hiv epidemiology in the prairies

GREG RIEHL, R.N., SASKATCHEWAN HIV HCV NURSING ED ORG

Epidemiology in the Prairies: Spotlight on

Saskatchewan

HIV is a great story.

It pushes all the news buttons: it is a health emergency, it has a human face, it has elements of science, medicine, religion, it has deep grief and moments of extreme joy.

It often has enemies: governments, the church, religious bodies, the fraudsters and snake-oil salesmen.

It has heroes: the people living with HIV, community groups and NGOs fighting on the frontline of the epidemic, the scientists and researchers working for new treatments, a vaccine, a cure, and the doctors and nurses caring for the sick and dying.

It is clear that HIV and AIDS is more than a disease that infects individuals.

It is a social, economic and, in some countries, security crisis.

Why is everyone talking about Saskatchewan

What is so unique about the epidemiology of this province?

How can these numbers help or hinder communities, agencies and, most importantly, people in the Prairies living with HIV.

We will not be doing this . . .

DEFF = 1 + (m – 1)rr = sc2/(s2 + sc2)

Epidemiology

• epi = upon; demos = the people; ology = to speak of (to study)

• Definitions vary but each definition seems to include reference to:• "the study of," • "disease and health-related conditions," and • "populations and groups."

Statistics

Epidemiologic statistics are mere estimates of the parameters they wish to estimate.

Epidemic

The term epidemic is used when HIV and AIDS are widespread in a community.

The term epidemic can be applied to any disease or health-related condition that occurs in clear ______________ of normal expectancy.

Does Saskatchewan have an HIV epidemic?

In order to understand the many epidemics of HIV that are spreading around the world, and the AIDS epidemics which follow in their footsteps, it is necessary to look at certain figures.

The figures we need include: the number of people living with HIV (the HIV

prevalence), the number of new infections (the HIV incidence), and the number of people who have died of AIDS.

Because HIV is mostly transmitted via unprotected sex, a society’s myths, taboos and societal norms can often cloud debate on the disease and prevent accurate information getting into the public domain.

HIV/AIDS media guide IFJ media guide and research report on the media's

reporting of HIV/AIDS http://www.ifj.org/assets/docs/117/252/83d8475-9cb28fc.pdf

Fast facts

Less than 20 per cent of people at risk of contracting HIV have access to preventative measures such as condoms.

UNAIDS estimates that at best, only one person in ten in Africa and one in seven in Asia in need of antiretroviral treatment were receiving it.

More than 600 people contract HIV every hour.

Women account for nearly 50 per cent of all HIV/AIDS cases.

What is Infection?

Infection = biologic agent living and replicating within host

Infectious disease = infection accompanies by pathologyInfection ≠ disease!

Viruses (submicroscopic; incapable of multiplication outside of host)

04/10/2311Pathos

Analogy

Before the HIV was discovered, epidemiologists noticed that AIDS and Hepatitis B had analogous risk groups, suggesting similar types of agents and transmission

Analogy

• Early in the AIDS epidemic, before HIV was discovered (circa 1983), epidemiologists realized groups at high risk of HIV groups shared characteristics with groups at high risk of Hepatitis B.

• This suggested the diseases were spread by similar mechanisms.

• What data do we collect and why?• Age, gender, risk factor, ethnicity, etc.

What does the public think is happening?

Where does the public get their information?

Where does the media get their information?

Do we all collect the same data?

There are two main types of national HIV and AIDS statistics:

Reports of actual cases tell us the minimum number of people who are affected, but are of limited use if many cases go unreported.

Estimates based on surveys give the proportion of people living with HIV, as well as other statistics, according to certain assumptions.

Where do we collect data in SK?

The Problem of Induction

Why can you never prove that all swans are white?

Will all IDU’s get HIV? HCV?

Who do we collect data from? And what do we do with the information?

Do we treat all communicable diseases the same?

Surveillance

• Obtaining an estimate of the number of people infected with HIV in a country or region is important for the purpose of evaluation, programme planning and advocacy.

• Estimates are usually obtained from surveillance systems, but because HIV epidemics develop differently in different countries, different surveillance systems are required (UNAIDS/WHO– (UNAIDS/WHO Working Group on Global HIV/AIDS and STI

Surveillance, 2000).

– http://data.unaids.org/pub/manual/2005/20050101_gs_guidemeasuringpopulation_en.pdf

Surveillance

• In all epidemic states, surveillance systems aim to provide information that will increase and improve the response to the HIV epidemic.

• In countries where HIV is uncommon, biomedical surveillance and behavioural data can provide an early warning of a possible epidemic. – (UNAIDS/WHO Working Group on Global HIV/AIDS and STI



Surveillance

• Where HIV is concentrated in subgroups with high-risk behaviour, surveillance can provide valuable information for designing focused interventions.

