Time for a New Approach to Guidance for Human Immunodeficiency Virus and Hepatitis C Virus Testing Among Persons Who Inject Drugs

( See the Major Article by Bull-tterson et al, on pages 940–7.)

The United States is experiencing an epidemic of opioid use disorder and injection drug use [1]. In this context, there have been outbreaks of human immunodeficiency virus (HIV) infections among persons who inject drugs (PWID) in both rural and urban settings, as well as a rising incidence of hepatitis C virus (HCV) among individuals aged 15–40 years [2]. These disturbing increases in incidence come at the same time that the public health community is focused on ending the HIV epidemic in the United States and eliminating the transmission of HCV.

Eliminating HIV and HCV transmission requires prompt identification and treatment of infection, such that we limit the time that individuals are viremic and at risk for transmitting. It is important, therefore, to test PWID for HIV and for HCV and periodically retest those with ongoing risk. Guidance from the Centers for Disease Control (CDC) [3], the American Association for the Study of Liver Diseases and the Infectious Diseases Society of America [4], and the US Preventive Services Task Force (USPSTF) [5] all endorse routine and periodic HIV and HCV testing among PWID.

In the current issue of The Journal of Infectious Diseases, Bull-Otterson and colleagues from the CDC [6] used commercial insurance claims data to investigate the real-world practice of HIV and HCV testing among individuals who were known to be PWID, based on billing codes. Their analysis included individuals with commercial health insurance between 2010 and 2016, who were aged 15–49 years, and who had ≥1 medical diagnosis, procedure, or initiation of medication (eg, methadone, a medication for opioid use disorder) indicative of injection drug use during that time. The team identified the first medical encounter associated with an injection drug use–related diagnosis or procedure and then determined the proportion who were tested for HIV and HCV at least once in the following 12 months. Strikingly, the results demonstrate that even among those with diagnosed opioid use disorder, who were being seen for an opioid overdose or a complication of injection drug use, the testing rate was <10%. How can we ever hope to end HIV or the transmission of HCV among drug users if we are missing 90% of the opportunities for diagnosis?

Unfortunately, these findings fit within a larger literature documenting missed opportunities for testing, even when providers know that a patient is a drug user [7]. Clearly, it will not be possible to achieve HIV and HCV public health goals if we are testing only 10% each year. The finding that the current approach to testing underperforms is well documented. It is time to consider tools we can use to improve.

First, ambitious guidelines for testing are an important tool. Although guidelines themselves are not a panacea, prior work demonstrates that when the CDC and the USPSTF change guidance for HCV testing, testing rates do increase significantly among those who are recommended for routine testing [8, 9]. Further, guidance defines the goal for testing and provides a metric by which we can measure progress.

At this time, however, we have little guidance on when to test PWID. The CDC identifies people who currently use or have ever used drugs as being appropriate for periodic risk-based targeted testing [3], but it provides no indication of how often to test among those with ongoing risk. Similarly, both the American Association for the Study of Liver Diseases–Infectious Diseases Society of America and the USPSTF identify PWID as being high risk and appropriate for periodic testing, but the guidelines remain silent about how often to test among PWID.

One change that should be simple and would define clear testing goals would be to identify and formalize the optimal frequency of HIV and HCV testing among PWID. Is annual testing adequate? Or does eliminating transmission require more frequent testing (and treatment) to prevent viremic time? Providing an explicit target for periodic testing would allow healthcare systems and providers to measure progress and innovate quality improvement initiatives.

A second change that is more substantial, but also potentially more effective, would be to reconceptualize the way we frame HIV and HCV testing guidance away from patient-focused recommendations and toward venue-focused guidelines for care. One important finding of the analysis by Bull-Otterson et al is that that the venue to which one presented for care had an impact on the likelihood of being tested. Settings such as drug rehabilitation centers, sexually transmitted infection clinics, and mobile outreach vans—settings dedicated to working with PWID and which see a high prevalence of injection drug use, HIV, and HCV—had higher testing rates than office-based primary care practices. In fact, the impact of venue/setting on the odds of being HIV or HCV tested was approximately as great as the impact of having a diagnosis of substance use disorder based on International Classification of Diseases, Ninth Revision, codes.

The article by Bull-Otterson et al demonstrates that even when the ongoing risk is known, competing priorities, limited time, and stigma work together to reduce testing rates. One solution to providing guidance for routine periodic testing for HIV and HCV among those at high risk would be to decouple guidance from individuals, and instead formulate guidelines for venues. For example, rather than recommend that all PWID be tested every 12 months for HIV, guidance could recommend that all office-based addiction treatment programs test all of their patients every year. Clinics could simply designate “testing months,” and algorithmically test all patients for HIV and HCV in those months. Such a process would remove decision making from busy providers and, instead, use an algorithmic or “checklist” approach that has proven effective in other fields [10]. Other high-value venues for testing might include syringe service programs, acute residential drug detoxification, emergency departments, sexually transmitted infection clinics, jails, and prenatal care clinics, to name a few.

Venue-based guidelines would not be perfect. Some patients would miss testing if they happened not to be seen during months when their program was testing. Others may be “overtested” if they presented to multiple venues and did not report prior testing, or if they presented to the same venue many times each month (eg, syringe service programs). The rate of missed opportunities, however, would likely be lower than that observed under current guidance, and previous cost-effectiveness studies of both HIV and HCV testing make clear that even a substantial degree of overtesting among such high-risk populations is likely cost-effective [11].

Even if venue-based guidelines are not feasible, if we wish to end the epidemics of HIV and HCV among PWID in the United States, then we need to make testing more algorithmic. Risk-based targeted testing does not work. Many times, providers do not identify the risk behavior. Furthermore, as the article by Bull-Otterson et al demonstrates, even when providers do identify risk, they infrequently test for HIV and/or HCV.

The early stages of simultaneous efforts to end the epidemic of HIV and HCV transmission among PWID is an appropriate moment to reconsider guidance. Both the CDC and the USPSTF are already considering expanding guidance for routine 1-time HCV testing in the United States. That change would likely go a long way toward identifying occult HCV infection among those with a remote history of drug use who do not identify as drug users, and are, therefore, typically overlooked for testing. Such guidance for routine 1-time testing, however, does not speak to testing needs among recent and active drug users, who need more frequent testing given their ongoing risk. Many questions remain about how we can end the epidemics of HIV and HCV, but one thing is clear—we cannot end any epidemic among PWID unless we take concrete steps to address underperformance in identifying and treating new infections. It is time for a new approach to HIV and HCV testing among PWID.

Notes

Financial support. This work was supported by National Institute of Drug Abuse (NIDA) and National Institute of Allergy and Infectious Diseases (NIAID) (grants R01DA046527, P30 DA040500, and P30 AI042853).

Potential conflicts of interest. Author certifies no potential conflicts of interest. The author has submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed.