Social/Sexual Network

I’m writing a book about sexually transmitted infections (STIs). The goal of the book is to decrease the stigma that our culture conveys to people with STIs. I was fearful of adding to this stigma by pointing out that STI rates are significantly higher among minorities than among whites – but it is difficult to ignore. There is a danger that writing about disparities can lead to more stereotyping or misunderstanding.  But I am sharing my understanding of why STI rates are unequally distributed in the U.S. population because to find solutions to the STI epidemic, we need to understand the reasons behind it. When I uncovered the cause, I found structural racism.

Research in the U.S. has found that there is little difference in sexual behavior between white WSM (women who have sex with men) and Black WSM.[i] For example, the median number of lifetime sex partners for white WSM was 3.6 compared with 4.1 for Black WSM; 10% of white WSM have had 15 or more male sex partners in their lifetime, compared with 9% for Black WSM.[ii] Yet Black women have far higher rates of STIs than white women do. In 2017, the rates for Black women were five times higher for chlamydia, eight times higher for gonorrhea, and five times higher for syphilis.[iii] Similar disparities in STI rates exist between Black and white men who have sex with women (MSW) and between Black and white men who have sex with men (MSM).[iv] (In general, health research with women who exclusively have sex with women (WSW) is rare and such research stratified by race is even more scarce.) How do we account for the racial differences in STI rates?

I think this a really important question. It has puzzled researchers for decades, often resulting in inaccurate guesses and speculation that may have contributed to perpetuating racism and sexism. With few exceptions, Black Americans have much higher rates of STIs than do white Americans. This is true for other minority groups as well – Hispanic Americans, Native Americans and Alaskan Natives, Native Hawaiians and other Pacific Islanders – all have higher rates of STIs than do white Americans. What might they have in common that results in more STI cases per population?

In compiling my facts for the book, the brutal disparities in STI rates among different race and ethnicities was conspicuous. The reasons, at least to me, were not immediately obvious; I had to do some research.

First of all, please note that I am speaking in generalities here. Our exploration of the issue of disparities in STI rates between Black and white populations in the U.S. requires us to look at population-level data about groups of people. The findings do not, ever, apply to everyone within the groups. I’ve also chosen to focus on the Black-White disparities in STI rates because therein lie the biggest differences, but we can apply our findings to other minority groups as well.

Secondly, if we want to bring down the high rates of STIs, we need to understand why they are so high so that we can design interventions that address the underlying issues. You may have noticed that just telling someone to practice abstinence or use a condom does not work too well.

And lastly, one of the most effective ways to decrease stigma is to understand the fear behind it. People tend to stigmatize things of which they are afraid. Cancer, for example, used to be a disease that people would only speak about in hushed tones because we didn’t know much about it except that it was deadly. Once we learned to understand it, the stigma lessened and we were better able to combat it.

In the field of public health, we talk about the social determinants of health and how they impact countries, neighborhoods, and individual people. According to the U.S. Centers for Disease Control and Prevention (CDC), social determinants of health are “conditions in the environments in which people are born, live, learn, work, play, worship, and age that affect a wide range of health, functioning, and quality-of-life outcomes and risks.”[v] These include factors like education, economic stability, neighborhood and “built” environments, health and health care, and social and community context. Where you are born determines a lot about you. One of the differences between Black Americans and white Americans is the environments into which we are born.


Let’s start by taking a look at the U.S. history of the Black environment and how it got to be the way it is. (I have relied heavily on an eloquently written paper[vi] by Thomas Farley MD, MPH, who is a professor at the School of Public Health at Tulane University in New Orleans, and whom I will paraphrase and quote directly below.)

Hundreds of years of slavery were followed by over one hundred years of racism (which continues today) that impacts education, employment opportunities, housing, voting rights, etc. By the second half of the 1900s, rural farming and American manufacturing had both been disrupted by a shift to a conglomerated farming and business structure and the off-shoring of jobs to cheaper labor markets. The lower-skilled job market dried up, creating high rates of unemployment and lower rates of health care insurance in Black and White communities because, unlike other countries, in the U.S., health care coverage is tied to employment.

