Controlling Infectious Diseases with Harm Reduction
During the past decade, the number of severe infectious disease outbreaks has been alarming. Ebola in 2014, Zika in 2015, COVID-19 in 2019, and mpox (formerly known as monkeypox) in 2022 when outbreaks reached global significance, but there were also many other less publicized outbreaks of various infectious diseases. Many factors contribute to infectious diseases reestablishing themselves as major health concerns to the global community. Climate change; increased population, crowding, and movement; decreased vaccination rates; and uneven global access to basic health and social services are just some contributing factors.
Ebola, Zika, and mpox can spread through sexual contact. In fact, sexually transmitted cases of at least five other lesser-known infections have also been increasing globally. Because most sexual activities involve prolonged skin-to-skin contact and/or exchanging body fluids, it is unsurprising that many infections can be transmitted this way. However, just like for more common sexually transmitted infections (STIs) (e.g., chlamydia, gonorrhea, syphilis, and HIV), behavioral modifications can greatly reduce the risk of contracting these nontraditional STIs. The mpox outbreak in the United States is an example of how important harm reduction behaviors can be for controlling such infections.
Although mpox affected people of all ages, genders, and sexual identities, the majority of cases occurred among men who have sex with men (MSM). During the outbreak, the World Health Organization and the U.S. Centers for Disease Control and Prevention emphasized refraining from sexual contact as a means of preventing mpox, suggesting an abstinence-based approach to prevention. While abstinence from sexual activities will certainly reduce the likelihood of getting mpox, previous abstinence-based sexual health campaigns show that this approach is ineffective at the population level. Indeed, as researchers evaluate the mpox epidemic, it is evident that many MSM adopted harm reduction-based behaviors rather than completely refraining from sexual contact and that these choices helped control the outbreak.
Studies evaluating behavior changes among MSM during the mpox outbreak suggest that about half of this community modified their behaviors in response to the risk of mpox. One study conducted in Illinois found that more than 80 percent of MSM adopted at least one behavior to reduce mpox risk.
Although many MSM modified their behavior during the mpox outbreak, the number and type of changes were not universal. Reducing the number of sexual partners was one of the most common harm reduction strategies the MSM community used. Decreasing the number of one-time sexual encounters; avoiding or limiting attendance at social events that involved sexual activity, group sex, or close contact; and condom use were also common adaptations. Many of these strategies are applicable to preventing other STIs, as well.
Behavior change might have been especially important because, at the height of the outbreak, there was uneven access to mpox vaccines due to limited supply. The challenge of managing two, simultaneously occurring epidemics (mpox and COVID-19) also meant that public health resources were spread particularly thin.
Because demand for vaccines exceeded supply and the mpox vaccine is not 100 percent effective at preventing illness, both vaccination and behavior change contributed to controlling the outbreak. In fact, a modeling study suggests that initial declines in cases were likely due to behavior modification, and subsequent vaccination efforts shortened the duration of the outbreak. The same study estimated that vaccination and behavior change together prevented 84 percent of infections in the first year of the outbreak, suggesting that the outbreak could have been far more extensive than it was with vaccination alone.
As the world faces new and resurging infections that can be transmitted through sexual contact, the mpox outbreak provides some lessons. First, relying on biomedical interventions only, such as vaccines and curative treatment, may not be as effective as combining these tools with behavioral modifications. Second, empowering communities with accurate communication about risks, prevention, symptoms, testing, and treatment helps individuals take ownership of their response and choose the adaptations that are most feasible for them. Third, and perhaps most importantly, the mpox outbreak once again shows how harm reduction can be a more practical and successful strategy for managing risk than the expecting full abstinence from an activity.