X HIV/AIDS Prevention and Care in Resource-Constrained Settings

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INTRODUCTIONWe are in the third decade of what hasbecome the most important infectiousdisease epidemic of the last century. SinceAIDS was first recognized in 1981, an estimated 60million men, women and children have becomeinfected with the virus worldwide. Nearly half of allpersons who acquire HIV are under age 25 and mostwill die before they reach 35. As of the end of 2000,22 million people had died of AIDS. Approximately13 million children under age 15 have lost one orboth parents to AIDS, and the number of AIDSorphans is expected to exceed 40 million by 2010.HIV/AIDS is now the fourth leading cause of deathworldwide, and the single leading cause of death insub-Saharan Africa.Over the past 20 years, we have continued to besurprised, shocked and devastated by this pandemic,which the global community has consistently underestimated.We have underestimated the level of HIVprevalence that has been attained in some generaladult populations (such as in Botswana andZimbabwe); the scope of the pandemic around theworld (HIV infection is now found in even the mostremote and isolated countries such as Bhutan andMongolia); and the rapid growth of specific countryepidemics (such as those in Cambodia and the countriesof Southern Africa). At the beginning of the 21stcentury, HIV/AIDS prevalence among adults hasexceeded 20 percent in seven countries in the developingworld—all in Africa—and is above 10 percent innine additional countries. In another 38 countries,prevalence equals or exceeds one percent; 22 of theseare in Africa, 11 in Latin America, four in Asia andone in Eurasia. In contrast, HIV/AIDS prevalence inthe United States was 0.6 percent at the end of 2000.AIDS was first described in 1981, and it appearslikely that the virus is less than 100 years old. It istheorized that the various strains and subtypes of HIVoriginated through multiple mutations of animalretroviruses, which facilitated a “species leap” tohumans. Through back-estimating the time needed toachieve the existing varieties of viral mutations, itappears this jump from animal to humans probablyoccurred in the late 1930s or early 1940s. The mutationsthat resulted in HIV-1 most likely arose in westcentralAfrica, in the countries of Gabon, EquatorialGuinea and Cameroon. What occurred after humansbecame infected demonstrates a pattern that we haveseen repeatedly throughout the world. Due to theupheavals that were occurring in the Belgian Congoduring the 1950s, it is likely that the earliest infectedhumans seeded the Great Lakes region of the AfricanRift Valley. Mass movements of people, disruptions offamilies and culture, changing sexual behavior, anincrease of other risk behaviors and fluxes in economicstatus have all fueled the pandemic—in Africa andaround the world. Because HIV is new to humanity,we still have much to learn.PAUL R. DE LAYGUNILA ERNBERGKAREN STANECKIHIV/AIDS Prevention and Care in Resource-Constrained Settings VII
F igure 1Factors That InfluenceThe Spread of HIVViral Factors■ HIV-1 strains■ ViremiaLocal Genital Factors■ Presence of STDs■ Male cicumcision■ Use of vaginal productsSexual Behavior■ Rate of partner exchange■ Sexual mixing patterns■ Type of intercourse■ Size and rate of contact with core groups■ Level of condom useDemographic Factors■ Percentage of sexually active age groups toother age groups■ Male to female ratio■ Urban: rural percentage■ Migration patternsEconomic and Political Factors■ Level of poverty■ War and social conflicts■ Status of transport and mobility of population■ Performance of health care system■ Response to epidemic(from Piot-1994)STATUS AND TRENDS OFTHE HIV/AIDS EPIDEMICSAlthough the AIDS pandemic is complex, trackingand analyzing its evolution and diversity enables us tointervene more effectively and to more accuratelypredict future trends. We assumed in the late 1980sthat any country with evidence of widespread riskconditions for HIV transmission would inevitablysuffer an extensive epidemic once HIV was introducedinto the population. This “evidence” of risk behaviorsincluded the presence of a commercial sex industry,high background prevalence of other sexually transmitteddiseases (STDs) in the population, low condomuse by men and the existence of injection druguse (IDU). But this was a far too simplistic view of theunderlying dynamics of the pandemic. In Asia, forexample, we have seen the epidemic explode inCambodia, Burma, Thailand and in some states ofIndia, yet remain very concentrated and in low prevalencein the Philippines and Indonesia.The pandemic continues to defy simple modelsand formulas. We now recognize that there are anumber of host, viral and social factors that determinetransmission and vulnerability. These interact in acomplex manner in the mosaic of global settings.Figure 1 lists the most predominant determinants.It has become increasingly important to integrateimproved biological surveillance data with detailedinformation about the social and economic patternsthat lead to increased risk behaviors and vulnerability.These “second generation” surveillance systems willimprove our ability to describe the state of local epidemicsand target our interventions for the future. Butit is challenging to collect this range and depth of datafor each country. Among this array of determinants,there are a number of predominant factors. Sexualbehaviors and the pattern of sexual networks areclearly the most important factors in the most severesexually transmitted epidemics. We have recentlylearned that subtle quantitative differences in behaviorcan either cause the epidemic to explode or stabilize ata relatively low level of prevalence. It is not a matterof whether commercial or casual sex exists in a society,but how much, of what kinds, when it is practicedand by whom.Besides risk behavior patterns, there are increasingdata on the possible role of STDs, HIV-1 subtypesand male circumcision in the efficiency of variousVIII HIV/AIDS Prevention and Care in Resource-Constrained Settings
Page 1 and 2: Edited byPeter R. Lamptey, MD, DrPH
Page 3 and 4: © 2001 Family Health International
Page 5 and 6: SECTION II:Chapter 6PAGE 137Chapter
Page 7 and 8: Chapter 21PAGE 501Chapter 22PAGE 51
Page 9: I N T R O D U C T I O NPAUL R. DE L
Page 13 and 14: F igure 3HIV Seroprevalence for Pre
Page 15 and 16: F igure 5HIV Seroprevalence for Com
Page 17 and 18: F igure 7HIV Seroprevalence for Pre
Page 19 and 20: F igure 9Life Expectancy With and W
Page 21 and 22: F igure 11Population of Zimbabwe,Wi
Page 23 and 24: invest; and feedback further amplif
Page 25 and 26: R EDUCING MOTHER-TO-CHILDTRANSMISSI
Page 27 and 28: F igure 13HIV Seroprevalence in Adu
Page 29 and 30: ACKNOWLEDGEMENTSWe wish to express
Page 32 and 33: SOFIA GRUSKIN, JD, MIAAssistant Pro
Page 34 and 35: THOMAS M. PAINTER, PHDBehavioral Sc
Page 36 and 37: glossary of A C R O N Y M SACTG AID

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