MICROBIOLOGY

• Common community-acquired respiratory pathogen. Can also be transmitted vertically from mother to child, and through blood products, bone marrow and solid-organ transplants.
• Roughly 80% of all adults have antibodies to the virus; 65% of HIV-infected adults have antibodies. An inability to maintain the humoral response has been postulated to account for the lower level of antibody detection in PLWH.
• Viral agent of fifth disease, a childhood exanthem.
• Viral exposure typically leads to neutralizing antibody production and viral clearance. In immunocompetent hosts antibody production leads to resistance to further infection.
• Virus has tropism for erythroid precursors in the bone marrow. Infection can progress to pure red blood cell aplasia (PRCA) particularly in immunocompromised patients.