Parvovirus B19: A-to-Z Guide from Diagnosis to Treatment to Prevention

Parvovirus B19 is a very common virus that causes infections in humans. The most commonly recognized form is called “fifth disease” or “slap-cheek.”

If anything comes to mind when parents hear the word “parvovirus,” it’s usually something to do with dogs or cats. This makes sense. Parvoviruses have long been known to be significant causes of disease in animals. But animal strains of parvovirus do not cause infections in humans and human parvovirus does not cause infection in other animals.

What is it?

Parvovirus B19 is a very common virus that causes infections in humans. The infection can take many forms, but the most commonly recognized is an illness called “fifth disease” or “slap-cheek.” It can also cause serious infections in unborn children and children with sickle cell disease.

Who gets it?

This is a very common infection – about half of the people in the world have had it. The typical time to be infected with parvovirus B19 is during the elementary and middle school years.

Parvovirus B19 infections are most common during the late winter and early spring.

What are the symptoms?

Many children with parvovirus B19 have no symptoms at all. Of those who do, the most common appearance is the childhood illness called fifth disease. It may be confused with the other childhood exanthems (rash illnesses).

Some children with parvovirus B19 infections have arthritis or joint pain, either alone or along with fifth disease.

Some develop temporary, but significant, anemia from decreased production of red blood cells. For those children who are losing red blood cells for other reasons such as sickle cell anemia, this can cause an “aplastic crisis”, where there is a severe shortage in red blood cells.

Also, in children whose immune systems are not working well, such as those with HIV infection, parvovirus B19 can cause serious illness.

If mothers become infected with parvovirus B19 for the first time during pregnancy, most babies will be fine, but some will have serious illness or death.

Is it contagious?

Yes. Parvovirus B19 is spread by respiratory droplets. It can also be spread in blood and blood products, and from mother to unborn child.

How long does it last?

The length of infection varies, but may last for weeks or months.

How is it diagnosed?

Often the diagnosis is based on a typical pattern of symptoms. Lab tests are available to aid in diagnosis and to detect immunity or recent infection.

How is it treated?

Most children need no treatment. Those with anemia or other complications may need transfusions or other specific treatment. Since this is a virus and not a bacteria, antibiotics are not useful in treating parvovirus infections.

How can it be prevented?

Because children with the parvovirus B19 rash are no longer contagious, avoiding them will not prevent infections. Routine hand washing and avoiding contact with used facial tissues can decrease spread.

Pregnant women who have been exposed to parvovirus B19 should discuss this with their obstetricians. About half of adults tested have already had it and are thus immune. Even when women get fifth disease for the first time during pregnancy, most of the babies do well. Still, some babies do need treatment, and the pregnancy should be monitored closely.

Last medical review on: October 29, 2013
About the Author
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Dr. Greene is a practicing physician, author, national and international TEDx speaker, and global health advocate. He is a graduate of Princeton University and University of California San Francisco.
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