Social capital

Social capital (community networks of banks, businesses, and people that facilitate upward mobility) is built into communities over time. Blacks and other minority groups were systematically denied mortgages and housing in white and affluent communities and few banks and national business chains were located in their neighborhoods for many generations. With little social capital, individuals have limited opportunities to improve their circumstances through legitimate means. Alternatives like gang membership and drug peddling provide an illegal local economy in which individuals (mostly men) can acquire money and social status. Drug and alcohol use and violence assuage feelings of boredom, failure, and hopelessness. These factors destabilize communities even further by inviting new drug users in and by driving away those individuals who have acquired legitimate means of social success who could buttress the local community. External forces like alcohol advertising and policing join the community.

“Socially acceptable” norms of behavior are subsumed by drug culture, endless poverty, violence, depression and other untreated mental health conditions. Minimal income opportunities, daily stressors, substance abuse, and a constricted supply of men (due to high levels of incarceration) undermine marriage, long-term relationships, and strong parent-child bonds. According to Dr. Farley, drug and alcohol use and exchanging sex for drugs increase casual sexual encounters. A community-wide pattern of unstable relationships and casual sex causes dense sexual networks in which reservoirs of STIs are maintained, especially when lack of access to health care (structurally tied to joblessness) limits early medical treatment of STIs. This entire process takes place in both urban and rural communities.”[vii]

I want to stress that this history of community collapse is not related to race. These descriptions are applicable to both Black and white communities that have struggled with the loss of economic and educational opportunities in post-WWII America. Blacks, in addition to loss of economic opportunity, have had to contend with long-term racism, segregation, and incarceration. In 2016, the poverty rate for Whites was 8.8% (17.3 million), for Hispanics it was 19.4% (or 11.1 million) and for Blacks it was 22.0% (or 9.2 million).[viii] In the U.S., income is a strong predictor of health. One recent study found that, for women, STI rates were lower in states with higher minimum wages.[ix] You can see in Figure 1. that, within any group, the richer you are, the lower your risk of having an STI.

Sexual networks

People tend to associate most closely with the people with whom they interact at their place of residence or where they work. Census data indicate that about 60% of communities are racially homogenous, whether due to internal factors like person choice or external factors like segregation. For African Americans, who make up approximately 14% of the population, this means that their communities consist of a smaller proportion of the total population than for whites, who constitute about 60%.[xi]  This is, of course, true for all minority groups.

Consequently, minority sexual networks, the groups of people from which one usually finds one’s sex partners, are proportionately smaller as well. Partner choices are even more limited by long-standing environmental inequalities that have resulted in low sex ratios (more women than men). Factors that have removed men from minority communities include higher rates of male infant mortality, male adolescent and young adult deaths due to violence, and high male incarceration rates resulting from racial profiling and a focus on Black communities in the “war on drugs.”[xii] These factors exist regardless of the economic levels of the community, though they are exacerbated in low-functioning, high-risk communities like the ones I described above.

Concurrency and Sexual Networks

There is one host-related factor that could contribute to the increased rate of STIs among Blacks. That behavioral factor is called concurrency. Concurrency is the practice of having more than one sexual partner at the same time, or overlapping during a change between partners. This behavior is more common among Blacks than other racial/ethnic groups.[xiii] Concurrency has been found to greatly accelerate STI infections within a sexual network. In communities with low sex ratios, men are less inhibited about having multiple sex partnerships[xiv] and women, especially those with low socioeconomic status, have less power to negotiate condom use, monogamy, and marriage.

 A woman in a small sexual network is more likely to encounter a sex partner who has an STI than a woman in a larger sexual network, especially if she or her partner(s) are not monogamous. The smaller the network, the larger the impact of the introduction of an STI.

Because of sexual networks, most ethnic minorities have higher rates of STIs than those that live in more diverse communities. When an STI is introduced into a small, tight network, it can spread more easily among the network members who are interacting only amongst themselves. Sexual networks may at least partially explain the higher rate of STIs among some Black women. This does not apply to many Black women, yet it provides a thoughtful analysis of some of the factors that may explain the disproportionately higher STI rate among Black Americans. These are not factors of race, but rather they are factors affecting American communities.

