Transcript Presentation

HIV
“Myths, controversies and challenges”
Dr Emmanuel Nsutebu
Consultant Infectious Diseases Physician
Tropical and Infectious Diseases Unit
Royal Liverpool Hospital
“10 questions ....”
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1. What is the difference b/w HIV and AIDS
2. What is the origin?
3. How is it transmitted?
4. Does the risk of transmission vary?
5. Can you know when a person got infected?
6. Is lengthy pretest counselling needed before a test is done?
7.How is HIV treated?
8. Can it be cured?
9. What is the life expectancy?
10. What about a vaccine and is there hope?
How many people are affected?
 Globally 34 million PLHAs, 1.7M deaths a year, 2.5M new
infections a year
 15 million eligible for treatment and 8 million on treatment.
 24 million cases in Africa
 5% adult prevalence in Cameroon (2011) – 900000 PLHA
 UK – 70000 PLHA
 No. Of new cases and deaths
Falling due to success of treatment
1. What is the difference b/w HIV and
AIDS?
Not the same thing but related. AIDS is a stage of
HIV infection.
NOT ALL HIV INFECTION = AIDS
Most people with HIV have no symptoms
2. Origin? Jump from chimpanzees to
humans - SIV
Figure 1
Source: The Lancet Infectious Diseases 2011; 11:45-56 (DOI:10.1016/S1473-3099(10)70186-9)
Terms and Conditions
3. How is HIV transmitted?
 Unprotected sex – 70% of infections
 Mother to child transmission – mum must be positive –
during pregnancy, at birth or during breastfeeding!
 Intravenous drug use – sharing needles
 Blood transfusion and other blood products
 Medical equipment
Mother to child transmission
30% risk of transmission reduced to <2% with ARVS
How is HIV not transmitted?
 Cutlery
 Mosquitoes
 Kissing
 Hugging
4. Does the risk of transmission vary?
 Varies depending on
 Positive person
 Negative person
 Route of transmission
 Sex 3/1000 but can happen with first contact
 Transmission to women easier
 IV drug user high risk
5. Can you know when a person acquired
the infection?
 No but can guess!!!
Viral load & CD4 after HIV Infection
[without treatment]
Death
No symptoms
Symptoms
AIDS
2 million
1000
CD4 count
HIV viral load
50
0
200
0
0
4-8 wks
2-12 mo
Up to 12 years
2-3 years
Time
Understanding HIV Treatment and adherence.
April 15
Development of AIDS is like an
impending train wreck
Viral Load = Speed of the train
CD4 count = Distance from cliff
HIV
infection
J. Coffin, XI International Conf. on AIDS, Vancouver, 1996
Infections and cancer!
6. Is lengthy pretest counselling
needed?
 An HIV test is a routine test!!!
7. How is HIV treated and it is
effective?
HIV Replication Cycle and Sites of Drug Activity
NNRTIs
Cellular DNA
nRTI
NRTIs
Protease Inhibitors
Nucleus
New HIV
particles
HIV Virions
Reverse
Transcriptase
Protease
Integrase
Capsid
proteins
and viral
RNA
CD4
Receptor
Fusion
Inhibitors
Viral RNA
Unintegrated
double stranded
Viral DNA
Integrated
viral DNA
CCR5
or
CXCR4
co-receptor
1
3
2
Attachment
Uncoating
Reverse
Transcription
Integration
Viral
mRNA
4
Transcription
At least 3 drugs to stop the virus from multiplying
gag-pol
polyprotein
5
Translation
6
Assembly and
Release
clinicaloptions.com/hiv
HIV Medication Timeline
 Between ’87 and ’95 (9 years), 4 antiretrovials were launched.
 Since ’95 (11 years), 25 new products have been introduced!!
stavudine
lamivudine
zalcitabine
lamivudine/zidovudine
nevirapine
didanosine
delavirdine
zidovudine
emtricitabine
emtricitabine/
tenofovir
efavirenz
tenofovir
abacavir/
lamivudine/
zidovudine
abacavir
’87 ’88 ’89 ’90 ’91 ’92 ’93 ’94 ’95 ’96 ’97 ’98 ’99 ‘00 ’01 ‘02 ‘03 ‘04 ‘05 ‘06
NRTI
saquinavir
NNRTI
ritonavir
PI
indinavir
FI
atazanavir
tipranavir
darunavir
nelfinavir
saquinavir
amprenavir
Kaletra
didanosine
enfuvirtide
fosamprenavir
Corrections Curriculum Development, NY/NJ AETC
Many drugs available and more in development – outlook is good!
Treatment & Treatment as prevention
Most patients on one or two tablets a day!
After HIV treatment (ARVs):
effect on CD4 and viral load
Start treatment
Viral load <50 copies/mL
2 million
1000
CD4+
cells/mm3
viral load (RNA)
copies/mL
50
0
200
< 50 copies/mL
0
0
1-12 yrs
+ 1-40+ years !!
+1-6 mo
Chronic
Infection
Understanding HIV Treatment and adherence.
Time
April 15
8. What is life expectancy like?
 We don’t know for sure however we have estimates....
 HIV survival similar to other chronic diseases!
 Life expectancy at 25 years diagnosis estimated to be 70
years
9. What about a cure?
10. What about a vaccine?
 Problem is variability of the virus!!!
 Stays one step ahead of immune system!!!
What are challenges?
 Early diagnosis
 Access to treatment in developing countries
Thank you
[email protected]