Review Question - QID 106228

The child has the 'slapped-cheeks' rash commonly associated with erythema infectiosum (fifth disease). The etiologic agent the B19 virus of the parvovirus family.

Parvovirus B19 is a single-stranded negative linear DNA virus. It is the only single stranded DNA virus, and the smallest of the DNA viruses. Infants infected with B19 present similarly to the patient in the question stem, with low-grade fever, headache, and cold symptoms. B19 can cause hydrops fetalis if contracted in utero, and may cause symptoms of arthritis in adults.

Servey et al. review parvovirus B19 infection. Most persons who are infected are asymptomatic or have mild cold symptoms. The virus is highly infectious and spreads predominantly through respiratory droplets. Of note, because the rash lags initial infection, the virus is no longer infectious once the rash has appeared.

Lassen et al. evaluated the relationship between parvovirus and fetal loss in a Denmark population case control study. 2,918 women with fetal loss were identified in the National Patient Register, and 8,429 control women with live-born children were identified in the Medical Birth Register. Parvovirus B19 first-trimester immunoglobulin M positivity was associated with a 71% increased risk of fetal loss (odds ratio = 1.71, 95% confidence interval: 1.02, 2.86).

Figure A demonstrates the slapped-cheek rash of parvovirus. The rash spares the nose and perioral area, but may spread to other parts of the body.

Incorrect Answers:
Answer 1: Hepadnavirus is a family of DNA viruses that causes hepatitis B infection.
Answer 2: Herpesvirus is a family of DNA viruses that causes herpes simplex types 1 and 2, varicella-zoster, and others.
Answer 4: Togavirus is a family of RNA viruses best known for causing rubella.
Answer 5: Picornavirus is a family of RNA viruses that cause several enteric diseases including herpangina and hepatitis A.