Shingles, also known as Herpes Zoster, is a painful rash caused by the reactivation of the Varicella-Zoster Virus (VZV), the same virus responsible for chickenpox. After an initial chickenpox infection, VZV remains dormant within nerve cells and can reawaken years later to cause Shingles. Determining whether Shingles requires droplet or airborne precautions depends entirely on the specific presentation of the disease in the individual. Since the virus can be transmitted through different routes depending on the severity of the rash, infection control measures must be adjusted accordingly.
Defining Infection Control Precautions
Standard Precautions form the baseline for all patient care in healthcare settings, involving basic practices such as hand hygiene and the use of personal protective equipment (PPE) when exposure to bodily fluids is anticipated. When Standard Precautions are insufficient to interrupt the spread of an infectious agent, Transmission-Based Precautions are added. These additional measures are categorized based on the mechanism by which a pathogen travels from an infected person to a new host.
Contact Precautions are implemented for infections spread through direct physical contact with the patient or indirect contact with contaminated environmental surfaces or objects. This typically involves using a gown and gloves to prevent the transfer of microorganisms. Droplet Precautions target pathogens transmitted by large respiratory droplets expelled during coughing, sneezing, or talking. These droplets generally travel short distances, usually less than six feet, and require the use of a surgical mask when near the patient.
Airborne Precautions are reserved for infections spread by tiny particles, known as aerosols, which can remain suspended in the air for extended periods and travel long distances. Patients requiring Airborne Precautions must be placed in a specialized Airborne Infection Isolation Room (AIIR). This room uses negative pressure to safely vent the air outside or through a high-efficiency particulate air (HEPA) filter, preventing infectious aerosols from escaping into common areas. Staff entering these rooms must wear a fit-tested N95 or higher-level respirator mask.
How Shingles Spreads
The method of VZV transmission from a person with Shingles varies significantly depending on the nature of their rash. For the most common presentation, known as localized Shingles, the virus is contained within the fluid of the active blisters. Transmission occurs primarily through direct contact with the open lesions or indirect contact with materials contaminated by the blister fluid. This contact-based transmission means the virus is not shed through the respiratory system, eliminating the need for Droplet Precautions.
The risk of transmission remains until all the Shingles lesions have fully dried and crusted over, at which point the virus is no longer considered infectious. If a person who has never had chickenpox or is not immune to VZV comes into contact with the blister fluid, they will develop chickenpox, not Shingles.
A different and more concerning scenario arises with disseminated Shingles, where the rash is widespread, presenting with more than 20 lesions outside the primary area, or when the disease affects internal organs. In these cases, the virus can be shed through the respiratory tract, making Airborne transmission a significant concern. This respiratory shedding of VZV is similar to how chickenpox spreads, which is why the distinction between localized and disseminated disease is so important for infection control. Disseminated Shingles requires a heightened level of precaution due to the potential for the virus to aerosolize.
Isolation Requirements Based on Disease Presentation
Infection control requirements for Shingles are highly specific and based on a risk assessment of the patient’s health and the rash’s presentation. For an immunocompetent person with localized Shingles, the standard requirement is Contact Precautions in addition to Standard Precautions. The lesions must be completely covered at all times, and isolation is maintained until all lesions are dry and crusted. Covering the lesions effectively controls the source of the virus, making Droplet or Airborne Precautions unnecessary for an otherwise healthy individual.
If the localized Shingles rash cannot be reliably covered, or if the patient is immunocompromised, the precautions escalate significantly. Immunocompromised patients, even with localized disease, are at a much higher risk of the virus disseminating and shedding via the respiratory route. Therefore, localized Shingles in an immunocompromised patient requires the immediate implementation of Contact and Airborne Precautions until a disseminated infection can be ruled out. This means the patient must be placed in an Airborne Infection Isolation Room with negative air pressure.
The most stringent precautions are required for any patient, regardless of immune status, presenting with disseminated Shingles. This widespread rash indicates a high viral load and the potential for respiratory shedding, which necessitates both Contact and Airborne Precautions. Isolation in a negative pressure room must be maintained until all the disseminated lesions have completely crusted over. These varied requirements highlight that while typical Shingles is a Contact precaution issue, the risk of airborne spread in specific patient groups or with a widespread rash mandates the use of Airborne Precautions.