Rapid selection of complement-inhibiting protein variants in group A Streptococcus epidemic waves.

Serotype M1 group A Streptococcus strains cause epidemic waves of human infections long thought to be mono- or pauciclonal. The gene encoding an extracellular group A Streptococcus protein (streptococcal inhibitor of complement) that inhibits human complement was sequenced in 1,132 M1 strains recovered from population-based surveillance of infections in Canada, Finland and the United States. Epidemic waves are composed of strains expressing a remarkably heterogeneous array of variants of streptococcal inhibitor of complement that arise very rapidly by natural selection on mucosal surfaces. Thus, our results enhance the understanding of pathogen population dynamics in epidemic waves and infectious disease reemergence.

Invasive pneumococcal infection in Baltimore, Md: implications for immunization policy.

BACKGROUND: Streptococcus pneumoniae is a leading cause of infectious morbidity and mortality. Although blacks are known to have a higher incidence of invasive pneumococcal infection than whites, detailed analyses of these differences and their implications for vaccine prevention have not been reported. OBJECTIVE: To describe the epidemiological characteristics of invasive pneumococcal infection in Baltimore, Md, and its implications for immunization policy. METHODS: Analysis of active, laboratory-based surveillance during 1995 and 1996 among residents of the Baltimore metropolitan area. RESULTS: Of 1412 cases, 615 patients (43.6%) were classified as white and 766 (54.2%) as black. The annual incidence of invasive pneumococcal infection among white and black residents of the Baltimore metropolitan area was 17.8 and 59.2 per 100000 population, respectively (P<.01). Among patients aged 18 years and older, the median age of blacks with invasive pneumococcal infections was 27 years younger than that of whites (P<.01). Among males 40 to 49 years old, blacks had a 12-fold higher average incidence than whites (average incidence, 114.5 and 9.3, respectively; P<.01). By the age of 65 years, 83.8% of cases had occurred in black adults, as compared with 43.8% in white adults (P<.01). In a regression model, age, black race, male sex, low median family income, and county prevalence of acquired immunodeficiency syndrome were each independently associated with a higher incidence of pneumococcal infection. CONCLUSIONS: Young urban black adults in the Baltimore metropolitan area have a dramatically higher incidence of invasive pneumococcal infection than whites. The vast majority of cases of invasive pneumococcal infection in blacks occur before age 65 years. Current immunization efforts have not addressed the high incidence of pneumococcal infection in this population.

Evaluation of effectiveness of the 23-valent pneumococcal capsular polysaccharide vaccine for HIV-infected patients.

BACKGROUND: We conducted a retrospective case-control study to evaluate effectiveness of pneumococcal vaccine against invasive disease among adults with human immunodeficiency virus (HIV) infection in San Francisco, Calif, and Atlanta, Ga. METHODS: Case patients were 18- to 55-year-old subjects with HIV infection who were admitted to selected hospitals in Atlanta or San Francisco from February 1992 to April 1995 from whom Streptococcus pneumoniae was isolated from a normally sterile site. Controls were HIV-infected patients of similar age matched to cases by hospital of admission and CD4 lymphocyte count (<0.20, 0.20-0.499, >/=0.50 x 10(9)/L [<200, 200-499, >/=500 cells/mm(3)]) or clinical stage of acquired immunodeficiency syndrome. Case and control subjects were restricted to persons known to have HIV infection before hospital admission. Analysis used matched univariate and conditional logistic regression. RESULTS: One hundred seventy-six case patients and 327 controls were enrolled. By univariate analysis, persons with pneumococcal disease were more likely to be black, be current smokers, and have close contact with children. Adjusted for these factors and CD4 cell count, pneumococcal vaccine effectiveness was 49% (95% confidence interval [CI], 12%-70%). Adjusting for all variables and key interaction terms, vaccine effectiveness among whites was 76% (95% CI, 35%-91%), whereas effectiveness among blacks was 24% (95% CI, -50% to 61%). Among controls, vaccination was significantly less common among blacks (29% vs 45%; P<.005). CONCLUSIONS: Pneumococcal vaccine demonstrated protection against invasive pneumococcal infections among white but not black HIV-infected adults. Failure to demonstrate effectiveness among blacks may be due to limited power because of low use of the vaccine in this population, immunization at more advanced stages of immunosuppression, or unmeasured factors. These data support current recommendations for use of pneumococcal vaccine in HIV-infected persons and highlight a clear need for strategies to improve vaccine-induced protection.

