Search

Background: Intrapartum antibiotics can prevent early-onset neonatal group B streptococcal (GBS) disease but have not been widely used. Obstacles include difficulty in implementing screening for GBS colonization and uncertainty about cost-effectiveness. The GBS vaccines for disease prevention are now being developed.Methods: We developed a decision analysis model and used standard cost-effectiveness and cost-benefit analysis methods. We compared the outcomes and costs of the recent practice of no intervention with those expected for three prevention strategies: (1) intrapartum antibiotics administered to colonized women with labor complications, (2) an alternative strategy that does not require screening but uses epidemiologic criteria and labor complications to target intrapartum antibiotics, and (3) maternal vaccination. We used data from multistate population-based surveillance to estimate the potential impact of each strategy on disease and costs in the United States.Results: Intrapartum antibiotic prophylaxis of high-risk women identified by screening could prevent approximately 3300 cases (47% of neonatal disease) annually in the United States and could save approximately $16 million in direct medical costs. Chemoprophylaxis of high-risk women identified using epidemiologic criteria could potentially be equally effective (3200 cases prevented) and would avoid the logistical difficulties of screening; the net savings would be approximately $66 million. Vaccinating 80% of pregnant women with a vaccine that prevents 80% of cases among infants born at or after 34 weeks of gestation would prevent approximately 4100 neonatal cases annually with a net savings of $131 million.Conclusions: Universal prenatal screening for GBS and chemoprophylaxis of colonized women with labor complications is likely to be cost-beneficial in the United States. Development of alternative strategies should be further explored for populations in which GBS screening is impractical. Continued development of a GBS vaccine is an important public health priority. [ABSTRACT FROM AUTHOR]

Serum bactericidal activity (SBA) and ELISA antibody levels elicited by two efficacious serogroup B meningococcal vaccines were measured in a controlled trial involving 408 15- to 20-year-olds. Subjects were given two doses at a 6-week interval of a serogroup B or control vaccine. Response was defined as > or = 4-fold rise in antibody level. After two doses of the Finlay Institute (Havana) vaccine at 12 months, the proportions of SBA and ELISA responders were not different from those of the control group (15% and 17% [vaccine] vs. 13% and 9% [control], P > .05). After two doses of the National Institute of Public Health (Oslo) vaccine, there were more SBA and ELISA responders than in the control group (47% and 34% [vaccine] vs. 10% and 1% [control]) or the Finlay Institute vaccine group (P < .05 for both). SBA and ELISA may be insensitive correlates for protective efficacy for some outer membrane protein-based serogroup B meningococcal vaccines. [ABSTRACT FROM AUTHOR]

The safety and immunogenicity of a group A plus group C meningococcal polysaccharide-CRM197 conjugate vaccine was evaluated in 304 8- to 10-week-old Gambian infants. Infants were immunized with one, two, or three doses of conjugate vaccine or with two doses of a meningococcal A plus C polysaccharide vaccine. The conjugate vaccine produced few systemic side effects, and local reactions were similar to those produced by the polysaccharide vaccine. Postvaccination group A meningococcal polysaccharide antibody levels, measured by ELISA, increased progressively after one, two, or three doses of conjugate vaccine. However, one dose of conjugate vaccine given at the age of 6 months induced a higher group C meningococcal antibody response than did two doses of conjugate vaccine given at 2 and 6 months. Two doses of conjugate vaccine induced higher levels of antibody than did two doses of polysaccharide vaccine. Thus, this new meningococcal conjugate vaccine proved to be safe and immunogenic. [ABSTRACT FROM AUTHOR]

To identify characteristics of day care facilities associated with H. influenzae disease, we compared 92 licensed facilities in which a case of H. influenzae disease had occurred with randomly selected facilities at which no cases occurred. Matched univariate analysis showed that personnel at facilities where H. influenzae disease occurred were more likely than those at control facilities to use towels or handkerchiefs to wipe childrens' noses, admit children who were not toilet trained or had diarrhea ('liberal fecal policy'), had a narrower age range, were more likely than control facilities to be for-profit and less likely to use volunteers. In a multivariate model that adjusted for age range, profit status and liberal fecal policy, towel or handkerchief use (OR 5.5, 95% CI: 1.1, 30) was the only variable independently associated with case facilities. This is the first association of a specific day care practice with H. influenzae disease. [ABSTRACT FROM AUTHOR]

