Causative agent of Fifth disease?

• A. Varicella zoster
• B. Epstein-Barr virus
• C. Human parvovirus
• D. Parainfluenza virus

Answer: (C)

Fifth disease, or erythema infectiosum, is caused by human parvovirus B19. This small, non-enveloped DNA virus infects erythroid precursor cells in the bone marrow, which is why it can be mild in most children but raise concerns in those with hemolytic disorders due to potential an aplastic crisis. Clinically, it often presents with a bright red “slapped-cheek” facial rash followed by a lacy, reticular rash on the trunk and limbs. It spreads through respiratory droplets and is most common in school-age kids. In pregnant women, parvovirus B19 infection can pose risks to the fetus, including anemia. The other viruses listed are associated with different illnesses: Varicella zoster causes chickenpox and shingles, EBV causes infectious mononucleosis, and parainfluenza viruses cause croup and other upper respiratory infections. Hence, the causative agent of Fifth disease is human parvovirus B19.