Management of community-acquired pneumonia in the era of pneumococcal resistance: a report from the Drug-Resistant Streptococcus pneumoniae Therapeutic Working Group.

OBJECTIVE: To provide recommendations for the management of community-acquired pneumonia and the surveillance of drug-resistant Streptococcus pneumoniae (DRSP). METHODS: We addressed the following questions: (1) Should pneumococcal resistance to beta-lactam antimicrobial agents influence pneumonia treatment? (2) What are suitable empirical antimicrobial regimens for outpatient treatment of community-acquired pneumonia in the DRSP era? (3) What are suitable empirical antimicrobial regimens for treatment of hospitalized patients with community-acquired pneumonia in the DRSP era? and (4) How should clinical laboratories report antibiotic susceptibility patterns for S pneumoniae, and what drugs should be included in surveillance if community-acquired pneumonia is the syndrome of interest? Experts in the management of pneumonia and the DRSP Therapeutic Working Group, which includes clinicians, academicians, and public health practitioners, met at the Centers for Disease Control and Prevention in March 1998 to discuss the management of pneumonia in the era of DRSP. Published and unpublished data were summarized from the scientific literature and experience of participants. After group presentations and review of background materials, subgroup chairs prepared draft responses, which were discussed as a group. CONCLUSIONS: When implicated in cases of pneumonia, S pneumoniae should be considered susceptible if penicillin minimum inhibitory concentration (MIC) is no greater than 1 microg/mL, of intermediate susceptibility if MIC is 2 microg/ mL, and resistant if MIC is no less than 4 microg/mL. For outpatient treatment of community-acquired pneumonia, suitable empirical oral antimicrobial agents include a macrolide (eg, erythromycin, clarithromycin, azithromycin), doxycycline (or tetracycline) for children aged 8 years or older, or an oral beta-lactam with good activity against pneumococci (eg, cefuroxime axetil, amoxicillin, or a combination of amoxicillin and clavulanate potassium). Suitable empirical antimicrobial regimens for inpatient pneumonia include an intravenous beta-lactam, such as cefuroxime, ceftriaxone sodium, cefotaxime sodium, or a combination of ampicillin sodium and sulbactam sodium plus a macrolide. New fluoroquinolones with improved activity against S pneumoniae can also be used to treat adults with community-acquired pneumonia. To limit the emergence of fluoroquinolone-resistant strains, the new fluoroquinolones should be limited to adults (1) for whom one of the above regimens has already failed, (2) who are allergic to alternative agents, or (3) who have a documented infection with highly drug-resistant pneumococci (eg, penicillin MIC > or =4 microg/mL). Vancomycin hydrochloride is not routinely indicated for the treatment of community-acquired pneumonia or pneumonia caused by DRSP.

Adverse and beneficial secondary effects of mass treatment with azithromycin to eliminate blindness due to trachoma in Nepal.

Mass administration of azithromycin to eliminate blindness due to trachoma has raised concerns regarding the emergence of antimicrobial resistance. During 2000, we compared the antimicrobial resistance of nasopharyngeal pneumococcal isolates recovered from and the prevalence of impetigo, respiratory symptoms, and diarrhea among 458 children in Nepal before and after mass administration of azithromycin. No azithromycin-resistant pneumococci were isolated except from 4.3% of children who had received azithromycin during 2 previous mass treatments (P<.001). There were decreases in the prevalence of impetigo (from 14% to 6% of subjects; adjusted odds ratio [OR], 0.41; 95% confidence interval [CI], 0.21-0.80) and diarrhea (from 32% to 11%; adjusted OR, 0.26; 95% CI, 0.14-0.43) 10 days after azithromycin treatment. The absence of macrolide-resistant isolates after 1 mass treatment with azithromycin is encouraging, although the recovery of azithromycin-resistant isolates after 2 mass treatments suggests the need for resistance monitoring when multiple rounds of antimicrobial treatment are given.

