The virus which causes aplastic anemia in chronic hemolytic diseases is -

Ans. is 'd' i.e., Parvo virus B-19 "Parvovirus B-19 induces aplastic crisis in children with chronic hemolytic anemias, as in sickle cell disease". Parvovirus . Non-enveloped DNA (ss DNA) viruses. . Only DNA virus which has single stranded DNA. . Smallest virus . Has smallest genome . Only one medically impoant human parvovirus - Parvovirus B 19 . Transmission is by respiratory route and through blood. . Infection is commonly acquired in childhood (5-10 yrs). . Most of the infections are asymptomatic. . Most common presentation is respiratory infection with an erythematous maculopapular rash and ahralgia - Erythema infectiosum or Fifth disease. . Stas with prominant erythema of cheeks --> slapped cheek disease. . Parvovirus B-19 induces aplastic crisis in children with chronic hemolytic anemias, as in sickle cell disease. . Parvovirus B-19 infection during second or third trimester of pregnancy may result in nonimmune fetal hydrops.