Bocavirus Infection

Bocavirus Infection



Bocavirus (also termed HBoV or human bocavirus) is a small (20 nm in size) non-enveloped virus with a single strand of DNA that comprises its genome. The bocavirus genus is a member of the Parvoviridae family, and to date, three strains have been identified: HBoV, HBoV-2, and HBoV-3. Bocavirus is a new viral genus that was discovered in 2005 in upper respiratory secretions from acutely ill children. The name bocavirus was derived by combining the names bovine parvovirus with canine minutevirus with which bocavirus shares some genetic and structural characteristics. The ICTVdB (International Committee on Taxonomy of Viruses database) has detailed its genome and structure.

Although this virus has been found worldwide in humans and animals, there is ongoing research and discussion about this virus as being a pathogen that causes infection, either alone or in conjunction with other virus types. Many investigators consider this newly discovered virus genus as an "emerging viral pathogen" because it is only proven to be associated with infections but not yet proven to be a cause of them, either alone or in conjunction with other viruses. However, another member of the Parvoviridae family, a parvovirus termed B19, causes erythema infectiosum (fifth disease or "slapped cheek" syndrome), hydrops fetalis (severe anemia in pregnant women), and aplastic crisis (cessation of red blood cell production) in individuals that have sickle cell disease. Bocavirus has not been associated with these conditions caused by parvovirus B19.

What are the symptoms and signs of bocavirus infection?

Because bocavirus is usually only found in individuals (usually infants, children, and infrequently in young adults) with lower respiratory infections or diarrhea, these are the following symptoms and signs associated with the presence of bocavirus:

* ARTI (also termed RTIs, acute respiratory tract infections), especially in infants and children


* Cough


* Wheezing


* Fever


* Cyanosis (bluish or grayish tint to skin due to lack of oxygen)


* Rhinorrhea (runny nose)


* Diarrhea


* Vomiting

The infants and children with these nonspecific symptoms often are very ill and require hospitalization. It is important to note that it is not clear yet that bocavirus is either completely or partially responsible for these signs and symptoms. Currently, most of the clinical articles that discuss bocavirus describe patients with at least several of the symptoms and signs listed above, with pneumonia as the major problem. One study found bocavirus rarely associated with patients with COPD (chronic obstructive pulmonary or respiratory disease) so the authors suggest it has no role in COPD. Some investigators report months of bocavirus shedding (having tests demonstrate the presence of the virus in body secretions) in patients with cancer (leukemia), but the significance of this shedding is not clear.