Risk factors and opportunities for prevention of early-onset neonatal sepsis: a multicenter case-control study.

BACKGROUND: Early-onset group B streptococcal (GBS) prevention efforts are based on targeted use of intrapartum antibiotic prophylaxis (IAP); applicability of these prevention efforts to infections caused by other organisms is not clear. METHODS: Multicenter surveillance during 1995 to 1996 for culture-confirmed, early-onset sepsis in an aggregate of 52 406 births; matched case-control study of risk factors for GBS and other sepsis. RESULTS: Early-onset disease occurred in 188 infants (3.5 cases per 1000 live births). GBS (1.4 cases per 1000 births) and Escherichia coli (0.6 cases per 1000 births) caused most infections. GBS sepsis less often occurred in preterm deliveries compared with other sepsis. Compared with gestation-matched controls without documented sepsis, GBS disease was associated with intrapartum fever (matched OR, 4.1; CI, 1.2-13.4) and frequent vaginal exams (matched OR, 2.9; CI, 1.1-8. 0). An obstetric risk factor-preterm delivery, intrapartum fever, or membrane rupture >/=18 hours-was found in 49% of GBS cases and 79% of other sepsis. IAP had an adjusted efficacy of 68.2% against any early-onset sepsis. Ampicillin resistance was evident in 69% of E coli infections. No deaths occurred among susceptible E coli infections, whereas 41% of ampicillin-resistant E coli infections were fatal. Ninety-one percent of infants who developed ampicillin-resistant E coli infections were preterm, and 59% of these infants were born to mothers who had received IAP. CONCLUSIONS: Either prenatal GBS screening or a risk-based strategy could potentially prevent a substantial portion of GBS cases. Sepsis caused by other organisms is more often a disease of prematurity. IAP seemed efficacious against early-onset sepsis. However, the severity of ampicillin-resistant E coli sepsis and its occurrence after maternal antibiotics suggest caution regarding use of ampicillin instead of penicillin for GBS prophylaxis.

Maternal carriage of group B streptococci in developing countries.

BACKGROUND: Group B streptococcus (GBS) is a leading cause of neonatal sepsis in many industrialized countries, but reports from the developing world infrequently identify this pathogen among newborns with sepsis. Studies of GBS colonization among women living in developing countries were reviewed to determine whether lower colonization rates might account for these findings. METHODS: Literature was reviewed with the use of Medline Express (1980 to 1996) and Abstracts on Tropical Agriculture and Rural Development in the Tropics (1975 to 1995). The methods of each report were considered adequate if specimens were collected from the vagina and if selective broth media were used. RESULTS: Thirty-four studies reported results of cultures from 7730 women; overall colonization was 12.7%. Among only those studies in which methods were adequate, 17.8% (675 of 3801) women were identified as colonized. Studies with adequate methods found significantly higher colonization rates (relative risk, 2.3; 95% confidence interval, 2.0 to 2.6) than those using inadequate methods. When analysis was restricted to reports with adequate methods, the prevalence of colonization by region was as follows: Middle East/North Africa, 22%; Asia/Pacific, 19%; Sub-Saharan Africa, 19%; India/Pakistan, 12%; and Americas, 14%. CONCLUSION: Although there is significant geographic variation in the proportion of women colonized with GBS, the range of colonization reported from developing countries is similar to that identified in populations studied in the United States. Specimen collection and microbiologic methods are important factors in identification of women colonized with GBS.

