HIV Lecture Anucha Apisarnthanarak, MD Division of Infectious Diseases Thammasart University Hospital
End-2001 global estimates for children and adults People living with HIV/AIDS New HIV infections in 2001 Deaths due to HIV/AIDS in 2001 40 million 5 million 3 million
Adults and children estimated to be living with HIV/AIDS as of end 2001 North America 940 000 Caribbean 420 000 Latin America 1.4 million Western Europe 560 000 North Africa & Middle East 440 000 Sub-Saharan Africa 28.1 million Eastern Europe & Central Asia 1 million East Asia & Pacific 1 million South& South-East Asia 6.1 million Australia & New Zealand 15 000 Total: 40 million
Estimated number of adults and children newly infected with HIV during 2001 North America 45 000 Caribbean 60 000 Latin America 130 000 Western Europe 30 000 North Africa & Middle East 80 000 Sub-Saharan Africa 3.4 million Eastern Europe & Central Asia 250 000 East Asia & Pacific South & South-East Asia 800 000 270 000 Australia & New Zealand 500 Total: 5 million
About 14 000 new HIV infections a day in 2001 More than 95% are in developing countries 2000 are in children under 15 years of age About 12 000 are in persons aged 15 to 49 years, of whom: almost 50% are women about 50% are 15 24 year olds
HIV/AIDS Estimation in Thailand at the end 2001 People living with HIV/AIDS People living with AIDS New HIV infections in 2001 Deaths due to HIV/AIDS in 2001 665,000 67,000 25,000 55,000
1400 1200 1000 800 600 400 200 0 HIV Infection in Thailand 1990 1995 2000 2005 2010 2015 2020 Living w/hiv and AIDS Cumulative HIV New HIV 1985 thousands of HIV infections
Number of STD cases and condom use rate among male & CSW (1984-2000) thousands 300 male Percent condom use -100-200 prostitute Condom use rate -75-100 - 50 0 1984 1986 1988 1990 1992 1994 1996 1998 2000 0
HIV Prevalence among Injecting Drug Users at Treatment Clinics, Thailand 1989-2000 60 50 % 40 30 20 10 0 Jun-89 Dec-89 Jun-90 Dec-90 Jun-91 Dec-91 Jun-92 Dec-92 Jun-93 Dec-93 Source: Sentinel Serosurveillance, Division of Epidemiology, MoPH Remark: Switching from bi-annually (June and December) to annually in June since 1995 Jun-94 Dec-94 Jun-95 Jun-96 Jun-97 Jun-98 Jun-99 jun00 Year
HIV Prevalence Among Pregnant Women, Male Conscripts, Donated Blood:Thailand 1989-2001 4.5 4 3.5 3 % Conscripts (age 21) 2.5 2 1.5 1 Pregnant women Donated blood 0.5 0 Jun-89 Dec-89 Jun-90 Dec-90 Jun-91 Dec-91 Jun-92 Dec-92 Jun-93 Dec-93 Jun-94 Dec-94 Jun-95 Dec-95 Jun-96 Jun-97 Jun-98 Jun-99 Jun-00 Jun-01 Source: Sentinel Serosurveillance, Division of Epidemiology, Ministry of Public Health. Remark: Switching from bi-annually (June and December) to annually in June since 1995 Conscript data in November of each year since 1995 were not shown here Month/Year
Reported AIDS Cases by year, Thailand 1984-2001 2,676 6,949 13,923 20,686 24,709 26,817 27,304 26,528 24948 20372 Number of cases 30,000 25,000 20,000 15,000 10,000 5,000 0 1984-1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 Source: Division of Epidemiology, MOPH, Thailand data as of December 31, 2001 Delay effec
Trend of AIDS incidence by region 90 80 70 60 50 40 30 20 10 0 North Central South Norteast 95 96 97 98 99 2000 2001
Distribution of Reported AIDS cases by Age-group of Diagnosis in Thailand, September 1984-31 January 2002 40000 35000 30000 25000 20000 15000 10000 5000 0 0-4 5-9 10-14 15-19 20-24 25-29 30-34 35-39 40-44 45-49 50-54 55-59 60+ Male Female unk.
Transmission Sexual intercourse, anal and vaginal Persons at higher risk of heterosexual transmission ulcerative STD multiple sex partners partner of IVDA male-to-female is 7 to 9 x more efficient partner of uncircumcised males
Transmission Casual contact is NOT a significant risk Parenteral transmission contaminated blood (1%) IVDA-needle sharing occupational risks (0.3%) perinatal infection (>90%of pediatric case) breast feeding
Mode of HIV Transmission in Thailand Sexual Transmission 83.10% IDU 4.97% Blood products 0.03% MTCT 4.87% Others 0.01% Unknown 7.15%
Pathogenesis
HIV Infection via Mucosa Intact mucosa? R5 virus infects dendritic cells Transport of virus to regional LN Transmit to CD4+ T cells in regional LN Walker et al. NEJM 1998
Dendritic Cells and HIV Infection Steinman RM. Cell 2000:100:491-94.
Dendritic Cells (DCs) It can stabilize HIV-1 for more than 4 days, because binding to DC-SIGN protects HIV from proteases that are present in plasma. This then likely allows for transport of the virus to regional lymph nodes, where infection can be propagated further. van Kooyk et al 2001
HIV Infection Lymph nodes Viremia Dissemination to other organs Brain Spleen Gut Within few days Walker et al 1998
HIV-1 Life Cycle
Pathogenesis
Clinical Presentation Primary HIV infection-viral syndrome or mononucleosis-like illness fever, pharyngitis, adenopathy, rash A high viral load >50,000 copies/ml An immune response develops but will not eliminate viral replication HIV is trapped by follicular dendritic cells and replicates in germinal center
Natural Course of HIV Infection and Host Responses Relative Levels CD4+ T-cellsAnti-HIV Ab HIV-CTL+CD8 activity Plasma HIV Viremia Months Years After HIV Infection Acute HIV infection Symptom AIDS-related illness
Clinical Presentation
ELISA, EIA OraSure: oral collection device OraQuick Home Access False-negative Positive ELISA
Western Blot Test Is the confirmatory test for final diagnosis looks for the glycoprotiens of the HIV virus (i.e., gp 120, gp 41)
Detection Markers Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) Measures the amount of HIV-RNA viral load in copies/ml The test used to develop a baseline viral load and for monitoring therapeutic response to treatment
Natural Course of HIV Infection and Common Complications CD4+ cell Count 1000 900 800 700 600 500 400 300 200 100 0 Acute HIV infection syndrome Asymptomatic TB TB HZV OHL PPE OC CMV, MAC PCP CM 0 1 2 3 4 5 1 2 3 4 5 6 7 8 9 10 11 Months CD4+ T cells Years After HIV Infection VL Relative level of Plasma HIV-RNA
Five Most Common Opportunistic Infections Thailand 1984-2000 Tuberculosis (27.4%) Pneumocystis carinii (19.5%) Cryptococcosis (16.7%) Candidiasis Recurrent Pneumonia (5.3%) (3.7%) Source: Epidemiology Section, Ministry of Public Health
Approach for Opportunistic Infections 1) Symptoms 2) Onset of Symptoms 3) CD 4 cell count 4) Prophylactic medications 5) Compliance to prophylactic medications 6) Specific pattern (CXR) 7) Diagnostic Microbiology