Estimating the vaccine-preventable burden of hospitalized pneumonia among young Mozambican children

Polysaccharide-protein conjugate vaccines against Haemophilus influenzae type b (Hib) and Streptococcus pneumoniae have proven efficacy against radiologically confirmed pneumonia. Measurement of pneumonia incidence provides a platform to estimate of the vaccine-preventable burden. Over 24 months, we conducted surveillance for radiologically confirmed severe pneumonia episodes among children <2 years of age admitted to a rural hospital in Manhiça, southern Mozambique. Study children were tested for HIV during the second year of surveillance. Severe pneumonia accounted for 15% of 5132 hospital admissions and 32% of in-hospital mortality among children <2 years of age. Also, 43% of chest radiographs were interpreted as radiologically confirmed pneumonia. HIV-infection was associated with 81% of fatal pneumonia episodes among children tested for HIV. The minimum incidence rate of radiologically confirmed pneumonia requiring hospitalization was 19 episodes/1000 child-years. Incidence rates among HIV-infected children were 9.3-19.0-fold higher than HIV-uninfected. Introduction of Hib and pneumococcal conjugate vaccines would have a substantial impact on pneumonia hospitalizations among African children if vaccine effects are similar to those observed in clinical trials.

Impact of conjugate Haemophilus influenzae type b (Hib) vaccine introduction in South Africa

OBJECTIVE

To analyse trends in reported invasive Haemophilus influenzae disease in South Africa within the first five years of introduction of conjugate Haemophilus influenzae type b (Hib) vaccine in the routine child immunization schedule.

METHODS

We used national laboratory-based surveillance data to identify cases of invasive H. influenzae disease between July 1999 and June 2004, and submitted isolates for serotyping and antimicrobial susceptibility testing.

FINDINGS

The absolute number of Hib cases (reported to the national surveillance system) among children below one year of age decreased by 65%, from 55 cases in 1999-2000 to 19 cases in 2003-04. Enhanced surveillance initiated in 2003, identified human immunodeficiency virus (HIV)-infection and incomplete vaccination as contributing factors for Hib transmission. The total number of laboratory-confirmed cases of H. influenzae remained unchanged because non-type b disease was being increasingly reported to the surveillance system concomitant with system enhancements. Children with non-typable disease were more likely to be HIV-positive (32 of 34, 94%) than children with Hib disease (10 of 14, 71%), P = 0.051. Recent Hib isolates were more likely to be multidrug resistant (2% in 1999-2000 versus 19% in 2003-04, P = 0.001).

CONCLUSION

Data from a newly established national laboratory-based surveillance system showed a decrease in Hib disease burden among South African children following conjugate vaccine introduction and identified cases of non-typable disease associated with HIV infection.

Immunogenicity, safety, and memory of different schedules of Neisseria meningitidis A/C-diphtheria toxoid conjugate vaccine in infants in Niger

We studied one to four doses of meningococcal polysaccharides A and C conjugated to diphtheria toxoid (Men D) versus A/C polysaccharide (Men PS) vaccine in 618 infants in Niger. Men PS at 24 months permitted evaluating memory. Two Men D doses (at 3 and 9 months) induced higher serum bactericidal activity (SBA) than other regimens. SBA titers after Men PS at 24 months were higher in those given Men D in infancy versus Men PS. While responses were lower for serogroup C, hyporesponsiveness was not evident. Men D was well-tolerated. A single Men D dose in infancy appeared to induce memory.

Multistate evaluation of invasive pneumococcal diseases in adults with human immunodeficiency virus infection: serotype and antimicrobial resistance patterns in the United States

Persons with acquired immunodeficiency syndrome (AIDS) have a higher incidence of invasive pneumococcal disease (IPD) than other adults, and many receive long-term trimethoprim-sulfamethoxazole (TMP-SMZ) prophylactic therapy. We used 1998-1999 data from the Active Bacterial Core surveillance of the Emerging Infections Program Network to compare IPD infections between adults aged 18-64 years with human immunodeficiency virus (HIV) infection and other adults. Of 2346 patients with IPD, 416 (18%) had HIV or AIDS (HIV/AIDS). Certain serotypes (serotypes 6A, 6B, 9N, 9V, 18C, 19A, 19F, and 23F) were more common among patients with HIV/AIDS than in adults with no underlying disease (P<.05, vs. serotype 4), even when TMP-SMZ-nonsusceptible isolates were excluded. HIV/AIDS (adjusted odds ratio [aOR], 1.93; 95% confidence interval [CI], 1.44-2.59), immunocompromising conditions other than HIV/AIDS (aOR, 1.56; 95% CI, 1.12-2.18), and black race (aOR, 1.50; 95% CI, 1.20-1.88) were independent risk factors for infection with these serotypes. HIV/AIDS was not an independent risk factor for TMP-SMZ nonsusceptibility. Vulnerability to certain serotypes among adults with HIV/AIDS may have implications in prevention strategies.