The case-control methodology is frequently used to evaluate vaccine effectiveness post-licensure. The results of such studies provide important insight into the level of protection afforded by vaccines in a 'real world' context, and are commonly used to guide vaccine policy decisions. However, the potential for bias and confounding are important limitations to this method, and the results of a poorly conducted or incorrectly interpreted case-control study can mislead policies. In 2012, a group of experts met to review recent experience with case-control studies evaluating vaccine effectiveness; we summarize the recommendations of that group regarding best practices for data collection, analysis, and presentation of the results of case-control vaccine effectiveness studies. Vaccination status is the primary exposure of interest, but can be challenging to assess accurately and with minimal bias. Investigators should understand factors associated with vaccination as well as the availability of documented vaccination status in the study context; case-control studies may not be a valid method for evaluating vaccine effectiveness in settings where many children lack a documented immunization history. To avoid bias, it is essential to use the same methods and effort gathering vaccination data from cases and controls. Variables that may confound the association between illness and vaccination are also important to capture as completely as possible, and where relevant, adjust for in the analysis according to the analytic plan. In presenting results from case-control vaccine effectiveness studies, investigators should describe enrollment among eligible cases and controls as well as the proportion with no documented vaccine history. Emphasis should be placed on confidence intervals, rather than point estimates, of vaccine effectiveness. Case-control studies are a useful approach for evaluating vaccine effectiveness; however careful attention must be paid to the collection, analysis and presentation of the data in order to best inform evidence-based vaccine policies., (Published by Elsevier Ltd.)

Case-control studies are commonly used to evaluate effectiveness of licensed vaccines after deployment in public health programs. Such studies can provide policy-relevant data on vaccine performance under 'real world' conditions, contributing to the evidence base to support and sustain introduction of new vaccines. However, case-control studies do not measure the impact of vaccine introduction on disease at a population level, and are subject to bias and confounding, which may lead to inaccurate results that can misinform policy decisions. In 2012, a group of experts met to review recent experience with case-control studies evaluating the effectiveness of several vaccines; here we summarize the recommendations of that group regarding best practices for planning, design and enrollment of cases and controls. Rigorous planning and preparation should focus on understanding the study context including healthcare-seeking and vaccination practices. Case-control vaccine effectiveness studies are best carried out soon after vaccine introduction because high coverage creates strong potential for confounding. Endpoints specific to the vaccine target are preferable to non-specific clinical syndromes since the proportion of non-specific outcomes preventable through vaccination may vary over time and place, leading to potentially confusing results. Controls should be representative of the source population from which cases arise, and are generally recruited from the community or health facilities where cases are enrolled. Matching of controls to cases for potential confounding factors is commonly used, although should be reserved for a limited number of key variables believed to be linked to both vaccination and disease. Case-control vaccine effectiveness studies can provide information useful to guide policy decisions and vaccine development, however rigorous preparation and design is essential., (Published by Elsevier Ltd.)

This report discusses CDC's role in the early detection of threats to public health, including linkage of detection to other preparedness functions, and provides an update on recent progress in improving these capabilities. CDC's role has been fivefold: 1) identifying and adopting information system standards; 2) providing funding; 3) defining critical surveillance functionalities; 4) accelerating Internet-based surveillance systems and electronic reporting of laboratory results; and 5) implementing BioSense, a secure, Internet-accessible, national early detection system that includes syndromic surveillance. Ongoing iterative efforts and consultation are needed to ensure future progress.

Public health departments and their clinical partners are moving ahead rapidly to implement systems for early detection of disease outbreaks. In the urgency to develop useful early detection systems, information systems must adhere to certain standards to facilitate sustainable, real-time delivery of important data and to make data available to the public health partners who verify, investigate, and respond to outbreaks. To ensure this crucial interoperability, all information systems supported by federal funding for state and local preparedness capacity are required to adhere to the Public Health Information Network standards.

