How Long Does Shingles Stay Contagious When Untreated?

If you are infected with shingles and have developed a rash with blisters, you can infect other people you with the varicella zoster virus, states the Centers for Disease Control and Prevention. It is not possible to transmit the virus prior to the blisters' appearance or after the blisters disappear.

You cannot actually transmit shingles to other people, notes the CDC. It is only possible for you to infect other individuals with the virus responsible for causing the shingles, which is the varicella zoster virus. The varicella zoster virus may result in a chickenpox infection among individuals who have not been infected with chickenpox or who have not received the chickenpox vaccine. An individual may contract the varicella zoster virus if he or she comes into direct contact with fluid released from the shingles blisters. Therefore, transmission is less likely if you conceal the rash, avoid touching and scratching the rash, and regularly practice proper hand-washing techniques.

During the contagious period, it is important to avoid infants who were born prematurely or who had a low birth weight, pregnant women who have not had chickenpox or who have not been vaccinated for chickenpox, and people with weakened immune systems, suggests the CDC.