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.

Early-onset neonatal sepsis in the era of group B streptococcal prevention

OBJECTIVE

To determine whether intrapartum antibiotic prophylaxis for neonatal group B streptococcal (GBS) disease has resulted in an increased rate of non-GBS or antibiotic-resistant early-onset invasive neonatal disease.

METHODS

Maternal and infant chart review of all infants with bacteria other than GBS isolated from blood or spinal fluid in 1996 through 1999 in 19 hospitals (representing 81% of in-state births to state residents) throughout Connecticut. Suspected cases were identified through clinical microbiology laboratory records or through International Classification of Diseases, Ninth Revision codes when microbiology records were incomplete.

RESULTS

Ninety-four cases of non-GBS early-onset sepsis or meningitis were detected between 1996 and 1999. The rate of GBS-related early-onset infection (days 0-6 of life) dropped from 0.61/1000 to 0.23/1000 births, but the annual rate of non-GBS sepsis remained steady, ranging from 0.65 to 0.68/1000 during the surveillance period. There was an increase in the proportion of Escherichia coli infections that were ampicillin resistant between 1996 and 1998, but the proportion decreased. in 1999

CONCLUSION

There was no increase in the incidence of non-GBS early-onset neonatal infections between 1996 and 1999. Fluctuations in the annual incidence of E coli infections, including ampicillin-resistant infections, suggest the need for continuation of surveillance in Connecticut and expansion to monitor larger populations.

Clinical outcomes of bacteremic pneumococcal pneumonia in the era of antibiotic resistance

Limited data are available about the impact of antimicrobial resistance on clinical outcomes in cases of pneumococcal pneumonia. This was studied in 146 persons hospitalized with invasive pneumonia due to Streptococcus pneumoniae (minimum inhibitory concentration of cefotaxime, > or = .25 microg/mL) who were identified through population-based active surveillance for the period of November 1994 through April 1996. Compared with matched control subjects who had infection with more-susceptible S. pneumoniae, the proportion of subjects who died or who were admitted to an intensive care unit did not differ significantly. Multivariable analysis showed no significant contribution of antimicrobial resistance to mortality or the requirement for care in an intensive care unit. The ability to detect an effect of antimicrobial resistance on these important outcome measures may have been influenced by aggressive multidrug empirical therapy in this group of hospitalized patients. Factors other than resistance, such as severity of illness at presentation and advance directive status ("do not resuscitate" orders), appear to have a stronger influence on pneumococcal pneumonia outcomes.

Group B streptococcal disease: from trials and tribulations to triumph and trepidation

Group B streptococci garnered attention during the 1970s when they surpassed Escherichia coli and Staphylococcus aureus to become the principal causes of sepsis in early infancy. During the 1980s, several clinical trials demonstrated that administration of antimicrobial agents during labor could interrupt vertical transmission and prevent invasive disease in the first week of life (i.e., early-onset disease). However, prophylaxis was not widely used during the next 10 years. On the basis of efforts by clinician-researchers, professional organizations, community-based parent advocacy groups, and the public health community, consensus recommendations for group B streptococcal prophylaxis were finally issued in 1996. By the end of 1999, the incidence of early-onset disease in selected counties within the United States had decreased by 70%, and the gap between black and white persons with disease narrowed by 75%. This recent triumph leaves the professional community treading lightly, alert to the need to monitor for unintended consequences that may threaten recent progress.

Surveillance for meningococcal disease and strategies for use of conjugate meningococcal vaccines in the United States

BACKGROUND

Neisseria meningitidis is a leading cause of bacterial meningitis in US; new capsular type-specific conjugate vaccines offer an opportunity for improved control of meningococcal disease. We evaluated the relative burdens of invasive meningococcal disease in US and examined the projected impact of various meningococcal conjugate vaccination strategies on rates of meningococcal disease.

METHODS

Meningococcal disease incidence rates were determined from active, population-based surveillance in selected US areas. Models were created to determine impact of vaccination of infants, toddlers, adolescents or college students with meningococcal conjugate vaccines, with assumptions for vaccine coverage, efficacy and duration of protection. Although we examined possible conjugate vaccine formulations including serogroups A, C, Y and W-135, the final vaccine impact analysis excluded serogroups A and W-135. Outcome measures were cumulative meningococcal disease incidence, and incidence 10 years after initiating vaccination among 0-22-year-olds.

