of the population at risk
  • period during which we are calculating the rate
• Rate = (number of cases / population at risk) x 100
• On Day 1 of a technology conference in San Diego, 15 presenters who were setting up for their session in Annex X became ill with flu-like symptoms. During the course of the conference, 20 participants who attended session in Annex X also became ill with the same symptoms

  
  

  To being calculating the rate of this outbreak, investigators should first determine

  • size of the conference population
  • number of cases of illness
  • number of days of the conference was held
  • location of the conference

  Answer: B
• Experimental - investigators can control certain factors within the study in the beginning (ex. vaccine efficacy trial)