Shingles, also known as herpes zoster, is a viral infection that causes a painful rash, typically appearing as a stripe of blisters on one side of the body. This condition is caused by the varicella-zoster virus (VZV), which is the same virus responsible for chickenpox. After a person has recovered from chickenpox, the virus remains inactive in the body and can reactivate years later, leading to shingles.
How Shingles Spreads
The varicella-zoster virus spreads primarily through direct contact with blister fluid. Unvaccinated individuals or those who haven’t had chickenpox can contract the virus and develop chickenpox if they contact this fluid. A person exposed to the virus from someone with shingles will develop chickenpox, not shingles directly.
Contagion begins when the rash appears and lasts until all blisters have fully crusted over. Once the blisters are dry and crusted, the individual is no longer contagious. While direct contact is the main route, the virus can, in rare instances, spread through airborne particles from the blisters.
Why Swimming is Not Recommended
Swimming is not recommended when shingles blisters are open or weeping. The primary concern is the risk of transmitting the varicella-zoster virus to other swimmers. Direct contact with fluid from open blisters can spread the virus, especially to vulnerable individuals like infants, pregnant people, or those with compromised immune systems.
Beyond the risk to others, swimming with open blisters also poses a risk to the affected individual. Pool water, even if chlorinated, can irritate open lesions, causing pain or discomfort. There is also a risk of secondary bacterial infections entering the rash, complicating healing.
Chlorine in swimming pools effectively kills bacteria, but it is not as effective at neutralizing viruses like VZV in the short contact time typical in a pool environment. This applies to all types of communal swimming environments, including chlorinated pools, saltwater pools, and hot tubs, because the main issue is the presence of open lesions and the potential for transmission and infection.
When It’s Safe to Swim Again
It is safe to return to swimming once all shingles blisters have completely dried out and crusted over. This stage indicates the virus is no longer actively shedding, significantly reducing transmission risk. Typically, this process can take about 7 to 10 days after the rash initially appears, though the complete healing of the rash can take up to four weeks.
Ensuring no new blisters are forming is also an important sign that the contagious period has passed. Even after the blisters have crusted, it is advisable to keep the affected area covered if possible, particularly in communal settings. For personalized guidance, especially if there are any complications or if the individual has a weakened immune system, consulting a healthcare professional is recommended before resuming activities like swimming.