Blind spots in the epidemiology of HIV in black Americans.

In the USA, annual rates of new human immunodeficiency virus (HIV)/AIDS diagnoses are seven and 21 times higher in black men and women, respectively, than in whites. Epidemiological inquiry on this disparity has chiefly focused on contextual factors; such emphasis has eclipsed study of direct HIV vectors. The US Centers for Disease Control and Prevention recently announced its intention to curb HIV propagation in black communities, recommending culturally appropriate HIV/AIDS strategies. Contemplated societal interventions should be informed by data evaluating more direct (and under-assessed) HIV transmission vectors, specifically anal intercourse and unsuspected blood exposures. This recommendation involves tracing sexual and non-sexual contacts of recently infected persons and uninfected controls, coupled with DNA sequencing of HIV isolates. Public health authorities do not know the extent to which unmeasured yet plausible HIV transmission vectors can account for ethnic disparities. Appropriate prevention strategies depend critically on direct, rather than ecologic, evidence.

Male and female circumcision associated with prevalent HIV infection in virgins and adolescents in Kenya, Lesotho, and Tanzania.

PURPOSE: Remarkable proportions of self-reported virgins and adolescents in eastern and southern Africa are infected with HIV, yet non-sexual routes of transmission have not been systematically investigated in such persons. Many observers in this region have recognized the potential for HIV transmission through unhygienic circumcision procedures. We assessed the relation between male and female circumcision (genital cutting) and prevalent HIV infection in Kenyan, Lesothoan, and Tanzanian virgins and adolescents. METHODS: We analyzed data from recent cross-sectional national probability sample surveys of adolescents and adults in households, focusing on populations in which circumcision was common and usually occurred in puberty or later. RESULTS: Circumcised male and female virgins were substantially more likely to be HIV infected than uncircumcised virgins (Kenyan females: 3.2% vs. 1.4%, odds ratio [OR] = 2.38; Kenyan males: 1.8% vs. 0%, OR undefined; Lesothoan males: 6.1% vs. 1.9%, OR 3.36; Tanzanian males: 2.9% vs. 1.0%, OR 2.99; weighted mean phi correlation = 0.07, 95% confidence interval, 0.03 to 0.11). Among adolescents, regardless of sexual experience, circumcision was just as strongly associated with prevalent HIV infection. However, uncircumcised adults were more likely to be HIV positive than circumcised adults. Self-reported sexual experience was independently related to HIV infection in adolescent Kenyan females, but was unrelated to HIV infection in adolescent Kenyan, Lesothoan, and Tanzanian males. CONCLUSIONS: HIV transmission may occur through circumcision-related blood exposures in eastern and southern Africa.

Partner referral tools and techniques for the clinician diagnosing a sexually transmitted infection.

Public health agencies have insufficient resources to trace and refer to medical evaluation the sexual partners of patients with sexually transmitted infections (STI). Only a minority of such patients receives formal sex partner referral services. Hence this responsibility rests, by default, with the diagnosing clinician or with the infected patient. Unfortunately, clinicians do not sufficiently appreciate this public health lacuna, and patients with STI usually perform poorly at notifying partners. Clinician and patient obstacles to successful partner referral are discussed, and brief counselling techniques are suggested. Use of patient-delivered therapy, via medication or prescription (dispensed with appropriate warnings), probably serves to emphasize the urgency and importance of notifying partners. Successful referral to medical attention has been shown to help prevent re-infection of the index patient and to curtail community transmission.

Efficiency of human immunodeficiency virus transmission through injections and other medical procedures: evidence, estimates, and unfinished business.

OBJECTIVE: To estimate the transmission efficiency of human immunodeficiency virus (HIV) through medical injections and other invasive procedures. DESIGN: We searched our own files and Medline (from 1966-2004, using the keywords ["iatrogenic" or "nosocomial" or "injections"] and "HIV") for reports of iatrogenic outbreaks worldwide, except outbreaks traced to receipt of contaminated blood or blood products. We also analyzed information from a case-control study of percutaneous exposures to healthcare workers. SETTING: Worldwide healthcare settings. EVENTS: We identified 8 iatrogenic outbreaks that met our study criteria; published information from 4 outbreaks was sufficient to estimate transmission efficiency. RESULTS: From the 4 documented iatrogenic outbreaks, we estimated that 1 iatrogenic infection occurred after 8-52 procedures involving HIV-infected persons. Although only 0.3% of healthcare workers seroconvert after percutaneous exposure, a case-control study reported that deep injuries and other risk factors collectively increased seroconversion risk by as much as 50 times. Laboratory investigations demonstrate HIV survival through time and various rinsing regimens. We estimate that the transmission efficiency in medical settings with no or grossly insufficient efforts to clean equipment ranges from 0.5% to 3% for lower risk procedures (eg, intramuscular injections) and from 10% to 20% or more for high-risk procedures. Efforts to clean equipment, short of sterilization, may cut the transmission efficiency by 0%-100%. Procedures that contaminate multidose vials may accelerate transmission efficiency. CONCLUSION: To achieve better estimates of the transmission efficiency for a range of medical procedures and settings, investigations of iatrogenic outbreaks should be accorded high priority.

