The characteristics, symptoms and epidemiology of parvovirus B19 (also known as slapped cheek syndrome, fifth disease, or erythma infectiosum).
Parvovirus B19 is a single-stranded DNA virus belonging to the Parvoviridae family of viruses, which includes a number of animal parvoviruses such as the canine parvovirus and feline panleukopenia virus. Parvoviruses are species specific, and animal parvoviruses do not infect humans.
The most common symptom of parvovirus B19 is a facial rash, which spreads to the trunk and limbs, usually preceded by a non-specific flu-like illness. For most people, infection is mild and treatment is not required.
Infection is most common in children aged 6 to 10 years, but can occur at any age.
At least 50 to 70% of pregnant women are likely to already be immune to parvovirus B19. In women who are not immune, infection in the first 20 weeks of pregnancy can lead to serious adverse outcomes in the fetus: hydrops fetalis and intrauterine death. These consequences usually occur some 3 to 5 weeks after the onset of maternal infection, but can be later.
There is no vaccine available to prevent infection.
The Immunisation and diagnosis unit (IDU) provides diagnostic and reference services for parvovirus B19.
See the [guidance for control of parvovirus B19 infection in healthcare settings and the community](https://academic.oup.com/jpubhealth/article/21/4/439/1516446.
Infection in pregnancy
Rash illness at any stage of pregnancy should be investigated and this should not be restricted to parvovirus B19 infection. The guidance on viral rash in pregnancy provides information and advice for health professionals on the investigation, diagnosis and management of viral rash illness such as parvovirus, or exposure to viral rash illness in pregnancy.
For reports from 2012 and earlier, see the UK government web archive.