RESULTS

In models of serogroup C+Y meningococcal conjugate vaccination of infants, toddlers and adolescents, the cumulative incidence of meningococcal disease was reduced by 54, 48 and 25%, respectively; the toddler strategy had the greatest impact per dose. After 10 years of routine meningococcal conjugate vaccination, meningococcal disease could be reduced by 50% and deaths by 64%.

CONCLUSIONS

Use of meningococcal conjugate vaccine could markedly reduce meningococcal disease incidence. Our data, along with vaccine formulation and vaccination program considerations, will be important in determining the optimal choice of vaccination strategy.

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.

Epidemiology of invasive Streptococcus pneumoniae infections in the United States, 1995-1998: Opportunities for prevention in the conjugate vaccine era

CONTEXT

Pneumococcal polysaccharide vaccine is recommended for elderly persons and adults with certain chronic illnesses. Additionally, a recently licensed pneumococcal 7-valent conjugate vaccine has been recommended for use in young children and could dramatically change the epidemiology of pneumococcal disease.

OBJECTIVES

To assess pneumococcal disease burden in the United States, estimate the potential impact of new vaccines, and identify gaps in vaccine recommendations.

DESIGN AND SETTING

Analysis of data from the Active Bacterial Core Surveillance (ABCs)/Emerging Infections Program Network, an active, population-based system in 9 states.

PATIENTS

A total of 15 860 cases of invasive pneumococcal disease occurring between January 1, 1995, and December 31, 1998.

MAIN OUTCOME MEASURES

Age- and race-specific pneumoccocal disease incidence rates per 100 000 persons, case-fatality rates, and vaccine preventability.

RESULTS

In 1998, overall incidence was 23.2 cases per 100 000, corresponding to an estimated 62 840 cases in the United States. Incidence was highest among children younger than 2 years (166.9) and adults aged 65 years or older (59.7). Incidence among blacks was 2.6 times higher than among whites (95% confidence interval [CI], 2.4-2.8). Overall, 28.6% of case-patients were at least 65 years old and 85.9% of cases in this age group were due to serotypes included in the 23-valent polysaccharide vaccine; 19.3% of case-patients were younger than 2 years and 82.2% of cases in this age group were due to serotypes included in the 7-valent conjugate vaccine. Among patients aged 2 to 64 years, 50.6% had a vaccine indication as defined by the Advisory Committee on Immunization Practices (ACIP). The case-fatality rate among patients aged 18 to 64 years with an ACIP indication was 12.1% compared with 5.4% for those without an indication (relative risk, 2.2; 95% CI, 1.7-2.9).

CONCLUSIONS

Young children, elderly persons, and black persons of all ages are disproportionately affected by invasive pneumococcal disease. Current ACIP recommendations do not address a subset of persons aged 18 to 64 years but do include those at highest risk for death from invasive pneumococcal disease.

Invasive group B streptococcal disease in Maryland nursing home residents

Between 1991 and 1995, among 999 nonpregnant adult Maryland residents with group B Streptococcus (GBS) isolated from a normally sterile site, 84 resided in nursing homes (NHs). The age-adjusted annual incidence of GBS infection (per 100,000 population) among those > or = 65 years old was 72.3 for NH residents and 17.5 for community residents (relative risk, 4.1; P < 0.001). Thirty-four case patients resided in 11 NHs with > or = 2 cases; 1 NH had 8 case patients within 22 months. Six of 8 case patients from 3 NHs had serotype V GBS. Molecular subtyping of several isolates identified 2 case patients in 1 NH with identical subtype patterns. NH residents have a markedly higher incidence of invasive GBS than do community residents > or = 65 years old and may serve as a target group for immunization when GBS vaccines become available. Further evaluation of intra-NH transmission of GBS is warranted.

Introduction of the new Centers for Disease Control and Prevention group B streptococcal prevention guideline at a large West Coast health maintenance organization

OBJECTIVE

Our purpose was to assess the impact of new consensus guidelines issued by the Centers for Disease Control and Prevention, The American College of Obstetricians and Gynecologists, and the American Academy of Pediatrics to prevent perinatal group B streptococcal disease.

STUDY DESIGN

We performed a descriptive analysis and a before-and-after analysis of implementation of the group B streptococcal disease prevention guidelines among singleton-birth pregnancies in 2 Group Health Cooperative hospitals from October 1, 1995, through December 31, 1997. We studied the speed and completeness of implementation and the effect on pregnancy care practices including intrapartum antibiotic use, test ordering, and maternal and neonatal health.