As with comparisons of Black women and white women’s behaviors, there are no significant differences in the prevalence of risky sexual behavior between Black men who have sex with men (MSM) and non-Black MSM.[xv] However, Black MSM are more than twice as likely to encounter a sexual partner living with HIV within their sexual network.[xvi] Because the prevalence of HIV is higher in the Black community, the risk of a Black MSM acquiring HIV from someone within his sexual network is higher per sex act than it is for a non-Black MSM within his sexual network.[xvii]

In general, Black Americans utilize medical services less than white Americans. Researchers have identified a lack of generational modeling of health care seeking behavior, a distrust in the medical system due to unethical past conduct in clinical research and health care provision, and a lack of health care insurance coverage as factors. Thus, Blacks living with HIV are less likely to be participating in routine medical care and less likely to be taking antiretroviral therapy or pre- and post-exposure prophylaxis (medications taken before (PrEP) or after (PEP) sexual activity that significantly decrease the risk of transmitting or acquiring HIV) than whites.[xviii] This results in sustained levels of HIV within sexual networks and communities. Adherence to daily doses of combined antiretroviral medication can achieve viral suppression to the point where the virus is no longer detectable in the blood. Once that point is reached, the virus is no longer transmissible to a sex partner. This applies to heterosexual, homosexual, and any other sexual activities. With this pharmaceutical achievement, a world without new HIV cases can be envisioned and pursued. For Black Americans, addressing barriers to medical care and pharmacotherapy are more urgently needed than targeting individual risk behaviors and drug abuse.

The sexual network concept can be applied to the evaluation of other groups and help explain why they may have higher rates of infection than average:

  • Substance abusers typically hang out with other substance abusers, often sharing needles or exchanging sex for drugs and money. STI rates are higher in those communities but not necessarily higher in the cities in which they live.
  • Aboriginal peoples and Native Americans have higher rates of STIs than those who live in more diverse communities. In the U.S., Native Americans had the second highest rates of chlamydia, gonorrhea, and syphilis (in women) after Blacks.[xix] Limited sexual mixing between these ethnicities and other ethnic groups tend to confine STIs within their networks and make their networks more risky.[xx]
  • Many white communities in rural Appalachia have higher rates of STIs than many Black communities in large cities. Yet, in general, cities have higher rates of STIs than rural areas, likely due to population (and social network) density.

Concurrent partners in sexual networks also explain why people in low-risk groups can become infected. Literally one, but usually more than one, sexual encounter with an infected person from a high-risk group can allow an STI to infiltrate, so to speak, a low-risk group. It takes only one or two individuals in the network having concurrent partners to make the risk of being infected with the STI increase exponentially. Because many STIs can be asymptomatic, by the time one person learns of their infection, the STI may have already spread among members of the network.


The U.S. Centers for Disease Control and Prevention, who supplied the figures in this essay, conclude that “Inequities in the burden of disease for chlamydia, gonorrhea, syphilis and other STIs by race and Hispanic ethnicity continue to persist at unacceptable levels in the United States. These disparities are not explained by individual or population-level behavioral differences; rather they result in large measure from stubbornly entrenched systemic, societal, and cultural barriers to STI diagnoses, treatment and preventive services accessible on a routine basis. Some progress has been achieved in recent years in reducing the magnitude of disparities in some STIs, especially for Blacks, but much more needs to be done to address these issues through individual, group, and structural-level health care interventions.”[xxi]


[i] Hogben, Matthew & Leichliter, Jami. (2008). Social Determinants and Sexually Transmitted Disease Disparities. Sexually transmitted diseases. 35. S13-8. 10.1097/OLQ.0b013e31818d3cad.

[ii] Mosher WD, Chandra A, Jones J. Sexual behavior and selected health measures: Men and women 15–44 years of age, United States, 2002. Hyattsville, MD: National Center for Health Statistics, 2005. Advance Data from Vital and Health statistics; No 362.