• In generalized epidemics, sentinel HIV surveillance among the general population can provide essential information for planning care and support and for indicating the success of the current response – (UNAIDS/WHO Working Group on Global HIV/AIDS and STI



Surveillance

Most sentinel surveillance systems have limited geographical coverage, especially in smaller and more remote rural areas.

Can an event or condition ever be said to have a single cause?

Population-based survey to measure HIV prevalence

• Countries that do not have existing population-based surveys to which HIV testing can be added have to design and conduct new seroprevalence surveys.

• Do we need to do surveys, or more research in Saskatchewan?

Population-based survey to measure HIV prevalence

• The primary objective of a population-based HIV prevalence survey is typically to obtain:• Accurate HIV prevalence estimates• Information on risk factors related to HIV infection • To inform the design, implementation and evaluation

of the response to the HIV/AIDS crisis or epidemic.

• Do provincial reports in Saskatchewan and Canada meet this criteria?

Prevalence

'HIV prevalence' is given as a percentage of a population.

If a thousand truck drivers, for example, are tested for HIV and 30 of them are found to be positive, then the results of a study might say that HIV prevalence amongst truck drivers is 3%.

Prevalence?

• A prevalence count includes all cases (old and new). An incidence count includes only recent onsets (i.e., onsets that occurred during the period of observation).

• Perception of risk often differs from reality. Identify factors that shape misapprehensions of risk. – Factors that shape misapprehensions about risks

include: (a) fear (b) lack of control (c) media attention (d) the inability to deal with numerical information

Prevalence?

• What goes into the numerator of a prevalence calculation?

• What goes into the denominator of prevalence? • What units are associated with prevalence

estimates? • List ways in which prevalence differs from

incidence. • If the rate of a disease remains constant, but the

death rate of the disease decreases (through improved treatment), what happens to its prevalence of the condition over time?

Prevalence

In a country with a low-level or concentrated epidemic (where high levels of infection are found only in specific groups), the national estimate of HIV prevalence is mainly based on data collected from populations most at risk - usually sex workers, injecting drug users or men who have sex with men - and on estimates of the sizes of the populations at high risk and at low risk.

Better understanding of the nature of an HIV epidemic allows better prevalence estimates to be produced. This is why, each year when a new set of estimates is brought out, the figures for previous years may change.

Prevalence

(c) B. GerstmanChapter 6

30

Point prevalence = prevalence at a particular point in time

Period prevalence = prevalence over a period of time

Interpretation A: proportion with conditionInterpretation B: probability a person

selected at random will have the condition

people of no.

cases new and old no.Prevalence

Incidence

'HIV incidence' is the number of new HIV infections in the population during a certain time period.

People who were infected before that time period are not included in the total, even if they are still alive.

True or False?

Changes in HIV incidence statistics can give an idea of whether prevention strategies are being successful in reducing the number of new infections.

A society that shows regularly declining incidence figures is one that is experiencing fewer and fewer new infections, which is certainly desirable.

Denominators


33

Denominators: reflection of population size

Numerators & Denominators

“Rates” are composed of numerators and denominators

Numerator case countIncidence count onsetsPrevalence count old +

new casesDenominators

reflection of population size


34

Saskatchewan population

Saskatchewan populations

“Rate”

GerstmanChapter 2

37

00933.098,765

921 rateMortality

sindividual 98,765in death 921 :Example

size population

events of no.Rate

Loosely, the “rate” of an event is the number of events divided by population size

NEP

The problem with insisting on one-for-one exchange is that research shows that this can restrict access to clean needles and therefore increase infection rates.

Do needle-exchange programs really work?

Key Terms

GerstmanChapter 1

39

Morbidity = related to disease or disabilityMortality = related to death Endemic = normal occurrence of a conditionEpidemic = much greater than normal

occurrence of a conditionPandemic = an epidemic on multiple continentsIncidence = rate or risk of developing a

conditionPrevalence = proportion of population with a

condition

HIV Morbidity

In 2008, 173 laboratory-confirmed HIV cases were reported compared to 127 in 2007,

101 in 2006 and 80 in 2005 (an increase of 36% from 2007). There was a total of 707

HIV infected individuals identified in the 10 years, 1999 to 2008.

Prenatal statistics

In generalized epidemics, HIV testing among pregnant women is considered a good proxy for prevalence in the general population.

In countries with low levels of HIV prevalence, strategically placed sentinel sites can provide an early warning for the start of an epidemic.

Antenatal clinic surveillance does not provide information about HIV prevalence in men.

