Congenital cytomegalovirus effects on postnatal neurological development of squirrel monkey ( Saimiri sciureus) offspring

Abstract

Prenatal cytomegalovirus (CMV) infection has been reported to cause sensory deficits, neurological damage, mental deficiency, low birth weight, microcephaly, impairment of neuromuscular coordination, and retardation of postnatal growth in human offspring. The close taxonomic relationship of diurnal primates to man is reflected in great similarities of sensory, cognitive, motor capacity, timing of the “brain growth spurt” in relation to birth, and other aspects of embryonic, fetal, and postnatal stages of development. Susceptibility of squirrel monkey fetuses to SqCMV was shown by the isolation of the virus from the tissues of one of two stillborn offspring and by the presence of SqCMV-specific IgM antibodies in two of three liveborn, nursery-reared offspring all exposed to the virus during gestation. Reflexes and neuromuscular responses of SqCMV offspring were less accurate, poorly coordinated, and required more time for completion than those of controls. Visual acuity of SqCMV offspring was less at birth and also improved at a slower rate during the first month after birth. SqCMV offspring were significantly inferior in percentage correct responses in tests of visual orientation and discrimination and reversal learning. Prenatal SqCMV effects on postnatal somatometric growth rates included significant reductions of head circumference and crown-rump length, and to a lesser degree, offspring body weight from birth to 90 days. We conclude that diurnal primates provide appropriate models to study congenital CMV effects on the brain as the target organ in terms of sensory impairment, learning capacity, neurological damage, and neuromuscular performance of offspring.