Statutory authority for public health surveillance is necessarily broad as previously uncharacterized diseases are regularly discovered. This article provides specific information about general disease reporting provisions in each state. The intent of these reporting laws and the Health Insurance Portability and Accountability Act Privacy Rule is to support this critical disease surveillance function for the benefit of the entire population.

In 1993 a placebo-controlled field trial of a Haemophilus influenzae type b (Hib) conjugate vaccine was started in The Gambia. At that time Hib conjugate vaccines had been shown to be efficacious in Europe and North America for the prevention of Hib meningitis. However doubts remained about their value in developing countries, where the epidemiology of Hib disease is quite different and the most important manifestation of Hib disease is pneumonia. The ethical issues facing the investigators before and during the trial are outlined in this paper, along with the views of the different groups involved in the trial. The trial demonstrated the efficacy of the vaccine in this setting and revealed the proportion of childhood pneumonia that is likely due to Hib, which was much higher than had previously been estimated. Since the completion of the trial Hib vaccines are now recommended for use in developing countries by the World Health Organization, largely based on the results of this trial. After a delay of 17 months following the completion of the trial, national Hib vaccination was started in The Gambia in 1997 using vaccine provided by a donation from industry.

Two hundred twenty-one Gambian children vaccinated previously with one, two, or three doses of a meningococcal conjugate vaccine or two doses of polysaccharide vaccine before the age of 6 months were revaccinated at the age of 18-24 months with either meningococcal polysaccharide, conjugate, or inactivated polio vaccines. Children who had previously received one, two, or three doses of conjugate vaccine had significantly (P < .001) higher anti-group C meningococcal antibody levels following revaccination than did children vaccinated with a polysaccharide vaccine for the first time. Children vaccinated previously with two doses of polysaccharide vaccine had a lower group C antibody response than did control children. Group A antibody responses following revaccination of children who had previously received polysaccharide or conjugate vaccine were not significantly higher than those in control children. Thus, immunologic memory was probably induced by the group C but not by the group A component of the conjugate vaccine.

Listeria bacteremia occurred in 2 pregnant women whose only common exposure was attendance at a party. The incubation period, the possibility of mild disease due to Listeria infection, and foods associated with risk of disease were evaluated. Ten (28%) of 36 party attenders met a case definition, which included isolation of Listeria monocytogenes from blood or stool or two of the following: fever, musculoskeletal symptoms, nausea, vomiting, diarrhea. One of 25 stool cultures was positive. The 2 blood isolates and 1 stool isolate were serotype 4b and identical by enzyme typing. The incubation periods for illness in the 2 pregnant women were 19 and 23 days. Consumption of large amounts of shrimp, nonalcoholic beverages, Camembert cheese, and cauliflower was significantly associated with illness. Eating shrimp remained a significant risk factor for illness after controlling for consumption of other foods. This study suggests a milder illness may exist in healthy persons who consume foods contaminated with L. monocytogenes and demonstrates a prolonged incubation period for disease.

The current epidemic of violence in America threatens not only our physical health but also the integrity of basic social institutions such as the family, the communities in which we live, and our health care system. Public health brings a new vision of how Americans can work together to prevent violence. This new vision places emphasis on preventing violence before it occurs, making science integral to identifying effective policies and programs, and integrating the efforts of diverse scientific disciplines, organizations, and communities. A sustained effort at all levels of society will be required to successfully address this complex and deeply rooted problem.

