Parvovirus Infection: Trivial Except when It’s Not
Each year, around late winter to spring, we see an increase in the number of serologically-confirmed infections with parvovirus B19. These infections are usually trivial in nature and benign in outcome, but there are important exceptions to this rule. This article will review the typical presentation and course of infection with parvovirus B19, discuss its potential adverse outcomes and in whom that potential is greatest.
Parvovirus B19 was discovered and named in 1975 by virologists working at the University of Sydney. It is the predominant genotype (of three) which are pathogenic for humans. Infection is common, occurring sporadically and in clusters, it has a clear seasonality (late winter through to spring) and also has an epidemic cycle with a 4–5 year periodicity.
While 50–80% of adults have parvovirus IgG and are regarded as immune, there remains a significant proportion of the adult population who are susceptible to infection.
Infection and its complications
Humans are the only known host for parvovirus B19.
The anaemia and thrombocytopenia which are usually subclinical in a normal individual may, in those with increased red blood cell turnover (for example, sickle-cell disease, haemoglobinopathies), lead to significant falls in haemoglobin and, potentially, aplastic crisis.
Because B19 is cytotoxic to fetal red blood cell precursors, fetal ...