PARVOVIRUS B19 CLEARANCE FROM PERIPHERAL-BLOOD AFTER ACUTE INFECTION

The clearance of B19 parvovirus from peripheral blood was followed aft er acute infection to determine how long the virus is present in blood , even at low titer. The presence of B19 DNA in serum was investigated with dot blot hybridization during an epidemic. Fourteen patients pos itive for B19 DNA were followed for up to 1 year for its presence in s amples taken monthly, using both dot blot hybridization and nested pol ymerase chain reaction (PCR). All patients examined showed medium to h igh viremic titers (detectable with hybridization assay) only at the b eginning of observation; later the virus titer decreased and was detec table only by nested PCR. Of the 14 patients followed, 13 were positiv e for B19 DNA by nested PCR for 2-6 months; 1 patient showed a persist ent infection associated with chronic arthritis and was positive for B 19 DNA for 1 year without clearance of the virus.