Objective: To determine pneumococcal polysaccharide vaccine efficacy in selected populations at risk for serious pneumococcal infection for whom vaccination is currently recommended and to assess duration of protection after vaccination., Design: Vaccine efficacy was estimated using indirect cohort analysis to compare the proportion of pneumococcal infections caused by serotypes included in the vaccines of vaccinated and unvaccinated persons who were identified during 14 years of national surveillance., Setting: Hospital laboratories in the United States that submitted pneumococcal isolates to the Centers for Disease Control and Prevention between May 1978 and April 1992., Participants: A total of 2837 persons older than 5 years who had pneumococcus isolated from blood or cerebrospinal fluid., Results: Overall efficacy for preventing infection caused by serotypes included in the vaccine was 57% (95% confidence interval [CI], 45% to 66%). Efficacy among persons with diabetes mellitus was 84% (95% CI, 50% to 95%); with coronary vascular disease, 73% (95% CI, 23% to 90%); with congestive heart failure, 69% (95% CI, 17% to 88%); with chronic pulmonary diseases, 65% (95% CI, 26% to 83%); and with anatomic asplenia, 77% (95% CI, 14% to 95%). Efficacy was not documented for patients with alcoholism or cirrhosis, sickle cell disease, chronic renal failure, lymphoma, leukemia, or multiple myeloma, although sample sizes were small for these groups. Efficacy for immunocompetent persons older than 65 years was 75% (95% CI, 57% to 85%). Efficacy did not decline with increasing interval after vaccination: 5 to 8 years after vaccination it was 71% (95% CI, 24% to 89%), and 9 years or more after vaccination it was 80% (95% CI, 16% to 95%)., Conclusions: Intensified efforts to improve pneumococcal vaccine coverage among certain populations for whom vaccination is currently recommended is indicated, but universal revaccination is not warranted at this time.

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.

Objective: Effective Haemophilus influenzae type b (Hib) conjugate vaccines were first licensed for use in US children at least 18 months old in December 1987 and for infants at least 2 months old in October 1990. We evaluated trends in Hib disease associated with licensure of Hib conjugate vaccines., Design: Data from two sources, an intensive laboratory-based active surveillance system and the National Bacterial Meningitis Reporting System (NBMRS), were used separately to evaluate disease incidence. Data from vaccine manufacturers on Hib vaccine doses distributed in the United States were compared with trends in Hib disease incidence., Results: The age-specific incidence of Hib disease among children less than 5 years old decreased by 71% from 37 per 100,000 persons in 1989 to 11 per 100,000 persons in 1991 (active surveillance data). Haemophilus influenzae meningitis incidence decreased by 82% between 1985 and 1991 (NBMRS data). Increases in doses of Hib vaccine distributed in the United States coincided with steep declines in Hib disease. Both surveillance systems showed decreased rates of Hib disease in infants less than 1 year old before vaccine was licensed for use in this age group. Haemophilus influenzae type b disease incidence in persons at least 12 years old and pneumococcal meningitis incidence in children less than 5 years old did not change substantially during the same period; therefore, decreased Hib disease in children less than 5 years old is not likely to be explained solely by changes in surveillance sensitivity or decreases in bacterial disease due to changes in medical practice., Conclusion: Our data suggest that conjugate vaccines have already had a marked impact on the incidence of Hib disease in the United States, preventing an estimated 10,000 to 16,000 cases of Hib disease in 1991. The decline of disease in infants less than 1 year old before licensure for this age group warrants further investigation.

Three selective enrichment procedures-the U.S. Food and Drug Administration (FDA) method, the U.S. Department of Agriculture (USDA) method, and the Netherlands Government Food Inspection Service (NGFIS) method-were compared for isolating Listeria monocytogenes from contaminated foods. The foods were obtained from the refrigerators of patients with culture-proven listeriosis who were identified through multistate active surveillance in a U.S. population of 19 million. The study was designed to identify foods that may be important in transmission of L. monocytogenes in sporadic cases of human listeriosis. Of 899 foods analyzed by all three methods, 121 were positive for L. monocytogenes by at least one method. The three enrichment methods detected L. monocytogenes in 65% (FDA), 74% (USDA), and 74% (NGFIS) of the foods shown to contain L. monocytogenes . The differences among the three methods were not statistically significant. However, the recovery of L. monocytogenes by a combination of any two methods (USDA-FDA 88%, USDA-NGFIS 91%, FDA-NGFIS 87%) was significantly better than that by one method alone (p < 0.02). The differences among the combinations of methods were not statistically significant. These results suggest that at least two enrichment methods must be used in combination to recover L. monocytogenes from contaminated foods with a success rate near 90%. Correlations were observed between negative results and low (<0.3 CFU/g) level of L. monocytogenes contamination for the USDA (p << 0.001) and NGFIS (p << 0.001) methods. A similar but somewhat weaker association was observed for the FDA method (p < 0.06).

