Parvovirus B19

Q: Associated with parvovirus B19 — which is the odd one out?

Is teratogenic. Parvovirus B19 causes fetal hydrops and anaemia in utero, but it is not classically teratogenic in the way rubella or CMV are. Options a, c, d and e are all true.

Caused by alphavirus, parvovirus B19, rubella, EBV, hepatitis B and C.

PARVOVIRUS B19

Structure: Smallest DNA virus. Non-enveloped, icosahedral, ssDNA (linear). Only one serotype. Only B19 causes human disease.
Epidemiology: 65% adults infected by age 40. Peak: late winter/spring. Children 4–15 yrs = main reservoir/source.
Pathogenesis — Two-Stage Disease:
Stage 1 (Infectious/Febrile): B19 replicates in nasopharynx → viremia → bone marrow → kills erythroid precursor cells → stops RBC production ~1 week. Patient is CONTAGIOUS here. Flulike symptoms. Large viremia; antibody eventually stops it.
Stage 2 (Symptomatic/Immune-mediated): Rash + arthralgia appear WHEN antibody appears + immune complexes form. Patient is NO LONGER contagious during the rash.

Read this in Medical Virology: Parvovirus B19 & Adenovirus Exam Guide

What our notes say

Caused by alphavirus, parvovirus B19, rubella, EBV, hepatitis B and C. (Bone & Joint Pathology: Basic Structure, Cells, and Fractures)
Parvovirus B19 infects red cell precursors and causes an aplastic crisis. (Junior Clerkship in Internal Medicine (MBIM4100) main exam, Paper One: 31 Januar)
Parvovirus B19 infects erythroid precursors and can lead to an aplastic crisis in persons with hemoglobinopathies. (hematopathology — Past Paper Questions & Answers)
Complications: vaso-occlusive crisis, sequestration crisis, aplastic crisis (parvovirus B19), autosplenectomy, stroke, avascular necrosis (Renal, Liver, Cardiac & Adrenal Function Tests for Year 3)
Aplastic crisis — parvovirus B19 suppressing erythropoiesis (Haematopathology MCQs: Blood Disorders & Anemia Explained)
Aplastic crisis from parvovirus B19 — requiring supportive red cell transfusion only (Haematopathology MCQs: Blood Disorders & Anemia Explained)

Study material on Parvovirus B19

Practice questions on Parvovirus B19

Associated with parvovirus B19 — which is the odd one out?

Causes erythema infectiosum
Is teratogenic
Causes fifth disease
May cause abortion
May cause aplastic crisis in persons with haemolytic anaemia

Answer: B. Parvovirus B19 causes fetal hydrops and anaemia in utero, but it is not classically teratogenic in the way rubella or CMV are. Options a, c, d and e are all true.