Evidence-based recommendations for shower-out practices: assessing virus removal from hair using a surrogate...

Area of Science:

• Biosafety and Biocontainment
• Virology
• Infectious Disease Control

Background:

• Non-enveloped viruses, such as Foot and Mouth Disease Virus (FMDV), pose significant risks in livestock due to their stability and infectivity.
• Fomite transmission via contaminated surfaces, including hair, is a critical concern in biocontainment facilities.
• Current shower-out protocols may not adequately address virus removal from diverse hair types and styles.

Purpose of the Study:

• To evaluate the efficacy of personal shower practices in removing non-enveloped viruses from various hairstyles and hair types.
• To assess the virucidal activity of common hair care products against a surrogate virus.
• To identify potential risks associated with specific hair products and styles in biocontainment settings.

Main Methods:

• Used Bovine Rhinitis B virus (BRBV), a surrogate for FMDV, for safety at lower biocontainment levels.
• Assessed inactivation of BRBV and an enveloped virus by shampoos and conditioners in liquid suspension.
• Investigated mechanical removal of BRBV from synthetic and human hair using different hairstyles, products, and a 2-minute water rinse.

Main Results:

• Only one tested shampoo inactivated BRBV; all shampoos inactivated the enveloped virus.
• Co-wash and leave-in conditioners showed no antiviral activity against either virus.
• Water rinsing alone effectively removed BRBV from most hair types and styles.
• Exceptions included voluminous curly/kinky synthetic hair and synthetic braids, where water rinsing was less effective.
• Co-wash treatments showed residual virus, suggesting potential impediment to mechanical removal.

Conclusions:

• Mechanical removal via water rinsing is the primary method for decontaminating hair of non-enveloped viruses.
• Hair volume and density significantly influence viral persistence after showering.
• Specific shower procedures tailored to hairstyles and hair types are necessary for effective biocontainment.
• The use of oil-rich, low-surfactant products like co-wash may pose an underestimated risk in preventing fomite transmission.