We conducted a population based case control study of deaths in children < 5 years old from Bagamoyo District, Tanzania, to evaluate factors associated with death, and factors associated with not utilizing Government health care system. Six hundred and ten children who died between 1 July, 1986 and 30 June 1987 were enrolled as cases; 1,160 healthy control children were selected by multistage random cluster sampling. Twenty-five percent of deaths were ascribed to pneumonia based on "verbal autopsy"; 39% of acute respiratory deaths occurred in children < 6 months of age. In a multivariate analysis, significant independent associations were found with mother as sole decision maker for treatment (O.R = 0.13; 95% C:I. 0.07, 0.22); use of water from village well, pond, or river vs. tap water (O.R. = 11.86; 95% C.I., 5.46, 25.72); the child eating with others (O.R. = 9.42; 95% C.I. 5.68, 15.62) and the child sleeping in the room where cooking is done (O.R. = 2.78; 95% C.I. 1.79, 4.33). Overall only 45% of families utilized Government health care (village health worker, dispensary or health centre) during their child's terminal illness. Families utilizing Government health care were significantly more likely to say that the mother alone could make treatment decision (O.R. = 2.49, 95% C.I. 1.39, 4.46), and to be closer to a dispensary. The main reasons for not utilizing Government health care were 'traditional medicine is better' (41%) and 'no drugs available' (38%).

Persistent conjunctival carriage of the Haemophilus influenzae biogroup aegyptius (Hae) strain (BPF clone) responsible for Brazilian purpuric fever (BPF) has been documented. Topical chloramphenicol is routinely used to treat conjunctivitis in areas affected by BPF in Brazil. Although the BPF clone is susceptible to chloramphenicol, we observed a number of children treated with topical chloramphenicol for conjunctivitis who still developed BPF. During an investigation of an outbreak of BPF in Mato Grosso State, Brazil, we compared oral rifampin (20 mg/kg/day for 4 days) with topical chloramphenicol for eradication of conjunctival carriage of H. influenzae biogroup aegyptius among children with presumed BPF clone conjunctivitis. Conjunctival samples were taken for culture on the day treatment was initiated and a mean of 8 and 21 days later. At 8 days the eradication rates for oral rifampin and topical chloramphenicol were 100 and 44%, respectively (P = 0.003); at 21 days they were 100 and 50% (P = 0.01). Oral rifampin was more effective than topical chloramphenicol for eradication of the BPF clone and may be useful in prevention of BPF.

An epidemic of meningococcal disease occurred in Nairobi, Kenya, during 1989, outside the "meningitis belt" of sub-Saharan Africa. About 3800 cases occurred between April and November (250/100,000 population). The case-fatality rate was 9.4% among hospitalized patients. Areas that included Nairobi's largest slums had particularly high attack rates. The epidemic displayed an unusual age distribution, with high attack rates among those 20-29 years old. A vaccination campaign was conducted. By early January, the weekly case count had fallen to 25 from a high of 272 (in September). A case-control study estimated the vaccine efficacy to be 87% (95% confidence interval, 67%-95%). A model estimated that the vaccination campaign reduced the number of cases by at least 20%. Multilocus enzyme electrophoretic typing demonstrated that the strain responsible for this large epidemic is closely related to strains that caused other recent epidemics, documenting further spread of what may be a particularly virulent clonal complex of group A Neisseria meningitidis.