Barriers to prevention of perinatal group B streptococcal disease.

During 1992 the American College of Obstetricians and Gynecologists (ACOG) and the American Academy of Pediatrics (AAP) issued statements on prevention of group B streptococcal (GBS) disease. To assess prevention practices and identify barriers to preventing GBS disease, we surveyed obstetricians, family practitioners and general practitioners in Georgia during 1993. A standard questionnaire was mailed to 1190 clinicians in August and to nonresponders again in September. Of 436 (38%) physicians who responded, 192 (44%) provided obstetric care. Among these 192 obstetric care providers, 121 (63%) screened patients for GBS carriage antenatally. The most frequently cited reasons for not screening were "no clear guidelines" and "not cost-effective" (52 and 39%, respectively). Clinicians who screened patients were significantly more likely to believe that screening was cost-effective (P = 0.05). Of obstetric care providers who screened, only 9% obtained specimens using culture sites recommended by ACOG or AAP. Although most clinicians were aware that antenatal antibiotic treatment of carriers does not prevent perinatal GBS disease, 64% of those who screened reported that they gave oral antibiotics when carriage was detected during pregnancy. Of clinicians who reported using obstetric risk factors to guide prophylaxis choices, < 15% reported using intrapartum antibiotics for the conditions identified in the ACOG and AAP statements as those that suggest the need for prophylaxis when screening is not performed. Many Georgia obstetric care providers do not use effective practices to prevent perinatal GBS disease. Education on appropriate culture methods, obstetric risk factors and the cost effectiveness of prevention strategies might lead to more effective preventive practices.

Outbreak of neonatal listeriosis associated with mineral oil.

In June, 1989, an outbreak of nosocomial listeriosis occurred in Costa Rica. Listeria monocytogenes was isolated from 9 ill infants 4 to 8 days old who were born after the delivery of an infant with early onset listeriosis. One nosocomial infection was fatal, 2 required mechanical ventilation and 1 resulted in hemiparesis. A higher proportion of cases than other infants born during the outbreak were delivered by cesarean section (55% vs. 24%, P = 0.04). Compared with the mothers of 36 random controls, case mothers were more often primiparous (odds ratio, 6.2, P = 0.03) or received general anesthesia before delivery (odds ratio, 4.4, P = 0.09). All infants were bathed with mineral oil from a multidose container. Culture of the oil by cold enrichment grew L. monocytogenes 4b with the same electrophoretic enzyme type as the outbreak strain. We hypothesize that aspiration of contaminated oil may have resulted in systemic listeriosis. General anesthesia may have increased the risk of aspiration. Lung tissue from the infant who died showed lipid-laden macrophages consistent with oil aspiration and had evidence of L. monocytogenes DNA detected by polymerase chain reaction. This is the first nosocomial outbreak of listeriosis in which a common source suggested epidemiologically was microbiologically confirmed. The high attack rate (greater than 200 times the United States rate of perinatal listeriosis) emphasizes the susceptibility of healthy neonates to L. monocytogenes. The results of our study led to the discontinuation of the use of mineral oil for bathing neonates in Costa Rica.

Multistate case-control study of maternal risk factors for neonatal group B streptococcal disease. The Active Surveillance Study Group.

Risk factors for early onset disease (EOD) caused by Group B streptococci (GBS) that are the foundation of prevention guidelines were identified in studies conducted in a few hospital centers. We investigated cases of EOD identified through laboratory-based active surveillance during 1991 and 1992 in a multistate population of 17 million. Ninety-nine cases were compared with 253 controls matched for hospital, date of birth and birth weight. Prematurity (< 37 weeks of gestation) was present in 28% of cases; 53% of case mothers had rupture of membranes > 12 hours; and 48% reported intrapartum fever. The incidence of EOD in each surveillance area was higher among blacks. By multivariate analysis, case mothers were more likely than controls to have rupture of membranes before labor onset (adjusted odds ratio 8.7, P < 0.001), intrapartum fever (adjusted odds ratio 11.9, P < 0.001), and history of urinary infection during pregnancy (adjusted odds ratio 4.3, P < 0.05). Young maternal age was also associated with risk of disease. Three-fourths of case mothers had intrapartum fever, < 37 weeks of gestation and/or prolonged rupture of membranes, indicators previously used to select high risk women for intrapartum chemoprophylaxis. Our findings extend data from single hospitals and suggest prenatal screening and selective intrapartum chemoprophylaxis of high-risk mothers could potentially prevent the majority of EOD in the United States.