A passage to India's HIV epidemics: sending out an SOS.

The official view is that India's epidemics are driven, directly and indirectly, by heterosexual prostitution. Review of available evidence by researchers in India undermines this weakly supported orthodoxy and suggests that correcting weaknesses in its AIDS surveillance system can lead to a more reliable picture of HIV propagation and hence to evidence-based interventions. Contenders for leading roles in HIV transmission are under-suspected and unmeasured skin-puncturing exposures.

Extent, trends, and perpetrators of prostitution-related homicide in the United States.

Prostitute women have the highest homicide victimization rate of any set of women ever studied. We analyzed nine diverse homicide data sets to examine the extent, trends, and perpetrators of prostitution-related homicide in the United States. Most data sources substantially under-ascertained prostitute homicides. As estimated from a conservative capture-recapture analysis, 2.7% of female homicide victims in the United States between 1982 and 2000 were prostitutes. Frequencies of recorded prostitute and client homicides increased substantially in the late 1980s and early 1990s; nearly all of the few observed pimp homicides occurred before the late 1980s. These trends may be linked to the rise of crack cocaine use. Prostitutes were killed primarily by clients, clients were killed mainly by prostitutes, and pimps were killed predominantly by pimps. Another conservative estimate suggests that serial killers accounted for 35% of prostitute homicides. Proactive surveillance of, and evidence collection from, clients and prostitutes might enhance the investigation of prostitution-related homicide.

Heterosexual transmission of HIV in Africa: an empiric estimate.

For more than a decade, most experts have assumed that more than 90% of HIV in African adults results from heterosexual transmission. In this exercise, we show how data from studies of risk factors for HIV can be used to estimate the proportion from sexual transmission, and we present our estimates. Calculating two ways from available data, our two point estimates - we do not estimate confidence intervals - are that 25-29% of HIV incidence in African women and 30-35% in men is attributable to sexual transmission; these estimates assume 10% annual epidemic growth. These findings call for reconceptualization of research to more accurately assess routes of HIV transmission.

Confound it: latent lessons from the Mwanza trial of STD treatment to reduce HIV transmission.

In 1995, an international team reported that improved syndromic management of sexually transmitted disease (STD) in Mwanza, Tanzania, had reduced HIV incidence by 38% in intervention compared to control communities. However, the team has not addressed confound: project interventions might have reduced HIV transmission during health care through provision of syringes and benzathine (replacing short acting) penicillin and through interactions with a coeval safe injection initiative. Mwanza's success in lowering HIV incidence is a puzzle, since it was achieved with only minor reductions in observed STD prevalence. Despite incomplete analyses, reports from Mwanza have encouraged expansion of STD treatment. However, should success be attributed to injection safety rather than to decreased STD prevalence - an hypothesis that fits published data - expanded STD treatment without attention to injection safety could, ironically, increase rather than decrease HIV incidence. To control for confound, additional data and analyses from the Mwanza study are warranted.

Review of evidence from risk factor analyses associating HIV infection in African adults with medical injections and multiple sexual partners.

Studies of risk factors for human immunodeficiency virus (HIV) infections in sub-Saharan Africa present a wealth of evidence relevant to ongoing debates about the contributions of unsterile health care and sexual transmission to Africa's HIV epidemics. From studies which meet search criteria (n = 39) we calculate population attributable fractions (PAFs) for incident and prevalent HIV infections associated with exposure to medical injections and with having more than one sexual partner. Median and mean crude PAFs for injections for both incident and prevalent HIV exceed those for multiple partners. Evidence suggests that adjustments for reverse causation (people with HIV-related symptoms seeking injections) and confounding do not explain away the large PAFs for injections. Misreporting of sexual behaviour has an unknown impact on PAFs for multiple partners. However, most PAFs for incident HIV infections are from communities with low-growth epidemics; hence data about the most important risk factors fuelling high-growth epidemics are sparse. Empirical resolution of ongoing debates may be possible with the aid of future research-especially in high-growth epidemic settings-that investigates risks for HIV transmission through a full range of sexual and parenteral exposures with attention to reverse causation, confound, and quality of sexual behaviour data.

Establishing valid AIDS monitoring and research in countries with generalized epidemics.

The authors present guidelines for valid HIV/AIDS surveillance and epidemiologic research, and for clarification of uncertainties in transmission dynamics, particularly in countries with generalized epidemics. The consensus assumption that most HIV/AIDS cases in many developing regions, particularly sub-Saharan Africa, are explained by 'heterosexual' transmission (interpreted, by default, to mean penile-vaginal intercourse) has been challenged by recent reviews demonstrating an important contribution from unsafe health care practices. Resolution of existing uncertainties about the proportions of HIV transmission accounted for by specific parenteral exposures and sexual practices (e.g., vaginal and anal intercourse, considered separately) is crucial for the design and implementation of efficacious prevention strategies. Accurate risk-factor information is the best foundation upon which people living in countries with generalized epidemics can learn to protect themselves and their families. Multimethod approaches for developing sound HIV/AIDS research are presented.