RESULTS

Guideline implementation occurred rapidly. The proportion of term pregnancies screened according to the guideline increased markedly, and overall intrapartum antibiotic use more than doubled. Among group B streptococci-positive women, intrapartum antibiotic prophylaxis increased from 24% before to 74% after guideline implementation. Median duration of treatment before delivery increased from 1.8 to 4.3 hours. The rate of rash did not increase, and there were no cases of anaphylaxis or pseudomembranous colitis. The proportion of infants undergoing evaluation decreased after implementation of the neonatal guidelines; among infants of group B streptococci-negative women, test ordering dropped by almost 40%.

CONCLUSIONS

Implementation of the new guidelines is feasible and can be accomplished rapidly. The guidelines were associated with increased maternal intrapartum antibiotic use, particularly among women at highest risk, and with a decrease in laboratory use for infants.

Physicians' prevention practices and incidence of neonatal group B streptococcal disease in 2 Canadian regions

BACKGROUND

The impact of expert guidelines on the prevention of neonatal group B streptococcal (GBS) disease has not been studied in Canada. Our aim was to determine physician practices with regard to this condition before and after publication of Canadian guidelines and to monitor concurrent trends in the incidence of neonatal GBS disease.

METHODS

We used repeat cross-sectional surveys, distributed by mail to all family practitioners and obstetricians attending deliveries in Alberta and in the Metropolitan Toronto and Peel region, Ontario, in 1994, 1995 and 1997, to document prevention practices. Audits were conducted for a subset of respondents to confirm reported practices. Population-based surveillance involving all microbiology laboratories in both regions for 1995-1998 was used to document rates of neonatal disease.

RESULTS

The overall survey response rates were as follows: for 1994, 1128/1458 (77%); for 1995, 1054/1450 (73%); and for 1997, 1030/1421 (72%). During 1995 and 1997, significantly more obstetric care providers were screening at least 75% of pregnant women in their practices than had been the case in 1994 (747/916 [82%] and 693/812 [85%] v. 754/981 [77%]; p < 0.001). The percentage of obstetric care providers who reported practice that conformed completely with any of 3 consensus prevention strategies increased from 10% in 1994 to 29% in 1997 (p < 0.001). There was a concurrent overall significant decrease in incidence of neonatal GBS disease during the same period.

INTERPRETATION

The adoption by Canadian obstetric care providers of neonatal GBS prevention practices recommended by expert groups was slow but improved significantly over time. These findings highlight the difficulties associated with achieving compliance with diverse and frequently changing recommendations. However, the associated incidence of neonatal GBS disease, which was low or declining, suggests that efforts to disseminate current GBS prevention guidelines have been moderately successful.

Association between colonization with group B streptococci during pregnancy and preterm delivery among Danish women

OBJECTIVE

We studied the relationship between group B streptococcal colonization and preterm delivery.

STUDY DESIGN

In this prospective study at a single hospital in Odense, Denmark, cervicovaginal cultures were obtained at < or = 24 weeks' gestation from all the women, at delivery from women with preterm deliveries, and from a random sample of women delivering at term.

RESULTS

In 2846 singleton births, there was no significant association between group B streptococcal colonization at <or = 24 weeks' gestation and preterm birth. After adjustment for the risk factors for preterm delivery, more women with preterm delivery (12/84, 14%) were colonized at delivery with group B streptococci than women with term deliveries (22/300, 7%; adjusted odds ratio, 3.0; 95% confidence interval, 1.4-6.8). Group B streptococcal colonization at < or = 24 weeks' gestation and at delivery was significantly less likely to occur in the presence of normal vaginal flora.

CONCLUSION

Group B streptococcal colonization at delivery, but not at < or = 24 weeks' gestation, was associated with preterm delivery.

Active bacterial core surveillance of the emerging infections program network

Active Bacterial Core surveillance (ABCs) is a collaboration between the Centers for Disease Control and Prevention and several state health departments and universities participating in the Emerging Infections Program Network. ABCs conducts population-based active surveillance, collects isolates, and performs studies of invasive disease caused by Streptococcus pneumoniae, group A and group B Streptococcus, Neisseria meningitidis, and Haemophilus influenzae for a population of 17 to 30 million. These pathogens caused an estimated 97,000 invasive cases, resulting in 10,000 deaths in the United States in 1998. Incidence rates of these pathogens are described. During 1998, 25% of invasive pneumococcal infections in ABCs areas were not susceptible to penicillin, and 13.3% were not susceptible to three classes of antibiotics. In 1998, early-onset group B streptococcal disease had declined by 65% over the previous 6 years. More information on ABCs is available at www.cdc.gov/ncidod/dbmd/abcs. ABCs specimens will soon be available to researchers through an archive.

