virology

1980: Beginning of the disease Pandemic threat human life 1981: Acquired immunodeficiency syndrome (AIDS) Starting of search for causative agent 1983: Luc Montagnier (Pasteur Institute) (L AV) 1983: Abraham Karpas (Cambridge) (C-LAV)  Paul Feorine (CDC) Atlanta  Virus resembles animal virus  1984: Robert Gallo (NCI) Maryland HTLV-I, III  E.M comparison of all isolates same virus 1986: ICTV HIV

* Oncorna (human) or Lentivirus (animal) ? HIV common ancestor with African Monkey virus (Simian virus) Origin shrouded in tropical darkness Virus jump species barrier in central Africa * Politics: genetically engineered * Genetics: human genome contains sequence of HIV

* Destroyed by heat (autoclave or hot air oven). 100 fold each hour at temperature 60 Co. * Survive up to 15 days at RT or body temp. * Disinfectant (2% gluteraldehyde and hypochloride at 103 ppm kills 105 unit of virus. * Veridical activity of alcohol is relatively low.

Exact number of people infected !?

* Test is not compulsory * 3rd world countries * Political reason

* Sex homo and heterosexual

Traumatic sexual activity or ulceration of GT Not necessary for transmission artificially
Healthy women develop Abs to HIV inseminated principle factor is number of sexual contact

* Blood

Blood transfusion (no risk for donor) Hemophiliacs Possibly following: ear piercing acupuncture Dialysis Tattooing Sharing needles ( I.V drugs and drug addicts) * From mother to child Pregnancy At birth Breast milk

Small minority of HIV infected people harbor HIV in saliva No cell free virus in the saliva * Saliva contains IgA which neutralize viral infectivity * HIV inhibitory factor ( high m.wt. mucins) * Salivary leukocytes protease inhibitor which block cell surface receptor * Loss of viral infectivity when virus exposed to mixed saliva for 30 min * Animal study showed impossibility to transmit HIV by sutface application on oral mucosa * High dose of HIV is required for infection


No transmission by: * Causal and social contact * Human bite and kissing * Swimming pool Insects: * HIV replicates in narrow range of cells Malaria enter mosquito to salivary gland

Injected to other person * Age distribution of HIV in Africa ! Malaria is more common in children HIV is rare in children

Receiving contaminated blood born with it

A: Subclinical HIV infection HIV +ve clinically well 25-50% seropositive AIDSB: Persistent generalised lymphadenopathy (PGL) * Asymptomatic * lymphadenopathy of 2 or more LN * Reactive hyperplasiaC: AIDS Related Complex (ARC) * fever ≥ 3 months * lymphadenopathy ≥ 3 or more * Weight loss * Fatigue *Diarrhea ≥ 3 months * Night sweat

D: AIDS: 1. Diagnostic for HIV: * Kaposi sarcoma * Pneumocystic carinii * Opportunistic infections: Protozoal: Toxoplasmosis, Cryptosporidium, isospora Fungal: Candida, Cryptococcus, Aspergellosis, Histoplasmosis Bacterial: T.B, Salmonella, Pygenic infections Viral: HSV, VZV, CMV 2. Diagnostic only if HIV +ve Antibody test: Histoplasmosis , isosporiasis, broncheal and pulmonary candidiasis, Non-Hodgkin lymphoma, Kaposi sarcoma in older than 60 years.

Enlargment of 1-2 cervical LN and persist for 3 months Persistent oral candidiasis Painful herpes stomatitis Oral Kaposi sarcoma Sever gingivitis and periodontitis

ELISA detection of Abs ( does mean patient has AIDS) Patient infected with HIV Time between infection & appearance of Abs 1-4 mon. or longer +ELISA confirmed by Western Blot analysis

gp 120 gp 40 carrier

Western Blots
Negative: no bands Positive: reactivity to gp41 + gp120/160 or p24+120160 Indeterminate: Presence of any band patterns that does not meet positive criteria
Envelope
Polymerase
Core

Western Blot Analysis

Band pattern Interpretation Lane 1, HIV+ serum (positive control) Lane 2, HIV- serum (negative control) Lane A, Patient A = negative Lane B, Patient B =indeterminate Lane C, Patient C = positive

AZT Blocks RT (prevent RNA to DNA) Combination of AZT and protease inhibitor In the absence of vaccine * prevent spread of the disease by reduce transmission * care should be taken in dental clinic ( gloves, mask, autoclave) * public education Advertising * Do not die of ignorance * The only way to reduce the transmission is by persuading people to change their habit *Once you get it, that is it, that is for your life and you will die sooner or later