Outbreak of early onset group B streptococcal sepsis.

During January and August, 1990, 23 cases of early onset Group B Streptococcus (GBS) disease occurred in a Kansas City, MO, hospital with an attack rate of 14/1000 live births, compared with an annual rate of 1.2 cases/1000 live births for 1988 through 1989. Case infants were compared with controls matched by birth weight, race, maternal age and day of delivery and to a second group of infants of mothers colonized with GBS to identify risk factors and consider intervention strategies during the outbreak. The presence of multiple serotypes among the invasive strains suggested that the outbreak was not caused by a common source. Case mothers were more likely than control mothers to have chorioamnionitis, intrapartum fever or rupture of membranes > 12 hours, and premature case infants were more likely to have a history of rupture of membranes before onset of labor. Multiparous mothers of case infants were more likely to have a history of spontaneous abortion (odds ratio, 6.7; 95% confidence interval, 1.0 to 45.9). No single factor could explain the increase in GBS disease. If intrapartum antibiotic prophylaxis had been used for selected GBS carriers based on presence of either rupture of membranes > 12 hours, intrapartum maternal fever or preterm labor, 7.4% of all deliveries would have received antibiotics and 73% of cases could potentially have been prevented. We conclude that identification of colonized mothers with perinatal risk factors and use of intrapartum antibiotics could be expected to prevent substantial disease during an outbreak of early onset GBS disease.

Safety and immunogenicity of three doses of a Neisseria meningitidis A + C diphtheria conjugate vaccine in infants from Niger.

BACKGROUND: High rates of endemic disease and recurrent epidemics of serogroup A and C meningococcal meningitis continue to occur in sub-Saharan Africa. A meningococcal A + C polysaccharide diphtheria-toxoid-conjugated vaccine may address this issue. METHODS: In Niger three doses of a bivalent meningococcal A + C diphtheria-toxoid-conjugated vaccine (MenD), containing 1, 4 or 16 microg of each polysaccharide per dose, administered at 6, 10 and 14 weeks of age, were compared with Haemophilus influenzae type b-tetanus toxoid-conjugated (PRP-T) vaccine given with the same schedule or with a meningococcal A + C polysaccharide vaccine (MenPS) given at 10 and 14 weeks of age. One blood sample was taken at the time of enrollment (6 weeks of age) and another was taken 4 weeks after the primary series. RESULTS: All doses of MenD were well-tolerated. After the primary series a higher proportion of infants had detectable serum bactericidal activity against serogroup A for each dose of MenD (from 94% to 100%) than for MenPS (31%) or H. influenzae type b-tetanus toxoid-conjugated vaccine (18.9%); P < or = 0.05. Significant differences were also observed for serogroup C MenD 4 microg or MenD 16 microg (100%) vs. MenPS (69.7%) or Haemophilus influenzae type b-tetanus toxoid-conjugated vaccine (24.3%); P < or = 0.05. When MenPS vaccine was given to 11-month-old children, the immune response measured by both enzyme-linked immunosorbent assay and serum bactericidal assay was greater in those previously immunized with MenD than in those immunized with MenPS vaccine. CONCLUSION: MenD was safe among infants in Niger, and immunization led to significantly greater functional antibody activity than with MenPS. The 4-microg dose of MenD for both the A and C serogroups has been selected for further studies.

