Descriptive Epidemiology and Surveillance of HIV/AIDS

1. Teacher Note: Module 1 Overview Content Area: Descriptive epidemiology, Surveillance, and Hypothesis-Generation Essential Questions: How is the health or disease outcome distributed in terms of person, place, and time? What are some possible explanations for this distribution? Enduring Understanding: Health and disease are not distributed haphazardly in a population. There are patterns to their occurrence that can be identified through surveillance. Analysis of the patterns of health and disease distribution can provide clues for formulating hypotheses about possible causes. Lessons: 1-1 Introduction to Curriculum 1-2 Surveillance 1.2 A – Counting/Describing HIV/AIDS 1-3 Patterns and Hypotheses 1-4 Describing Health-Related Behaviors in Youth 1-5 Creating a Surveillance Question 1-6 Respect – Part I 1-7 Surveillance Studies – In Class 1-8 Surveillance Studies – In School Core Concepts: • CDC • Ethics • Hypothesis • Human subjects • Prevalence rate • Person, place, and time • Surveillance • Survey questions New Lesson 1-3: Patterns and Hypotheses Revised Oct 22, 2011

2. Module 1 - Descriptive Epidemiology and Surveillance Lesson 1-2 A Counting and Describing HIV/AIDS Content • Justification for surveillance of HIV/AIDS • Sampler of HIV/AIDS surveillance information • Consideration of HIV/AIDS surveillance in light of case definition, the surveillance population, surveillance methods, strengths and limitations of HIV/AIDS surveillance information, HIV/AIDS incidence versus prevalence, ethical issues in the collection and use of HIV/AIDS data • Uses of HIV/AIDS surveillance data Big Ideas • HIV/AIDS surveillance in the U.S. is justified, extensive and useful • Surveillance data tell us about changes in HIV/AIDS incidence and prevalence over time, differences in occurrence within subgroups of the population, and differences by geographic location This project is supported by a Science Education Drug Abuse Partnership Award, Grant Number 1R24DA016357-01, from the National Institute on Drug Abuse, National Institutes of Health.

3. The number of people living with HIV has increased from approximately 8 million in 1990 to nearly 40 million today, and continues to increase

4. HIV/AIDS is a pandemic (global epidemic) and poses one of the greatest challenges of global public health. • HIV has variable patterns of transmission and impact among world regions and disproportionately affected disadvantaged persons such as commercial sex workers, injection drug users, men who have sex with men and persons living in poverty.

5. Significance of Health Problem: - Justifying Surveillance Criteria • Frequency • Severity • Cost • Preventability • Communicability • Public Interest

6. HIV/AIDS is the leading cause of death in Africa and the sixth leading cause of death worldwide. • Interventions to prevent transmission have been a challenge due to controversial prevention programs that contradict established practices and social norms.

7. Counts In 2014, the estimated number of diagnoses of AIDS in the United States was 44,073 • Adult and adolescent AIDS cases totaled 43,112 with 35,745 cases in males and 8,328 cases in females • Also in 2013, there were fewer than 10 AIDS cases estimated in children under age 13.

8. http://www.cdc.gov/hiv/

9. HIV / AIDS Descriptive Epidemiology - Adolescents

10. HIV / AIDS Descriptive Epidemiology Adolescents

11. HIV / AIDS - Children Infected at Birth

12. Perinatally acquired AIDS – means that if a pregnant woman has HIV / AIDS, her newborn child may become infected during birth. This is called mother-to-child transmission. Medication prevents mother-to-child transmission (implemented in 1993). After this, screening and antiviral therapies was widely employed and the numbers of infected infants began to drop. This is an example of a highly successful prevention effort. CDC: Since the time that therapy was shown to be effecting in preventing mother-to-child transmission and universal screen was recommended, there has been a 95% reduction in the number of perinatally-acquired cases of AIDS in the United States.

13. HIV / AIDS - By Race / Ethnicity

14. HIV / AIDS - By Race / Ethnicity and Heterosexual Contact

15. Five Considerations in HIV / AIDS Surveillance • Case Definition - What exactly is being counted? • Surveillance Population: Who is being monitored to obtain counts? • Surveillance Methods - How are these counts determined? • Quality of Surveillance Information - Are the data accurate, complete, representative of the population, unbiased • Ethics - Are the data collected and used in an ethical manner?