Increasing prevalence of multidrug-resistant Streptococcus pneumoniae in the United States

BACKGROUND

The emergence of drug-resistant strains of bacteria has complicated treatment decisions and may lead to treatment failures.

METHODS

We examined data on invasive pneumococcal disease in patients identified from 1995 to 1998 in the Active Bacterial Core Surveillance program of the Centers for Disease Control and Prevention. Pneumococci that had a high level of resistance or had intermediate resistance according to the definitions of the National Committee for Clinical Laboratory Standards were defined as "resistant" for this analysis.

RESULTS

During 1998, 4013 cases of invasive Streptococcus pneumoniae disease were reported (23 cases per 100,000 population); isolates were available for 3475 (87 percent). Overall, 24 percent of isolates from 1998 were resistant to penicillin. The proportion of isolates that were resistant to penicillin was highest in Georgia (33 percent) and Tennessee (35 percent), in children under five years of age (32 percent, vs. 21 percent for persons five or more years of age), and in whites (26 percent, vs. 22 percent for blacks). Penicillin-resistant isolates were more likely than susceptible isolates to have a high level of resistance to other antimicrobial agents. Serotypes included in the 7-valent conjugate and 23-valent pneumococcal polysaccharide vaccines accounted for 78 percent and 88 percent of penicillin-resistant strains, respectively. Between 1995 and 1998 (during which period 12,045 isolates were collected), the proportion of isolates that were resistant to three or more classes of drugs increased from 9 percent to 14 percent; there also were increases in the proportions of isolates that were resistant to penicillin (from 21 percent to 25 percent), cefotaxime (from 10 percent to 15 percent), meropenem (from 10 percent to 16 percent), erythromycin (from 11 percent to 16 percent), and trimethoprim-sulfamethoxazole (from 25 percent to 29 percent). The increases in the frequency of resistance to other antimicrobial agents occurred exclusively among penicillin-resistant isolates.

CONCLUSIONS

Multidrug-resistant pneumococci are common and are increasing. Because a limited number of serotypes account for most infections with drug-resistant strains, the new conjugate vaccines offer protection against most drug-resistant strains of S. pneumoniae.

The emergence of Streptococcus pneumoniae resistant to macrolide antimicrobial agents: a 6-year population-based assessment

From 1994 through 1999, the available isolates (4148 isolates) from active population-based surveillance of invasive pneumococcal disease in metropolitan Atlanta were serotyped and were tested for antimicrobial susceptibility. Macrolide-resistant isolates were studied for the presence of ermAM (a ribosomal methylase gene), mefE (a macrolide efflux gene), and tetM (the class M tetracycline resistance gene). Macrolide resistance increased from 16% of all invasive isolates in 1994 to 32% in 1999. Of the macrolide-resistant pneumococcal isolates studied, 99% contained genomic copies of mefE or ermAM. Isolates with ermAM were mainly serotypes 6B, 23F, 14, or 19F and contained tetM; mefE-associated isolates were predominantly serotypes 14, 6A, or 19F, and most did not contain tetM. The frequency of the ermAM-mediated phenotype in invasive Streptococcus pneumoniae remained stable over the 6-year surveillance. However, the mefE-mediated phenotype increased from 9% in 1994 to 26% of all isolates in 1999 and was noted in new serotypes. By 1999, 93% of the mefE-containing strains had minimum inhibitory concentrations >/=8 microgram/mL. Dissemination of the mefE determinant accounted for the rapid increase in the rate of macrolide resistance in our S. pneumoniae 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.

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.

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.

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.

Epidemic nephritis in Nova Serrana, Brazil

BACKGROUND

Outbreaks of nephritis have been rare since the 1970s. From December, 1997, to July, 1998, 253 cases of acute nephritis were identified in Nova Serrana, Brazil. Seven patients required dialysis, and three patients died. We did a case-control study to investigate the cause of the outbreak.

METHODS

Using a matched cluster design, we examined seven recent patients, their family members (n=23), and members of neighbourhood-matched control households (n=22). We subsequently interviewed 50 patients and 50 matched controls about exposure to various dairy products. We also cultured dairy foods and took udder-swab and milk samples from cows.