Neonatal group B streptococcal disease: how infection control teams can contribute to prevention efforts.

Group B streptococcal (GBS) disease is a leading cause of morbidity and mortality among newborns. Many cases of newborn GBS disease can be prevented by the administration of intrapartum antibiotic prophylaxis. Current consensus guidelines for prevention of perinatal GBS disease have led to substantial declines in the incidence of GBS disease occurring in newborns <7 days of age (early-onset disease). Despite declines in the incidence of early-onset disease, approximately 20% of pregnant women are colonized with GBS at the time of labor and thus have the risk of transmitting the bacteria to their newborns. Consequently, continued and improved implementation of prevention efforts is essential. Infection control teams can contribute uniquely to prevention of perinatal GBS disease by serving as hospital champions of GBS disease prevention. In particular, teams can coordinate with administration and staff to encourage establishment and effective implementation of GBS prevention policies; facilitate improved laboratory processing of prenatal GBS screening specimens; monitor any adverse consequences of increased use of intrapartum antibiotics within the hospital; and investigate GBS cases that occur to determine whether they could have been prevented. By spearheading efforts to improve implementation of perinatal GBS disease prevention at the hospital level, hospital epidemiologists and infection control practitioners can play an important role in reducing the burden of early-onset GBS disease.

Opportunities for prevention of perinatal group B streptococcal disease: a multistate surveillance analysis. The Neonatal Group B Streptococcal Disease Study Group.

OBJECTIVE: To evaluate the potential impact of ACOG and Centers for Disease Control and Prevention (CDC) consensus strategies for the prevention of perinatal group B streptococcal disease. METHODS: We evaluated cases of early-onset group B streptococcal disease identified by active surveillance during 1995, in four areas in North America with an aggregate 186,000 births per year. We reviewed the hospital records of mothers and infants and any prenatal records available on site. Cases were determined to be preventable based on whether group B streptococcal screening could have been performed prenatally, sensitivity of screening, presence of obstetric complications, and opportunity to administer antibiotics. RESULTS: We reviewed records for 245 of 246 infants with early-onset group B streptococcal disease in the surveillance areas. Most of the 53 case-mothers who delivered preterm and 192 who delivered full-term had had at least one prenatal visit (83% and 99%, respectively). Few case-mothers had prenatal group B streptococcal screening cultures, although compliance was high for other prenatal screening tests. Fifty-four percent of case-mothers had a recognized obstetric risk factor for group B streptococcal disease: labor or rupture of membranes at less than 37 weeks, rupture of membranes for 18 hours on longer, or temperature 38C or greater. The estimated preventable portion of early-onset group B streptococcal cases was 78% for the screening-based approach (range 74% to 82% by area), compared with 41% for the risk-based approach (range 39% to 53% by area). CONCLUSION: Comprehensive implementation of either of the recommended prevention strategies could potentially prevent a substantial proportion of early-onset group B streptococcal disease.

Effects of hospital policies based on 1996 group B streptococcal disease consensus guidelines. The Active Bacterial Core Surveillance Team.

OBJECTIVE: To determine whether the 1996 consensus guidelines for prevention of early-onset group B streptococcal disease developed by the Centers for Disease Control and Prevention, ACOG, and the American Academy of Pediatrics are affecting obstetric practice and disease occurrence. METHODS: Personnel in hospitals with obstetric services in seven surveillance areas completed surveys about their programs, patient populations, and group B streptococcal disease prevention policies. Survey results were linked to group B streptococcal disease cases identified by active surveillance in 1996 and 1997. An early onset case was defined as a case in which group B streptococci were isolated from a sterile site in the 1st 6 days of life. The number of cases in 1996 and 1997 were compared using a paired t test. Linear regression was used to assess hospital characteristics associated with group B streptococcal disease cases. RESULTS: Of 177 hospitals, 165 (93%) responded, and 96 (58%) of those had group B streptococcal disease prevention policies. Hospitals that established or revised their policies in 1996 had a lower mean number of cases in 1997 than in 1996 (0.58 versus 1.29, P = .006). Linear regression analysis, controlling for number of births, indicated that a hospital's having more black mothers and location in particular states were associated with more cases of disease. Citing the 1996 ACOG reference as the source for hospital group B streptococcal disease prevention policy was associated with fewer cases of group B streptococcal disease (P = .038). CONCLUSION: The publication and adoption of the guidelines were associated with decreasing occurrence of group B streptococcal disease.