Cause

Definition of “cause” • Any event, act, or condition preceding disease or illness without which disease would not have occurred or would have occurred at a later time

• Disease results from the cumulative effects of multiple causes acting together (causal interaction)

Cause

Definition of “cause” • Necessary cause = found in all cases

• Contributing cause = needed in some cases

• Sufficient cause = the constellation of necessary & contributing causes that make disease inevitable in an individual

Confounding

A distortion brought about by extraneous variables

From the Latin meaning “to mix together” The effects of the exposure gets mixed with the

effects of extraneous determinants

04/10/23 44

Properties of a Confounding Variable

Associated with the exposure

An independent risk factor

Not in causal pathway

04/10/23 45

Challenge the government: ask the hard questions

What is the government doing to prevent the spread of HIV?

What is it doing to help those already infected?Does it have a program to provide antiretroviral

treatments and drugs for opportunistic infections for people with HIV?

Does it involve people with HIV, along with scientists, researchers, doctors, nurses and community groups in the development of its HIV Strategy? Does it even have a strategy? Is the Strategy an actual Strategy?

How much money does it devote to HIV? What about sexually transmitted infections, which are often a precursor to HIV? What about NEP?

Does it promote the use of condoms and encourage safer sex campaigns that accurately reflect the reality of people’s sexual lives?

HIV STRATEGY FOR SASKATCHEWAN 2010 - 2013

A COMPREHENSIVE STRATEGY IS REQUIRED TO REDUCE THE RAPID INCREASE OF NEW CASES OF HIV IN SASKATCHEWAN AND TO IMPROVE THE QUALITY OF LIFE FOR HIV-POSITIVE PEOPLE

http://www.health.gov.sk.ca/adx/aspx/adxGetMedia.aspx?DocID=3ffeca87-ac63-4b67-87a1-c09abf14434b&MediaID=3775&Filename=hiv-strategy-exec-summary-2010.pdf&l=English


• Executive Summary • Saskatchewan has seen a significant increase in new

cases of HIV since 2003 and currently has the highest rates in Canada at twice the national average. (20.8 vs 9.3/100,000) The epidemiology of HIV in Saskatchewan is different than the rest of Canada, with new HIV cases associated predominantly with injection drug use (75%) with First Nations and Métis women under age 30 accounting for a disproportionate number of those cases.

•http://www.health.gov.sk.ca/adx/aspx/adxGetMedia.aspx?DocID=3ffeca87-ac63-4b67-87a1-c09abf14434b&MediaID=3775&Filename=hiv-strategy-exec-summary-2010.pdf&l=English

Tips for journalists and for people who read their articles...

Common stereotypes It is often thought, wrongly, that only “bad” people get HIV – those who have sex with multiple partners, or are injecting drug users or sex workers. Another misconception is that if someone is in a group that has high rates of HIV – such as injecting drug users or sex workers – that he or she is or will be infected. It is important to remember that it is not the group that someone belongs to that makes them vulnerable to HIV infection, but their behaviour and the social or economic circumstances that may have contributed to it. Journalists should steer clear of making value judgements on how someone contracted HIV and instead report on how it affects them, their community, their work and their family.

HIV is a great story.

It pushes all the news buttons: it is a health emergency, it has a human face, it has elements of science, medicine, religion, it has deep grief and moments of extreme joy.

It often has enemies: governments, the church, religious bodies, the fraudsters and snake-oil salesmen.

It has heroes: the people living with HIV, community groups and NGOs fighting on the frontline of the epidemic, the scientists and researchers working for new treatments, a vaccine, a cure, and the doctors and nurses caring for the sick and dying.

It is clear that HIV and AIDS is more than a disease that infects individuals.

It is a social, economic and, in some countries, security crisis.


• Surveillance

• The Goals • Earlier detection of cases • Decrease in number of new cases (within 4 to 5 years) • A decrease in the number of sexually transmitted

infections

• The Plan • Increased access to testing • Increased understanding of the at-risk groups • Improved information and communication at all levels•http://www.health.gov.sk.ca/adx/aspx/adxGetMedia.aspx?DocID=3ffeca87-ac63-4b67-87a1-c09abf14434b&MediaID=3775&Filename=hiv-strategy-exec-summary-2010.pdf&l=English


• Clinical Management • The Goals • Increased quality of life for HIV patients • Increased proportion of HIV-positive pregnant women receiving pre-

and post-natal care • Decreased number of HIV patients progressing rapidly to AIDS • Decrease hospital admissions for HIV-related illnesses • Zero perinatal transmission