FINDINGS

Throat cultures indicated that nephritis was associated with group C Streptococcus equi subspecies zooepidemicus, a cause of bovine mastitis. S. zooepidemicus was detected in four of seven case households (six of 30 people) and no control households (p=0.09). Patients were more likely than matched controls to have consumed a locally produced cheese called queijo fresco (matched odds ratio 2.1, p=0.05). The nephritis attack rate was 4.5 per 1000 in Nova Serrana but 18 per 1000 in the village Quilombo do Gaia (p=0.003). The largest supplier of unpasteurized queijo fresco was a farm in Quilombo do Gaia. S. zooepidemicus was not detected in food samples or in swabs collected from cows in August, 1998, although mastitis was evident among cows on the suspected farm. Throat cultures of the two women who prepared cheese on this farm yielded the outbreak strain of S. zooepidemicus. After the cheese was removed from the distribution system, no further cases were reported.

INTERPRETATION

A large outbreak of glomerulonephritis was attributed to S. zooepidemicus in unpasteurised cheese. This outbreak highlights the dangers of consuming unpasteurized dairy products and need for global efforts to promote food safety.

Epidemiology of pneumococcal infections in the elderly

The risk of invasive Streptococcus pneumoniae infection (primarily bacteraemia and meningitis) is greatest among the very young and the very old. Persons in certain racial groups, including African-Americans, American Indians, Native Alaskans and Australian Aborigines, are also at increased risk of disease. Other factors that appear to increase the risk of pneumococcal infection are lower socioeconomic status, recent infection with influenza and possibly other viral respiratory tract infections, chronic medical conditions, and immunosuppressive medications. Reported annual incidences of invasive pneumococcal disease among persons aged > or = 65 years in North America and Europe range from 25 to 90 cases/100,000 persons. In the US and Canada, these rates represent between 15,000 and 30,000 cases annually among the elderly. Mortality caused by pneumococcal infections is highest among the elderly, with nearly 1 in 5 cases resulting in death. Worldwide, S. pneumoniae is the leading cause of community-acquired pneumonia requiring hospitalisation. The high fatality rates, as well as recent outbreaks of pneumococcal infection among unvaccinated nursing home residents and the emergence of drug-resistant pneumococcal strains, highlight the importance of preventing invasive infection by vaccination.

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.

Mortality from invasive pneumococcal pneumonia in the era of antibiotic resistance, 1995-1997

OBJECTIVES

This study examined epidemiologic factors affecting mortality from pneumococcal pneumonia in 1995 through 1997.

METHODS

Persons residing in a surveillance area who had community-acquired pneumonia requiring hospitalization and Streptococcus pneumoniae isolated from a sterile site were included in the analysis. Factors affecting mortality were evaluated in univariate and multivariate analyses. The number of deaths from pneumococcal pneumonia requiring hospitalization in the United States in 1996 was estimated.

RESULTS

Of 5837 cases, 12% were fatal. Increased mortality was associated with older age, underlying disease. Asian race, and residence in Toronto/Peel, Ontario. When these factors were controlled for, increased mortality was not associated with resistance to penicillin or cefotaxime. However, when deaths during the first 4 hospital days were excluded, mortality was significantly associated with penicillin minimum inhibitory concentrations of 4.0 or higher and cefotaxime minimum inhibitory concentrations of 2.0 or higher. In 1996, about 7000 to 12,500 deaths occurred in the United States from pneumococcal pneumonia requiring hospitalization.

CONCLUSIONS

Older age and underlying disease remain the most important factors influencing death from pneumococcal pneumonia. Mortality was not elevated in most infections with beta-lactam-resistant pneumococci.

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.

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.

Group B streptococcal disease in the era of intrapartum antibiotic prophylaxis

BACKGROUND

Group B streptococcal infections are a leading cause of neonatal mortality, and they also affect pregnant women and the elderly. Many cases of the disease in newborns can be prevented by the administration of prophylactic intrapartum antibiotics. In the 1990s, prevention efforts increased. In 1996, consensus guidelines recommended use of either a risk-based or a screening-based approach to identify candidates for intrapartum antibiotics. To assess the effects of the preventive efforts, we analyzed trends in the incidence of group B streptococcal disease from 1993 to 1998.

METHODS

Active, population-based surveillance was conducted in selected counties of eight states. A case was defined by the isolation of group B streptococci from a normally sterile site. Census and live-birth data were used to calculate the race-specific incidence of disease; national projections were adjusted for race.

