The normalized resistance interpretation offers a new approach to comparative surveillance studies whereby the inhibition zone diameter results from disk tests in clinical laboratories can be used for calibration of the test.

There were a total of 41 isolates from blood cultures from 40 infants. The study showed that the traditionally known acute respiratory infection pathogen Streptococcus pneumoniae was most common in this extended neonatal age group, found in 10 of 41 blood isolates. Streptococcus pyogenes was a common pathogen in this setting (9 of 41 blood isolates), whereas Salmonella group B was found in 5 of 41 isolates. Streptococcus agalactiae, which is a common pathogen in developed countries, was absent. A study of the susceptibility pattern of these organisms suggests that a combination of ampicillin with an aminoglycoside is adequate for initial treatment of these serious bacterial infections, but the combination is not optimal for the treatment of Salmonella infections. Among 202 infants on whom immunofluorescent antibody studies for viruses were performed based on nasopharyngeal aspirates, respiratory syncytial virus was found in 57 (28%) infants, and Chlamydia trachomatis was isolated in 32 (15.8%) of 203 infants.