• The Plan • Adopting a non-discriminatory patient first approach with cross-

disciplinary teams • Focused learning opportunities for all health care providers • Best practice plans and protocols in place for enhanced clinical

management •http://www.health.gov.sk.ca/adx/aspx/adxGetMedia.aspx?DocID=3ffeca87-ac63-4b67-87a1-c09abf14434b&MediaID=3775&Filename=hiv-strategy-exec-summary-2010.pdf&l=English


• Prevention and Harm Reduction • The Goals • Increased access to holistic centers focusing on prevention and well-being • Fixed and mobile locations offering mix of services including health and social

services • Decrease in transmission of blood-borne viruses and sexually transmitted diseases • Reduction of injection drug use

• The Plan • Review of medical/nursing curriculums for substance abuse and chemical

dependency • Establish prevention and wellbeing centers with expanded access to needle

exchange programs and other harm reduction measures to promote and encourage safe behaviors

• Expand addictions prevention and treatment • Incorporate mental health and addictions programming into holistic center

approach •http://www.health.gov.sk.ca/adx/aspx/adxGetMedia.aspx?DocID=3ffeca87-ac63-4b67-87a1-c09abf14434b&MediaID=3775&Filename=hiv-strategy-exec-summary-2010.pdf&l=English


• Community Engagement and Education • The Goals • Reduce stigma and increase understanding of HIV among the residents

of Saskatchewan • Increased support to HIV-positive people by their families and

communities • Increased community and leadership engagement to address community

related risk factors ie: adequate housing

• The Plan • Engage elders of First Nations and Métis communities • Establish HIV positive peer to peer networks (positive teens, IDU’s, and

HIV-positive mothers) • Public education on prevention and awareness of HIV • Targeted prevention treatment and healthy living for HIV-positive

individuals • Strengthen prevention measures that protect children and youth. ie:

KidsFirst programming focuses on areas such as home visiting, parent engagement, and mental health and addictions services

•http://www.health.gov.sk.ca/adx/aspx/adxGetMedia.aspx?DocID=3ffeca87-ac63-4b67-87a1-c09abf14434b&MediaID=3775&Filename=hiv-strategy-exec-summary-2010.pdf&l=English


The success of the strategy will mean that, over the next couple of years, we will see increased HIV rates due to increased testing and tracing. It is expected that the HIV rates will decline in years three or four as the intervention/prevention initiatives start showing effectiveness.

http://www.health.gov.sk.ca/adx/aspx/adxGetMedia.aspx?DocID=3ffeca87-ac63-4b67-87a1-c09abf14434b&MediaID=3775&Filename=hiv-strategy-exec-summary-2010.pdf&l=English


The overarching goals of the Saskatchewan HIV Strategy are to: increase the rate of testing; ensure access to therapy and treatment; reduce the rate of new infections, including no new HIV-positive babies; increase quality of life and decrease discrimination. It is essential we have a sustainable plan that can adapt to meet a growing need. http://www.health.gov.sk.ca/adx/aspx/adxGetMedia.aspx?DocID=3ffeca87-ac63-4b67-

87a1-c09abf14434b&MediaID=3775&Filename=hiv-strategy-exec-summary-2010.pdf&l=English

Thank you

[email protected]

Check slideshare.net for this presentation with references in the near future.

References

Epidemiology Kept Simple: An Introduction to Traditional and Modern Epidemiology, 2nd Edition http://www.sjsu.edu/faculty/gerstman/eks/ (Awesome resource, loved it)

HIV/AIDS media guide http://www.ifj.org/assets/docs/117/252/83d8475-9cb28fc.pdf

HIV and AIDS In Saskatchewan http://www.health.gov.sk.ca/hiv-aids-annual-report-2008

HIV rise sparks warning: Recent jumps linked to usage of injected drugs http://www.thestarphoenix.com/health/rise%20sparks%20warning/2772120/story.html

HIV STRATEGY FOR SASKATCHEWAN : 2010 - 2013 http://www.health.gov.sk.ca/Default.aspx?DN=3ffeca87-ac63-4b67-87a1-c09abf14434b&l=English

Nightmare HIV scenario for Sask. First Nations unlikely: Health officer http://www.canada.com/health/

Nightmare+scenario+Sask+First+Nations+unlikely+Health+officer/1924062/story.html Understanding the HIV and AIDS epidemics

http://www.avert.org/statistics.htm Volunteers pick-up used needles in Regina neighbourhoods

http://www.leaderpost.com/health/Volunteers+pick+used+needles+Regina+neighbourhoods/2774710/story.html

WHEN PLAGUES END; NOTES ON THE TWILIGHT OF AN EPIDEMIC http://www.independent.co.uk/arts-entertainment/when-plagues-end-notes-on-the-twilight-of-an-

epidemic-1278905.html

hiv epidemiology in the prairies

Health & Medicine