[iii] US Centers for Disease Control and Prevention. STIs in racial and ethnic minorities. Last update July 2018. Accessed 27April202. Available at

[iv] US Centers for Disease Control and Prevention. STIs in racial and ethnic minorities. Last update July 2018. Accessed 27April202. Available at

[v] US Department of Disease Prevention and Health Promotion. Healthy People 2020.

[vi] Farley, Thomas A. MD, MPH Sexually transmitted diseases in the southeastern United States: location, race, and social context, Sexually Transmitted Diseases 2006;33(7):S58-S64. doi: 10.1097/01.olq.0000175378.20009.5a

[vii] Farley, Thomas A. MD, MPH Sexually transmitted diseases in the southeastern United States: location, race, and social context, Sexually Transmitted Diseases 2006;33(7):S58-S64. doi: 10.1097/01.olq.0000175378.20009.5a

[viii] US Centers for Disease Control and Prevention. STIs in racial and ethnic minorities. Last update July 2018. Accessed 27April202. Available at

[ix] Ibragimov U, Beane S, Friedman SR, Komro K, Adimora AA, Edwards JK, et al. (2019) States with higher minimum wages have lower STI rates among women: results of an ecological study of 66 US metropolitan areas, 2003-2015. PLoS ONE 14(10): e0223579.

[x] Harling G, Subramanian S, Bärnighausen T, Kawachi I. Socioeconomic disparities in sexually transmitted infections among young adults in the United States: examining the interaction between income and race/ethnicity. Sex Transm Dis. 2013;40(7):575‐581. doi:10.1097/OLQ.0b013e31829529cf

[xi] United States Census Bureau. QuickFacts July 2018. Available at

[xii] Adimora AA and Schoenback VJ. Social context, sexual networks, and racial disparities in rates of sexually transmitted infections. Journal of Infectious Diseases 2005;191(Suppl 1):S115-S122.

[xiii] Adimora AA and Schoenback VJ. Social context, sexual networks, and racial disparities in rates of sexually transmitted infections. Journal of Infectious Diseases 2005;191(Suppl 1):S115-S122.

[xiv]Adimora AA and Schoenback VJ. Social context, sexual networks, and racial disparities in rates of sexually transmitted infections. Journal of Infectious Diseases 2005;191(Suppl 1):S115-S122.

[xv] Millett GA, Peterson JL, Flores SA, Hart TA, Jeffries WL, Wilson PA, et al. Comparisons of disparities and risks of HIV infection in Black and other men who have sex with men in Canada, UK, and USA: a meta-analysis. The Lancet 2012;380:341-348.

[xvi]  Rosenberg E, Kelley C, O’Hara B, Frew P, Peterson J, Sanchez T, et al. Equal behaviors, unequal risks: the role of partner transmission potential in racial HIV disparities among men who have sex with men (MSM) in the US. International AIDS Conference; Washington, DC. 2012. Available at

[xvii] Newcomb ME, Mustanski B. Racial differences in same-race partnering and the effects of sexual partnership characteristics on HIV Risk in MSM: a prospective sexual diary study. J Acquir Immune Defic Syndr. 2013;62(3):329–333. doi:10.1097/QAI.0b013e31827e5f8c

[xviii] Allen VC Jr, Myers HF, Ray L. The Association Between Alcohol Consumption and Condom Use: Considering Correlates of HIV Risk Among Black Men Who Have Sex with Men. Aids and Behavior. 2015 Sep;19(9):1689-1700. DOI: 10.1007/s10461-015-1075-1.

[xix] US Centers for Disease Control and Prevention. STIs in racial and ethnic minorities. Last update July 2018. Accessed 27April202. Available at

[xx] Jolly AM, Muth SQ, Wylie JL, Potterat JJ: Sexual networks and sexually transmitted infections: a tale of two cities. J Urban Health. 2001;78(3):433-45. F1000Research 2019, 7:1880 Last updated: 13 FEB 2019.

[xxi] US Centers for Disease Control and Prevention. STIs in racial and ethnic minorities. Last update July 2019. Accessed 18Mar2021. Available at

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