Aplastic anemia induced by human parvovirus B19 infection in an immunocompetent adult male without prior hematological disorders: A case report.

Introduction and importance: Parvovirus B19 (B19V) is a human pathogenic virus of clinical relevance. Human parvovirus B19 infection can be asymptomatic or frequently associated with erythema infectiosum, or joint symptoms in healthy adults. Aplastic anemia as a complication of human parvovirus infection is rare in healthy adults without prior hematological disorders. Case presentation: We report a case of severe aplastic anemia in a 22-years-old immunocompetent adult male without any hematological dysfunction who presented with periumbilical pain, loose watery stools, and fever with chills and rigor. General examination, laboratory investigation, and peripheral blood smear revealed anemia with leucopenia and relative lymphocytosis, thrombocytopenia, and severe neutropenia. Bone marrow biopsy revealed hypocellular bone marrow with maturation arrest at the proerythroblast stage with intranuclear inclusions and no blast and hematopoietic cells replaced by mature adipocytes in marrow spaces. Parvovirus B19 infection was confirmed by viral serology and polymerase chain reaction. Clinical discussion: Asymptomatic or mild infection occurs most often when B19 affects immunocompetent adults. However, this is the fourth case reporting severe aplastic anemia in immunocompetent adults and the first case reported in immunocompetent adult males. The patient was admitted for close monitoring and supportive management, which effectively improved the patient's clinical condition, and discharged with a strict follow-up schedule in an outpatient setting. Conclusion: Thus, acute infection with this virus must be considered a cause of acquired aplastic anemia even in individuals without underlying disease.