RESULTS

Disease in infants less than seven days old accounted for 20 percent of all 7867 group B streptococcal infections. The incidence of early-onset neonatal infections decreased by 65 percent, from 1.7 per 1000 live births in 1993 to 0.6 per 1000 in 1998. The excess incidence of early-onset disease in black infants, as compared with white infants, decreased by 75 percent. Projecting our findings to the entire United States, we estimate that 3900 early-onset infections and 200 neonatal deaths were prevented in 1998 by the use of intrapartum antibiotics. Among pregnant girls and women, the incidence of invasive group B streptococcal disease declined by 21 percent. The incidence among nonpregnant adults did not decline.

CONCLUSIONS

Over a six-year period, there has been a substantial decline in the incidence of group B streptococcal disease in newborns, including a major reduction in the excess incidence of these infections in black infants. These improvements coincide with the efforts to prevent perinatal disease by the wider use of prophylactic intrapartum antibiotics.

Clinical outcomes of meningitis caused by Streptococcus pneumoniae in the era of antibiotic resistance

Limited data are available on clinical outcomes of meningitis due to cefotaxime-nonsusceptible Streptococcus pneumoniae. We analyzed data from 109 cases of pneumococcal meningitis in Atlanta, Baltimore, and San Antonio, which were identified through population-based active surveillance from November 1994 to April 1996. Pneumococcal isolates from 9% of the cases were resistant to cefotaxime, and isolates from 11% had intermediate susceptibility. Children were more likely to have cephalosporin-nonsusceptible pneumococcal meningitis, but mortality was significantly higher among adults aged 18-64 years. Vancomycin was given upon admission to 29% of patients, and within 48 h of admission to 52%. Nonsusceptibility to cefotaxime was not associated with the following outcomes: increased mortality, prolonged length of hospital or intensive care unit (ICU) stay, requirement of intubation or oxygen, ICU care, discharge to another medical or long-term-care facility, or neurological deficit. Empirical use of vancomycin, current prevalence of drug-resistant S. pneumoniae, and degree of nonsusceptibility to cefotaxime may have influenced these findings.

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.

The changing epidemiology of meningococcal disease in the United States, 1992-1996

New meningococcal vaccines are undergoing clinical trials, and changes in the epidemiologic features of meningococcal disease will affect their use. Active laboratory-based, population-based US surveillance for meningococcal disease during 1992-1996 was used to project that 2400 cases of meningococcal disease occurred annually. Incidence was highest in infants; however, 32% of cases occurred in persons >/=30 years of age. Serogroup C caused 35% of cases; serogroup B, 32%; and serogroup Y, 26%. Increasing age (relative risk [RR], 1.01 per year), having an isolate obtained from blood (RR, 4.5), and serogroup C (RR, 1.6) were associated with increased case fatality. Among serogroup B isolates, the most commonly expressed serosubtype was P1.15; 68% of isolates expressed 1 of the 6 most common serosubtypes. Compared with cases occurring in previous years, recent cases are more likely to be caused by serogroup Y and to occur among older age groups. Ongoing surveillance is necessary to determine the stability of serogroup and serosubtype distribution.

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.

Outbreaks of salmonellosis associated with eating uncooked tomatoes: implications for public health. The Investigation Team

Laboratory-based surveillance of salmonella isolates serotyped at four state health departments (Illinois, Michigan, Minnesota and Wisconsin) led to the identification of multistate outbreaks of salmonella infections during 1990 (176 cases of S. javiana) and 1993 (100 cases of S. montevideo). Community-based case-control studies and product traceback implicated consumption of tomatoes from a single South Carolina tomato packer (Packer A) MOR 16.0; 95% CI2.1, 120.6; P < 0.0001 in 1990 and again in 1993 (MOR 5.7; 95 % CI 1.5, 21.9; P = 0.01) as the likely vehicle. Contamination likely occurred at the packing shed, where field grown tomatoes were dumped into a common water bath. These outbreaks represent part of a growing trend of large geographically dispersed outbreaks caused by sporadic or low-level contamination of widely distributed food items. Controlling contamination of agricultural commodities that are also ready-to-eat foods, particularly fruits and vegetables, presents a major challenge to industry, regulators and public health officials.

