Prevention of Skin and Soft Tissue Infections in People Who Inject Drugs

Background: Skin and soft tissue infections (SSTI) are a common preventable complication of intravenous drug use in people who inject drugs (PWID) and the leading cause of emergency department and hospital admissions in this population. Solutions containing 2%-3% chlorhexidine gluconate (CHG) in 70% isopropyl alcohol (IPA) have extended antimicrobial activity and are extremely effective in hospital settings to prevent catheter-related and surgical site infections but have not been evaluated for SSTI prevention in PWID. The purpose of this study was to evaluate the acceptability of topical CHG/IPA single-use applicators as a topical disinfectant in combination with a brief safer injection training to prevent SSTI and other infectious complications of intravenous drug use.

Methods: From October 2018-May 2019, researchers recruited 56 active PWID from a needle exchange site located on Chicago’s westside to participate in a pilot randomized controlled trial of CHG/IPA versus IPA only for routine skin cleansing before injection. After informed consent, researchers gathered information about participant demographics, drug injection patterns, and SSTI history. Study clinicians then delivered a 10-minute safer injection training to each participant. After the training, participants were randomized equally to receive a 2-week supply of either CHG/IPA single-use swabs or IPA only swabs, which they were instructed to use exclusively for skin cleansing before injection. After two weeks, participants completed a second study visit, during which researchers gathered information about the acceptability and tolerability of CHG/IPA swabs and attitudes toward safer injection using a structured questionnaire.

Results: About half of participants (54%) reported an SSTI within the past 30 days, often complicated by an abscess (n=11, 20%) or open wound (n=10, 18%). From multivariate logistic regression, SSTI within the past 30 days was associated with female sex (aOR 9.0, 95%CI: 1.7-46.7, p=0.009), recent missed injections (aOR 1.7, 95%CI: 1.0-2.9, p=0.044), and negatively associated with skin cleaning prior to injection (aOR=0.7, 95%CI: 0.5-1.0, p=0.039). At follow-up (n=43), both groups showed increases in skin cleansing frequency, intentions for skin cleansing, and belief that skin cleansing can prevent infection. CHG/IPA swabs versus IPA only showed no differences in measures of participant acceptability or tolerability.

Conclusion: SSTI are common in PWID and a neglected area for harm reduction. A brief behavioral intervention shows promise to increase awareness and behavioral intentions for routine skin cleansing and may reduce SSTI incidence in PWID, irrespective of the type of antimicrobial agent used. CHG/IPA warrants further study as a longer-acting agent to reduce SSTI in PWID.

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Learning Objective: 1. Participants will be able to list the risk factors correlated with skin and soft tissue infections in people who inject drugs and explain the burden these infections and the associated complications have on hospital systems.
2. Participants will be capable of identifying the needs of future prevention efforts that are necessary to reduce skin and soft tissue infections in people who inject drugs.