Elevated IgG and IgM antibody titers to parvovirus suggest a diagnosis of which one of the following?

B. burgdorferi, the causative agent of Lyme disease, elicits an acute antibody response. IgM appears within days to a few weeks following tick bite, and 19G appears a few weeks later. 19G persists; IgM does not. Cross-reactions occur with other treponemes. Fifth disease is a viral exanthema commonly seen in children 8 to 12 years old. Children are ill for a few days but recover without incident. Unfortunately, if a pregnant female acquires the disease in the first trimester of pregnancy, the fetus is at risk. The causative agent is thought to be a Parvovirus (Parvovirus B 19).