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HIV/AIDS
 How it all started
o 1981- first case of HIV/AIDS identified
o Unexplained occurrence of Pneumocystis carinii pneumonia (PCP) and
Kaposi’s sarcoma (KS) in previously healthy homosexual men
o Later – noted among injection drug users, recipients of blood transfusion,
hemophiliacs
 The Agent
o 1984- HIV as causative agent of AIDS
 Family Retroviridae
o Human retroviruses
 Transforming retroviruses
- Human lymphotropic virus I (HTLV I)
- Human lymphotropic virus II (HTLV II)
 Cytopathic viruses
- Human immunodeficiency virus 1 (HIV-1)
- Human immunodeficiency virus 2 (HIV-2)

o

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o
o

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Spread of virus to CD4+ T cell
 Virus interacts with dendritic cell on mucosal surface
 Infected dendritic cell travels via afferent lymph channels to
paracortical regions of lymph node
 Infected dendritic cell interacts with CD4+ T cells allowing viral
replication and spread
Pathophysiology
Invading Virus

Macrophage

Invading HIV

T Cell
Antibodies

Helper T Cells

B Cell



o
o HIV is not like a cold…
o You can’t just “catch it”
Transmission
o Sexual transmission
 Heterosexual – most common worldwide
o Higher risk of transmission

HIV growing
in T Cell

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 Receptive anal intercourse
 Male-to-female versus female-to-male transmissions
 Lack of circumcision
o Via blood & blood products
 Needle sharing  1: 150
o Occupational transmission
 From patient to HCW
- Occupational needlestick exposure  0
...
09%
 From HCW to patient
o Mother & child transmission
 Most commonly – perinatal period
 1: 4
 15-25% (25-35%) in the absence of prophylactic ART
 Higher rate of transmission: maternal level of plasma viremia
 Breastfeeding
You can’t get HIV/AIDS from
o Swimming pool
o Mosquito bite
o Kissing
o Sharing utensils
Epidemiology
o Global summary of the AIDS epidemic, December 2007

Number of people living
with HIV in 2007

Total
Adults
Women
Children under 15 years
People newly infected with Total
HIV in 2007
Adults
Children under 15 years
AIDS deaths in 2007

Total
Adults
Children under 15 years

33 mil (30-36 mil)
30
...
2-34
...
5 mil (14
...
9 mil)
2
...
9-2
...
7 mil (2
...
2 mil)
2
...
9-2
...
0 mil (1
...
3 mil)
1
...
6-2
...
kansasii, disseminated or extrapulmonary
o Mycobacterium tuberculosis, any site (pulmonary or EP)
o Pneumocystis jiroveci pneumonia
o Pneumonia, recurrent
o Progressive multifocal leukoencephalopathy
o Salmonella septicemia, recurrent
o Toxoplasmosis of brain
o Wasting syndrome due to HIV
Diagnosis
o Standard screening test – EIA
 Sensitivity/specificity
o Confirmatory test – Western blot (repeated postive screening)
o EIA - at least 2 reactive tests before Western blot done
o Western blot interpretation
 Negative – no bands
 Positive – Reactivity to gp41 + gp120/160 or p24 + gp120/160
 Indeterminate – presence of band pattern that does not meet criteria
for positive result (advice for retest in 3 month)
o False-negative results during the window period
 Window period- time delay from infection to presence of antibodies,
average 14-22 days
 Antibodies present within 6 months
o False-positive results- 0
...
0007%
 Causes:
- Autoantibodies- lupus & end-stage renal disease
- HIV vaccines

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o

Factitious HIV infection- patient who reports a history of a + test
that is erroneous, due to misunderstanding or intent to deceive
- Technical or clerical error
Algorithm for the use of serologic tests in the diagnosis of HIV-1 or HIV2 infection




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Stable indeterminate blot 4-6 weeks later makes HIV infection
unlikely
...
Alternatively, one may test for HIV-1 p24 antigen of HIV
RNA
o HIV antigen (p24)
o HIV RNA by polymerase chain reaction (PCR) – detecting nucleic acids
Laboratory monitoring of patients with HIV infection
o CD4+ T cell counts
 Total lymphocyte count (TLC) – not as accurate in resource limited
facilities as whole lymphocyte count, not just CD4+, is considered
o HIV RNA
o HIV Resistance Testing
Persons who should be tested for HIV
o High risk behavior
 MSMs
 IDUs
 Persons with multiple sex partners
 Persons who have exchanged money or drugs for sex
 Persons who have had sexual contact with an HIV+ or a person at risk
o Persons with certain medical conditions

