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HIV and the Surgeon. Paul MacPherson PhD, MD, FRCPC Assistant Professor of Medicine Division of Infectious Diseases Ottawa Hospital, General Campus University of Ottawa. Summary. HIV today HIV infection and natural history Current treatments for HIV infection
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HIV and the Surgeon Paul MacPherson PhD, MD, FRCPC Assistant Professor of Medicine Division of Infectious Diseases Ottawa Hospital, General Campus University of Ottawa
Summary • HIV today • HIV infection and natural history • Current treatments for HIV infection • Indications for surgery in HIV+ patients • Surgical outcomes for HIV+ patients • Needlestick injuries
6,850/day 285/hour
5,753/day 240/hour
Demographic Trends 1. HIV+ tests (all ages) highest in 1995 at 2,990 lowest in 2000 at 2,106 increased in 2001 and 2002 and then plateaued at 2,500 2. Increasing among older adults (age >40 yrs) 3. HIV+ tests among MSM: increasing since 2001 4. Steady decline among injection drug users 5. Steady increase among Heterosexuals 68% increase in Ontario over the past 5 years (11%/yr)
HIV Epidemiology Developing World • Heterosexual men and women • Children Developed World • Men who have sex with men • People from endemic countries • Aboriginals • People who use injection drugs • Heterosexual men and women
Transmission • Sexual contact with exchange of bodily fluids • Exposure of mucous membranes • Sharing injection drug paraphernalia • Needles, snorting straws • Transfusion of infected blood or blood products • Currently 1 in 500,000 • Mother to child (vertical) • Perinatal and breast feeding
Sexual Transmission of HIV: HIV is contained in: • Semen • Vaginal secretions • Rectal secretions • (Saliva at very low levels)
Exposure to HIV In these fluids: • HIV is present as free virus • HIV is contained in infected CD4 cells
Mucous Membranes: the target Mucous membranes are the moist epithelial linings of body cavities including the: • oral cavity • rectum • vagina and cervix • inner foreskin Live cells line the surface.
Mucous Membrane: the target • Only 2% of the body’s immune cells circulate in the blood • 98% of the body’s immune cells are located in the lymph nodes and the mucous membranes • Mucous membranes are rich in T-cells and macrophages to provide defence • The majority of these cells are organized into “lymphoid follicles” just under the surface of the mucosal membrane
Mucous Membrane: rectum • Lymphoid follicles: 15/cm2 in the colon and increase to 25/cm2 in the rectum.
Mucous Membrane: the target M-cells transport HIV directly into the lymphoid follicle Owen, RL. Pathobiology, 1998.
Mucous Membrane: cervix • Lymphoid follicle in the cervix. CD4 cells are stained brown. Kobayashi, Am J Pathology, 2002
Mucous Membrane: the target Hladik F. Immunity, 2007. McCoombe. AIDS, 2006.
Transmission: Injection drug paraphernalia Sharing injection drug paraphernalia • Access to clean needles • Drug rehabilitation programs
Transmission: Blood transfusion Transfusion of infected blood or blood products • Screening donated blood • ELISA: 2-3 month window period • PCR: essentially no window period
Transmission: Mother to child Mother to child (vertical) • In utero (trans-placental) • Peri-natal accounts for majority of cases • By blood-blood mixing • Breast feeding.
Immunologic: Peripheral Blood • CD4 T-cells: infected, decrease, dysfunction, alterations in subsets • CD8 T-cells: dysfunction, anergic, alterations in subsets • Macrophages: infected, dysfunction • NK cells: dysfunction • B-cells: dysfunction- polyclonal hypergammaglobulinemia • Cytokine dysregulation Lymph Nodes • Hyperplastic and eventually fibrotic
HIV Disease • HIV enters the body and slowly destroys the immune system • without treatment, HIV is continuously active • without treatment, the average length of time between infection and the onset of symptomatic disease is 10 - 12 years • the competency of the immune system is reflected by the CD4 count
Viral Load What is the viral load? How much virus per ml of blood Range 100’s to >500,000 Viral load and progression are roughly correlated Each patient has their own “set-point”
CD4 Count What is the CD4 count? 800-1000 is normal >500 no worry 200-500 a bit of a gray zone. <200 at risk <50 at significant risk
Risk of Illness based on CD4 Count >500: usually no symptoms. May have fever, night sweats, lymphadenopathy, weight loss 200-500: recurrent HSV, zoster, sinusitis, pneumonia candidiasis (oral, vaginal), lymphoma <200: PCP, Toxo, KS, Cryptococcus <50: MAC, CMV, PML, dementia, wasting