Cytomegalovirus Infection in Guinea Pigs. II. Transplacental and Horizontal Transmission

Abstract

Transplacental transmission of cytomegalovirus (CMV) was demonstrated in guinea pigs, but transmission only occurred during acute primary maternal infection. Infectious CMV was isolated from 27 of 44 placental tissues and nine of 37 fetal tissues (including brain, lung and kidney) tested 5-24 days after maternal infection. Fetal infection occurred at different stages of gestation ranging from 28-60 days. No virus was detected in the tissues of 43 fetuses examined that were taken from pregnant guinea pigs that were infected for > 30 days. The maternal animals had significant levels of circulating neutralizing antibody concurrent with infectious CMV in the salivary glands at the time of sacrifice. Contact infection was accomplished when infected and uninfected animals of either the same sex or opposite sexes were paired and housed together for one to 3 mo. Among the 7 male contact guinea pigs housed with infected females, 5 showed virus in their salivary glands, and all 7 showed rises in titer of antibody; 5 of the females became pregnant. When infected and uninfected animals of the same sex were paired and housed together, only 1 of 13 contact animals had virus in the salivary gland, and 4 of 13 had rises in titer of antibody. Thus, sexual contact appeared to be more efficient than environmental contact in the spread of CMV infection.