Novel PCR assay for differential detection and screening of erythrovirus B19 and erythrovirus V9

Diagnosis of erythrovirus B19 relies on serology and the detection of viral DNA. These techniques were believed to detect all field isolates because e rythrovirus B19 has been known to undergo little genetic variation (1 - 2%) . Recently, a distinct erythrovirus isolate termed V9, markedly different f rom erythrovirus B19 (> 11% nucleoticle disparity), was isolated from a chi ld in France suffering from transient aplastic anemia. Standard PCR assays and serological tests failed to demonstrate an acute erythrovirus B19 infec tion. Subsequent sequencing of the erythrovirus V9 genome shows that the nu cleoticle discrepancies encompass the entire genome, indicating that standa rd erythrovirus B19 PCR assays will not reliably detect erythrovirus V9 DNA . As a tool for studying the epidemiological role and medical importance of this erythrovirus variant, a PCR assay is described that allows simultaneo us detection of, and distinction between, erythrovirus B19 and the V9 isola te. Examination of 100 erythrovirus B19 IgM positive samples as well as pla sma pools representing 100,000 Danish blood donor units for the presence of B19 and V9 DNA was performed. Despite the apparent absence of erythrovirus V9 in the clinical samples at present, the DNA sequence variability demons trates that the erythrovirus group may be more divergent than thought previ ously and the child harboring this isolate may herald erythrovirus V9 as a possible emerging virus. (C) 2001 Wiley-Liss, Inc.