16. HIV / AIDS Case Definition What exactly is being counted?

17. Case Definition Case definition: A set of standard criteria for deciding whether a person has a particular disease or other health-related condition • Characteristics of a case definition (depending on the condition), this may include signs, symptoms, time frame, location • Why needed?

18. HIV / AIDS Case Definition Definitions of AIDS have changed over the years as more specific virus testing was developed. • Surveillance definitions were revised again in Jan 2000 • CDC now recommends HIV surveillance as an extension of AIDS surveillance (as more HIV+ people are treated and do not progress to AIDS)

19. HIV / ADIS Surveillance Population Who is being monitored to obtain counts?

20. Surveillance Population Who will be surveyed? Sample population – who to study (and where, when) Sampling issues – Should everyone be studied, or a sample? If using a sample, need to do it in a valid way (e.g., a random sample) HIV / AIDS: Survey entire population - reporting from all 50 states, District of Columbia, and territories and possessions

21. HIV/AIDS Surveillance Methods How are these counts determined?

22. HIV / AIDS Surveillance Flow Chart

23. HIV / AIDS Surveillance Methods • HIV / AIDS surveillance in the U.S. has a combination of: • Passive Reporting - combination of health care practitioners, hospitals, clinics and laboratories report cases of HIV/AIDS to state and local health departments • Active Reporting – state and local health department personnel collect information by contacting health care practitioners and reviewing medical records in hospitals and clinics

24. Types of Information Collected on HIV / AIDS What frequencies and distributions are being collected? • Frequencies (how many cases) - New cases of HIV / AIDS – Incidence - Number presently living with HIV / AIDS – Prevalence • Distributions - Person characteristics such as gender, ethnicity - Place, such as by state - Trends over time from 1981 to the present • CDC also monitors: - Mode of exposure to HIV - Opportunistic illnesses and virologic and immunoligic status - Supplemental information such as prescription of antiretroviral and prophylactic therapies

25. Review: Incidence and Prevalence

26. HIV / AIDS - New Cases, Deaths, and Prevalence

27. Quality of HIV / AIDS Surveillance Data Are the data accurate, complete, representative of the population, unbiased? What are the strengths and limitations of the HIV/AIDS information?

28. HIV / AIDS Data: Strengths and Limitations • Strength: Based on entire population rather than on a sampling strategy • Strength: Cases that are reported are accurate, based on lab test • Limitation: CDC acknowledges that HIV / AIDS data are underestimates of the true incidence and prevalence of HIV / AIDS - only “confidential, identified” cases are recorded - not all states report with same degree of completeness

29. Ethics in HIV / AIDS Surveillance • Data protection is crucial for this disease - associated with stigma for many • CDC goes to great lengths to enforce data protection rules - Checked privacy practices in 1994 - Ongoing activities to enhance privacy protection

30. Uses of HIV / AIDS Surveillance Data • Assessment of the status of a health condition • Establishment of priorities • Evaluation of programs • Conduct of research

31. Uses of HIV / AIDS Surveillance Data • Assessment of the status of a health outcome Tracking new cases over time provides a measure of the speed of an epidemic (uses “Time” information) • Establishment of priorities Early cases of HIV / AIDS among IV drug use helped determine the early public health programs in the U.S. (“Person”) • Evaluation of programs Can evaluate clean-needle programs by comparing change in disease rates in cities with and without such programs (“Place”) • Conduct of research Increases in HIV+ newborns AIDS provided impetus to develop and test drugs for pregnant women with AIDS (“Person”)

32. Re-Cap Big Ideas in this Lesson (1-2 A) • HIV/AIDS surveillance in the U.S. is justified, extensive, and useful • Surveillance data tell us about changes in HIV/AIDS incidence and prevalence over time, differences in occurrence within subgroups of the population, and differences by geographic location This project is supported by a Science Education Drug Abuse Partnership Award, Grant Number 1R24DA016357-01, from the National Institute on Drug Abuse, National Institutes of Health.

33. How This Relates to the Next Lesson (1-2 B) Counting High School Marijuana Use • What question would you ask to be able to determine marijuana use? (Case Definition, Methods) • Who would you include in your survey? (Population) • How would you conduct the survey (telephone, mail, personal interview, internet, or group)? (Methods) • How would you assure that the survey answers are accurate? (Methods, Quality) • What would the limitations of your plan be? (Quality, Ethics)