Parvovirus B19

Next is parvovirus B19. The infection in pregnant women results in infection of the fetus and the timing of that depends a bit on what happens. But in the first half of pregnancy you get red cell aplasia and it may lead to fetal hydrops and abortion. The risk of abortion in maternal infection is about 5-8%. An important thing is that in babies that survive there has been no evidence of congenital malformations. So you don’t want to do what some obstetricians do, and that is perform an abortion to prevent an abortion. The important thing to realize in outbreaks to begin with, about 50% of adult women of child-bearing age already have antibody and they are at no risk. So there is not much you can do, but the big concern is with school teachers who are pregnant. One of the things you can do is antibody studies on them and if they are positive they have no risk.

The next is toxoplasmosis. Toxoplasmosis gets missed. The congenital infection that anywhere between 70-90% are asymptomatic at birth, so this leads to sort of a lower estimate of the risk of this problem because many of these babies who are asymptomatic at birth go on to have problems later on in childhood, or to have evidence of retinitis later on in life. The actual infection rate is somewhere between 1:1000 births to 1:10,000 births. The manifestations; the list looks sort of like that that I showed you for rubella. The findings that you see here. The outcomes are retardation in 85% of diagnosed cases, convulsions 80%, spasticity 65%, impaired vision 60%, hydrocephalus and microcephalus 20%, deafness 15%. Of recognized cases at birth, only 10% are normal. Those staggering statistics bothered people for a long time. Now about ten years ago a national study was undertaken to look at treatment. I think that many of these babies look pretty bad and yet the amazing thing with treatment and a standardized protocol, or several protocols, that the treated babies had actually rather marked responses to treatment. So any baby today should be treated and treatment is complicated. So in general, if in doubt you should get help from somebody else and at least refer to a center where treatment can be done under controlled conditions. Pyrimethamine is difficult to administer, particularly in young babies because you suppress the blood count – both white cells and red cells – and the treatment is for a prolonged period; up to a year. But the results are very clear and it does lessen morbidity and prevents mortality.

Okay, last congenital infection is syphilis. Risk of transmission, major risk after 16 weeks but there is evidence of some transmission before 16 weeks. In primary syphilis 70-100% chance of transmission, secondary syphilis 90% and latent syphilis there is still a 30% chance of transmission. The manifestations here again are those of active infection of fair duration with hepatomegaly, skeletal abnormalities similar to those of rubella, low birth weight, bullous lesions of the skin – which are teeming with spirochetes and a lot of people don’t recognize that but are highly contagious – hyperbilirubinemia, a severe pneumonia and splenomegaly. Anemia, hydrops, nasal discharge, painful limbs. They have meningitis and meningoencephalitis, nephritis and failure to thrive. This is a picture of the hand of a baby, and this is a very large lesion but these are loaded with organisms.

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