HIV

Dr. Maitham Fadhil Jalal MB.CH.B F.I.C.M.S Neurology

H.I.V.

WHAT IS HIV??

“Human Immunodeficiency Virus”A unique type of virus (a retrovirus)Invades the helper T cells (CD4 cells) in the body of the host (defense mechanism of a person)Threatening a global epidemic.Preventable, managable but not curable.

WHAT IS AIDS ???

“Acquired Immunodeficiency Syndrome” HIV is the virus that causes AIDS Disease limits the body’s ability to fight infection due to markedly reduced helper T cells.Patients have a very weak immune system (defense mechanism)Patients predisposed to multiple opportunistic infections leading to death.

AIDS (definition)

Opportunistic infections and malignancies that rarely occur in the absence of severe immunodeficiency (eg, Pneumocystis pneumonia, central nervous system lymphoma). Persons with positive HIV serology who have ever had a CD4 lymphocyte count below 200 cells/mcL or a CD4 lymphocyte percentage below 14% are considered to have AIDS.

“THE VIRAL GENOME” Icosahedral (20 sided), enveloped virus of the lentivirus subfamily of retroviruses. Retroviruses transcribe RNA to DNA.
Two viral strands of RNA found in core surrounded by protein outer coat. Outer envelope contains a lipid matrix within which specific viral glycoproteins are imbedded. These knob-like structures responsible for binding to target cell.

Modes of HIV/AIDS Transmission

Through Bodily Fluids

Blood products Semen Vaginal fluids

IntraVenous Drug Abuse

Sharing Needles Without sterilization Increases the chances of contracting HIV Unsterilized blades

Mother-to-Baby

Before Birth During Birth

Myths about transmission

NATURAL COURSE OF HIV/AIDS

Stage 1 - Primary

Short, flu-like illness - occurs one to six weeks after infection Mild symptoms Infected person can infect other people



Stage 2 - Asymptomatic
Lasts for an average of ten years This stage is free from symptoms There may be swollen glands The level of HIV in the blood drops to low levels HIV antibodies are detectable in the blood

Stage 3 - Symptomatic

The immune system deteriorates Opportunistic infections and cancers start to appear.

Stage 4 - HIV  AIDS The immune system weakens too much as CD4 cells decrease in number.

Opportunistic Infections associated with AIDS
CD4<500Bacterial infectionsTuberculosis (TB)Herpes SimplexHerpes ZosterVaginal candidiasisHairy leukoplakiaKaposi’s sarcoma

Opportunistic Infections associated with AIDS

CD4<200Pneumocystic cariniiToxoplasmosisCryptococcosisCoccidiodomycosisCryptosporiosisNon hodgkin’s lymphoma


CD4 <50 Disseminated mycobacterium avium complex (MAC) infection Histoplasmosis CMV retinitis CNS lymphoma Progressive multifocal leukoencephalopathy HIV dementia

TB & HIV CO-INFECTION

TB is the most common opportunistic infection in HIV and the first cause of mortality in HIV infected patients (10-30%) 10 million patients co-infected in the world. Immunosuppression induced by HIV modifies the clinical presentation of TB : Subnormal clinical and radiological presentation High rate of MDR/XDR High rate of treatment failure and relapse


Testing Options for HIV

Anonymous Testing

No name is used Unique identifying number Results issued only to test recipient
23659874515
Anonymous

Blood Detection Tests

HIV enzyme-linked immunosorbent assay (ELISA)
Screening test for HIV Sensitivity > 99.9%
Western blot
Confirmatory test Speicificity > 99.9% (when combined with ELIZA)
HIV rapid antibody test
Screening test for HIV Simple to perform
Absolute CD4 lymphocyte count
Predictor of HIV progression Risk of opportunistic infections and AIDS when <200
HIV viral load tests
Best test for diagnosis of acute HIV infection Correlates with disease progression and response to HAART

Urine Testing

Urine Western Blot As sensitive as testing blood Safe way to screen for HIV Can cause false positives in certain people at high risk for HIV

Oral Testing

Orasure The only FDA approved HIV antibody. As accurate as blood testing Draws blood-derived fluids from the gum tissue. NOT A SALIVA TEST!

Treatment Options

HAART = highly active anti-retroviral treatment

Antiretroviral Drugs (HAART)

Nucleoside Reverse Transcriptase inhibitors AZT (Zidovudine) Non-Nucleoside Transcriptase inhibitors Viramune (Nevirapine) Protease inhibitors Norvir (Ritonavir)

EFFECTIVENESS OF HAART IN REDUCING MORTALITY

HEALTH CARE FOLLOW UP OF HIV INFECTED PATIENTS

For all HIV-infected individuals: CD4 counts every 3–6 months Viral load tests every 3–6 months and 1 month following a change in therapy PPD INH for those with positive PPD and normal chest radiograph RPR or VDRL for syphilis Toxoplasma IgG serology CMV IgG serology Pneumococcal vaccine Influenza vaccine in season Hepatitis B vaccine for those who are HBsAb-negative Haemophilus influenzae type b vaccination Papanicolaou smears every 6 months for women

PRIMARY PREVENTION:Five ways to protect yourself?

Abstinence Monogamous Relationship Protected Sex Sterile needles New shaving/cutting blades

Abstinence

It is the most effective method of not acquiring HIV/AIDS. Refraining from unprotected sex: oral, anal, or vaginal. Refraining from intravenous drug use

ESCALATING EPIDEMIC !!!

Source: WHO/UNAIDS/UN The Millennium Development Goals Report, 2009, p.32 and WHO.

HIV PREVALENCE IN VARIOUS REGIONS

Source: UNAIDS, AIDS Epidemic Update, December 2004.
Total = 39.4 million
Sub-Saharan Africa
South/South-East Asia
Oceania
Caribbean
North Africa/Middle East
Western Europe
North America
East Asia
Eurasia
Latin America
<
42%

NEWLY INFECTED CASES OF HIV IN VARIOUS REGIONS

Source: UNAIDS, AIDS Epidemic Update, December 2004
Total = 4.9 million
63%

LIVING WITH HIV/AIDS