Antigen detection was found to be a rapid and useful technique in diagnosing group B streptococcal (GBS) infections. Of the two techniques described, latex agglutination was more sensitive than countercurrent immunoelectrophoresis. Concentrated urine was the best body fluid to test with 100% containing antigen. Though no false-positive reactions were noted, this is a potential problem. Gram-positive cocci in the gastric aspirate were associated with severe systemic infections with these organisms in almost half of the neonates with clinical signs of infection or respiratory distress syndrome (RDS). There was only a 4% infection rate in clinically similar neonates without Gram-positive cocci in the gastric aspirates. Apnea and/or hypotension was seen commonly in both early onset GBS pneumonia and RDS, making this finding alone of little clinical use.