Objective: To identify dietary risk factors for sporadic listeriosis., Design: Case-control study with blinded telephone interviews., Setting: Multistate population of 18 million persons, November 1988 through December 1990., Participants: One hundred sixty-five patients with culture-confirmed listeriosis and 376 control subjects matched for age, health care provider, and immunosuppressive condition., Results: The annual incidence of invasive listeriosis was 7.4 cases per million population; 23% of the infections were fatal. Cases were more likely than matched controls to have eaten soft cheeses (odds ratio [OR], 2.6; 95% confidence interval [CI], 1.4 to 4.8; P = .002) or food purchased from store delicatessen counters (OR, 1.6; 95% CI, 1.0 to 2.5; P = .04); 32% of sporadic disease could be attributed to eating these foods. Sixty-nine percent of cases in men and nonpregnant women occurred in cancer patients, persons with the acquired immunodeficiency syndrome, organ transplant recipients, or those receiving corticosteroid therapy. Among these immunosuppressed patients, eating undercooked chicken also increased the risk of listeriosis (OR, 3.3; 95% CI, 1.2 to 9.2; P = .02)., Conclusions: Foodborne transmission may account for a substantial portion of sporadic listeriosis. Prevention efforts should include dietary counseling of high-risk patients and continued monitoring of food production.

Objective: To evaluate the role of foods in sporadic listeriosis., Design: Microbiologic survey of foods collected from refrigerators of patients with listeriosis identified through active laboratory-based surveillance. Patient and food Listeria monocytogenes isolates were subtyped to identify foods contaminated with the same strain of L monocytogenes that caused illness in the patient; samples of these foods were obtained from the retail source., Setting: Multistate population-based study conducted between 1988 and 1990., Results: Listeria monocytogenes grew from at least one food specimen in the refrigerators of 79 (64%) of 123 listeriosis patients; 11% of more than 2000 food specimens collected in the study contained L monocytogenes. Twenty-six (33%) of 79 refrigerators with foods that grew L monocytogenes contained at least one food isolate of the same strain as that in the corresponding patient, a frequency much higher than would be expected by chance (P less than .001). Multivariate analysis showed that of the food specimens that grew L monocytogenes, foods that were ready-to-eat, foods that grew L monocytogenes by a direct-plating method (a measure of the level of contamination), and foods that contained serotype 4b isolates were independently associated with an increased likelihood of containing the patient-matching strain., Conclusion: We identified specific food and L monocytogenes isolate characteristics--ready-to-eat foods, foods containing higher concentrations of L monocytogenes, and foods containing serotype 4b--which were associated with disease-causing strains. These results can provide guidance to industry and regulatory agencies in developing strategies to prevent listeriosis.

Portions of sub-Saharan Africa are subject to major epidemics of meningococcal meningitis that require early detection and rapid control. We evaluated the usefulness of weekly meningitis rates derived from active surveillance data in Burkina Faso for detecting a meningitis epidemic. By analysing the rates of disease in 40 x 40km2 areas within a study region of Burkina Faso, we found that a threshold of 15 cases/100,000/week averaged over 2 weeks was 72-93% sensitive and 92-100% specific in detecting epidemics exceeding 100 cases/100,000/year. During epidemic periods, the positive predictive value of this threshold approached 100% for detecting local epidemics. Additionally, meningitis incidence was proportional to village size, with villages greater than 8000 having the highest disease rates during a major group A meningococcal epidemic in 1983-1984. Despite the rudimentary nature of surveillance data available in many developing countries, these data can be used to detect the early emergence of meningitis epidemics. Additional studies are needed to determine the relevance of this approach for detecting epidemics.

The "Gold standard" in vaccine testing is the randomized, placebo controlled, double-blind efficacy trial. Once a protective immune mechanism is defined, e.g., from an efficacy trial, vaccine performance can then be judged by serologic parameters. Although immunogenicity studies can provide important information, in many instances the answer has to come from efficacy trials. For rare diseases like meningococcal disease, these trials are expensive and difficult to conduct. It is therefore incumbent to learn as much as possible from each trial. Issues in pre-licensure studies include: vaccine selection, site selection, trial design, assignment to treatment and control groups, definition and surveillance for endpoints (cases, adverse reactions), identification of surrogate markers for protection, and utilization of monitoring committees.

