Shingles, also known as herpes zoster, is a viral infection that causes a painful rash and blisters. It is caused by the varicella-zoster virus, which is the same virus that causes chickenpox. Shingles can be very contagious to people who have never had chickenpox or the chickenpox vaccine. However, the contagious period is limited, and quarantine is usually not necessary.
Is shingles contagious?
Yes, shingles is contagious, but only during the blister phase. The varicella-zoster virus is present in the fluid inside the shingles blisters. If someone who has never had chickenpox comes into direct contact with the shingles blisters or fluid, they are at risk of developing chickenpox.
The virus can spread through:
- Direct contact with shingles blisters
- Touching objects contaminated by shingles blister fluid
- Inhaling viral particles dispersed from shingles blisters
However, once the shingles blisters scab over and are completely dry, the virus is no longer contagious. Usually, this occurs within 7-10 days after the rash appears.
What is the contagious period for shingles?
The contagious period for shingles is limited to when the blisters are present and actively “weeping.” This is usually about 7-10 days after the initial symptoms of pain, burning, or tingling appear. However, people with shingles are considered contagious until all of the blisters have scabbed over.
It’s important to note that shingles scabs still contain traces of the virus, but at levels too low to pose a significant risk. Once the scabs have dried out and fallen off, the person is no longer contagious.
The contagious period can be shorter or longer in some cases:
- If antiviral medication is started within 72 hours of rash onset, viral shedding may be reduced to only 2-5 days.
- In people with weakened immune systems, viral shedding may last over a month.
- If lesions reoccur in the same area, viral shedding can restart.
Overall, most experts consider people with shingles contagious for 7-10 days from rash onset if blisters are present.
Who is at risk of getting shingles from someone contagious?
The only people at risk of developing chickenpox from exposure to a shingles rash are those who have never had chickenpox or received the varicella vaccine. That includes:
- Newborns and infants
- Children and adults never vaccinated against chickenpox
- People with compromised immune systems who may not have full protection from the vaccine
More than 99% of adults born in the United States before 1980 have had chickenpox. And routine childhood vaccination against chickenpox began in 1995. So today, the vast majority of the population is not susceptible to infection.
People who have had chickenpox in the past or who have received the full course of the varicella vaccine cannot “catch” shingles from another person. Their immune systems have antibodies that provide protection against reinfection.
Should someone with shingles be quarantined?
Routine quarantine of people with shingles is not recommended. Isolation is only necessary under special circumstances due to the limited contagious period:
- Patients with active shingles should avoid newborns, pregnant women, and immunocompromised individuals until lesions have crusted over.
- In hospital settings, patients with uncontrolled shingles lesions should be isolated from at-risk patients. Precautions are recommended for staff handling bandages or entering rooms.
- People with active shingles should avoid public settings like work, school, or large events during the contagious period.
- Immunocompromised individuals with active lesions that may shed virus for an extended period may need to quarantine for a longer duration.
However, quarantine is not required or recommended for most people with routine cases of shingles. Isolation should be limited based on a physician’s assessment of individual patient risk factors.
How to prevent spreading shingles
If you have shingles, you can take simple precautions to avoid spreading the virus during the contagious period:
- Keep lesions covered with clothing, dressings or bandages until crusted over.
- Avoid skin-to-skin contact with others.
- Do not share personal items like towels, bedding, or clothes.
- Wash hands frequently with soap and water or use an alcohol-based hand sanitizer.
- Clean surfaces and objects touched by lesions with a disinfectant.
- Avoid contact with infants, pregnant women, and immunocompromised individuals.
- Stay home from work, school, and public places until blisters have dried.
Antiviral medications like acyclovir, valacyclovir, and famciclovir can help shorten the contagious period by speeding healing time. Over-the-counter pain relievers can help manage discomfort.
People exposed to shingles may benefit from varicella-zoster immune globulin (VZIG) or antiviral medications as preventive treatment in some cases.
Conclusion
In summary, shingles has a limited contagious period of around 7-10 days. Only those susceptible to chickenpox face infection risk. Routine quarantine is not required in most cases. But it is prudent for those with active shingles to stay home when lesions are weeping and avoid contact with vulnerable groups. With proper precautions, the risk of transmission can be minimized until the rash has healed.