Performance of a group B streptococcal prophylaxis protocol combining high-risk treatment and low-risk screening

This study was undertaken to evaluate a group B streptococcal protocol in a large community hospital that combined treatment of high-risk patients with rapid screening of low-risk patients.

In a prospective cohort study from 1994 through 1996 laboring patients in a level III community hospital were considered to be at high risk for neonatal group B streptococcal transmission if they were at <37 weeks' gestation, if they had rupture of membranes >12 hours, if they were known carriers of group B streptococci, if they had a temperature > or =100 degrees F, if the gestation was complicated by fetal growth restriction or was a multiple gestation, or if they had a previous neonate infected with group B streptococci. High-risk patients were treated intravenously with antibiotics during labor. Low-risk patients were screened for group B streptococcal antigen by means of a rapid optical immunoassay. Patients with positive screening results were treated. Neonatal morbidity and mortality were evaluated.

Two of 9932 infants delivered had group B streptococcal sepsis diagnosed. In the 2 previous years without a protocol 9 cases of neonatal group B streptococcal sepsis had been diagnosed in 8188 deliveries (P =.0287 by Fisher exact test). The 2 cases of group B streptococcal sepsis during the protocol were as follows: 1 infant born to a high-risk mother with delay in treatment and 1 infant born to a low-risk mother with negative results of both culture and rapid screen during labor. During the previous period 7 infected infants had been born to high-risk mothers and 2 had been born to low-risk mothers. The maternal group B streptococcal carriage rate during the study was 18%. Group B streptococcal rapid optical immunoassay sensitivity was 81%. Elapsed time from screening to treatment was < or =2(1/2) hours for 93% of patients. No maternal anaphylaxis, no increase in bacterial neonatal sepsis caused by organisms other than group B streptococci, and no protocol-related group B streptococcal antibiotic resistance were noted.

Successful implementation and maintenance of a protocol combining treatment of high-risk patients with rapid screening of low-risk patients during labor reduced neonatal group B streptococcal sepsis.