Objective: To define the incidence and clinical spectrum of group B streptococcus infection in adults. To characterize groups at increased risk for infection., Design: Retrospective population-based surveillance of group B streptococcus infections occurring in adults. Patients were identified by review of microbiology records at all surveillance area hospital laboratories. Demographic and clinical data were abstracted from patient medical records., Setting: Metropolitan Atlanta, Ga, 1982 through 1983., Patients: We identified 70 adult patients with invasive group B streptococcus infections; 14 infections occurred in pregnant women and 56 in nonpregnant adults., Results: The annual incidence of group B streptococcus infection in men and nonpregnant women was 2.4 cases per 100,000 population. Incidence increased with age and was higher in blacks than in whites. The case-fatality rate was 32%. Group B streptococcus was most often isolated from blood (71%) and soft tissue (16%). Common clinical presentations included skin and soft-tissue infection (36%), bacteremia without focus (34%), pneumonia (11%), arthritis (9%), and endocarditis (9%). Compared with the general population's risk of infection, the risk of infection in persons with diabetes mellitus was increased 10.5-fold (95% confidence interval [CI], 7.8 to 14.4); in persons with cancer, it was increased 16.4-fold (95% CI, 11.5 to 23.3)., Conclusions: Group B streptococcus infections cause serious disease in adults as well as in neonates, providing an additional rationale for vaccine development. Determining the incidence of adult disease and groups at greatest risk will help in focusing prevention efforts.

Vaccines prepared from the polyribosylribitol phosphate (PRP) capsule of Haemophilus influenzae b (Hib) have not consistently shown good efficacy in protecting children aged over 18 months from invasive Hib disease. To evaluate the efficacy of conjugate-PRP vaccines in this age-group, and to compare their effect with that of PRP vaccines, a post-marketing case-control study was conducted among 10,400,000 persons. Between Oct 1, 1988, and Feb 28, 1990, 75 patients with Hib disease and 161 control children between 18 and 60 months of age were enrolled. To minimise potentially confounding socioeconomic variables, controls were selected either from among patients' classmates at their day-care centre or from among family acquaintances. 9 of the 75 patients had received the diphtheria toxoid conjugate Hib vaccine more than 2 weeks before onset of illness. After adjusting for age and household crowding, the efficacy of PRP Hib vaccine was 64% (95% Cl = -20,89) and efficacy of the diphtheria toxoid conjugate Hib vaccine was 74% (95% Cl = 30,90). The study shows that the protective efficacy of this conjugate vaccine is less than ideal and highlights the need for additional post-licensing studies to confirm and expand understanding of the efficacy of these new products.

We compared the cold enrichment (CE) and U.S. Department of Agriculture (USDA) methods for isolating Listeria monocytogenes by examining 402 food samples. The food samples were collected from refrigerators of listeriosis patients as part of a multistate active surveillance project to determine the role of foods in sporadic listeriosis in the United States. L. monocytogenes was isolated from 51 food samples (13%). The USDA method was significantly better (P less than 0.001) than the CE method. The isolation efficiencies of the USDA and CE methods were 96 and 59%, respectively. Quantitation of L. monocytogenes in the food samples revealed that many food samples containing less than 0.3 CFU/g were negative as determined by the CE method but positive as determined by the USDA method.

Active surveillance for invasive meningococcal disease was conducted during 1986 and 1987 in six areas of the United States with a total population of approximately 34 million persons. The incidence of meningococcal disease was 1.3:10(5). The highest incidence of disease among the surveillance areas was in Los Angeles County (1.65:10(5). Neisseria meningitidis serogroups B and C caused about equal amounts of disease, which reflects a recent increase in the incidence of group C disease. Group C caused more than half of the cases of meningococcal disease in Los Angeles and Tennessee but less than one-third of the cases in Missouri and Oklahoma. Multilocus enzyme electrophoresis demonstrated that a group of closely related isolates of N. meningitidis was prevalent in Los Angeles during the surveillance period and was associated with an increased incidence of meningococcal disease there.