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

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 AIDS-defining illness
 Oral candidiasis
 Generalized unexplained lymphadenopathy
 Symptoms consistent with acute retroviral syndrome
 Any sexually transmitted disease
 Tuberculosis
 Persons who have been sexually assaulted
 Persons who have had occupational exposures
o Prerequisites of HIV testing
 Should be voluntary and confidential
 Should have written informed consent
 Pre-test counseling needed prior to blood extraction
 Post-test counseling needed
Initial Evaluation of the Patient with HIV Infection
o History and physical examination
o Routine chemistry and hematology, fasting glucose, lipid panel
o CD4+ T lymphocyte count
o Two plasma HIV RNA levels
o RPR test
o Anti-Toxoplasma antibody titer
o PPD skin test
o Mini-mental status examination
o Serologies for hepatitis A, hepatitis B and hepatitis C
o Immunization with pneumococcal polysaccharide; influenza as indicated
o Immunization with hepatitis A and hepatitis B if seronegative
o Counseling regarding natural history and transmission
o Help contacting others who might be infected
When to start anti retroviral treatment?
o Indications of Anti-Retroviral Therapy
I
...
Chronic Infection
A
...
Asymptomatic Disease
1
...
Pregnancy
III
...
Start antiretroviral treatment in all patients with HIV who have CD4
count 350 cells/mm3 irrespective of clinical symptoms
- Strong recommendation, moderate quality of evidence
2
...
Start antiretroviral treatment in all patients with HIV and WHO
clinical stage 3 or 4 irrespective of CD4 count
- Strong recommendation, low quality of evidence
Principles of therapy of HIV infection
1
...

2
...
CD4+ T cell counts indicate the
current level of competence of the immune system
3
...
Maximal suppression of viral replication is a goal of therapy; the greater
the suppression the less likely the appearance of drug-resistance
quasispecies
5
...

6
...
The number of available drugs is limited
...

8
...

9
...
The treatment of HIVinfected children involves unique pharmacologic, virologic, and
immunologic considerations
...
Compliance is an important part of ensuring maximal effect from a given
regimen
...

Anti-Retroviral Drugs

Reverse Transcriptase inhibitor
 NNRTI: Non-nucleoside reverse transcriptase inhibitor
 NRTI: Nucleoside reverse transcriptase inhibitor
o Protease inhibitor
o Fusion inhibitor
o Integrase inhibitor
VSMMC Treatment Hub
o Regimen
 2 NTI (Zidovuidne & Lamivudine) + NNRTI (Efavirenz)
 2 NTI (Stavudine & Lamivudine) + NNRTI (Efavirenz)
Prophylaxis for Opportunistic Infections
o Examples:
 Pneumocystis jiroveci, Mycobacterium tuberculosis, Toxoplasma
gondii
Recommendend Immunizations
o Hepatitis A and B if seronegative
o Influenza
o Streptococcus pneumoniae
o HPV
HIV AIDS Law in the Philippines (RA 8504)
o Testing, Screening and Counseling
 Consent is a must
 Compulsory testing is not allowed
- Exceptions: Blood and Organ Donation
 Free pre-test and post-test counseling
o Confidentiality
 Strict confidentiality in handling of all medical information
- Exceptions:
 When informing other HCW directly involved in the care of a
person with HIV/AIDS
 When complying with reportorial requirements
 When responding to a subpoena
Release
of HIV/AIDS test results

- Results given only to:
 Patient
 Parent of a minor child who has been tested
 A legal guardian of orphans or insane persons
 Disclosure to sexual partners
o

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Any person with HIV is obliged to disclose his/her HIV status to
his/her spouse or sexual partner
Current HIV Vaccine concepts based on WHO and UNAIDS

o
ABCs of HIV prevention
o Abstinence from sex and needle use
 This is the only 100% safe way to prevent HIV
o Best to have only one partner
o Condom use if you have sex
o Don’t do drugs



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