Molecular characterization of human erythrovirus B19 strains obtained from patients with several clinical presentations in the Amazon region of Brazil.

Background: Human erythrovirus B19, endemic in the Amazon region since 1990, is associated with a wide spectrum of clinical presentations.
Objectives: To assess the prevalence of erythrovirus B19 infection and the relative frequency of erythrovirus B19 genotypes in patients in the Amazon region with various clinical presentations.
Study Design: A total of 487 clinical samples obtained from patients with symptoms suggestive of erythrovirus infection were tested using specific IgM and IgG antibody assays (ELISA) and PCR for viral DNA detection. Partial VP1 and VP2 regions were sequenced and genotyped by phylogenetic reconstruction.
Results: B19 DNA was detected in 117 (24%) of 487 samples. Of these, 106 (91%) isolates were genotype 1 and 11 (9%) were genotype 3. No genotype 2 was found. Genotype 1 had three clusters (A1, A2 and B) and all genotype 3 sequences were subtype 3b. All patients with hematological disorders within cluster B of genotype 1 were infected by the same B19 lineage, suggesting that this lineage of B19 may have been transmitted via transfusion of blood products.
Conclusion: We reported two genotypes, 1 and 3b, with three genotype 1 clusters co-circulating in the Amazon region during the past 10 years.