We used population-based surveillance in New Jersey in 1986 to quantify the risk of invasive pneumococcal disease in persons with the acquired immunodeficiency syndrome (AIDS) and in those who went on to develop AIDS. Using pneumococcal surveillance, we also devised a method to estimate the size of the immunosuppressed population infected with the human immunodeficiency virus (HIV), the so-called pre-AIDS population. From rates of pneumococcal disease that occurred in areas with a low incidence of AIDS, we calculated the number of patients expected to contract pneumococcal disease in areas with a high incidence of AIDS. There were 59 more cases of pneumococcal disease observed than expected; 14 of these patients had AIDS by the time of pneumococcal infection. We attributed the remaining 45 cases to the increased risk of pneumococcal infection in pre-AIDS. The pre-AIDS pneumococcal cases and the attack rate of pneumococcal disease in pre-AIDS were used to estimate the size of the 1986 pre-AIDS New Jersey population as 8823 pre-AIDS cases (95% confidence interval, 7377 to 10,714) or 0.37% of the adult New Jersey population. Surveillance for marker diseases may provide a simple, independent method of estimating the pre-AIDS population.

An outbreak of meningococcal disease among children on a school bus offered the opportunity to study a proposed association between this infection and preceding influenza infection. Five students who rode the bus became ill with invasive group C meningococcus. Transmission was limited to the bus; there was no evidence for school transmission. All five students reported influenza-like symptoms within several weeks before the development of meningococcal disease. School absenteeism, principally due to upper respiratory tract illness, was higher during the 3 weeks before the outbreak of meningococcal disease than during any period in the preceding 3 1/2 years, suggesting an unusually severe outbreak of respiratory illness. A case-control study comparing students with and without influenza symptoms revealed that the outbreak of respiratory disease was due to B/Ann Arbor/1/86 influenza (geometric mean titers, 86 for 80 patients and 33 for 47 controls [P = .0007]). These data add to the evidence suggesting that influenza respiratory infection predisposes to meningococcal disease.

During the 1980s, investigation of several large epidemics of listeriosis confirmed that transmission of L. monocytogenes in food causes human disease. Progress in laboratory detection and subtyping of the organism has enhanced our ability to compare human and environmental isolates of L. monocytogenes. Transmission by foodborne organisms is now recognized as causing both epidemic and sporadic listeriosis. Continued study of dietary risk factors associated with listeriosis is needed in order to develop dietary recommendations for the expanding population at increased risk of disease. Current research application of new molecular methods to the study of L. monocytogenes may improve the ability to diagnose pregnancy-associated disease and permit the rapid detection and control of L. monocytogenes in the food supply.

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.

To determine the morbidity and mortality due to listeriosis in the United States, the authors undertook an active surveillance project in 1986 to identify all cases in which Listeria monocytogenes was isolated from cultures of ordinarily sterile sites in a population of 34 million persons. The authors estimated that at least 1,700 cases of listeriosis and 450 deaths occurred in the United States in 1986; 27% of these cases occurred in pregnant women, with 22% of perinatal cases resulting in stillbirths or neonatal deaths. The risk of listeriosis in adults (0.5 per 100,000 population) was similar in all regions studied; the incidence of perinatal listeriosis was three times higher in Los Angeles County, California, than in the other areas (24.3/100,000 live births vs. 7.8/100,000 live births). Geographic variation may have resulted from underdiagnosis of perinatal listeriosis in five of the study areas. Multilocus electrophoretic enzyme typing was useful for elucidating the molecular epidemiology of L. monocytogenes; perinatal listeriosis was significantly associated with one group of related strains. Multilocus electrophoretic enzyme typing also identified three clusters representing possible common-source outbreaks. These findings document the substantial morbidity due to listeriosis in the United States; to the extent that sporadic listeriosis is foodborne, this morbidity could be reduced by appropriate preventive measures, particularly in persons known to be at increased risk of infection.

There has been a substantial reduction in the incidence of toxic shock syndrome in the 10 years since the association between tampons and toxic shock syndrome was first recognized. The decreased incidence is real, and not the result of decreased reporting to the passive surveillance system. The decreased incidence of menstrual toxic shock syndrome can primarily be explained by changes in the absorbency and composition of tampons available to the consumer. The reduction in the occurrence of menstrual toxic shock syndrome can be attributed to the withdrawal of Rely brand, which consisted of a unique composition, and subsequently to the lowering of absorbency of all brands of tampons. The conclusions of the early studies of toxic shock syndrome pointed the way to prompt public health interventions and resulted in the prevention of substantial morbidity.