Assessing the role of anal intercourse in the epidemiology of AIDS in Africa.

Public health authorities have long believed that the preponderance of AIDS cases in Africa are attributable to 'heterosexual transmission'; most people silently assume this rubric to indicate penile-vaginal intercourse only. Recent epidemiologic analyses suggest that the majority of HIV cases in sub-Saharan Africa may be due to non-sterile health care practices. The present paper reviews the anthropological, proctologic, and infectious disease literature, and argues that both homosexuality and heterosexual anal intercourse are more prevalent in Africa than has traditionally been believed. The authors hypothesize that perhaps the majority of HIV transmission not accounted for by iatrogenic exposure could be accounted for by unsuspected and unreported penile-anal intercourse. Given the authors' findings, properly conducted studies to measure this HIV transmission vector, while controlling for iatrogenic exposure confound, are clearly warranted in Africa and in countries with similar epidemiologic characteristics.

Running on empty: sexual co-factors are insufficient to fuel Africa's turbocharged HIV epidemic.

The hypothesis that heterosexual transmission drives sub-Saharan Africa's HIV epidemics requires much faster transmission dynamics in Africa than in the US and Europe, where heterosexual transmission is arguably insufficient to maintain existing levels of HIV prevalence. Initially, experts surmised that Africans had more sexual partners; however, studies of sexual behaviour circa 1990 undermined this assumption. Next, it was supposed that the high burden of bacterial sexually transmitted disease (STD) in Africa explained greater HIV transmission efficiency; however, during the 1990s, community studies in Africa showed that STD had much less than expected impact on HIV transmission. Current attempts to explain HIV as a primarily sexual epidemic in Africa propose multiple factors, including herpes simplex virus type 2, lack of male circumcision, concurrency, and others. These factors also fail for various reasons to account for Africa's HIV epidemics: they are present also in the US and/or Europe; they do not correlate with differences in HIV prevalence across Africa; etc. While behavioural and biological variables influence personal risk for HIV acquisition, the available evidence suggests that they do not differentiate African from US and European epidemics, nor do they determine the differential HIV epidemic trajectories noted across Africa.

Let it be sexual: how health care transmission of AIDS in Africa was ignored.

The consensus among influential AIDS experts that heterosexual transmission accounts for 90% of HIV infections in African adults emerged no later than 1988. We examine evidence available through 1988, including risk measures associating HIV with sexual behaviour, health care, and socioeconomic variables, HIV in children, and risks for HIV in prostitutes and STD patients. Evidence permits the interpretation that health care exposures caused more HIV than sexual transmission. In general population studies, crude risk measures associate more than half of HIV infections in adults with health care exposures. Early studies did not resolve questions about direction of causation (between injections and HIV) and confound (between injections and STD). Preconceptions about African sexuality and a desire to maintain public trust in health care may have encouraged discounting of evidence. We urge renewed, evidence-based, investigations into the proportion of African HIV from non-sexual exposures.

Does selected ecological evidence give a true picture of HIV transmission in Africa?

Current reconsideration of the contributions of various modes of transmission to HIV epidemics in sub-Saharan Africa has important implications for HIV prevention. In recent reviews, we argue that accumulated evidence supports the hypothesis that unsafe health care fuels Africa's HIV epidemics. In response, critics have presented selected ecological evidence - age and sex distribution of HIV infections and geographic distribution of hepatitis C virus infections - to support the conventional hypothesis that sexual contact accounts for most HIV infections. In this communication, we examine critics' evidence and arguments. Critics ignore or reject important evidence including, for example, large numbers of unexplained HIV infections in children, strong associations between incident HIV and injections, and genetically-linked infections in persons with no known sexual contact. We urge that research projects in Africa disclose unpublished relevant evidence on risks for incident HIV. In any case, because each iatrogenic infection causes subsequent linked infections, the impact of HIV transmission through health care has been underestimated. We commend the emerging consensus to improve the safety of health care delivery. In countries with generalized HIV epidemics, we urge public education about the risks for HIV acquisition from unsterile health care.

Four policies to reduce HIV transmission through unsterile health care.

Residents of many developing countries face risks for themselves and their families to contract HIV and other bloodborne pathogens during unsterile health care. Helping people to understand and reduce these risks enlists their assistance to control the HIV/AIDS epidemic. To reduce HIV transmission through health care, we recommend four policies that international, foreign, and local public and private organizations can adopt and begin to implement even with little or no additional funds: (1) Educate the public about risks to contract HIV through unsterile health care. (2) Promote transparent practices for injections and other procedures that allow patients to see and know that care is safe (e.g., taking a new auto-disable syringe out of a sealed package and taking injecta from a single-dose vial). (3) Promote safe health care practices equally for clients and staff. (4) Establish a zero-tolerance policy for iatrogenic HIV infections, with publicly reported monitoring and investigations.