Cryptococcosis: population-based multistate active surveillance and risk factors in human immunodeficiency virus-infected persons. Cryptococcal Active Surveillance Group

To determine the incidence of cryptococcosis and its risk factors among human immunodeficiency virus (HIV)-infected persons, population-based active surveillance was conducted in four US areas (population, 12.5 million) during 1992-1994, and a case-control study was done. Of 1083 cases, 931 (86%) occurred in HIV-infected persons. The annual incidence of cryptococcosis per 1000 among persons living with AIDS ranged from 17 (San Francisco, 1994) to 66 (Atlanta, 1992) and decreased significantly in these cities during 1992-1994. Among non-HIV-infected persons, the annual incidence of cryptococcosis ranged from 0.2 to 0.9/100,000. Multivariate analysis of the case-control study (158 cases and 423 controls) revealed smoking and outdoor occupations to be significantly associated with an increased risk of cryptococcosis; receiving fluconazole within 3 months before enrollment was associated with a decreased risk for cryptococcosis. Further studies are needed to better describe persons with AIDS currently developing cryptococcosis in the era of highly active antiretroviral therapy.

Group B streptococcus

During the 1990s the focus of group B streptococcus (GBS) disease research has shifted to prevention. Increased use of intrapartum antimicrobial prophylaxis in North America and Australia has led to substantial declines in perinatal disease. Vaccine development (initiated two decades earlier) has yielded results--for example, polysaccharide-protein conjugate vaccines given to women of reproductive age proved to be highly immunogenic and well tolerated. Also economic evaluations have assessed the cost-effectiveness of prevention strategies in different populations. Although GBS has traditionally been considered a perinatal pathogen, the burden of invasive GBS disease among nonpregnant adults has been measured. Adverse outcomes of pregnancy attributable to GBS were addressed through a multicentre study which confirmed the important role of heavy colonisation with GBS in preterm low-birthweight deliveries. Finally, the pathogen itself has continued to evolve: new capsular serotypes described in the past decade are now causing an important proportion of clinical infections.

Epidemiology of bacterial meningitis in Niamey, Niger, 1981-96

In the African meningitis belt the importance of endemic meningitis is not as well recognized as that of epidemics of meningococcal meningitis that occur from time to time. Using retrospective surveillance, we identified a total of 7078 cases of laboratory-diagnosed bacterial meningitis in Niamey, Niger, from 1981 to 1996. The majority (57.7%) were caused by Neisseria meningitidis, followed by Streptococcus pneumoniae (13.2%) and Haemophilus influenzae b (Hib) (9.5%). The mean annual incidence of bacterial meningitis was 101 per 100,000 population (70 per 100,000 during 11 non-epidemic years) and the average annual mortality rate was 17 deaths per 100,000. Over a 7-year period (including one major epidemic year) for which data were available, S. pneumoniae and Hib together caused more meningitis deaths than N. meningitidis. Meningitis cases were more common among males and occurred mostly during the dry season. Serogroup A caused 85.6% of meningococcal meningitis cases during the period investigated; three-quarters of these occurred among children aged < 15 years, and over 40% among under-5-year-olds. Both incidence and mortality rates were highest among infants aged < 1 year. In this age group, Hib was the leading cause of bacterial meningitis, followed by S. pneumoniae. The predominant cause of meningitis in persons aged 1-40 years was N. meningitidis. Use of the available vaccines against meningitis due to N. meningitidis, S. pneumoniae, and Hib could prevent substantial endemic illness and deaths in sub-Saharan Africa, and potentially prevent recurrent meningococcal epidemics.

Toxic shock syndrome in the United States: surveillance update, 1979 1996

Menstrual toxic shock syndrome (TSS) emerged as a public health threat to women of reproductive age in 1979 80. We reviewed surveillance data for the period 1979 to 1996, when 5,296 cases were reported, and discuss changes in the epidemiologic features of TSS.

Impact of a risk-based prevention policy on neonatal group B streptococcal disease

OBJECTIVE

Neonatal group B streptococcal infections can be prevented by intrapartum antibiotic prophylaxis. Beginning in 1992, women with obstetric risk factors at University of Miami-Jackson Memorial Medical Center were targeted to receive intrapartum antibiotic prophylaxis. We evaluated these preventive efforts.

STUDY DESIGN

A case was defined as isolation of group B streptococci from a sterile site in an infant <7 days old born during the study period, 1992-1995. We reviewed systematic samples of women with preterm delivery and prolonged rupture of membranes to assess use of intrapartum antibiotic prophylaxis.

RESULTS

Group B streptococcal cases declined from 1.7 cases/1000 live births to 0.2 cases/1000 live births (Poisson regression, P =.002). Intrapartum antibiotic prophylaxis use increased from 13% of preterm deliveries in 1992 to 42% in 1995, and from 20% of deliveries with prolonged rupture of membranes in 1992 to 72% in 1995 (chi2 test for linear trend P =.007 and P <.001, respectively).

CONCLUSION

Provision of intrapartum antibiotic prophylaxis on the basis of risk factors was associated with decreased group B streptococcal disease.

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.