[Five family members infection likely due to human parvovirus B19 (erythema infectiosum)].

We encountered five members of the same family infected with parvovirus B19. The latency period in these patients was 17 to 20 days, which matched that observed by Anderson et al. after inoculating humans with the virus. The latency period in 24 cases of familial infection observed in 17 families at the same time showed peaks at both 10 days and 20 days. Thus, it is still necessary to determine the actual latent period of erythema infectiosum infection.