The National Center for Infectious ...

The National Center for Infectious Diseases freshly issued revised guidelines for prevention of perinatal assemblage B streptococcal (GBS) disease. The thorough recommendations are available through the National Center for Infectious Diseases' Web site at www.cdc.gov/ncidod.

Since emerging as the leading infectious cause of neonatal morbidity and mortality in the United States during the 1970 rates of GB disease have dramatically declined, primarily because of the discovery in the early 1980 that administering antibiotics to at-risk women during labor could intercept invasive disease in the first week of life. However, GB disease remains undivided of the leading causes of newborn morbidity and mortality, resulting in an estimated 1600 early-onset cases and 80 deaths each year. Although alternatives to intrapartum antibiotics, of that kind as vaccines, might become available in the coming intrapartum chemoprophylaxis is currently the mostly effective intervention. Identifying at-risk women who should receive intrapartum antibiotics has been a major public health challenge.

When the Center for Disease dominion government and Prevention (CDC) issued guidelines in 1996 forward preventing GBS disease, two treatment strategies were offered: prenatal screening with intrapartum antibiotic prophylaxis for GBS-colonized women and intrapartum prophylaxis for women who evolveed risk conditions during labor. The novel recommendations call for universal prenatal screening for vaginal and rectal GB colonization of all pregnant women at 35 to 37 weeks' gestation. Other key-note changes include:

* Updated prophylaxis regimens for women with penicillin allergy.

* Detailed instructions forward prenatal specimen collection and expanded orderly dispositions of GBS culture processing, including instructions forward antimicrobial susceptibility testing.

* Recommendation against routine intrapartum antibiotic prophylaxis for GBS-colonized women undergoing planned cesarean deliveries who have not begun labor.

* A intimateed algorithm for managing patients with threatened preterm delivery.

* An updated algorithm for managing newborns expos to intrapartum antibiotic prophylaxis.

GB Colonization and Screening

The gastrointestinal tract is the natural reservoir for GB and the likely source of vaginal colonization. Approximately 10 to 30 percent of pregnant women are colonized with GB in the vagina or rectum GB colonization can be transient, chronic, or intermittent. Maternal intrapartum GB colonization is a major risk factor for early-onset (in the first week of life) disease in infants, and vertical transmission of GB from mother to fetus primarily come to one's minds after the onset of labor or membrane disruption Classic epidemiologic studies conducted during the 1980 revealed that women with prenatal GB colonization were more than 25 times more likely to deliver infants with early-onset GB disease than women with negative prenatal GB improvements However, colonization early in pregnancy is not predictive of neonatal sepsis, and tillage screening of the vagina and rectum for GB late in gestation (i.e., 35 to 37 weeks' gestation) is the make acceptableed method of detecting women who are likely to be colonized with GB at the time of delivery.

Numerous studies have documented that the timing of prenatal screening cultivations the anatomic sites swabbed, and the precise biologic orderly dispositions used for culture and detection of GB can affect the accuracy of identifying colonization status. The commited procedures for collecting and processing clinical specimens for GB cultivation are shown in the accompanying table.

RATIONALE FOR UNIVERSAL GB SCREENING

recent evidence of the potential protective meaning of prenatal GBS screening compared with the former risk-based approach provided the foundation for the universal-screening recommendation. Indications for intrapartum antibiotic prophylaxis to intercept perinatal GBS disease are at handed in Figure 1.

[FIGURE 1 OMITTED]

From the implementation perspective, universal screening has pair additional benefits over the 1996 recommendations. Communication of the public health messages associated with a single strategy is simpler than communicating and educating about multiple strategies. Screening also has clear indicators that help evaluate implementation compared with the risk-based approach.

Cost-effectiveness analyses have indicated that although the initial sumptuousnesss associated with specimen collection and processing make the universal-screening strategy more expensive than the risk-based approach, the overall savings from disease prevention do not differ significantly between the strategies.

Chemoprophylaxis for GBS

Before the widespread use of intrapartum antibiotics, the incidence of invasive neonatal GB disease ranged from pair to three cases per 1000 live births. In the 1990 a time of active prevention efforts, incidence of early-onset disease declined by dint of 70 percent to 0.5 cases through 1,000 live births in 1999 Projections from active surveillance data for 1999 from the Active Bacterial Core surveillance/Emerging Infections Programs Network estimate that intrapartum antibiotics hindered nearly 4,500 early-onset cases and 225 deaths that year. newly come estimates of early-onset disease incidence in the United States predict a slight increase from 1999 to 2000 consistent with a plateau in the impact of prevention efforts.