www.thelancet.com Vol 372 July 26, 2008 337
Understanding and responding to disparities in HIV and
other sexually transmitted infections in African Americans
Sevgi O Aral, Adaora A Adimora, Kevin A Fenton
Rates of infection with HIV and some other sexually
transmitted infections (STIs) are higher among African
Americans than among European Americans.1,2 Although
these health disparities are not unique to STIs; their
nature, pattern, and distribution are complex. This
complexity is not solely a result of individual risk
behaviours. Increasing evidence indicates that disease
epidemics, and, consequently, disparities in morbidity
rates, are outcomes of the functioning of systems.3
Populations function as complex systems, and disease
rates might result from the characteristics of individuals
in the population, the interactions and interdependencies
between individuals, the eff ects of population-level
factors on individual-level health outcomes, and the
interplay between individual-level and population-level
factors.3 This view of population health provides a best fi t
to understanding the importance of social determinants
of disease and health within populations.4
Recent analyses in the USA demonstrate that reported
sexual behaviour in terms of number of partners,
practices, condom use, and other individual-level factors
does not solely account for the observed racial and ethnic
disparities in rates of HIV or other STIs.5 In most
analyses, African American women have among the
highest HIV and STI prevalence but do not have the
highest levels of risk behaviours. Data from the
2002 national survey of family growth indicates that
fewer black women than white women reported having
had four or more partners in the past year and 15 or more
in their lifetime.6 However, for each unit increase in risk
behaviour, the adverse health outcomes for black women
are many times those for white women. Whereas white
Americans acquire STIs predominantly when they
engage in high-risk behaviours, African Americans
acquire them through low-risk behaviours because
prevalence of infection in the population is high.5 Thus,
at the individual level, the most important risk factor for
STIs is sex with an infected partner, the probability of
which is partly determined by the prevalence of infection
in the population from which one chooses partners.
At the population level,
partnerships and high levels of sexual mixing between
high-risk and low-risk groups facilitate more effi cient
spread of STIs among African Americans. There is
emerging evidence that black Americans and white
Americans participate in largely separate sexual networks
and have diff erent numbers of concurrent sexual
partnerships. Assortative sexual mixing is the formation
of partnerships between people with similar character-
istics (eg, racial background or risk for infection). Black
men and women in the USA are more likely to mix
assortatively by race than are white Americans, but more
likely to mix disassortatively by risk, a sexual mixing
pattern that disseminates and maintains infection within
Multiple concurrent sexual partnerships spread STIs
more rapidly than the same number of relationships held
sequentially.8 In empirical studies, people who had
concurrent partnerships were more likely to transmit
Chlamydia9 and syphilis10 than were those who did not. In
one study, having a partner who had concurrent
partnerships was a risk factor for heterosexual HIV
transmission among African Americans who were
otherwise at low risk.11 Black Americans are more likely
to report concurrent partnerships than are white
Americans. In the 1995 national survey of family growth,
21% of black women reported concurrent partnerships in
the previous 5 years compared with 12% in the general
population.12 However, adjusting for age at time of
interview, age at fi rst sexual intercourse, and marital
status attenuated the partner-concurrency disparity.12 A
similar analysis of the 2002 national survey of family
growth showed that black men in the USA were more
than twice as likely as white men to have concurrent
partnerships.13 There are also geographic variations: the
5 year prevalence of concurrent partnerships was higher
among heterosexual black men (53%) and women (31%)
from counties in North Carolina with high STI rates
than among black women in the national survey of family
growth (21%),14 and higher still among HIV-positive men
(63%) and HIV-positive women (58%) in North
Social forces aff ect the distribution of STIs through
their eff ects on behaviour, networks, and risk of exposure
to infection. A few studies have documented the eff ects
of these forces on the spread of HIV infection in Africa
and Asia, but the eff ect of social forces on the HIV and
STI epidemics among African Americans has received
little attention from researchers. Disproportionate
poverty among African Americans’ is well documented.
