How Is Chickenpox Spread? How Chickenpox Is Spread Between Adults

Chickenpox spreads through the air when someone who has it coughs, sneezes or simply breathes, and through contact with the fluid in its blisters. It is one of the most easily caught infections, and adult chicken pox is usually more severe than the childhood illness. So how is chickenpox spread before anyone knows they are sick, and what should you do if you have been near it? Here is what an adult needs to know.

Key takeaways

• It spreads through coughs, sneezes, breath and blister fluid, and passes easily within a household.
• People are infectious from a day or two before the spots appear until every blister has crusted over.
• Adults, pregnant women and people with weakened immune systems are more likely to become seriously unwell.
• Two doses of the vaccine protect adults who have never had chickenpox.

The Varicella Zoster Virus Behind Chickenpox

Chickenpox is caused by the varicella-zoster virus, a member of the herpes family of viruses. How is chickenpox spread so easily? The virus is shed in tiny droplets from the nose and throat and in the fluid of the blisters, and it can hang in the air of a room. After the illness, it stays asleep in the nerves for life and can wake up years later as shingles.

Chickenpox Symptoms From Fever to Rash

The first symptoms of chickenpox are usually a mild fever, tiredness, headache and aches, 10 to 21 days after contact. In adults these early symptoms can be stronger and last longer. How is chickenpox spread before anyone knows they have it? During this early stage, which can pass for a cold, the person is already infectious.

A day or two later the rash appears: small red spots that turn into itchy blisters, then crust over within about five days. New spots come in crops, so fresh spots and scabs sit side by side, mostly on the body, face and scalp, and sometimes in the mouth. Symptoms usually settle within one to two weeks.

How Chickenpox Spreads Through Droplets and Blisters

Most people catch chickenpox by breathing in droplets that someone with it has coughed, sneezed or breathed out, often in the same home, workplace or waiting room. The fluid inside the blisters is highly infectious, so touching the spots, or towels and bedding they have soaked, can also pass it on. How is chickenpox spread within a household? Very easily: most people living with someone who has it will catch it unless they are immune.

Anyone who has never had chickenpox or the vaccine is at risk of infection. Adults are more likely than children to have a serious illness, with a higher chance of pneumonia, a bacterial skin infection or, rarely, inflammation of the brain. Pregnant women, people with low immunity and smokers face the highest risk of the infection turning severe.

When Someone With Chickenpox Is Contagious

A person with chickenpox is contagious from one to two days before the rash appears until every blister has dried and crusted, usually about five days after the spots start. Adults should stay home from work for that whole time, even with a mild case, and keep away from anyone pregnant, newborn babies and people whose immune system is weak.

Because complications are more common in adult chicken pox, call a doctor early rather than waiting it out. Antiviral tablets, which are only available on prescription in Australia, work best when started within a day of the first spots. People who have had two doses of the vaccine can still get a milder form with fewer spots, and can still pass it on.

How Is Chickenpox Spread?

Chickenpox is spread from person to person by close contact: an hour in the same room, or a few minutes face to face, can be enough. If you have had an exposure and are not sure you are immune, a doctor can arrange a blood test to check, and the vaccine given within three to five days of contact can prevent the illness or make it milder.

Some people need help the same day, after contact or once the spots appear. If you are pregnant, have a weakened immune system or have any trouble breathing, this is urgent: see a doctor in person straight away, phoning ahead so the clinic can keep others safe, or call 000 if breathing is hard or you become drowsy or confused. Prompt treatment after contact can lower the risk of complications.

Stopping the Spread With Vaccination and Isolation

Vaccination is the most effective protection against chickenpox. Adults who have never had chickenpox or the vaccine are advised to have two doses at least four weeks apart, and a blood test can show whether you are already immune. It is a live vaccine, so it is not given in pregnancy or to people with a weakened immune system, and pregnancy should be avoided for a month after each dose.

If you are infected, isolation stops the spread: stay home until every blister has crusted, keep the spots covered, wash your hands often and do not share towels. Vaccination of the people around someone at high risk, such as the family of a pregnant woman, protects them too.

Catching Chickenpox From Someone With Shingles

You can catch chickenpox, but not shingles, from someone with shingles if you have never had chickenpox or the vaccine. It passes through direct contact with the fluid in shingles blisters, and covering the rash makes this much less likely. Shingles is far less catching than chickenpox, and people who are already immune are not at risk.

An exposure to shingles in a non-immune adult can still lead to adult chicken pox, with the same risk of complications. Anyone infected this way is cared for as with any other chickenpox, and anyone pregnant or with low immunity needs the same urgent advice. People who have had chickenpox can lower their own chance of shingles later with a vaccine.

Summary

Chickenpox spreads through the air and through blister fluid, from a day or two before the spots appear until every blister has crusted. This guide covered the virus, the symptoms, how chickenpox is spread and when it is infectious, what to do after contact, vaccination and shingles. If you are an adult with chickenpox or have been near it, a Medio doctor can assess you by phone, look at a photo of the spots sent securely and, where the doctor thinks it right, send an eScript or a medical certificate. A child with chickenpox is best seen by a GP in person.

Frequently asked questions

What does chicken pox look like?

Chickenpox starts as small red spots that turn into itchy, fluid filled blisters within hours, then crust into scabs. New crops appear over several days, so every stage is seen at once, mostly on the chest, back, face and scalp. On darker skin the spots can look darker or purple rather than red.

What's the difference between chickenpox and measles?

Both cause a fever and spots, but they look different. Chickenpox gives itchy, fluid filled spots that crust, while measles gives a flat, blotchy red rash that starts on the face and spreads down, with a cough, runny nose and sore red eyes. Measles is very serious and doctors must report it, so phone a clinic before you visit.

Which is more severe, chickenpox or shingles?

It depends on the person. In adults, chickenpox is more likely to cause serious complications such as pneumonia, while shingles is usually more painful and, in older people, can leave nerve pain for months. Both are more severe in people with weakened immune systems, who should see a doctor early.

Do I need shingles vaccine if I had chickenpox?

Yes, a shingles vaccine is worth having when you are older, because everyone who has had chickenpox carries the virus that causes shingles. In Australia it is recommended from age 50 and is free for people aged 65 and over, First Nations people aged 50 and over, and some adults at high risk because of illness or treatment.

What does the virus do in the body?

The varicella-zoster virus enters through the nose and throat, multiplies, then travels in the blood to the skin, where it causes the spots. The immune system clears the illness but leaves the virus asleep in the nerve roots for life. Chickenpox is mostly treated with rest, fluids and itch relief, and antiviral tablets help some adults.

How to prevent chickenpox?

The vaccine is the way to prevent chickenpox. Adults who are not immune need two doses, at least four weeks apart, unless they are pregnant or have low immunity. How is chickenpox spread once you have it? Through the air and blister fluid, so staying home until every blister has crusted protects others. A Medio doctor can talk through vaccination in a telehealth consult by phone.