1 Streptococcal Disease Section, Ecological Investigations Program, National Communicable Disease Center, Public Health Service, U.S. Department of Health, Education, and Welfare, Fort Collins, Colorado
Group A streptococcal infections and their nonsuppurative complications are rare in infancy in spite of the fact that there is ample opportunity for streptococcal acquisitions. In an attempt to define the long-recognized contribution of trans-placental antibody to this epidemiological phenomena, the present study of 107 maternalcord paired sera was undertaken. Seventy-eight percent of the maternal specimens contained antibody to at least one of the four M-types common in the area, and 62% had antibody to two or more of the serotypes.
The high prevalence of type-specific antibody (TSA) in maternal sera, along with the fact that both TSA and bactericidal activity cross the placental barrier and persist in the newborn infant, suggest that passively acquired immunity might be partially responsible for the low incidence of streptococcal acquisitions which occurs during the newborn period.
Other investigators have reported higher levels of antistreptococcal antibodies in cord sera than in the corresponding maternal specimen. Five cord specimens in the present study were found to have higher TSA titers as well as higher antistreptolysin and/or antihyaluronidase levels than found in the maternal sera. Cord macroglobulins were elevated in each case; however, treatment with 2 mercaptoethanol did not significantly decrease the type-specific titers in these sera. The reason for the higher levels of antistreptococcal antibodies in cord sera warrants further investigation.
Submitted on September 5, 1968