Furthermore, the sex ratio of men to women is much
lower among African Americans than all other ethnic
groups as a result of high mortality rates among black
men from disease and violence, and high rates of
incarceration.16,17 These two social forces, poverty and the
low sex ratio, are probably among the biggest deter-
minants of sexual network patterns among black people
in the USA.18 Poverty and low sex ratios are associated
with low marriage rates, and married people have lower
rates of concurrent partnerships than unmarried people.18
Moreover, the shortage of black men promotes partner
concurrency as well as partnering between women with
Lancet 2008; 372: 337–40
National Center for HIV/AIDS,
Viral Hepatitis, STD, and TB
Prevention (S O Aral PhD,
K A Fenton PhD), Centers for
Disease Control and
Prevention, Atlanta, GA, USA;
and Division of Infectious
Diseases (A A Adimora MD),
The University of North
Carolina at Chapel Hill, NC, USA
Kevin A Fenton, Director,
National Center for HIV/AIDS,
Viral Hepatitis, STD, and TB
Prevention, Centers for Disease
Control and Prevention,
1600 Clifton Road, NE,
Mailstop E07, Atlanta, GA 30333,
www.thelancet.com Vol 372 July 26, 2008
low-risk behaviours and men with high-risk behaviours.
Additionally, drug use, particularly intravenous drug use,
has an important role in the spread of HIV and other
STIs among African Americans.
Poverty, income, and socioeconomic status are
important cofactors that aff ect HIV and STI rates. But
public-health surveillance systems in the USA do not
routinely collect data on socioeconomic status. As a
result, our understanding of the contribution of these
factors to racial or ethic disparities in HIV and STIs in
the USA is limited. In one study that focused on
developing a method to monitor socioeconomic health
disparities in the USA, risk for all adverse health
outcomes, including STIs, increased with the proportion
of people living in poverty in a census district.19
Adjustment for census tract poverty substantially reduced
racial and ethnic disparities.19 In half of the study
outcomes, census tract poverty accounted for over 50% of
Recent research results suggest that socioeconomic
status, poverty, and geography might be important
correlates of racial disparities in health,20 and the gap
between the highest and lowest life expectancies for
combinations of race and county in the USA exceeds
35 years. Murray and colleagues21 found that combinations
of race and county clustered into eight distinct groups
and remained stable from 1982 to 2001, and
neighbourhood levels of economic wellbeing were highly
correlated with the cumulative incidence of HIV.
Subsequent unpublished analyses by the Centers for
Disease Control and Prevention with this approach
suggest that, in general, disparities in gonorrhoea and
syphilis rates mirror all other health disparities among
race–county units in the USA.
Residential segregation by race, one of the most
pervasive results of discrimination in the USA,
concentrates poverty and other negative infl uences
within the segregated group.22 Moreover, housing markets
infl uence not only where people live, but also anything
that is correlated with where one lives—and thus drives
the distribution of education, wealth, employment, safety,
and peer groups.23 Some people choose sex partners from
their neighbourhoods, so even if they don’t engage in
high-risk behaviours themselves, segregation increases
the likelihood of having a high-risk partner. Social,
economic, and legal systems tend to reinforce existing
hierarchies and protect the privileged.24 Thus, pathways
that remain largely beyond the control of individuals
connect social forces and STIs.
The disproportionate incarceration
Americans renders this social force a major part of the
life experience of many families. More than 12% of black
men age 25–29 years are in jail or prison;25 and, for the
same crime, the risk of incarceration is substantially
greater for black men than for white men.26 Incarceration
directly aff ects sexual networks by physically removing
people from partnerships.18 The partner entering prison
may have sex with others there who have a high
probability of HIV or STI infection. The partner who is
left behind loses the fi nancial, social, and other supports
of the incarcerated partner and may seek other partners.
As inmates return to the community, they may resume
old partnerships or start new ones, increasing the
likelihood of concurrency.14,15 While in prison, some
inmates join gangs and forge new long-term links with
antisocial networks that can aff ect sexual networks by
connecting previously low-risk people with new high-risk
subgroups. Incarceration reduces employment prospects,
which increases poverty risk and destabilises long-term
partnerships. The overall eff ect of incarceration is not
only a reduction in the absolute number of men, but also
an increase in the proportion of fi nancially insecure men
in the community.18
Finally, diff erential access to high-quality health care
contributes to racial and ethnic disparities in chronic
medical disorders.27 In infectious diseases in general, and
STIs in particular, timeliness of diagnosis and treatment
is both an important factor in restricting disease
transmission, and an important determinant of the
prevalence and incidence in the population. Population-
level factors of accessibility, acceptability, and quality of
health care consequently emerge as important social
determinants of racial and ethnic disparities in rates of
STIs. Chandra and co-workers20 showed that within
hospitals or provider groups black patients and white
patients are treated diff erently, and that African
Americans are likely to live in areas or seek care in
regions in which health-care quality is low for all patients.
