Rubella, also known as German Measles, is a viral infection that is typically mild in children but can cause serious complications if contracted during pregnancy. Understanding the exact method of viral spread is crucial for implementing the correct infection control protocol to prevent transmission in healthcare environments.
Transmission Routes of Rubella
Rubella is transmitted primarily through direct contact with respiratory droplets expelled from the nose or throat of an infected person when they cough, sneeze, or talk. The virus enters a susceptible person through the mucous membranes of the eyes, nose, or mouth.
The infectious period is extensive, beginning about one week before the rash appears. Viral shedding continues for approximately one week after the rash has faded, meaning much of the transmission occurs pre-symptomatically.
Required Isolation Protocol
A patient with suspected or confirmed rubella infection must be placed on Droplet Precautions. These precautions are implemented in addition to Standard Precautions, which include baseline practices like hand hygiene.
For Droplet Precautions, placing the patient in a private room is preferred to contain respiratory secretions. If a single room is unavailable, patients with the same infection may be grouped together, a practice known as cohorting. Any healthcare personnel entering the patient’s room must wear a surgical mask upon entry.
Limiting the patient’s movement outside the room is also a key component of this protocol. If the patient must leave for essential medical procedures, they should wear a surgical mask to minimize the dispersal of infectious droplets. This combination of isolation and masking manages the short-range transmission risk posed by the virus.
Droplet Versus Airborne Precautions
The distinction between droplet and airborne transmission is based primarily on the size of the infectious particles and how far they can travel. Droplet transmission involves larger respiratory particles that are too heavy to remain suspended in the air for long. These particles typically travel a short distance, usually less than three to six feet from the source, before gravity causes them to settle onto surfaces.
Airborne transmission, in contrast, involves much smaller particles, often called aerosols or droplet nuclei, that can evaporate and remain suspended in the air for extended periods. Because these smaller particles can travel long distances on air currents, they require more stringent isolation measures. The difference in particle behavior mandates different levels of protective equipment and room environments.
For infections spread by droplets, like Rubella, a standard surgical mask is considered sufficient to protect the wearer’s nose and mouth. Airborne pathogens, such as Measles or Tuberculosis, require a fit-tested N95 respirator mask and placement in a negative pressure room with specialized ventilation.
Duration of Isolation Measures
Isolation duration is determined by the period during which the patient actively sheds the virus. For most patients with acquired rubella, Droplet Precautions must be maintained for seven days following the onset of the rash. After this seven-day mark, the risk of transmission is significantly reduced, and isolation can typically be discontinued.
A notable exception is infants born with Congenital Rubella Syndrome (CRS). These infants shed large amounts of the virus for a prolonged time after birth. For CRS infants, isolation measures often continue for up to one year of age. Isolation can be terminated sooner only if viral cultures from clinical specimens are repeatedly negative.