Staph Intervention for Effective Local Defense

Staphylococcus aureus (SA) is a common cause of skin and soft tissue infections (SSTI) and invasive infections in the United States (US). Infections caused by methicillin-resistant SA (MRSA) are of particular concern because MRSA is harder to treat and associated with significant costs to healthcare systems and patients. The White Mountain Apache (WMA) Tribe experiences a higher burden of SA and MRSA infections than the general US population. Most cases of invasive SA occurred among adults with underlying conditions and led to significant morbidity.

SA carriage is an important factor for development of SA infections. When individuals or the household contacts have recurrent SA infections, the use of antimicrobial or antiseptic agents to suppress or eliminate SA carriage (so called "decolonization") may be recommended to help prevent infection. While there are several regimens available to suppress carriage, each has limitations (e.g., potential antimicrobial resistance following repeated use of mupirocin antibiotic ointment, lack of access to a bathtub or reliable water supply for bleach baths). These interventions are typically used over a short period of time (e.g., one-time administration over 5-10 days). Re-acquisition of carriage in the months following completion of the carriage suppression regimen is common. Use of the standard approaches to SA carriage suppression in the WMA community has been inconsistent and has been insufficient to control SA disease. New approaches are urgently needed.

In formative research conducted by the study team, in-depth interviews and focus group discussions were conducted with healthcare providers and community members to understand the culture and context of tribal communities as related to SA infections, disease, and prevention. The researchers found that there are gaps in community knowledge about SA as a cause of skin infections and how to prevent an infection. When asked about preferred method of intervention to reduce SA carriage, participants indicated a preference for the antiseptic nasal spray (daily use) and antiseptic body wash (regular use), which were easily administered and could be incorporated into a daily routine.

In this study, the investigators will conduct an open-label randomized controlled trial to determine the feasibility, acceptability, and efficacy of a carriage suppression regimen in reducing the prevalence of SA carriage and SA infections among adults at high risk of SA infections who are currently carrying SA on the skin. Following informed consent, participants will be randomized in a ratio of 1:1 to either: A) education about SA and receipt of household supplies to reduce SA transmission in the home plus use of a nasal antibiotic twice daily for 5 days then maintenance with an antiseptic regimen (N = 50; Group A); or B) education/household supplies alone (N = 50; Group B). The antiseptic regimen will consist of twice daily Nozin nasal antiseptic plus chlorhexidine gluconate wash three times a week. Participants assigned to Group A will continue the antiseptic regimen for 4 months. All participants will be followed for 4 months.

Study visits will occur at baseline (Day 0) and Days 14, 30, 60, 90, and 120. At each visit, a questionnaire will be administered and swabs will be collected at common carriage sites on the body (anterior nares, oropharynx, and groin). Group A will also receive reminder text messages or phone calls at a frequency of choice (e.g., once per day or once per week). After the Day 0 and Day 120 visits, the participant's medical record will be reviewed to document relevant medical history and outpatient and inpatient visits for SSTI and SA-related infections.

A home visit will be scheduled after Day 0 to collect environmental swabs at frequent hand-contact sites (e.g., bedroom, living room, bathroom) and swabs from indoor pet cats and dogs (e.g., dorsal fur and skin of groin). Household members will also be recruited to complete a brief questionnaire and sample collection (anterior nares, oropharynx, and groin).

A qualitative assessment will be conducted in a subset of index participants (n=6-10) in Group A to assess adherence and acceptability of the prevention regimen. Participants will be chosen using purposive sampling to represent a range of reported adherence at the D60 visit and invited to provide informed consent. The qualitative assessment will consist of one in-depth interview at the endpoint (4 months).