Parvovirus B19

Parvoviruses are members of the smallest and simplest eukaryotic viruses. There are two subfamilies of the parvoviruses: the Parvovirinae (vertebrate viruses) and the Densovirinae (invertebrate viruses). Some diseases in animals (including human) are caused by parvoviruses. Among them, Parvovirus B19 is the most dangerous one.

Parvovirus B19 has been associated with diseases such as arthritis, aplastic crisis in chronic hemolytic anemia, chronic anemia in immunodeficiency syndromes, and hydrops fetalis. However, B19 is most commonly associated with the disease erythema infectiosum (EI), also known as fifth disease.

Currently there is no vaccine to prevent infection with B19, but recently a cell line that expresses the virus's capsid proteins as noninfectious viruslike particles has been proposed as a source of antigen in development of a vaccine. No studies have yet been done as to the effectiveness of passive prophylaxis with immune globulins.

The treatments for the diseases, which include antivirals and normal human immunoglobulin are generally for relief of symptoms only. Immunoglobulin preparations are a good source of neutralizing antibodies because most of the adult population has been exposed to the B19 virus. These treatments are usually only given to pregnant nonimmune women, immunocompromised individuals, and those with chronic hemolytic anemia because these groups are at the highest risk of complicated parvovirus infections. Studies have indicated that relapse of the virus may be prevented by regular IgG infusions.

DIAGNOSIS

Although parvovirus infection can be quite apparent clinically, the virus's inability to grow in standard cell culture systems has made widespread laboratory testing of B19 quite difficult. Now it is available to detect the peptides derived from parvovirus B19 with immunological method. And also, to detect the DNA of the B19 by basepair hybridization is also an effient method.