Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download strategies to prevent hiv infection - UCLA Fielding School of Public
Document related concepts
Transcript
KEY ELEMENTS FOR SUCCESSFUL INTERVENTION • • • • • • • • • Mobilization of political will and commitment Good surveillance Learn and adapt from past experiences Unified national planning Rapid implementation Focused intervention especially to marginalized groups Access to intervention tools e.g. condoms, testing Community involvement Reduce stigmatization and discrimination MODES OF TRANSMISSION • Blood • Sexual activities • Mother to child NEED TO RETURN TO PUBLIC HEALTH PRINCIPLES • Discard concept of exceptionalism • Primary responsibility to protect the uninfected • Promote (risk-free) testing • Prevention of transmission USING ANXIETY AS A PUBLIC HEALTH TOOL Level of Anxiety Too little Sufficient Too much Consequences No action Appropriate action Fatalism and no action FACTORS PROMOTING SEXUAL TRANSMISSION • Rate of partner exchange • Sexual mixing patterns (multiple concurrent partners vs. serial monogamy) • Sexual practices (vaginal, anal, etc) • Condom use • Willingness to reduce partners/delay intercourse TARGET GROUPS FOR INTERVENTION STRATEGIES • • • • • • • • Homosexual/bisexual men Intravenous drug users Promiscuous heterosexuals Health care workers Biomedical laboratory workers Blood/plasma donors Pregnant women in high-risk populations Youth 13-25 years DETERMINANTS OF TRANSMISSION FROM AN INFECTED PERSON • • • • • • Duration of infection/stage of disease Risk of transmission per sexual act Presence/absence of concurrent STD infection Condom use Circumcision Partner exchange rate • mixing pattern • patterns of sexual behavior (anal, vaginal, etc.) STRATEGIES TO PREVENT HIV INFECTION Blood 1. 2. 3. 4. 5. 6. Prevent drug use Reduced use of whole blood Screening of blood donors Screening of blood donations Processing of blood products Institutionalization of routine safety procedures for health workers and biomedical laboratory technicians STRATEGIES TO PREVENT HIV INFECTION Injecting Drug Users 1. 2. 3. 4. 5. Reduce needle sharing Use of bleach or boiling Needle exchange programs Methadone clinics Health education/behavioral intervention for intravenous drug users 6. Improve access to and acceptability of testing STRATEGIES TO PREVENT HIV INFECTION (1) Sexual activities (male-female, male-male) • Health education/behavioral intervention •increase knowledge of HIV/AIDS at an early age •eliminate/reduce high-risk practices •promote use of condoms with every intercourse •promote monogamy/celibacy •improve sex education in schools STRATEGIES TO PREVENT HIV INFECTION (2) Sexual activities (male-female, male-male) • Reduce opportunities for promiscuity (e.g., close bath houses, reduce number of partners, avoid anonymous partners) • Regular screening and treatment for sexually transmitted diseases • Use of syndromic approach to treat STDs • premarital testing • Improve access to and acceptability of testing • voluntary partner notification STRATEGIES TO PREVENT HIV INFECTION High-Risk High-Fertility Women 1. 2. 3. 4. 5. 6. Selection of marital partners Testing before marriage and pregnancy Monogamy Education of spouses Screening and effective treatment of STDs Improve access to and acceptability of testing STRATEGIES TO PREVENT HIV INFECTION Mother to Infant • Screening of women in high-risk groups • Pre-pregnancy testing • Routine screening of pregnant women • Counseling and abortion • Antiretroviral treatment -- prenatal • PCR/isolation/IgA screening of infants STRATEGIES TO PREVENT HIV INFECTION Mother to Infant (continued) • Postnatal treatment • Education • Breast feeding only if no access to clean formula • Prophylaxis during breast feeding • Screening and effective treatment of STDs STRATEGIES TO PREVENT HIV INFECTION Commercial Sex Workers • Education on risk activities • Use of condoms • Persuasion of brothel owners/managers • Regular screening and effective treatment for STDs • Regular testing for HIV • Monitoring, not persecuting STRATEGIES TO PREVENT HIV INFECTION AIDS • Developed countries • Initiate HAART • CD4+ cell <250, regardless of symptoms • Symptoms of HIV infection present regardless of CD4+ cell level • CD4+ cell >250, viral load >30,000 • Diagnosis of AIDS STRATEGIES TO PREVENT HIV INFECTION AIDS (continued) • Developing countries • Pre-AIDS • Prophylaxis for most common opportunistic infections that constitute an AIDS diagnosis in the country • Post-AIDS • Multiple retroviral drugs, if possible • Treatment of specific opportunistic infection TARGET POPULATIONS • Vulnerable groups Poor Minorities Homosexuals • Adolescents • In utero/breast-feeding infants (mothers) • School children INTERVENTION STRATEGIES • Educational approaches • Behavioral (theory-based) “Empower” young people • Harm reduction • Community intervention EDUCATIONAL APPROACHES • • • • School-based Media: newspapers, posters, radio/TV Internet Health professionals – Train the trainers – Researchers – Administrators BEHAVIORAL (THEORY-BASED): “EMPOWER” YOUNG PEOPLE • Stages of behavior change – Knowledge – Persusion – Decision – Implementation – Confirmation ROLE MODELS • Popular opinion leaders • Recruitment • Training HARM REDUCTION • Condoms • Needle exchange • Methadone and other drug alternatives COMMUNITY INTERVENTION • Have community accept responsibility and initiate appropriate intervention activities • Recruit community leaders, teachers, health workers, peer leaders, media EDUCATION IS ESSENTIAL BUT INSUFFICIENT EVALUATION OF INTERVENTION STRATEGIES • Are the appropriate risk groups and areas targeted? • Is the intervention strategy culturally/ economically appropriate for the specific risk group/area? • How is effectiveness of intervention strategies measured? • Is the sentinel surveillance system a part of the evaluation scheme? • Is the strategy cost-effective? OBJECTIVES OF VACCINATION • Prevent infection • Prevent disease • Prevent transmission TARGET GROUPS FOR VACCINATION • • • • • • • Homosexual/bisexual men Intravenous drug users Promiscuous heterosexuals Sex workers Health workers Biomedical laboratory workers Spouses of risk group members REQUIREMENTS FOR A VACCINE • Must be safe • Must elicit a protective immune response • Must stimulate both humoral and cellular immunity • Must protect against different clades of HIV • Must provide long-lasting immunity • Must be practical to produce, transport and administer • Should stimulate mucosal immunity in genital tract, rectum and oral activity PRIMARY ISSUES FOR CONSIDERATION IN VACCINE DEVELOPMENT (1) • No long-lasting natural immunity yet demonstrated in humans • Disease progresses despite presence of neutralizing antibody • Variability of viral genome • Can a group antigen be found to induce immunity? Clades? • Antigenic drift • Need to induce humoral and especially cytotoxic cellular immunity • Potential of some vaccine candidates to induce enhancing antibodies PRIMARY ISSUES FOR CONSIDERATION IN VACCINE DEVELOPMENT (2) • Applicability of animals to HIV in humans • Ethics and sources of volunteers for safety and efficacy trials • Efficacy – – – – Against infection Against disease Against transmissibility Acceptable level • Who will be vaccinated? • Selection of optimal vaccine: safety vs. efficacy TYPES OF VACCINES • Non-live – Whole virus, killed – Subunit with adjuvant • Fractionation and use of specific particles • Synthetic • Anti-idiotypic • Live – Whole virus, attentuated – Subunit, recombinant • Viral substrate • Non-viral substrate (e.g., yeast) • Intracellular genetic transfer of “resistance” STAGES IN VACCINE RESEARCH AND DEVELOPMENT • Basic research • Animal studies – Safety – Immunogenicity (humoral and cell-mediated) – Efficacy • Clinical trials – Phase I – safety and immunogenicity in humans – small numbers of subjects • Who should be the guinea pigs? – Phase II – safety and immune response in humans – small trials – Phase III – larger population-based trials for efficacy SOCIOPOLITICAL CONSIDERATIONS • Cost of development – federal government and/or private industry? • Responsibility for liability – federal government, industry or insurance companies? • Priorities for funding and distribution of vaccine SUGGESTED FUTURE DIRECTIONS (1) Implement public health principles and eliminate concept of “exceptionalism” Recruit political will and intervention priority of HIV/AIDS International level National level Local level # Increase community awareness and acceptance of health threat # Promote community responsibility for intervention # Implement community intervention strategies Lower cost and improve quality of surveillance, SUGGESTED FUTURE DIRECTIONS (2) Promote health education for Health professionals Media Public, especially young, sexually active men and women School children before majority leave school Develop, implement, and evaluate culturally sensitive, economically feasible behavioral intervention strategies Improve treatment potential, especially in developing countries Promote concept of wealthy nation responsibility towards poorer nations, e.g. drug patent relief Implement mechanisms for distribution of low cost treatments SUGGESTED FUTURE DIRECTIONS (3) Implement “risk-free” testing (e.g. rapid saliva and urine testing with resources for confirmation of positives) Promote widespread testing Reduce stigmatization associated with being HIVinfected and with belonging to a “risk group” Increases willingness to learn HIV status Increases testing acceptability Facilitates earlier identification # Improves treatment effectiveness # Reduces period of unknowing transmissibility # Facilitates premarital testing SUGGESTED FUTURE DIRECTIONS (4) Improve control of sexually transmitted diseases Implement early health and sex education before majority of young people leave school Promote education of women Promote harm reduction Needle exchange, etc. Condom promotion Reduce cost of screening blood Reduce acceptance of multiple sexual SUGGESTED FUTURE DIRECTIONS (5) • Change gender realities (role of men and women) • Develop and promote an effective microbicide • Develop strategies to evaluate behavioral interventions • Continue intense efforts to develop an effective “vaccine”