The accuracy of late antenatal screening cultures in predicting genital group B streptococcal colonization at delivery.

OBJECTIVE: To determine the accuracy of late antenatal anogenital cultures in predicting group B streptococcal colonization at delivery. METHODS: Swabs of the vagina and rectum were obtained from 826 women during routine prenatal visits at approximately 35-36 weeks' estimated gestation. The same women were recultured at admission for delivery. Swabs were cultured in broth media. Test performance indices were calculated using culture status at the time of delivery as the reference. Based on the sensitivity and specificity of antenatal cultures derived from analysis of this study population, we estimated predictive values of late antenatal cultures for a range of group B streptococcal carriage rates. RESULTS: Group B streptococci were identified in specimens from 219 of 826 women (26.5%). The sensitivity of late antenatal cultures for identifying colonization status at delivery was 87% (95% confidence interval [95% CI] 83-92). Specificity was 96% (95% CI 95-98). Positive predictive value was 87% (95% CI 83-92), and negative predictive value was 96% (95% CI 95-98). Test performance was similar from 1-5 weeks before delivery, but declined when 6 or more weeks had elapsed between the antenatal culture and delivery. Among patients cultured 6 or more weeks before delivery, sensitivity was only 43%, specificity 85%, and positive and negative predictive values were 50 and 81%, respectively. We estimated positive and negative predictive values of 85 and 97% for a colonization rate of 20%, and 79 and 98% for a colonization rate of 15%. CONCLUSION: Anogenital cultures in broth media obtained during the late antenatal period are accurate in predicting group B streptococcal colonization status at delivery in term parturients, and they perform significantly (P < .01) better than cultures collected 6 or more weeks before delivery.

Prevention practices for perinatal group B streptococcal disease: a multi-state surveillance analysis. Neonatal Group B Streptococcal Disease Study Group.

OBJECTIVE: To evaluate hospital-based practices for perinatal group B streptococcal disease prevention and to identify institutional factors related to the disease. METHODS: We surveyed microbiology laboratories and obstetric programs during 1994 at hospitals in five states with active surveillance for invasive group B streptococcal disease. Institutions provided information on methods for detecting carriers and on obstetric policies for group B streptococcal disease prevention. We used linear regression to identify prevention practices and hospital characteristics that correlated with the number of cases of early-onset disease. RESULTS: Of 295 hospitals, 247 (84%) laboratories and 154 (52%) obstetric programs completed the survey. Most (83%) laboratories performed group B streptococcal cultures on rectal and vaginal specimens, but only 12 (6%) used selective broth media. Among the obstetric programs, 54 (35%) had policies on some aspect of group B streptococcal disease prevention. Of the hospitals with policies, 21 (48%) recommended intrapartum antimicrobial prophylaxis for women with risk factors outlined by the 1992 ACOG statement. Adjusting for the number of births, there were more cases of early-onset group B streptococcal disease in institutions providing care for more African American women and for more women with no prenatal care. Institutions that had group B streptococcal screening policies had fewer early-onset cases. CONCLUSIONS: Many institutions with prevention policies followed practices that differed from those recommended in published prevention statements. Having any screening policy, however, was associated with reduced early-onset disease, independent of the risk profile of the patient population. Adopting prevention policies is most urgent for practices serving individuals at increased risk, such as African American women and women without prenatal care.

Prevention of perinatal group B streptococcal infection: current controversies.