Consequently, assuring equal access to health care at the
local level, without simultaneous attention to improving
the quality of health care, might not be enough to erase
The multifaceted determinants of HIV and STI
epidemics among African Americans require preventive
responses with legal, human-rights, and health-equity
dimensions. Essential steps include improved targeting
and adequate implementation of behavioural and
biomedical interventions, including fully funded pre-
vention and treatment clinics to provide evidence based
services in underserved neighbourhoods; education,
screening and treatment in prisons; education about the
risks of partner concurrency and high-risk partners; and
expansion of health-care insurance coverage. In addition
to these prevention eff orts, accelerated progress is needed
in four key domains: research and evaluation, community
mobilisation, interagency collaboration, and leadership.
The African American HIV and STI prevention
research agenda needs to be more deliberately placed
within a social determinants and social justice framework.
Empirical evidence on the association between social
determinants and sexual-health outcomes for African
Americans and the public-health benefi ts associated with
a social-determinants approach can support integrated
prevention approaches that focus on upstream
www.thelancet.com Vol 372 July 26, 2008 339
interventions such as education, housing, and health-care
access. The academic and governmental sectors can help
by increasing funding for research and supporting the
translation of the resulting knowledge into prevention
programmes. Eff orts are needed to expand the cadre of
African American researchers and prevention-pro-
gramme leaders trained to do culturally relevant research
within their communities and to understand, to value,
and to prioritise, structural interventions.
Persistent stigma and silence surround HIV and STIs
among African Americans, but community mobilisation
eff orts can help mitigate their eff ect. Priority should be
given to identifying and enlisting African American
health professionals to do culturally appropriate
presentations, raise awareness, and mobilise local
public–private community coalitions against HIV and
STIs. Provision of adequate and appropriate information
on the prevalence, incidence, and transmission dynamics
of STIs to the communities is a necessary fi rst step.
Communities then need to be encouraged to set the
priorities and make the relevant choices themselves.
Other strategies might involve use of mobilisation to
create community change by connecting HIV and STI
prevention with eff orts against racism, homophobia,
joblessness, sexual violence, homelessness, substance
use, mental illness, and poverty.
Partnerships must be built across all levels of
government and between a range of public-sector and
private-sector institutions and departments if resources
for improving the health and wellbeing of African
Americans are to be harnessed to improve health. The
Centers for Disease Control and Prevention Heightened
National Response to HIV/AIDS among African
Americans and other recent HIV prevention strategies28,29
call for greater collaboration with traditional and
non-traditional partners and improved collaboration and
coordination across federal agencies within the context
of a national planning framework. Strategic partnerships
such as these can be used to build a consensus around
the social determinants of HIV and STI epidemics in
African Americans and strategies to overcome them. The
public-health system should strengthen collaboration
with the Department of Justice to reduce the adverse
health eff ects of incarceration and with the Department
of Education to help increase high-school graduation
rates among African Americans.
Finally, committed leadership at the highest levels in
the African American community and in governments
across the country is essential. Leadership committed to
expanding prevention eff orts to include reduction of
income inequalities and high rates of incarceration,
improvement of income security, improvements to access
to quality health care, provision of eff ective education in
schools, promotion of special eff orts to retain youth in
the school system, and public commitment to social
housing for the most vulnerable could lessen the eff ect of
STIs and HIV among African Americans. Although the
short-term focus needs to be on identifi cation and
treatment of infected individuals so as to reduce
prevalence and infectiousness in the community,
long-term prevention planning will have to include social
determinants. Societal eff orts to eff ectively address
stigma and discrimination will be crucial, in particular
among those who are socially isolated or marginalised
due to illnesses, disability, sexuality, race, culture, or
gender. Without eff orts to fundamentally improve
population health and wellbeing by addressing the root
causes of these epidemics, African Americans will
continue to be severely aff ected and disadvantaged.
SOA, AAA, and KAF conceived the paper. All authors contributed to the
paper design and acquisition of data for inclusion in this Viewpoint. All
authors were involved in drafting various sections of the paper and
critical revision of earlier and fi nal drafts. The fi ndings and conclusions
in this report are those of the authors and do not necessarily represent
the views of the Centers for Disease Control and Prevention or the
Agency for Toxic Substances and Disease Registry.
Confl ict of interest statement
We declare that we have no confl ict of interest.
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