2 AIDS- History and Progression Flashcards
Q: Describe our development in the understanding of AIDS over time. Virus discovered when? What was conducted and what was found? Test for virus when?
ART available when? Describe AIDS now.
A: virus discovered 1983
did case control study
No association was found with drugs
The only main common factor was the disease was seen amongst young gay men and seemed to be related to sexual contact with each other- called CASE CLUSTERING suggesting infectious agents
It was called GRID- Gay Related Immune deficiency
Test for virus- 1984 but still NO TREATMENT Antiretroviral Therapy(ARTs)) became available in mid 90s.
AIDS NOW
- Global disease
- Transmission (through bodily fluids) known: sexual contact, breast feeding or blood
- 90% of disease in developing countries
Q: What are the 3 aims set up by WHO for HIV/AIDS?
A: Getting to zero(WHO)
- No new infections
- No new babies infected
- No more HIV related deaths globally
Q: What does a case-control study set out? to determine? Provide an example.
A: Sets out known outcome and compares individuals with or without this outcome and determines what connects them
E.g. post op infections over a given time of an outbreak cases: knee op with infection controls knee op no infection
Q: Why is a case-control study retrospective?
A: it starts with an outcome then traces back to investigate exposures
Q: How do you design a case-control study?
A: 1 identify the cases (a group known to have the outcome) and the controls (a group known to be free of the outcome) -> makes it case specific
2 look back in time to learn which subjects in each group had the exposure(s), comparing the frequency of the exposure in the case group to the control group
Q: What is the aim of a case-control study and what will it test?
A: It will determine whether an exposure is associated with and outcome (i.e. disease or condition of interest)
Q: What is the advantage of a case-control study? (3)
A: Cheap
Quick
Good for investigating outbreaks to infectious disease
Q: Describe the successes of the AIDS epidemic response. (4)
A: Great success: the very broad access to antiretroviral therapy (ART) for HIV achieved in poor countries
Declines in HIV prevalence in pregnant woman in recent years
We now know how to eliminate mother to baby transmission- mother given ART prior to delivery
Number of effective HIV prevention methods available today, including safer sex, safer injection practices, condom use, and male circumcision
Q: Describe the challenges of the AIDS epidemic response. (4)
A: HIV treatment prolonging millions of lives BUT can’t treat our way out of epidemic
-For every 1 person on HIV therapy today, 5 are newly infected.
social obstacle attached to these eg safer sex/injection practices
Even when these interventions are fully funded and supported by states and social institutions, they have only been able to drive HIV infection rates down to a certain level.
Many people choose not to get tested
Q: How do we reduce further HIV incidence?
A: we need new biomedical tools – the most important of these will be an EFFECTIVE HIV VACCINE
Q: What are the key measures of disease in the population?
A: Case
Prevalence
Incidence
Q: Describe HIV infection in the UK? Incidence? Death rate? Duration of disease? Who should get HIV testing and treatment?
A: the numbers of new cases of HIV being diagnosed each year (incidence) is rising
The numbers of deaths from AIDS has declined, due to improved treatment with Highly Active Anti-Retroviral Therapy (HAART)
Therefore, the duration of disease is increasing. The consequence is a steep increase in the prevalence of HIV (the number of people living with HIV)
all HIV+ selected groups or according to ART availability and need?
Example Exam Q: How can we explain that as prevalence increases, incidence can reduce in the setting of HIV infection?
A: Antiretroviral therapy (ART) improves survival of people living with HIV as more people living with HIV receive ART (15 million people globally are on ART) the prevalence of HIV within a population increases
ART also reduces the risk of onward viral transmission by limiting the level of virus in the blood and secretions of people living with HIV to almost zero (HPTN052, PARTNER study, PMTCT studies)
Therefore, the more people taking ART the less people within a population transmit infection and so incidence reduces
Example Exam Q: Explain the relationship between prevalence and mortality.
A: – Define prevalence and mortality
– For diseases where treatment confers survival benefit (e.g. ART for people living with HIV) the mortality falls as people start ART. Hence these people survive and overall population level prevalence increases.
– For diseases that are rapidly fatal (e.g. Ebola) the mortality is rapid and high and so large number of cases but overall prevalence is low