Group B streptococcus (GBS) is the most frequent cause of neonatal sepsis in the United States. The Centers for Disease Control and Prevention (CDC) issued guidelines for its prevention in 1996. This article details areas of controversy with those guidelines and offers recommendations for resolution. We recommend that a prevention policy be adopted by all hospitals. If a screening-based policy is chosen, compliance is essential. Penicillin is the antibiotic of choice for GBS prevention. Increasing resistance to clindamycin and erythromycin might eliminate them as alternative choices in patients allergic to penicillin. Group B streptococcal prophylaxis might not be necessary in women who have repeat elective cesarean delivery. In asymptomatic women, a positive urine culture for GBS should be considered clinically equivalent to a positive vaginal or rectal sample for screening. Neonatal sepsis caused by organisms other than GBS must be monitored carefully by all hospitals providing obstetrics services.

Group B streptococcal disease prevention practices of obstetrician-gynecologists.

OBJECTIVE: To describe group B streptococcal (GBS) disease prevention practices of obstetrician-gynecologists. METHODS: We surveyed 1019 ACOG Fellows-the 419 members of the Collaborative Ambulatory Research Network (CARN) and 600 randomly selected non-CARN Fellows. RESULTS: There were 601 eligible respondents. More than 95% in both the CARN and the non-CARN groups reported adopting one of three GBS prevention strategies. The most commonly reported strategy was a combination approach not described in the consensus guidelines. The second most common strategy was the screening-based strategy; the risk-based strategy was third. Most respondents provided GBS information to all prenatal patients, but those using a risk-based strategy and those in solo practice were less likely to do so. Less than 60% in each group used penicillin as their first choice for GBS prophylaxis. More than 20% in each group who routinely screened for GBS did not collect both vaginal and rectal cultures. Respondents rated ACOG publications as the most important influence on their GBS prevention approach. CONCLUSION: Almost all ACOG Fellows have adopted a GBS prevention strategy. The importance of providing GBS prevention information to all patients, use of penicillin, and collection of both vaginal and rectal cultures should be reinforced.

Response to conjugate Haemophilus influenzae B vaccine among infants in Niamey, Niger.

Despite near elimination of Haemophilus influenzae b (Hib) meningitis from several industrialized countries following introduction of conjugate Hib vaccines into infant immunization schedules, Hib remains a major cause of meningitis and pneumonia in resource-poor countries. In Niger, Hib causes nearly 200 cases of meningitis per 100,000 children < one year of age, and > 40% of cases are fatal. We evaluated the immunogenicity of Hib polysaccharide-tetanus toxoid conjugate vaccine (PRP-T) administered in the same syringe as diphtheria-tetanus-pertussis (DTP) vaccine among infants in Niger. Infants were randomized into group 1 (PRP-T at six, 10, and 14 weeks), group 2 (PRP-T at 10 and 14 weeks), or a control group (meningococcal A/C polysaccharide vaccine). By 14 weeks of age, all subjects in groups land 2 had > or = 0.15 microg/ml of anti-PRP antibody, and 82% versus 76% had > or = 1.0 microg/ml of antibody (P=not significant). By nine months of age the proportion of infants with > or = 0.15 and > or = 1.0 microg/ml was group I=97% and 76%; group 2=93% and 67%; controls=10% and 2.6%. Four weeks after the first, second, and third doses of PRP-T, infants in group 1 showed geometric mean titers (GMTs) of 0.19, 3.97, and 6.09 microg/ml while infants in group 2 had GMTs of 2.40 and 4.41 microg/ml four weeks after the delayed first and second doses. Both PRP-T groups had significantly higher GMTs at 18 weeks and nine months of age than infants in the control group. The Hib PRP-T vaccine was immunogenic in infants in Niger. The strong response after PRP-T was initiated one month after the first DTP vaccination may reflect carrier priming. Two dose schedules of PRP-T should be given serious consideration, particularly if their reduced cost permits vaccine introduction that would be otherwise unaffordable.