2.  Heterosexual  Bi-sexual  Homosexual

3. Blood and Blood Products  Blood transfusion  Tissue Transplantation e.g Kidney Transmission Modes for HIV (2) [Non-Sexual]

4. Other  Injections  Contaminated instruments

5. Mother to Child  During Pregnancy  During labor (delivery)  After birth (breastfeeding)

6.  High Viral load in the infecting person  Lowered Immune status of the recipient  Presence of genital ulcers, abrasions  Lack of circumcision (male)  Multiple sexual partners  Specific sexual practice – anal sex  Age of the recipient – very young and very old  Type of the HIV strain infecting recipient

7. Avoiding exposure (abstinence) Use of condoms during all sexual encounters Treatment of concurrent Sexually Transmitted Infections (STIs) Post-exposure prophylaxis Antiretroviral therapy to prevent mother to child transmission

9.  Two types: HIV-1 and HIV-2, 40-60% Amino Acid homology  HIV-1 is found worldwide, HIV-2 is found primarily in West Africa  Subtypes (clades): M group (subtypes A-K) and Subtype O (55-70% homology with M subtypes), N (“new”) subtype  Diagnostic tests may preferentially detect a specific type or subtype  Vaccines may need to be subtype specific

10. Leukocytes (WBCs) play major role: ◦ Neutrophils (form pus, phagocytic) ◦ Macrophages (phagocytic, secrete chemicals that affect function of other cells) ◦ Lymphocytes  B lymphocytes (make antibodies)  T lymphocytes (secrete chemicals that affect function of other cells)  CD4+ ”helper” stimulate macrophages  CD8+ “suppressor” cells

13.  HIV is an RNA virus  HIV RNA is what is detected in blood  P24 antigen can be detected early in HIV infection, before antibodies (6 – 8 wks after)  Methods of testing HIV virus load: Different sensitivities, range: ◦ “Undetectable”: <50 copies/ml or <400 copies/ml ◦ > 750,000 copies/ml

14.  Play important role in immune response of healthy individual ◦ Activate B cells which produce antibodies ◦ Important in the production of growth factors  Stages of CD4 cell count in HIV infection 1.Before HIV infection: 800 – 1000/mm 3 2.Sero-conversion illness: ~500/mm 3 3.Adaptive immune response: ~700/mm 3 4.AIDS: <200/mm 3

15. ◦ HIV binds to the CD4 receptor sites, causing the CD4 cell to loose immune function ◦ HIV disrupts the cell membrane of the CD4 cell causing cell death ◦ Binding of HIV to the CD4 receptor may result in the CD4 programming its own death

16. HIV viral load ⍺ 1 CD4 As HIV viral load increases CD4 cell count decreases and vise-versa

17.  Play important role in controlling viruses ◦ Kill cells expressing these (foreign) antigens ◦ Suppress HIV replication  As HIV virus load increases, CD8 T cells increase in a bid to fight /suppress HIV

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20.  Fever  Lymphadenopath y  Pharyngitis  Rash  Myalgia / arthralgia  Diarrhoea  Headache  Nausea & vomiting  Weight loss  Thrush  Neurologic symptoms Syn. Sero-conversion illness

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22.  Clinical Stage One: ◦ Asymptomatic ◦ Persistent generalized lymphadenopathy Performance scale 1: Asymptomatic, normal activity

23.  Clinical Stage Two: ◦ Weight loss < 10% of body weight ◦ Minor mucocutaneous manifestations (seborrheic dermatitis, fungal nail infections, recurrent oral ulcerations, angular chelitis) ◦ Herpes zoster within the past 5 years ◦ Recurrent upper respiratory tract infections And/or performance scale 2: Symptomatic, normal activity

24.  Clinical Stage Three: ◦ Weight loss > 10% of body weight ◦ Unexplained chronic diarrhea (> 1 month) ◦ Unexplained prolonged fever (intermittent or constant) > 1 month ◦ Oral candidiasis (thrush) ◦ Oral hairy leukoplakia ◦ Pulmonary tuberculosis within the past year ◦ Severe bacterial infection (pneumonia, pyomyositis) And/or performance scale 3: bed-ridden < 50% of the day during the past month

25. Candidiasis  Fungal infection caused by C. albicans.  Commonly found in people with HIV infection  Occurs commonly in stages 3 & 4 of HIV disease  Other factors may predispose to candidiasis: Extremes of age, antibiotics, diabetes, other immunosuppressive states. Rx.Topical antifungals: clotrimazole, Nystatin Systemic: Ketoconazole, Fluconazole

26. Pulmonary Tuberculosis (PTB)  Bacterial infection caused by Myco.tuberculosis.  Found in late HIV disease (stage 3 & 4)  Symptoms mimic those of HIV infection:  Weight loss  Night sweats  Chronic fevers  H/o contact may not be revealing  Diagnosis is simple: Sputums, CXR Rx.2RHZE/6HE

27.  Clinical Stage Four: ◦ HIV wasting syndrome ◦ Pneumocystis carinii pneumonia ◦ CNS toxoplasmosis ◦ Cryptosporidiosis with diarrhea > 1 month ◦ Extrapulmonary cryptococcosis ◦ Cytomegalovirus (CMV) disease of an organ other than liver, spleen, or lymph nodes ◦ Visceral Herpes simplex virus (HSV) infection or mucocutaneous HSV infection > 1 month

28. HIV-Associated Wasting Definition: “Weight loss of at least 10% in 1.Disorders in food absorption the presence of diarrhoea or chronic weakness and documented fever for at least 30 days, that is not attributable to a concurrent condition other than HIV infection itself”.

29.  Rapid weight loss associated with acute infections  Depletion of fat and lean tissue  Reasons for weight loss: 1.Metabolic abnormalities 2.Decreased intake 3.Production of some immune factors

30.  Nutritional assessment ◦ Diet history ◦ Identify factors interfering with food intake ◦ Estimate current energy intake  Interventions ◦ Treat any underlying infection ◦ Institute ARVs where possible (gain: 0.4- 0.8kg/month) ◦ Increase intake of protein to 1.5 g/kg ◦ Supplement micronutrients: Vitamin A, B1,2,6 ◦ Appetite stimulators: Cyproheptadine (Periactin®), Tres Orix F®  Exercise

31.  Clinical Stage Four, continued: ◦ Progressive multifocal leukencephalopathy (PML) ◦ Any disseminated endemic mycosis (e.g. histoplasmosis, coccidiodomycosis) ◦ Candidiasis of the esophagus, trachea, bronchi or lungs ◦ Disseminated atypical mycobacterium ◦ Non-typhoid Salmonella septicemia ◦ Extrapulmonary tuberculosis ◦ Lymphoma ◦ Kaposi’s sarcoma ◦ HIV encephalopathy And/or performance scale 4: bed-ridden > 50% of the day during the last month