Parvovirus infection: Infection with one of a family of small single-stranded DNA viruses. (Parvovirus means small virus, from the Latin parvus, small.) One type, parvovirus B19, infects only humans. There are also animal parvoviruses, but they do not infect humans. A person cannot catch parvovirus B19 from a dog or cat. The diagnosis of parvovirus B19 can be confirmed by a blood test.
Parvovirus infection in childhood: The most common illness caused by parvovirus B19 is "fifth disease." It occurs most often in children. The child typically has a "slapped-cheek" rash on the face and a lacy red rash on the trunk and limbs. The rash may itch. The child does not usually seem very ill. The rash resolves in 7 to 10 days. Once a child recovers, he or she has lasting immunity and is protected against future infection.
Parvovirus infection in adulthood: Adults can and do become infected with the virus. In adults, the flu-like symptoms are often more severe and the condition is called parvovirus infection, not fifth disease. Adults typically do not get a rash of the face, but can have the lacey rash of the body.
Parvovirus arthritis: Adults with parvovirus commonly have joint pains and swelling. This form of arthritis usually resolves within weeks, but about 10% of patients can have a more prolonged arthritis that does mimic rheumatoid arthritis. (The rheumatoid factor blood test is usually negative, but can be positive.) Treatment involves medications that reduce inflammation in the joints.
Parvovirus infection during pregnancy: Parvovirus B19 infection during pregnancy can cause a miscarriage or cause the baby to have unborn baby to have severe anemia. This occurs in less than 5% of all pregnant women who are infected with parvovirus B19, most commonly during the first half of pregnancy. There is no evidence that parvovirus B19 infection causes birth defects or mental retardation.
Prevention: There is no vaccine or medicine to prevent parvovirus B19 infection. Frequent hand washing is recommended as a practical and probably effective method to reduce the spread of parvovirus. Excluding persons with fifth disease from work, child care centers, schools, or other settings is not likely to prevent the spread of parvovirus B19, since ill persons are contagious before they develop the characteristic rash.